AIRCRAFT OWNER’S & OPERATOR’S GUIDE: 747-200/ · PDF fileAIRCRAFT COMMERCE ISSUE NO. 41 • JUNE/JULY 2005 6 I AIRCRAFT OWNER’S & OPERATOR’S GUIDE T he 747-200 and -300 followed

AIRCRAFT OWNER’S & OPERATOR’SGUIDE: 747-200/-300

i) Aircraft specifications, page 6ii) Production & fleet analysis, page 8iii) Major modification & upgrade programmes, page 10iv) Maintenance requirements & analysis, page 13v) Values, lease rates & aftermarket activity, page 23

AIRCRAFT COMMERCE ISSUE NO. 41 • JUNE/JULY 2005

6 I AIRCRAFT OWNER’S & OPERATOR’S GUIDE

The 747-200 and -300 followedalmost instantly on the heels ofthe initial -100 series aircraft.The various combinations of

gross weight, engines, permissible weightat Stage 3, and range are analysed here.

A total of 476 -200s and -300s weremanufactured between August 1970 andOctober 1991. Of these, 395 were the -200 and 81 were the -300 with the 23ft4in extended upper deck that added 40economy seats.

The first -200 to roll off theproduction line was line number 88 inAugust 1970 for Northwest OrientAirlines, although KLM was first inservice with the -200B in February 1971.The last aircraft was line number 886delivered on 19th November 1991, a -200F for Nippon Cargo Airlines. The first-300 series aircraft was line number 570delivered in March 1983. The last -300was line number 810 completed inAugust 1990.

-200B & -300 development Even before the first flight of the -100,

Boeing announced a higher gross weightvariant with a choice of engines fromPratt &Whitney (PW), General Electric(GE) and Rolls-Royce (RR). The -200was the first 747 to be configured as afreighter, a combination passenger-freighter and a convertible.

Several developments have been madeto the -200 that allow more power,increased weight and range, and a varietyof seating combinations. Several specialistversions were produced, including thehinge-nosed -200F freighter, -200CConvertible, the -200 Combi with sidecargo (SCD) door, and the -200SUD(stretched upperdeck).

The first 747-300, with an extendedupper deck compared to the -200, wasbuilt in September 1982 (line number570) and entered commercial service inMarch 1983 with Swissair as a Combi.The extended upper deck increased seatcapacity by about 10%. The -300 alsohad improved engines with a reduced fuelburn of 25% per passenger. Passengercapacity was also increased by 10% bythe extended upper deck. Boeingdelivered 81 747-300s in passenger,

Combi and short-range configurations,the last being line number 810 in August1990 for Sabena.

The -200 and -300 production linewas closed on November 19th 1991, thelast aircraft being a -200F.

Technical description The technical capability of the 747-

200B and -300 series is determined by acombination of its installed engines,MTOW permitted by the installedengines, fuel volume and Stage 3compliant MTOW.

The earlier built 747-200B has astructure and landing gear to permit aMTOW of up to 775,000lbs. Furtherstructural changes were made from linenumber 409 to permit an MTOW up to833,000lbs.

The -200 fleet has a choice of Pratt &Whitney (PW) JT9D-3A, -7A, -7F, -7J, -7Q, and -7R4G2 engines. These are ratedat 45,000lbs to 54,000lbs thrust. GeneralElectric supplied the CF6-50E/-50E1/-50E2 variants rated at 52,500lbs thrust.The Rolls-Royce options are the RB211-524C2 and -524D4 rated at 51,500lbsand 53,100lbs thrust.

On the larger -300, engine options arethe JT9D-7R4G2 rated at 54,000lbsthrust, CF6-50E2 and newer CF6-80C2B1 rated at 56,700lbs thrust, andthe RB211-524D4 rated at 53,100lbsthrust.

The different MTOWs that arepossible for each engine type are shown(see first table, page 7), together with fuelvolume in US Gallons (USG).

Aircraft with the JT9D-7A installedhad an original certified MTOW of775,000lbs and 785,000lbs (see firsttable, page 7).

The later -7F/-7FW/-7J all allowed theaircraft to operate up to a MTOW of800,000lbs. These three variants werealso used on aircraft which originally hadMTOWs certified at 775,000lbs and785,000lbs (see first table, page 7).

Aircraft with the JT9D-70A hadMTOWs of up to 820,000lbs.

The later JT9D-7Q and -7R4G2variants, the CF6-50 and the RB211-524engines all permitted a MTOW of up to833,000lbs (see first table, page 7).

Stage 3 compliance These MTOWs are the original take-

off weight limits, and some engine-MTOW combinations are not Stage 3compliant. The non-Stage 3 compliantcombinations have had a limit imposedon their MTOW. This has the effect ofreducing engine throttle setting, and soreducing noise emissions.

The Stage 3 MTOW limits for theJT9D-7Q, JT9D-7R4G2, CF6-50 andRB211-524C2/D4 are unchanged fromthe original MTOWs (see second table,page 7). This gives the passenger-configured aircraft a range of 5,900-6,100nm, depending on engine installed.

Aircraft with the JT9D-7A are limitedto a MTOW of 734,000lbs for Stage 3compliance (see second table, page 7).Range for this aircraft is 4,250nm.

The JT9D-7F limits the MTOW to750,000lbs, and the corresponding rangeis 4,650nm. Aircraft with the JT9D-7Jare limited to a MTOW of 770,000lbsand a range of 5,000nm (see secondtable, page 7).

Payload capacity In a passenger configuration, the -

200B has a tri-class seat capacity of 360-420 seats. The 747-300’s tri-classcapacity is typically about 20-30 seatsmore.

All -200 and -300 models havesignificant belly cargo space of about5,250 cubic feet with containerised cargoin 30 LD-1 containers. They can also takepalletised cargo.

–200M Combi The -200M or ‘Combi’ has a

maindeck that has a SCD at the left rearof the fuselage. This allows freight to becarried in the rear section of themaindeck, while the front section isconfigured to carry passengers. TheCombi became popular in the late 1970sand early 1980s. Six 10-feet high palletscan be carried at the rear of the maindeck in Zone E. Each of these has avolume of 773 cubic feet, thus providing4,638 cubic feet of cargo volume. Thepassenger accommodation is reduced byup to 238 passengers in three-classlayout, depending on configuration.

The -200B Combi has the same rangecharacteristics as the -200B in all-passenger configuration.

–200C Convertible The -200C was made available at the

same time as the -200F. The -200C issimilar in appearance to the -200B exceptthat it has the upward-opening nose doorand strengthened floor of the -200F. Theinterior can be configured in either a

747-200/-300specificationsThere are several 747-200/-300 variants withdifferent MTOW & engine combinations, as wellas different MTOW limits for Stage 3 compliance.

passenger or freighter role. The conversion of the aircraft from

one role to another allows operators totake account of seasonal fluctuations inpassenger and freight traffic. The -200Cdid not prove particularly popular, andonly 13 were produced.

–200F Freighter The -200F, with a MTOW of

775,000lbs, had a larger payload-rangecapability than the -100F. The -200F hasthe upward hinging nose door. This is thefundamental difference between the -200F and the subsequently modified -200SF. The nose door is standard, withthe main deck SCD an option.

The nose door only permits eight-feethigh maindeck freight containers, whichhave an internal volume of 623 cubicfeet. The maindeck can accommodate 29of these, and so has a total freight volumeof 18,270 cubic feet (see third table, thispage).

The SCD allows 21 10-feet highcontainers to be carried in the mid andaft sections of the maindeck, while eighteight-feet high containers have to becarried in forward section. The 10-feethigh containers have an internal volumeof 773 cubic feet, and overall aircraftwith a SCD have a maindeck freightvolume of 20,685 cubic feet (see thirdtable, this page).

Combined with the 5,250 cubic feetprovided by the 30 LD-1 containers inthe belly, total freight volume is 23,520cubic feet for the -200F with only thenose door, and 25,935 cubic feet foraircraft with the SCD.

The -200F has a maximum zero fuelweight of 590,000lbs. Operating emptyweight, including tare weight ofcontainers, varies between 342,000lbsand 351,000lbs, depending on MTOWvariant and installed engine. This allowsan available structural payload of239,000-248,000lbs (see third table, thispage).

-200 SUD When Boeing announced the 747-300

programme in June 1980, Boeing and thepress referred to it as the -200 SUD. Thenew aircraft was later re-designated as the-300. A modification was available tooperators of -200Bs, however, to stretchthe upper deck to the same capacity asthe -300. KLM ordered the modificationof its 10 -200Bs to -200 SUD.

