Engine Nacelle Halon Replacement, FAA, WJ Hughes Technical Center

Engine Nacelle Halon Replacement,FAA, WJ Hughes Technical Center

Point of Contact : Doug Ingerson

Department of TransportationFederal Aviation Administration

WJ Hughes Technical CenterFire Safety Section, AAR-422

Bldg 205Atlantic City Int'l Airport, NJ 08405 USA

tel: 609-485-4945fax: 609-485-7074email: [email protected] page: http://www.fire.tc.faa.gov/

International Aircraft Systems Fire Protection Working GroupSeattle-Tacoma Airport, WA 12-13 March 2002

Federal Aviation AdministrationWJ Hughes Technical Center, Fire Safety Section, AAR-422

Atlantic City Int'l Airport, NJ 08405 USA

Three Major Topics for Review :

progress/current status

presentation of recent data

near term plans




PROGRESS/CURRENT STATUS

Test Fixture

Fuel System Prior system to heat the fuel and deliver it to the nozzles in the spray fire zone

deemed inadequate Replaced pump for fuel heating; heating time changes from 1+ hours to 20 minutes Replace pump for spray nozzles w/pressurized ullage system Fuel nozzles will be changed to alter flow rate to the spray fire zone

Fire Extinguisher Equilibrium system in place Agent/N2 solubility is a notable phenomena Firex servicing procedures now account for agent/N2 behavior Distribution plumbing altered to decrease discharge duration




PROGRESS/CURRENT STATUS

Test Fixture (cont’d)

Hot plates Spray hot plate failed 15Oct01

Process control thermocouples separate from plate; significant overheat resultsDifficulties repaired; operational 7Nov01

Electrical circuit for the pool hot plate faulted 31Jan02Plate removed, reason for fault found and correctedOperational 5Feb02




PRESENTATION OF RECENT DATA

Data Presentation

Fire Extinguishing System Problems w/past distribution results required system evaluation Evaluation produced the following areas likely causing the difficulty

Distribution plumbingAgent/N2 equilibrium

The resultant changes in the system yielded positive gains in performanceIncreased the the cross sectional area of the discharge pathway for the agent flowThe single flow split in the discharge pathway changed from a tee to a wyeAgent/N2 equilibrium behavior calculated (NIST computer program PROFISSY)Agent/N2 equilibrium attained prior to test discharge





1.25”OD WYEAS FLOW

SPLIT

5/8”OD tube

From firexball valve

1.25”OD TEEAS FLOW

SPLIT

From firex

ball valve

• 1/2” TUBE BUTT FOR NOZZLES

8” C/L-C/L8” C/L-C/L

1/2”OD tube

Within TestFixture Interior




• 5/8” TUBE BUTT FOR NOZZLES

• NOZZLES FARTHEST FROM CORE RESTRICTED BY 5/8”ODx3/8”ID WASHER

PRESENTATION OF RECENT DATAAgent/N2 Equilibrium Behavior

100

200

300

400

500

600

700

800

900

1000

1100

0 60 120 180 240

Time (min)

Pres

sure

(psig

)

-30

-20

-10

0

10

20

30

40

50

60

70

Age

nt/N

2 M

ixtur

e Te

mpe

ratu

re (°

F)

in firex, agent/N2 mixture in firex, "top-off" in equilibrium accumulator, agent/N2 mixture

in equilibrium accumulator, "top-off" mixture temperature mixture temperature

pr02

3C.x

ls

“Top-off” is the total pressure of the agent/N2 mixture when the system is in equilibrium for the given temperature.




PRESENTATION OF RECENT DATAImprovement of the Agent Discharge Duration

-100

0

100

200

300

400

500

600

700

20 22 24 26 28 30 32 34 36 38 40 42 44Time (sec)

Tem

p (°

F) a

nd P

res

(psi

g)

6 lb @ 51.8 lb/ft^3 3.5 lb @ 59.6 lb/ft^3 past plumbing, 3.7 lb @ 63.6 lb/ft^3

pr02

3C.x

ls





Data Presentation (cont’d)

Gas Analysis Analyzer completed; known as “Hal2 Rebuilt” Producing data from transducers as a Direct Current Voltage (VDC) history Sensor signal starts at a maximum value; as gas concentration increases, signal

decreases (converse behavior applies) Data manipulation

Raw signal run through a smoothing routineSmoothed data aligned at some consistent signal valueAll 12 channels reviewed as one distribution profileSecond review of data incorporates the minimum and maximum values for each time increment




PRESENTATION OF RECENT DATAComparing Raw and Smoothed Signal Data

3.5

3.6

3.7

3.8

3.9

4.0

4.1

4.2

4.3

4.4

4.5

5 7 9 11 13 15 17 19 21 23

Time (s)

Sens

or S

igna

l (VD

C)

Ch# 01, smooth Ch# 05, smooth Ch# 09, smooth RawData Ch1 RawData Ch5 RawData Ch9

NSa

0230

5_10




PRESENTATION OF RECENT DATAAgent Distribution Profile, HFC-125

3.4

3.5

3.6

3.7

3.8

3.9

4.0

4.1

4.2

31 32 33 34 35 36 37 38 39

Time (s)

Sens

or S

igna

l (VD

C)

Ch# 11

Ch# 09

Ch# 04

Ch# 08

Ch# 05

Ch# 03Ch# 01

Ch# 06Ch# 10

Ch# 12

Ch# 02

Ch# 07

CertificationActual

NSa

0230

5

as of 25Feb02...Ring location

ch# - clock position FWD MID AFT

11-12:00 05-1:00 10-12:0009-3:00 03-4:30 12-3:00 04-6:00 01-7:30 02-6:00 08-9:00 06-11:00 07-9:00




PRESENTATION OF RECENT DATAAgent Distribution Profile, Min/Max Evaluation, HFC-125

3.4

3.5

3.6

3.7

3.8

3.9

4.0

4.1

4.2

31 32 33 34 35 36 37 38 39

Time (s)

Sens

or S

igna

l (VD

C)

min/max signal

CertificationActual

NSa

0230

5




PRESENTATION OF RECENT DATAComparing Distribution Profiles, Hal2 RBLT

3.2

3.3

3.4

3.5

3.6

3.7

3.8

3.9

4.0

4.1

4.2

30 31 32 33 34 35 36 37 38 39 40

Time (s)

Sens

or S

igna

l (VD

C)

02227_15, min/max 02227_16, min/max 02228_11, min/max 02305_11, min/max 02306_11, min/max

pr02

3C.x

ls




NEAR TERM PLANS

Test Activity

Gas Analysis Cold agent testing on-going since latter Feb ‘02

Difficulty getting agent temperature to -65°FProcess refined

Testing continuing now (12-15March02)Will find acceptable distribution profiles for two air flow conditionsAir flow conditions => high flow/low temperature & low flow/high temperature

Closure analysis will include :Distribution profile measurements at agent storage conditions during fire testingDistribution profile measurements for agent storage conditions at depressed temperature




NEAR TERM PLANS

Test Activity (cont’d)

Fire Testing

Will follow on immediately after agent distribution work at depressed temperature is completed (mid-March ‘02)

Basic fire characterizations completed




Documents

Engine Nacelle Halon Replacement, FAA, WJ Hughes Technical Center