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Section/division Occurrence Investigation Form Number: CA 12-12a
AIRCRAFT ACCIDENT REPORT AND EXECUTIVE SUMMARY
Reference: CA18/2/3/8635
Aircraft Registration ZS-HFW Date of Accident 14 April 2009 Time of Accident 11:30Z
Type of Aircraft Robinson R44 II Type of Operation Training ( Conversion)
Pilot-in-command Licence Type Commercial Age 43 Licence Valid Yes
Pilot-in-command Flying Experience Total Flying Hours 245.1 Hours on Type 61.9
Last point of departure George Aerodrome (FAGG)
Next point of intended landing Mossel Bay Aerodrome (FAMO)
Location of the accident site with reference to easily defined geographical points (GPS readings if possible)
Threshold 09 at Mossel Bay Aerodrome.
Meteorological Information Surface wind 012˚/5kts. Visibility: CAVOK
Number of people on board 1 + 1 No. of people injured 0 No. of people killed 0
Synopsis
On 14 April 2009 the instructor pilot (IP) and student pilot (SP) took off from George Aerodrome (FAGG) to Mossel Bay Aerodrome (FAMO) on a training flight (conversion training flight).The SP was undergoing conversion training onto a Robinson R44 helicopter when the accident occurred. The training required that the hydraulic switch be deactivated or switched off. Following the deactivation of the hydraulic system, the SP informed the IP of the stiffness of the controls. The IP explained the need to have the hydraulic system off. The SP then managed to get the helicopter on to a hover and held a steady hover for a short period before loosing control. The instructor pilot instructed the student pilot to activate hydraulic switch which is situated only on the student’s side of cyclic control. The student did not activate the hydraulic switch timeously, resulting in the helicopter impacting the ground hard. The instructor and the student sustained no injuries, but the aircraft was destroyed.
Probable Cause Helicopter vertically impacted the ground hard following the pilot's loss of control during hover. Contributory Failure of the instructor to react by taking over control of the helicopter as it can be flown with the hydraulic switch in the off position. IARC Date Release Date
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Section/division Occurrence Investigation Form Number: CA 12-12a Telephone number: 011-545-1000 E-mail address of originator: [email protected]
AIRCRAFT ACCIDENT REPORT
Name of Owner : George Sky Aviation (Pty) Ltd Manufacturer : Robinson Helicopter Company Model : R44 II Nationality : South Africa Registration Marks : ZS-HFW Place : Mossel Bay Date : 14 April 2009 Time : 11:30Z All times given in this report are Co-ordinated Universal Time (UTC) and will be denoted by (Z). South African Standard Time is UTC plus 2 hours. Purpose of the Investigation: In terms of Regulation 12.03.1 of the Civil Aviation Regulations (1997) this report was compiled in the interest of the promotion of aviation safety and the reduction of the risk of aviation accidents or incidents and not to establish legal liability. Disclaimer: This report is given without prejudice to the rights of the CAA, which are reserved.
1. FACTUAL INFORMATION 1.1 History of Flight 1.1.1 On 14 April 2009 the instructor and student took off from George Aerodrome
(FAGG) to Mossel Bay Aerodrome (FAMO) on a training flight (conversion training flight). The training included the hydraulics “off” forward flight and hover. The instructor pilot (IP) mentioned that the student pilot (SP) brought the helicopter into hover position above threshold of runway 09 at FAMO into the direction of wind. The student pilot held a steady hover for a short period and then started losing control of the helicopter.
1.1.2 The IP instructed the SP to activate the hydraulic switch, however, and according to
the IP, the SP froze on the controls. The hydraulic control is situated on the student’s side of the cyclic controls.
1.1.3 According to the SP, the IP requested him to deactivate the hydraulic switch, which
he did. The SP advised the IP that the aircraft was difficult to control, as the controls were hard. The IP advised the SP that they needed to have the hydraulic switch off for this part of the training. The SP then managed to get the helicopter into a hover momentarily before he lost control. The IP then instructed the student to activate the hydraulic switch at a height of approximately 20 feet above ground level (AGL). The SP managed to switch on or activate the hydraulic switch timeously before the helicopter impacted the ground.
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1.2 Injuries to Persons
Injuries Pilot Crew Pass. Other Fatal - - - - Serious - - - - Minor - - - - None 1 1 - -
1.3 Damage to Aircraft 1.3.1 The helicopter was destroyed during impact. See photo 1 below.
Photo 1: Damage to helicopter 1.4 Other Damage 1.4.1 None 1.5 Personnel Information 1.5.1 Instructor pilot (IP)
Nationality South African Gender Male Age 43 Licence Number * * * * * * * * * * Licence Type Commercial Licence valid Yes Type Endorsed Yes Ratings Instructors Medical Expiry Date 30 June 2009 Restrictions Corrective lens Previous Accidents None
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Flying Experience:
Total Hours 245,1 Total Past 90 Days 43,5 Total on Type Past 90 Days 25,0 Total on Type 61,9
1.5.2 Student pilot (SP)
Nationality South African Gender Male Age 55 Licence Number * * * * * * * * * * Licence Type Private Licence valid Yes Type Endorsed Yes Ratings None Medical Expiry Date 20 February 2010 Restrictions Corrective lens Previous Accidents None
Flying Experience :
Total Hours 142,6 Total Past 90 Days 1,0 Total on Type Past 90 Days 1,0 Total on Type 1,0
1.6 Aircraft Information
Airframe Type R44 II Serial Number 11340 Manufacturer Robinson Helicopter Company Year of Manufacture 2006 Total Airframe Hours (At time of Accident) 629,8 Last MPI (Date & Hours) 27 January 2009 598.7 Hours since Last MPI 31,1 C of A (Issue Date) 31 August 2006 C of R (Issue Date) (Present owner) 30 August 2006 Operating Categories Standard
Engine Type Lycoming IO 540-AE1A5 Serial Number L-31371-48a Hours since New 629,8 Hours since Overhaul TBO not yet reached
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Figure1: Mass and Balance calculation at Take-off
R44 II Weight and Balance
WEIGHT LONG. ARM LONG. MOM. LAT. ARM LAT. MOM.