-300 series The -300 programme was announced

by Boeing on June 12th 1980, originallyas a modification to the existing models.Typical seating is 405 in a three-classconfiguration. The -300’s weights and

engine options are described (see firsttable, this page).

The Combi is identical to thestandard -300, except for a 120 x 134 inmain deck cargo door aft of the wing.Zones D and E have a strengthened floorwith cargo handling equipment. A typicalCombi configuration is 289 passengers inthree classes and seven 10-feet highpallets aft. The weights and engineoptions are described (see table, thispage).

-300 SR In 1987 Boeing offered the -300 in an

SR version for high-density trafficvolumes to Japan Airlines. In a two-class,high-density configuration, the -300SRcan seat 563 passengers. In single-classconfiguration it can carry 624 passengers.The -300SR is offered at MTOWs of520,000lbs and 600,000 lbs with fuelcapacities of 48,000USG and 48,500USG.Only four were built for JAL.


ISSUE NO. 41 • JUNE/JULY 2005 AIRCRAFT COMMERCE

747-200/-300 SERIES GROSS WEIGHT & ENGINE CONFIGURATIONS

Variant -200 -200 -200 -200/-300

MTOW lbs 775,000 785,000 800,000 833,000Fuel volume USG 52,410 52,035 52,410 52,410

Engine options¶ JT9D-7AW JT9D-7AW JT9D-7FW JT9D-7QJT9D-7FW JT9D-7FW JT9D-7JW JT9D-7R4G2JT9D-7JW JT9D-7JW CF6-50E2

RB211-524C2RB211-524D4

747-200/-300 MTOW & MLW LIMITS FOR STAGE 3 COMPLIANCE

Variant -200 -200 -200 -200/-300& engine JT9D-7A JT9D-7F JT9D-7J JT9D-7Q

MTOW lbs 734,000 750,000 770,000 833,000MLW lbs 630,000 630,000 630,000 666,000

Range nm 4,250 4,650 5,000 5,900(Pax aircraft)

Variant -200/-300 -200/-300 -200/-300& engine JT9D-7R4G2 CF6-50E2 RB211-524C4

RB211-524D4

MTOW lbs 833,000 833,000 833,000MLW lbs 666,000 666,000 666,000

Range nm 6,100 5,900 6,050(Pax aircraft)

747-200F FREIGHT SPECIFICATIONS

Aircraft model -200F -200FNose door only Nose door & SCD

Type maindeck containers: 96” X 125” X 96” 96” X 125” X 96”Number of containers: 29 8

Type of maindeck containers: 96” X 125” X 118”Number of containers: 21

Maindeck container volume cu ft: 18,270 20,685

Belly containers 30 30Belly container volume cu ft: 5,250 5,250

Total container volume cu ft: 23,520 25,935MZFW lbs 590,000 590,000OEW lbs 342,000-351,000 342,000-351,000Structural payload lbs 239,000-248,000 239,000-248,000



Of the 476 747-200 and -300sbuilt, 280 are still in service,mostly with tier-one operatorslike Japan Airlines (JAL) and

Northwest Airlines, and major cargocarriers.

The most desirable -200Bs are thosewith JT9D-7Q, JT9D-7R4G2 and CF6-50E2 engines which allow the aircraft tooperate at the highest MTOW of833,000lbs. Aircraft that haveaccumulated fewer than a total of 80,000flight hours (FH) and 15,000 flight cycles(FC) are also the most desirable. Thismakes it possible to operate the aircraftfor at least another 4,000FC beforeSection 41 termination modificationwould be required. This is equal tobetween six and eight years’ operation attypical rates of utilisation. Airlines arelikely to retire aircraft at this stage, sincethe cost of completing Section 41 wouldnot be economically attractive.

Airlines and potential purchasers andoperators also have to consider the timingand requirements of other modificationsand heavy maintenance. Many may notwant to perform a D5 check, and so willretire the aircraft just prior to reachingthis point. This will be due at about atotal time of about 100,000FH, while aD4 check will occur at about 80,000-82,000FH total time and a D3 check dueat about 60,000-65,000FH.

All -300s have the highest MTOW of833,000lbs, but the most desirable arethose equipped with CF6-50E2/-80C2and JT9D-7R4G2 engines.

Of the 395 -200Bs built, 212 remainoperational. Of the 81 and -300s built 69remain operational. The remainingaircraft have been retired, destroyed orstored.

-200B The early years of the passenger -

200B saw a significant number ofdeliveries followed by another peak in1979-1981. By 1982 190 aircraft weredelivered, most of which are now subjectto Section 41 termination (see 747-200/-

300 modification programmes, page 10)assuming 1,000 cycles a year.Increasingly, however, termination ofSection 41 is considered normal, ratherthan the exception.

Of 57 the-200Bs that remainoperational, the majority are powered byengines that permit the highest MTOWof 833,000lbs. The most numerous ofthis group are 22 JT9D-7Q-poweredaircraft. Many of these are high-timeaircraft, with only two that haveaccumulated about 15,000FC or less, butthese two have in excess of 80,000FH.

There are only five aircraft withJT9D-7R4G2 engines, and four areoperated by Northwest and the fifth byJapan Airlines. All five have 9,700-12,100FC.

There are just four civilian aircraftwith CF6-50E2 engines which were builtin the mid-1980s. There are 11 RB211-524-powered aircraft. Many are low-timeaircraft, but are generally less desirablebecause of their high empty weight.

A few other aircraft are powered bythe JT9D-7A/-7AW/-7J. These havelimited gross weights are high-timeaircraft.

-200SCDAbout 75 aircraft with side cargo

doors (SCD) are in operation. These are amixture of Combi aircraft and Combiand passenger aircraft that have beenmodified to freighter. The largest number,37, are equipped with CF6-50E2 engines,and have been the most desirable withfreight operators. Only 11 of theseaircraft have accumulated less than15,000FC and so could operate for atleast another four or five years beforecoming due for a D5 check.

Another 22 are powered by JT9D-7Qand -7R4G2 engines. These are operatedby Northwest, Japan Airlines, Air China,UPS, Kalitta Air, and Tradewinds. Mostof the -7R4G2-equipped aircraft haveaccumulated less than 15,000FC and aredesirable, while many of the -7Q-powered aircraft are high-time aircraft.

-200F Just over 60 -200Fs are in operation.

This includes 10 high-time aircraftequipped with JT9D-7A/-7F/-70Aengines. Of the more desirable types,there are also 17 aircraft with -7Qengines. These are mainly high-timeaircraft operated by JAL, Northwest, ElAl, and MK Airlines.

There are also eight aircraft with -7R4G2 engines. These are relatively lowtime, with between 9,000FC and15,000FC. Some of these are operated byJAL and Northwest, as well as by AirChina, Dragonair and Korean Air.

The largest group is the 24 aircraftequipped with CF6-50E2 engines. Fifteenof these have accumulated less than15,000FC and 80,000FH, making themsome of the most desirable 747-200s stillin operation. Many of these aircraft areoperated by Nippon Cargo, LufthansaCargo and Air France.

Only four -200Fs are powered by theRB211-524, and these are operated byCathay Pacific and Saudia.

Only five Convertibles remain inoperation, and four are powered by theCF6-50E2.

-300 & -300 Combi Most -300s were delivered from 1985

to 1987. Of the 81 built, 56 werestandard -300s and 21 were Combis,including the first -300 built for Swissairwhich is now retired. Only four of the -300s have been converted to freighters,most by TAECO.

The -300 fleet is dominated by theJT9D-7R4G2, which powers 27 of the 53aircraft that remain operational. Most ofthese are low-time aircraft which haveaccumulated 11,000-13,000FC and55,000-85,000FH. This fleet isdominated by aircraft operated by JALand Corsair. Smaller numbers areoperated by Air Atlanta Icelandic, PhuketAirlines and Korean Air.

The other large fleet of -300 passengeraircraft are the 21 powered by theRB211-524. These are operated by eitherQantas or Saudia, and have accumulated13,000-17,000FC and 55,000-75,000FH.

A few -300s are powered by the CF6-80C2B1, the engine’s first application onthe 747 family. Five aircraft with theseengines operate with Thai Airways andIberia.

Another 14 -300s are the Combivariant. This is split between six aircraftwith JT9D-7R4G2 engines and eight withCF6-50E2 engines. These are all low-timeaircraft, and operators include Dragonair,Korean Air, Air France and SurinamAirways. There are also two low-timeCF6-80C1B12-powered -300 Combisoperated by Air India.

747-200/-300 fleetanalysisWhile the 747-200/-300 have an image of beingold aircraft, there are several low-time, highspecification aircraft that can provide start-upairlines with high capacity at a low acquisitioncost.



There are four main categories ofmodifications applicable to the747-200/-300. These include:flightdeck and avionic

modifications; engine and weightupgrades; safety-related modifications;and passenger-to-freighter conversionprogrammes; available to enhance the747-200/-300’s productive life.

Most other upgrade packages andheavy modifications issued for the aircrafthave either been carried out or areeconomically unattractive to operators. Amodification is also available to upgradethe JT9D-7J engine to increase the Stage3-compliant MTOW.

Avionic upgrades One of the main improvements over

the 747-200/-300 was the use of a two-man flightdeck on the 747-400. Thisfeatures advanced on-board computingpower coupled with advanced glassdisplays, which make the third memberof the crew, the flight engineer,redundant, and bring significant costadvantages. In conjunction with this,there have been a series of regulationsaffecting all aircraft that requireimprovements to navigation andcommunications on-board aircraft toenhance safety and deal with ever morecongested airspace.

One of the pioneers of flightdeckavionic upgrades was KLM Engineering& Maintenance in the Netherlands.Marijan Jozic, modification programmemanager at KLM Engineering &Maintenance, and winner of the 2004Volare Award for Aircraft Maintenanceawarded by the AAI, has a wealth ofexperience on the classic jumbo. “Until1987 engineering activity was restrictedto replacing old cinema projectors withvideo projectors in the cabin. Then cameTCAS,” begins Jozic. “KLM Engineering& Maintenance expanded its activities tobecome a systems integrator andinstallation service provider. The waveended after the traffic collision avoidancesystem (TCAS) 1989 deadline. Then wehad SATCOM installation led by ourmarketing department. This was followedby reduced vertical separation minima(RVSM) requirements, and then the

channel spacing modifications on radiocommunications. We combined thefrequency spacing requirements with FMimmunity modifications.

“One of the most important newdevelopments we embarked on for the747 Classics was pioneering avionic andflightdeck upgrades,” continues Jozic.“Our original classics had DELCOinertial navigation systems (INS) whichhad poor reliability. We looked at variouscontrol panels and display options, but atthe same time also wanted to provide a747-400-like environment for theseclassic aircraft, and add FANS-1capability. The introduction of basic areanavigation (B-RNAV) in Europe was alsoa big driver. So our cockpit modificationgrew, adding a Canadian-Marconi (nowBAe Systems Canada) flight managementsystem (FMS) and a display from Smithsfor the attitude direction indicator (ADI)and horizontal situation indicator (HSI).We wanted to add replacement engineinstrument displays, but there were somechallenges with interfacing to the existingsystems remaining on the aircraft, and sothe displays were dropped. What we wereleft with accommodated precision areanavigation (P-RNAV) requirements, and adata link functionality for future andconventional ADS. The triple redundantGPS/FMS/INS configuration wouldpermit dispatch into RNP-4 airspace witha single point failure.”

The programme was certified onSeptember 10th 2001, which could nothave been worse timing. Although KLMEngineering & Maintenance completelymodified all its own aircraft, Martinairwas the only other airline that had thefull modification. “The new modificationpackage completed for Martinair during2003/2004 is actually an improvedupgrade,” comments Jozic. “We havemade it easier to install, with new wiringrouting and displays from Astronautics.One benefit of the upgrade is that pilotscan take advantage of special arrival anddeparture procedures (SID/STAR) withthis retrofitted configuration. This willassist in avoiding fines at a noise sensitiveairport like Amsterdam Schipol, and inenhancing operating costs.”

ARINC in fact went the furthest,developing a two-man flightdeck

modification for the 747 Classic, but thiswas shelved after September 11th 2001.There were other smaller flightdeckmodifications available, including onefrom Spirent Systems (now TeledyneControls) called AvVance. Not only doesit replace old, unreliable mechanicalinstruments, but it also provides real-timedata and exceedance recordingcapabilities. This allows maintenancecrews to download and analyse engineperformance data after each flight,reducing the reliance on pilot reporting,and extending service life. It can savemaintenance costs.

Of most recent interest is a projectthat Jozic has just completed for start-upairline Focus Air Cargo. Operating two747-200Fs and one 747-300F, Focuswanted to upgrade all the avionics, but itwas looking for a lower cost alternativeto the standard KLM package. “We cameup with a very interesting package that isideal for 747 Classics coming out ofstorage,” says Jozic. “We combined aLitton92 INS with a standalone GPSfrom Northrop Grumman, and added aHoneywell Enhanced Ground ProximityWarning System (EGPWS). We also didan enhanced transponder modification,which is mandated by 2007. The endresult is an extraordinary package thatshould be very attractive to 747 Classicoperators. In all, there are threesupplemental type certificates (STCs) withthe package, one with NorthropGrumman and two with a companycalled ECS, based in Wisconsin, USA.”

Mandatory avionics In Europe, it is mandatory for all

aircraft to have two sets of VHFcommunication transceivers installed andoperational with 8.33kHz frequencyspacing above FL245.

Additional proposed newcommunications rules are beingconsidered covering 8.33kHZ, extendingit to cover above FL195. Two sets ofVHF communication transceivers with25kHz frequency spacing are mandatedbelow FL245, and elsewhere not coveredby 8.33kHz requirements.

TCAS has already been mandated.There is also EGPWS, but this

747-200/-300modification programmesThe major modification and upgrade programme include mandatoryavionic installations, gross weight upgrades, structural modifications andfreighter conversions.

requirement is expected to expand astechnology moves on. RVSM is currentlyonly mandatory in Europe and theAtlantic ocean areas to support highertraffic densities. The B-RNAV ismandatory in Europe. P-RNAV isoptional for now, but will be required tofly into major airports in the near futurewith preferential slots. Mode-Stransponders are also mandatory, withthe elementary and enhanced surveillancebecoming mandatory in 2007.Strengthened flightdeck doors aremandated.

Requirements differ in NorthAmerica. As with Europe, 8.33kHzfrequency spacing and 25kHz frequencyspacing are mandated. TCAS mandatoryeffectivity was extended to January 2005and EGPWS also became mandatory in2005. Mode-S transponders aremandatory as in Europe. As with allaircraft, strengthened flightdeck doors aremandated in North America.

Engine and weight upgrades Aircraft from line number 260

incorporated an option to increase fuelcapacity to 53,986US Gallons, which isavailable if the engines have sufficientthrust. Engine type is an importantconsideration when assessing a 747Classic aircraft.

Upgrades are also available for Rolls-Royce engines, increasing their reliabilityand providing higher thrust ratings. Mostupgrades involved high pressure turbine(HPT) blade modifications and fittingnewer technology elements from theTrent 700 and 800 back into the RB211-524.

For aircraft from line 409 andbeyond, upgrading the maximum take-offweight (MTOW) to the maximum833,000lbs is possible, provided engineswith sufficient take-off thrust areinstalled.

Paper change upgrades to increaseMTOW that merely change charts andmanuals are available, but most MTOWincreases require modifications to thecrown section, wing spar and monocoqueor a stronger standard of landing gear.Most weight upgrades are usuallyincorporated as part of a freighterconversion programme.

Structural modifications In the 1990s, two total loss accidents

involving -200F aircraft operated by El Aland China Airlines, were caused byengine separation in flight. The four pointattachment of the original engine pylonwas meant to protect the fuel tanks in thewing by allowing pylon separation.

Boeing announced an upgradeprogramme to the Classic fleet based onthe 747-400’s pylon design whichstrengthened the fixing and introducedcorrosion-resistant fuse pins. Themodification required about 25,000 manhours (MH) and about 40 daysdowntime. Service bulletin (SB) 747-54A2159 is the overall and majorterminating action for this modification.All affected aircraft have been modified.

Ageing aircraft considerations for the747 Classic have been well defined andmandated. Section 41 remains the mostwell known modification to the 747-200/-300. Section 41 is the forward section ofthe fuselage, including the flightdeck andupper deck areas. In 1986 cracks werefound in the fuselage rings in this area,mainly because the fuselage had a cross-section in the shape of a pear. All aircraftbuilt up to line number 685, which wasbuilt in August 1987, are affected byAD86-23-06 (which superseded AD 86-03-51) which requires regular structuralinspections of the area.

Inspections start at a totalaccumulated time of 8,000 flight cycles(FC) and continue until 19,000FC. After19,000FC the inspections must beperformed more frequently. Section 41 is,however, divided into nine zones so thatan operator can opt to terminate certainzones and keep on inspecting others.

The extensive downtime involved inperforming these inspections, and the cost

of MH, means that most operators seekto terminate the AD and associatedinspections with structural modifications.Terminating the inspection requires thevirtual replacement of the nose section.Boeing provides kits free of charge, butall other costs have to be borne by theoperator. About 32,000MH may berequired to terminate all nine zones ofSection 41. The total cost can easilyamount to $2 million. Because of theextensive work involved in Section 41,operators tend to undertake the task atthe same time as a D check. SB53-2272covers this termination action.

The loss of TWA Flight 800 is still amystery. However operators of the 747already have to comply with newoperating standards to minimise the riskof an in-flight explosion of the fuel tank.This is accomplished by ensuring thatrelevant tanks are full and in checkingwiring for chafing. There are also moresevere modifications being considered,including the use of inert gas to containdangerous fuel vapour in tanks that arenot full.

Noise compliance Many 747-200s and -300s do not

meet the FAR Part 36 Stage 3 noiserequirements, without incurring weightpenalties and/or landing flap settings.

Details of compliance for aircraft withdifferent engine types and MTOWs are inBoeing document D6-13703 Section 1.2.Only Pratt & Whitney JT9D-7Q, JT9D-7R4G2, and General Electric CF6-50Eseries, and Rolls-Royce RB211-524D4engines allow the aircraft to operate atthe highest MTOW of 833,000lbs. A820,000lbs MTOW certification ispermitted for aircraft equipped with theJT9D-70A.



Major structural modifications include Section 41inspection termination. This has to be tocompleted by a total time of 20,000FC, and isestimated to have a total cost of up to $2.0million. There are many aircraft in operation witha total time of less than 16,000FC, and these aremore likely to be retired when reaching the20,000FC threshold than bear the cost of themodification.

For the JT9D-7J, there is a papermodification that improves performanceof the -200B when operating under Stage3 restrictions. The upgrade is achieved bymoving the centre of gravity, combinedwith a change in the aircraft trim. Thisallows a lower thrust setting to be used,resulting in lower noise levels at higherMTOW, increasing MTOW from770,000lbs to 791,000lbs and increasingcargo capability for the -200B by anestimated 10 tons.

Freighter conversions Over the past 20 years, the fleet of

factory-built 747 freighters has beenaugmented by conversion of about 100passenger 747s, mostly the -200 model.Boeing’s launch of a passenger-to-freighter conversion for the 747-400 willstart to affect the market for 747-200/-300 conversions. Many new start-upairlines, like US-based Focus Air Cargoand Cargo 360, turn to the 747-200/-300for low-cost freighter assets.

During conversion, sidewall freighterpanels are installed, primary andsecondary control cables relocated, and asmoke detection system installed. The air-conditioning system will also be modifiedfor a 747 freighter system. A side cargodoor and freighter floor beams areinstalled. The body frames are reinforcedto accommodate the heavier loads. Maindeck floor panels are replaced withfreighter floor panels. Combi aircraft arecheaper to convert, with fourorganisations able to undertake freighterconversions on the 747 Classics.

The cost of freighter conversion andaccompanying freight handling systeminstallation costs up to $16 million for apassenger aircraft, and up to $11 million

for a Combi. This cost is excessive inrelation to the 747-200’s/-300’s remaininglife, especially when other costs of Section41 and other modifications may also haveto completed. Moreover, the marketvalue, lower cash operating costs, higherpayload capacity, and remaining life ofthe 747-400 make it more attractive forfreighter conversion.

Boeing Boeing Wichita has undertaken many

such conversions on both the -200 and -300, but tends to be more expensive thanits competitors. The downtime for Boeingranges from 67-80 days. The cost ofconverting a -200B to a special freightervaries with specification. Converting aCombi to a freighter is about half theprice of converting a passenger aircraft.There are various changes to the MTOW,maximum landing weight (MLW) andmaximum zero fuel weight (MZFW),each adding to the base cost.

On the -300, the floor of the extendedupper deck drops down on the main deckcargo bay, making it less attractive as afreighter. The Boeing reconfiguration ofthe -300 requires reinforcement of theforward section of the cabin floor andremoval of the cabin facilities.

Bedek Aviation Israel Aircraft Industries (Bedek

Aviation) has become well known for 747conversions, and is the largest conversioncentre outside the US. Bedek hasperformed more than 36 747 Classicconversions.

Bedek’s pricing for conversion of -200passenger and combi aircraft is lowerthan Boeing’s.

GATX/Airlog GATX/Airlog also held an STC for

the conversion of 747s, but the FederalAviation Administration (FAA), admittedthat this was granted in error.GATX/Airlog does not have the ability toundertake conversions itself, but relies onother modification centres. Two ADswere issued affecting 10 aircraft that wereconverted using the GATX modification(nine 100s and one 200). AD 96-01-03makes it necessary to restrict the payloadof the aircraft to only 120,710lbs,compared to its full 220,195lbscapability, making the aircraftuneconomic to operate. The 13 aircraftthat have been converted using theGATX/Airlog modification from Combior CRAF units are not affected by therestrictions of the AD.

HAECO/TAECO HAECO is the fourth conversion

centre. During 1995, it completed thefirst -200SF conversion for South AfricanAirways. However the Hong Kong-basedcompany has preferred to focus onconversions for Combis. HAECO won alarge order from Atlas Air for Combiconversions.

TAECO’s Combi to freighter -200conversion is cheaper than the Boeingconversion.

747-200SF payloadEach conversion has an optional

maximum zero fuel weights (MZFW) of545,000lbs, 560,000lbs and 590,000lbs.The higher MZFW option is achieved byadditional structural modifications duringconversion, and commands a higherprice. The OEW of converted aircraft,including tare weight of containers isabout 356,000lbs. This gives the aircrafta structural payload of up to 234,000lbs.

With the side cargo door installed, the747-200SF can accommodate eight 96-inch high containers and 21 118-inchhigh containers. These provide about20,245 cubic feet. In addition, the aircraftcan carry 30 LD-1 belly containers whichprovide a total volume of 5,250 cubicfeet. Total volume in this configuration is25,495 cubic feet, which allows amaximum packing density of 7.4-9.1lbsper cubic foot. Other configurations, thatinclude pallets, provide less volume.



There are four different freighter conversionprogrammes for the 747-200/-300. Few -300swere converted, and some of the most populartypes for freighter modification were the CF6-50E2-powered 747-200 Combis.Modification to freighter provides up to 25,500cubic feet of cargo capacity and 234,000lbs ofpayload.



The 747-200/-300s that remain inservice are between 15 and 34years old (see 747-200/-300fleet analysis, page 8). This

means that virtually all aircraft inoperation have had three D checks, whilethe oldest will have been through five.Many 747-200s and -300s operate asfreighters or converted freighters, whileno more passenger-configured aircraft arebeing modified to freighter. Most aircraftwill continue in operation until theyreach their fifth D check or up to amaximum age of 30 years.

Most aircraft now accumulate about3,500 flight hours (FH) per year and havean average flight cycle (FC) time of5.0FH, thereby generating about 700FCannually.

Maintenance programme The 747-200/-300’s line maintenance

programme is standard for most types.The aircraft has transit and pre-flightchecks prior to each flight, and dailychecks. While daily checks on short-haulaircraft are performed at night when theaircraft are grounded, 747 operators stillhave to do daily checks when the aircraftreturn to home base, or occasionally atoutstations. Many operators arepermitted interval extensions of 48 hoursfor daily checks. Ameco Beijing, whichmanages the maintenance for Air China’s747-200F fleet, has a system with an AFcheck every 24 to 48 hours, as well as adaily check performed every five elapseddays of operation.

There are five A check multiples: the1A, 2A, 3A, 4A and 6A items. The Acheck cycle will therefore be completed atthe A12 check when all task groups are inphase. The basic interval for 1A items

varies. Ameco Beijing has an interval of300FH. “The A check cycle has aninterval of 3,600FH, which coincideswith our basic C check interval,” saysMichael Keller, manager of productionengineering & planning department atAmeco Beijing.

Maintenance schedules for A checksare similar for most airlines, althoughsome operators choose to equalise the Acheck packages. Air New Zealand had ablock check system, but had a basic 1Ainterval of 450FH which was laterescalated to 550FH.

El Al operates a unique ramp and Acheck system. “Until now we have used asystem of transit checks prior to eachflight, a daily check every 24 hoursperformed at Tel Aviv, and E800 andL800 checks to deal with engine-relatedand lubrication items from the A checkinstead of having a full A check. Thesetwo have an interval of 800FH,” explainsMoti Sonsino, director of aircraftoverhaul and logistics at El AlEngineering. “We then have a larger Bcheck every 1,600FH. Our fleet of fiveaircraft is now between 24 and 27 years

old, and we are going to change to asystem of having an A check every400FH to replace the E800, L800 and Bchecks. This is because the number ofdefects is gradually increasing and morefrequent line checks are needed tomanage it.”

The 747-200/-300 originally had anMSG-2 maintenance programme. Mostoperators have remained with it.

The 747-200-300 has a block C checkprogramme, with five multiples. “Thebasic C check interval is 3,600FH and 15months, whichever comes first,” explainsKeller. “The five multiples are 1C, 2C,3C, 4C and 6C groups of tasks. Thesecan be equalised, but we group multiplesaccordingly to perform block checks,with the C4 check having the 1C, 2C and4C items. The C6 check has the 1C, 2Cand 3C items. This has an interval of21,600FH, and the C7 check has aninterval of 25,000FH. There are also afew items at 20,000FH, which are de-escalated to the C5 check.

“The D check is independent of the Ccheck, and the D check interval variesaccording to which one has beenperformed,” continues Keller. “The D1has an interval of 25,000FH, the D2 aninterval of 22,000FH, and the D3, D4and D5 all have a 20,000FH interval.This 20,000FH interval coincides withthe probable timing of the C6 check, atwhich point the C check cycle isterminated.”

Other operators have longer C checkintervals. “We had an interval of5,000FH, and then escalated this to6,000FH and 15 months,” says GrahamWallace, project leader engineeringservices at Air New Zealand EngineeringServices (ANZES). “Our D check intervalwas 25,000FH and was then extended to

747-200/-300maintenance analysis& budgetThe 747-200/-300 has high maintenance costs,although operators can minimise these as aircraftapproach retirement.

The 747-200’s/-300’s ageing aircraft programmeadds a large number of MH to base checks. Fullworkpackages for D checks can be 90,000-100,000MH for aircraft at their D4 or D5checks.

30,000FH. We originally phased ourmaintenance programme by performing1/8 of 1C items, 1/16 of 2C items, and1/32 of 4C items in each check, whichwas performed about every eight weeks.We then changed to a block system, witha C check about every 13 months.”

El Al equalises its D check over six Cchecks. The C check has a basic intervalof 4,800FH and 24 months, whichevercomes first,” explains Sonsino. “We useabout 90% of the full cycle interval of28,800FH, and so complete it at about24,000FH.”

Ageing programme In addition to base maintenance

checks in the MSG-2 maintenanceprogramme, operators have to consideradditional maintenance requirementsconnected to the aircraft’s ageing aircraftprogramme. “There are four main partsto the 747-200/-300’s ageing aircraftprogramme,” explains Sven Pawliska,team leader system engineering atLufthansa Technik. “The first of these isthe corrosion prevention and controlprogramme (CPCP). This is a set of about30 inspection tasks to check forcorrosion, which have initial thresholdsof between four and 30 years. These alsohave repeat inspection intervals. Theseinspection intervals are not in the samephase as the C and D checks in the MSG-2 maintenance schedule. The addition ofthe CPCP to the C and D checks meansthey vary in workscope content and MHrequirement.

“The second main part of the ageingaircraft programme is the supplementalstructural inspection document (SSID).This is sometimes referred to as the SSIP,”

continues Pawliska. “This is independentof the MSG-2 maintenance programme,and the SSID should not be confused withthe significant structural items (SSI),which is a part of the MSG-2maintenance programme related to theaircraft structure. The SSID is also a setof structural inspections which add to theworkscope of the C and D checks.

“The other two parts of the ageingaircraft programme are the repairassessment programme (RAP) andwidespread fatigue damage (WFD)programme. The RAP requires aninspection of a structural repair15,000FC after it has been performed,while the WFD requires inspections iffatigue damage is found in several placeson an aircraft or on several aircraft in afleet,” explains Pawliska.

Boeing made an MSG-3 analysis forthe 747-200/-300 and issued themaintenance programme in 2002. A fewoperators have converted their aircraftfrom an MSG-2 to an MSG-3programme, although it is onlyconsidered to be beneficial if aircraftremain operational for an extendedperiod. “Changing to an MSG-3programme escalated a lot of inspectionand C and D check intervals andincorporated the ageing aircraftinspections into the MPD. Overall itresulted in fewer total MH beingconsumed in C and D checks,” saysPawliska. “As an example, the C checkinterval was extended from 3,600FH and15 months to 6,000FH and 18 months.The D check interval was changed to asix-year interval, with no FH limitation.Changing to an MSG-3 programmeobviously requires a bridging check,which is best done during a D check.”

Heavy modifications The 747-200/-300 has had several

highly publicised, major structuralmodification programmes. The first ofthese is the Section 41 modification,which affects the front section of thefuselage. The pear-shaped profile of thissection was found to cause cracks in thefuselage rings as early as an accumulationof 6,500FC. This was dealt with underairworthiness directive (AD) 86-03-51,which was later superseded by AD 86-23-06. This AD affected all 747s up to linenumber 603. This was an aircraft built in1984 for Singapore Airlines. The AD waslater revised and extended to line number685, a -200B built in late 1987 for the USAir Force. The extension brought some -300s into the group of aircraft affected bythe AD.

The AD requires a series of repetitiveinspections to some of the structural partsin Section 41. The threshold for theseinspections is 8,000FC, and the amountof Section 41 that is affected is initiallysmall, but increases up to 19,000FCwhen the whole of Section 41 must beinspected. After this threshold is reachedinspections have to be performed every1,500FC or 3,000FC. The need toperform these inspections can beterminated by replacing part of theoriginal structure. The 1,500FC repeatinterval after 19,000FC effectively meansthe modification has to be performed by atotal time of 20,000FC.

This modification was incorporatedon the production line for aircraft withline number 686 and higher, so that theseaircraft are not affected by the AD. Thisincludes all -400 series aircraft.

The modification can be carried out instages, since it concerns several zones ofthe Section 41 structure. Themodification can also be completed in asingle step, and is combined with a Dcheck. The full cost is estimated to be upto about $2.0 million, which includes alabour input of up to 40,000MH. Themodification kits are supplied free byBoeing.

Many, mostly older, 747s havecompleted their Section 41 modifications.The majority of the 281 aircraft still inoperation have accumulated less than20,000FC and so are unlikely to have had



Rotables can be paid for via a flight houragreement. The implosion of the 747-200/-300fleet, however, means many airlines can reducetheir cost of rotables by acquiring items at lowrates on the used market.

the full modification performed. This willbe required for continued operation after20,000FC. The age and market for used747-200s/-300s has to be consideredwhen assessing whether the Section 41modification should be completed. Nomore 747-200s/-300s are likely to beconverted to freighter, since the younger -400 is at an age and market value wheremodification to freighter is economic. The-400 has a larger payload capacity, longerrange and lower operating costs than a -200 or -300. The implications thereforeare that remaining 747-200s/-300s willcontinue in service until they reach the20,000FC threshold for Section 41modification, at which point the cost ofthe modification will be economicallyprohibitive and the aircraft will beretired. Many aircraft have accumulatedbetween 10,000FC and 15,000FC, and socould remain operationally viable for upto another 15 more years.

The second major structuralmodification for the 747 was the enginepylons. This was initiated by separationof the engines from the wing during flighton three aircraft, resulting in total loss.This led to an AD 95-13-05 being issuedin 1995 which required the modificationof engine pylons on all 747s up to linenumber 1,046. This affects all 747-200sand -300s built, as well as some of theearlier production -400 series aircraft.

The modification requires the fouroriginal engine mountings to bestrengthened with the installation ofstainless steel bolts and the addition oftwo new mountings. The deadline forcompleting this modification was three tofive years from the issuance of the AD in1994, and so all affected aircraft willhave been modified.

Line maintenance On the basis of an annual utilisation

of 3,600FH and 700FC per year, anaircraft will operate for up to about 330days per annum. This implies that about65 daily checks, 260 AF checks, about375 transit checks and 325 pre-flightchecks will be performed annually. This isa total of about 1,025 ramp checks peryear.

The completion of the A check cyclewill depend on the operator’s A checkinterval and how much of it is actuallyutilised. Intervals vary between 300FHand 500FH, and utilisation rates are 60-80%. The A check cycle will thus becompleted every 2,700-4,000FH, equal tobetween nine and 13 months ofoperation.

The total consumption of MH andmaterials for line, ramp and A checks willdepend on various factors: the A checkcycle completion interval; the number of

ramp checks performed during thisinterval; the number of MH used in eachcheck; the operator’s policy for managingdeferred defects; and labour efficiency.The policy of managing and clearingdeferred defects will affect the non-routine portion of the checks.

Completion of the A check cycle every2,700FH and nine months will result inabout 525 pre-flight and transit checks,195 AF checks and 50 daily checks beingcompleted during the same period. This isa total of 775 ramp checks.

Keller estimates that pre-flight andtransit checks each consume an averageof seven MH and $500 in consumablesand expendables. AF checks require 22MH on average and use about $1,000 inconsumables and expendables, whiledaily checks use about nine MH and asimilar amount for materials. The inputsfor these ramp checks over one A checkcycle total about 8,500MH and about$600,000 in consumables andexpendables. Line maintenance labourcharged at an industry average rate of$70 per MH takes this to a total cost ofabout $1.2 million. This equals a cost ofabout $446 per FH when amortised overthe 2,700FH interval.

Longer A check intervals of up to600FH might allow actual A checkintervals of 350FH, and the completionof the A check cycle every 4,200FH.



More line and ramp checks would becompleted in this period, and their totalcost would be $1.87 million. The overallcost per FH of performing these checkswould still be about $445 per FH (seetable, page 22).

The routine MH input for A checksvaries by check because of the blocksystem. In addition to routine inspections,MH will be required for rectification andclearance of deferred defects. The A4, A8and A12 checks will have the largestlabour inputs and will use in excess of1,000MH. An average consumption of600MH should be used for a conservativebudget for aircraft beyond their third D3cycle. This is equal to $42,000 for labourcharged at $70 per MH. Expenditure onmaterials and consumables will be$6,000, taking total cost for the check to$48,000. Performance of an A checkevery 350FH is equal to $138 per FH (seetable, page 22).

Base maintenance Operators have a variety of choices

for organising their base maintenanceschedules. The most common is thestandard MSG-2 system of block Cchecks and a D check performed at theC6 or C7 check, terminating the C checkcycle.

Workscopes of C and D checks haveseveral additions to the routineinspections of the MSG-2 task cards. Theageing aircraft programme will addinspections for the CPCP and SSIDprogrammes. These and the routine taskcards will result in findings and non-routine rectifications.

Another addition to this basicpackage of work will be engineeringorders, Service Bulletins (SBs),Engineering Orders (EOs) and ADs.These vary in total quantity for eachcheck, and according to the operator’spolicy for incorporating modifications. Afurther possible addition will be majormodifications, such as Section 41inspection. The third major addition to abase check work package will be interiorwork. This can involve cleaning andsmall rectifications, as well as majorrefurbishment of the galleys, toilets,overhead bins, sidewall panels, carpeting,seats, and in-flight entertainment (IFE)systems. In the case of freighter aircraft,many of these interior items will not beincluded, although the freight handlingsystem will require inspections andrectifications. This is despite on-goingrepairs being made to the freight handlingsystem during operation.

The last major item that can be addedto the work package of a C or D check isstripping and repainting, which adds asignificant number of MH and cost forpaint.

The number of MH for routineinspections will be influenced by thetiming of the specific ageing programmetasks included in each workscope, howwell planned each check is, and theefficiency of labour. The non-routinelabour requirement and ratio will also beaffected by planning and labourefficiency.

“The amount of MH used for MSG-2and ageing aircraft routine inspectionsvaries by a small amount for the actual Ccheck,” explains Ralf Riemann, manager

service engineering VIP & Governmentjet maintenance at Lufthansa Technik.“This can typically be 7,000-8,000MH ifthe check is planned and performedefficiently, but can rise to up to12,000MH for a less efficient check.

“The non-routine ratio for aircraftthat have accumulated a total time ofabout 60,000FH can be in the region of50%, and so the number of non-routineMH arising from these inspections will be3,000-4,000,” continues Riemann. “Thiswould take MH for routine and non-routine work to about 13,000MH.”

A higher non-routine ratio of 100% isnot uncommon in some aircraft, and socan be in the region of 8,000-12,000MHfor some aircraft that are in their D3 orD4 check cycles. This could take the totalfor just the MSG-2 and ageing aircraftinspections up to 24,000MH.

“While modifications incorporatedduring C checks vary, only certainmodifications can be made because of therestrictions imposed by downtime for thecheck and the requirement that power beswitched off,” explains Riemann.“Modifications, EOs, SBs and ADs cantypically add 2,000MH to a C check. Afurther 800-1,000MH can then be addedfor the cleaning of the aircraft interiorand maintenance of IFE equipment.Freighter aircraft will of course notrequire some of the work on interiorsthat passenger aircraft do, but the cargohandling system can still use 500-1,000MH for repairs. Therefore, evenwhen the MH for MSG-2 and ageingaircraft inspections total about13,000MH, the total labour consumptionfor the check would be in the region of



Total maintenance costs for the 747-200/-300can be close to $3,000 per FH. Airlines can makereductions on this cost by managing engines toavoid LLP replacement, acquiring cheap rotableson the used market, minimising base check workpackages, and even dispensing with reserves fora D check if its known the aircraft will be retired.

16,000MH. A higher non-routine ratiocould see that total rise to more than20,000MH for some aircraft. Downtimefor this size of check will be five to eightdays. The cost of consumables andexpendables commensurate with this sizeof check will be in the region of$100,000.”

Wallace at ANZES confirms thatworkscopes and inputs for C checks of747-200s/-300s can be high. “Our 747-200s consumed in the region of8,000MH when we first switched theaircraft to a block base system. The MHconsumption had already climbed to12,000-14,000 by the late 1990s justbefore we retired the aircraft,” saysWallace. “The C check workscopeincludes: routine task cards andconsequential rectifications; CPCP andageing programme inspections andrectifications; EOs and ADs; and cabinwork. The CPCP and ageing programmeportion itself could consume up to10,000MH, and the total for a C checkwould now be in the region of20,000MH.”

The D check will terminate the Ccheck cycle. Routine task cards willtherefore include various C check items.“Routine tasks and inspections for theMSG-2 items and ageing programmeinspections can be as high as 40,000-50,000MH in a D3 or D4 check. An

aircraft will have accumulated a totaltime of about 65,000FH at a D3 checkand about 82,000FH at a D4 check,”says Riemann. “The non-routine ratio foran aircraft of this age may only be as lowas 25%, and so only 12,000-13,000MHare generated from these routineinspections. The total MH is thus 52,000-63,000. A higher non-routine ratio of upto 75% is seen in many aircraft, with30,000-40,000MH being required. Atotal of 70,000-80,000MH is thereforeused for this portion of the workpackage. Besides major modifications, theamount of labour required for EOs, SBsand modifications is in the range of6,000MH to 8,000MH for most Dchecks. A similar amount of labour isrequired for interior refurbishment whereseats, sidewall panels, and toilets andgalleys are refurbished. Only 2,000-3,000MH would be required for interior-related work for freighter aircraft.Stripping and painting will use about3,000MH.”

This will take the total labourconsumption to 67,000-83,000MH for apassenger-configured aircraft with a lownon-routine ratio, but up to 95,000MHfor an aircraft with a high non-routineratio. Freighter aircraft will requiremarginally less MH. Downtime for asmaller work package will be about 50days, climbing to 75 days for a heavy

package. Riemann estimates the labourrequirement for a D5 check can easilyreach 100,000MH, since there is a higherrequirement from the SSID programme.One example is the need for removal andnon-destructive testing of the wing bolts.

Riemann estimates the cost ofconsumables and expendables associatedwith this check to be in the region of$700,000, which could easily climb to$900,000-1,000,000 for a check with ahigher MH consumption, higher level ofmodifications and extensive IFEinstallation.

A full D check cycle might becompleted about every 20,000FH,including five C checks. Consumption of18,000MH and $100,000 in materials foreach C check, and 90,000-100,000MHand $700,000-1,000,000 in materials forthe D check would result in a total cost of$10.2-11.0 million for the D check cycle.Over the 20,000FH interval, this wouldbe equal to $510-550 per FH (see table,page 22).

Heavy components This group includes four types of

component, each of which has either itsindependent maintenance programme or‘on-condition’ maintenance: wheels andbrakes; landing gear; auxiliary power unit(APU); and thrust reversers.





The maintenance and repair of thesecomponents is mainly FC-related, and sothe final cost per FH is dependent on theFH:FC ratio. This analysis assumes anaverage FC time of 5.0FH, although eachoperator’s actual FC time will vary.

The overall cost per FC for the repairof wheels and brakes is a combination ofthe cost per FC of tyre remoulds andreplacements and wheel inspections andrepairs. There are 16 main wheels andbrakes and two nose wheels. Average tyreremould intervals for main wheels are280FC. Tyres might be remoulded fourtimes at an average cost of $500 and thenreplaced at a typical cost of $1,800.Overall cost per FC for 16 main tyres is$43.

Nose wheels are remoulded aboutevery 350FC at an average cost of $400,and are replaced for about $1,000.Overall cost per FC for two nose tyres is$3. The total for main and nose wheeltyre remoulds and replacement is $46 perFC (see table, page 22).

Wheel inspections are made at tyreremoulds, with costs of $650 for mainwheels and $600 for nose wheels,resulting in a cost per FC of $40 (seetable, page 22).

Each main brake unit is repairedabout every third wheel removal, atabout 850FC, and at a cost of about$13,000. Overall cost per FC for mainbrake repairs is $245 (see table, page 22).

Landing gears can be removed every

eight to 10 years, equal to every second Dcheck. The most common method is anexchange of a landing gear shipset, whichin the current market costs about$575,000. This is equal to $85-105 perFC, depending on actual removalinterval, and $17-21 per FH (see table,page 22).

Thrust reversers are removed formaintenance on an on-condition basis.Shipsets are removed every 6,000-8,000FC for the JT9D and CF5-50engines. An average cost for a thrustreverser shipset shop visit is about$170,000. For the four shipsets, this isequal to about $115 per FC, or $24 perFH (see table, page 22).

The 747-200/-300’s APU is the GTCP660. This has an average shop visitinterval of about 3,000 APU hours. Onthe basis that an operator will use theAPU for an average of two hours everyflight, it will have an annual utilisation ofabout 1,400 hours. It will therefore havea shop visit about every two years. Anaverage shop visit cost of $180,000results in a cost per aircraft FC of $120,equal to $24 per FH (see table, page 22).

The total for all heavy components isabout $668 per FC, equal to $134 per FH(see table, page 22).

Rotables Remaining rotable components can

be maintained according to the

maintenance programme, on an on-condition basis or using soft timesderived from the history services of thesecomponents to provide a preventativemaintenance programme.

These rotables include: avionics;emergency equipment; galley and interioritems; flap mechanisms; flight controls;hydraulic system items; pneumatic systemitems; fuel system items; electrical systemitems; and a large number of othercomponents.

Collectively these rotables can be paidfor using a flight hour agreement with alarge 747-200/-300 maintenance provideror component specialist.

Rates will depend on exclusions,which are the items not covered in theflight hour agreement. These can vary. Insome cases wheels and brakes areincluded in the agreement for rotables,while other heavy components are notincluded. Flight hour agreements oftenexclude cabin and IFE items.

When the heavy componentspreviously described are excluded and allother rotables are included, a typicalflight hour agreement will be in theregion of $150 per FH for the lease of thecomponents and an additional $400-450per FH for the repair and management ofthe rotables. This would take the totalcost for rotables to $550-600 per FH (seetable, page 22). There is now a high supplyof many rotables on the aftermarket, whichmay allow lower costs.

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by a true commitment to overhaul and repair. So when you bring us your business,

you’ll be 100% satisfied. Every time. The people of Pratt & Whitney. Powering change.

IF I CAN’T GIVE MY CUSTOMERS 100% FLAWLESS EXECUTION,THENTHEY SHOULDN’T COME TO ME.

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Craig Thompson, Operations Manager, Overhaul and Repair Services



Engine maintenance The 280 747-200s/-300s still in

operation are powered by a combinationof JT9D, CF6-50 and RB211-524engines. Potential and current operatorsare interested in the highest gross weightaircraft with the largest payload andlongest range capability.

The majority of the lower grossweight aircraft are powered by the -7Aand -7F variants of the JT9D. There arefew of these left in operation. The highestmaximum take-off weight for the 747-200 and -300 is 833,000lbs. Theseaircraft are powered by the JT9D-7Q,JT9D-7R4G2, CF6-50 and RB211.About 240 of the aircraft left in operationare equipped with these engines.

About 55 747-200s have the JT9D-7Q, while the majority of the 52 aircraftwith the JT9D-7R4G2 are 747-300s. Themost popular of all 747-200s/-300s arethose with the CF6-50E2 engine. AtlasAir, for example, acquired all its 747-200s with CF6-50 engines. There are 86of these aircraft still in operation.

Less important and less popular arethe 40 aircraft with RB211-524 engines,the majority of which are the -524D4.

Aircraft with the JT9D-7Q/-7R4G2and CF6-50 engines will remain the mostimportant types in the future.

Like most Pratt & Whitney engines,the JT9D is usually managed so that itfollows an alternating pattern of a

performance restoration followed by anoverhaul. The engines are now mature,and only have EGT margins of 20-50degrees centigrade following an overhaul.These margins deteriorate at about 8-12degrees per 1,000 engine flight cycles(EFC), and so could potentially remainon-wing for 2,500-4,000EFC. Actualaverage removal intervals between shopvisits for an operation with an averageEFC time of 5.0EFH are in the region of6,000-7,000 engine flight hours (EFH) forthe JT9D-7J and 7,000-8,000EFH for the-7R4G2. Removals to the first shop visitare longer than to the second removal.

The workscope for performancerestoration shop visits for these twovariants consumes about 4,500MH,$800,000 in materials and another$450,000 for sub-contract repairs. Anaverage labour cost of $70 per MHresults in a total shop visit cost of $1.6million.

Overhauls use about 5,500MH, up to$1.5 million for materials and $550,000for sub-contract repairs. This would taketotal cost to about $2.5 million.

These two shop visits amortised overthe combined removal intervals of14,000FH for the JT9D-7Q and16,000FH for the JT9D-7R4G2 generatereserves of about $295 per EFH for theJT9D-7Q and $255 for the JT9D-7R4G2(see table, page 22). These rates would belower for aircraft operating with longeraverage cycle times, since removal

intervals are closely related to EFCs andshop visit inputs would be similar tothose described. Some operators are alsoable to achieve removal intervals up to2,000EFH longer than those described,which would also result in lower reservesper EFH.

The replacement of LLPs has to beconsidered in addition. All LLPs havelives of 15,000EFC for both variants, anda full set has a list price of about $1.7million. Given that in this scenario -7Qengines will accumulate about 2,600EFCbetween overhauls and -7R4G2 enginesabout 2,800EFC between overhauls, LLPreplacement would be most efficient atevery fourth or possibly fifth overhaul.This interval, however, is equal to about20 years of operation. Given that theyoungest aircraft are 15 years old and theoldest aircraft with -7Q engines are 25-26years old, and that most aircraft are onlylikely to be operated up to a maximumage of 30 years, airlines may be able toavoid the cost of replacing LLPs in mostof their engines. This is because LLPs willhave already been replaced one and areunlikely to require replacing a secondtime in their operational life.

Time-continued engines are oftenavailable on the market, as are LLPs, andvalues are likely to steadily decline overthe long term. Airlines will thus only needto replace LLPs in some of their enginesat a fraction of the cost of replacing all ofthem with complete new sets.

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our skills and knowledge, looking to be the best we can. By implementing

preventive practices, we ensure service excellence. Every time. The people

of Pratt & Whitney. Powering change.

TO BE CUSTOMER ORIENTEDIS TO BE HUMAN ORIENTED.

Yong-Mei Liu, Manager, Employee Global Learning

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The CF6-50 will achieve averageremoval intervals of 1,300-1,500EFC atan average EFC time of 5.0EFH, equal toabout 6,500-7,500EFH in most 747-200/-300 operations, although someairlines can achieve up to another1,000EFH on-wing.

The CF6-50 follows a shop visitpattern described by General Electric’sworkscope planning guide. This outlinesthe workscope at three levels for each offour modules based on the time since thelast overhaul. The CF6-50 generallyfollows a shop visit pattern of alternatingworkscopes similar the JT9D.

A performance restoration shop visitwill consume 4,000-5,000MH, about$600,000 for materials and $500,000 forsub-contract repairs. This will take totalcost for the shop visit to $1.4-1.5 million.

An overhaul will consume about5,500MH, $800,000-900,000 formaterials and up to $800,000 for sub-contract repairs, taking total shop visitcost to $2.0-2.2 million.

The two shop visits will generate areserve of about $260 per EFH. Like the

JT9D, the life of LLPs in the CF6-50 islong compared to the probable remaininglife of the aircraft. A full set of LLPs has alist price of more than $2 million, whilethe supply of time-continued engines andLLPs will be relatively high and somarket values low. Like the JT9D, LLPsin the CF6-50E2 will have already beenreplaced once in most engines and willnot need replacing a second time in theiroperational life. Airlines may be able toacquire time-continued LLPs at cheaprates on the used market for young enginesthat may require LLP replacement.

Maintenance cost summary The costs for almost all direct

maintenance for the 747-200/-300 aresummarised (see table, page 22). Absentcosts are reserves for engine LLPs andspare engine provisioning. LLPs havebeen omitted because the age of theaircraft means that in many cases it willnot be necessary to replace them again.Spare engine provisioning can now bevariable and also less with a high supply

of time-continued engines on the market. The total maintenance costs for the

aircraft are $2,800-3,050 per FH,depending on engine type, inputs requiredfor airframe checks, and the negotiatedterms for rotable support. This comparesto a total maintenance cost of $1,500-1,600 per FH for the 747-400. The 747-200/-300 suffers partly because itsassumed FH:FC ratio in this analysis isshort compared to most -400 operations.This automatically increased engine- andcomponent-related costs for the -200/-300. The 747-200/-300 is also at adisadvantage because of the high MHinputs into base checks and short removalintervals between shop visits.

There are also several limits tocontinued operation that operators mustconsider. The first of these is enginemaintenance costs, which are increasingper FH because of reducing intervals.Engine LLP replacement is also high, atabout $2 million per engine, which isequal to the current value of most someengines or about half the value ofpassenger-configured aircraft. The cost offour sets of engine LLPs exceeds themarket value of most 747-200 and -300s.

Another issue is the high inputsrequired at the D5 check, which is likelyto trigger retirement by most operators.There is also the issue of Section 41termination. Most 747-200s/-300s inservice have not reached the 20,000FCthreshold for termination, and the cost ofthis is another cost barrier that is likely totrigger retirement, unless the modificationhas already been completed.

Operators can find ways to reducemaintenance inputs and costs. Oneconsideration is to minimise the workperformed on interiors, EOs, ADs andmodifications during base checks. Time-continued engine modules and landinggear sets can sometimes be purchased onthe aftermarket for less than the cost of afull shop visit.

Long-term considerations Few of the aircraft that remain in

operation are unlikely to go through theirD5 check or pass the 20,000FC thresholdfor Section 41 modification. These bothrepresent timings for probable retirement.The cost of completing both of these willexceed $7.5 million. The reserve for this,plus cost of C checks, engine LLPreplacement and engine maintenancereserves make the maintenance costs ofageing 747-200/-300s excessive. Thisindicates that the remaining 280 aircraftin operation will retire at a high rate ,with few left in operation in another 10years. If Section 41 modification andengine LLP replacement can be avoided,the aircraft provides large capacity whenits combined low capital cost andmaintenance costs are considered.



DIRECT MAINTENANCE COSTS FOR 747-200/-300

Maintenance Cycle Cycle Cost per Cost perItem cost $ interval FC-$ FH-$

Ramp checks 1,870,000 4,200FH 445A check 576,000 4,200FH 137C & D checks 10,200,000-11,000,00 20,000FH 510-550

Heavy components:Landing gear 575,000 5,600FC 103 21Tyre remould & 66,000 1,400/1,750FC 46 10replacementWheel inspections 11,600 280/350FC 40 8Brake inspections 208,000 850FC 245 50Thrust reverser 680,000 6,000FC 113 23overhaulsAPU 180,000 1,500FC 120 24

Total heavy components 668 134

LRU component support 550-600

Total airframe & component maintenance $1,775-1,865/FH

Engine maintenance: 4 X JT9D-7Q $1,180/FH4X JT9D-7R4G2 $1,020/FH4X CF6-50E2 $1,040/FH

Total direct maintenance costs:

Aircraft equipped with JT9D-7Q: $2,955-3,045/FHAircraft equipped with JT9D-7R4G2: $2,795-2,885/FHAircraft equipped with CF6-50E2: $2,815-$2,905/FH

Annual utilisation:3,500FH700FCFH:FC ratio of 5.0:1.0



Values of most 747-200s havenow fallen to scrap level. Thatis, the intrinsic value of anaircraft is directly related the

market value of its engines and anysalvage value that can be derived from itsrotables. The aircraft that have valuesbetter than scrap are the youngest -200Fsbuilt in the late 1980s, 1990 and 1991that are powered by the JT9D-7R4G2and CF6-50E2, as well as -300s with thesame engines that have accumulated less80,000 flight hours (FH) and 15,000flight cycles (FC).

The poor value of the majority ofaircraft is explained by several reasons.The first is that the age of the youngestaircraft is 18 years, while some are up to30 years old. The implications of this arethat aircraft fall into two categories. Thefirst are those that have completed theirSection 41 modifications, but have alsosurpassed their D4 or D5 check. Theimplications of this are that these aircraftare most likely to be retired when theyreach their next D check, because ofescalating maintenance costs.

The second group is aircraft that havenot completed their Section 41modifications. While these will be

relatively young, the $1.5 million cost ofcompleting the Section 41 modificationwill present a high cost barrier when the20,000FC threshold is reached. Mostaircraft that fall into this category are 15-20 years old and have accumulated12,000-17,500FC. They will thus reachthe threshold for Section 41 modificationtermination in the next three to 10 years.The timing of this threshold will coincidewith a D check for some aircraft, and thetwo can total up to $7.5 million. Duringthis same period less maintenance-intensive 747-400s will come onto themarket and so operators will favouryounger aircraft.

No more of the remaining passenger-configured or Combi 747-200s and -300sare being converted to freighter. This isbecause of high on-going maintenancecosts, the cost of conversion being up to$16 million, the likelihood that tocontinue in operation aircraft willprobably require more avionic upgrades,and the useful remaining life of mostaircraft being less than 10 years.

There is thus little or no marketdemand for used 747-200s/-300s,resulting in a collapse in values.

The demand for good quality 747-

200SFs remains strong, however. Allgood quality aircraft are flying. This is aresult of a rebound in freight traffic, withvolumes back at pre-9/11 levels.

This has pushed lease rates for 747-200Fs/-200SFs back up to about$350,000 per month. The aircraft,however, have high maintenance costs inthe region of $2,800-2,900 per FH. Thiscompares to total maintenance costs inthe region of $1,600 per FH for the 747-400. The 747-400SF also has a payloadcapacity of about 253,000lbs, whichcompares to 190,000-230,000lbs for the747-200SF. Operators of 747-200SFs arethus using the aircraft as a stop gap until747-400s get converted in large enoughnumbers to provide replacements.

The 747-200SF provides low-riskcapacity for start-up freight operators.Cargo 360 based in Seattle, Washingtonand Focus Air Cargo, based in MiamiFlorida are both commencing operationswith 747-200SFs.

A few 747-200s and -300s have beenacquired by passenger carriers. Aircraftthat can operate for another five to eightor nine years before requiring heavymaintenance provide cheap lift for thelarge payload they provide. Better qualityand younger -200s and -300s have amarket value in the region of $8-12million. Although a large range of recentavionics modifications are onlymandatory in Europe and NorthAmerica, most aircraft around the worldwill have had these incorporated becauseof the long-distance nature of theiroperations. Most large one-offmaintenance or upgrade costs can thus beavoided with these aircraft. These -200sand -300s can provide capacity at a lowtotal cost until used 747-400s startcoming onto the market.

747-200/-300 values& aftermarket activity Values of most 747-200s/-300s are less than $10million. Low-time aircraft can provide airlines withlow-cost high capacity for up to 10 years. ¶

There are few low-time, high specificationaircraft available, but if operators can acquirethem these aircraft will provide low cost capacityfor up to another 10 years. Despite highmaintenance costs, low capital costs and leaserates mean total operating costs are low.

Documents

AIRCRAFT OWNER’S & OPERATOR’S GUIDE: 747-200/ · PDF fileAIRCRAFT COMMERCE ISSUE NO. 41 • JUNE/JULY 2005 6 I AIRCRAFT OWNER’S & OPERATOR’S GUIDE T he 747-200 and -300 followed