Empty Weight 1510,00 106.50 160815,00 0.00 0,00
Pilot 176 49,5 8712,00 +12,2 2147,20
Pilot Baggage
0 44.0 0.00 +11.5 0,00
Fore Passenger
220 49,5 10890.00 -10,4 -2288,00
Fore Passenger Baggage
0 44,0 0,00 -11,5 0,00
Right Aft Passenger
0 79,5 0,00 +12,2 0,00
Right Aft Baggage
0 79,5 0,00 +12,2 0.00
Left Aft Passenger
0 79,5 0,00 -12,2 0.00
Left Aft Baggage
0 79,5 0,00 -12,2 0.00
No Fuel Weight
No Fuel Long. C.G.
Long. Empty Moment
No Fuel Lat. C.G.
Lat. Empty Moment Total Weight &
Balance w/Zero Usable Fuel
1906,00 94,66 180417,00 -0,07 -140,80
Main Tank 92,00 106,0 9752 -13,5 -1242
Aux Tank 55,00 102,0 5610 +13,0 715
Take-Off Weight
Long. Full CG
Long. Full Moment
Lat. Full CG
Lat. Full Moment Total Weight &
Balance w/Take-Off Fuel
2053,00 95,36 195779,00 -0,33 -667,80
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Figure2: The helicopter’s Centre of Gravity was within the limits.
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Figure3: Perceived Mass and Balance calculations at time of Accident
R44 II Weight and Balance
WEIGHT LONG. ARM LONG. MOM. LAT. ARM LAT. MOM.
Empty Weight 1510,00 106.50 160815.00 0.00 0.00
Pilot 176 49,5 8712,00 +12,2 2147,20
Pilot
Baggage 0 44,0 0,00 +11,5 0,00
Fore Passsenger
220 49,5 10890,00 -10,4 -2288,00
Fore Passenger Baggage
0 44,0 0,00 -11,5 0,00
Right Aft Passenger
0 79,5 0,00 +12,2 0,00
Right Aft Baggage
0 79,5 0,00 0,00
Left Aft Passenger
0 79,5 0,00 -12,2 0,00
Left Aft
Baggage 0 79,5 0,00 -12,2 0,00
No Fuel Weight
No Fuel Long. C.G.
Long. Empty Moment
No Fuel Lat. C.G.
Lat. Empty Moment Total Weight &
Balance w/Zero Usable Fuel
1906,00 94.66 180417,00 -0.07 -140,80
Main Tank 35,00 106,0 3710 -13,5 -472,5
Aux Tank 25,00 102,0 2550 +13,0 325
Landing Weight
Long. Full CG
Long. Full Moment
Lat. Full CG
Lat. Full Moment Total Weight &
Balance with Landing Fuel
1966,00 94,95 186677,00 -0,15 -288,30
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Figure4: Perceived Mass and Balance diagram at time of Accident
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Figure 5 In-Ground Effect of the helicopter
According to figure 5 the helicopter could hover in ground effect up to a pressure altitude of 9700ft.
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Figure 6 Out-of-Ground effect of the helicopter According to figure 6 the helicopter could hover out of ground effect up to a pressure altitude of 6800ft. 1.7 Meteorological Information 1.7.1 Weather information as obtained from the IP’s questionnaires:
Wind direction 012˚ Wind speed 5 kts Visibility Clear Temperature 25˚ Cloud cover Nil Cloud base Nil Dew point Unknown
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1.8 Aids to Navigation 1.8.1 The aircraft was fitted with standard navigational instrument equipment. No defects
were reported prior to or during the accident flight. 1.9 Communications 1.9.1 The pilot was communicating his intentions on the frequency 124,20 MHz and no
defects were reported prior to or during the accident flight. 1.10 Aerodrome Information
1.11 Flight Recorders 1.11.1 The helicopter was not fitted with a cockpit voice recorder (CVR) or a flight data
recorder (FDR), and neither was required by regulations to be fitted to this type of helicopter.
1.12 Wreckage and Impact Information 1.12.1 The student pilot lost control of the helicopter while in a hover position at
approximately 20 feet AGL. The helicopter then vertically impacted the ground, damaging the airframe, skids, tail boom and the main and tail rotors. See photo 1 p. 3.
1.13 Medical and Pathological Information 1.13.1 Not applicable. 1.14 Fire 1.14.1 There was no evidence of a pre- or post-impact fire. 1.15 Survival Aspects 1.15.1 The aircraft sustained minor damage to the cabin area, hence the accident was
considered survivable. Both occupants were properly restrained with three-point safety harness.
Aerodrome Location Mossel Bay Aerodrome Co-ordinates S34 09 25 E022 03 41 Aerodrome Elevation 526 feet Runway Designations 09 27 Runway Dimensions 1126 x 18 1126 x 18 Runway Used On threshold of Runway 09 Runway Surface Asphalt Approach Facilities Runway lighting
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1.16 Tests and Research 1.16.1 Information below is extracted from the helicopter aviation manual.
Most helicopters use hydraulics to reduce the force needed to move the controls. Usually there is still a mechanical connection. In some helicopters there might not be a mechanical connection, or the forces acting on the controls may simply be too high for the pilot to overcome unassisted. Generally such helicopters will have redundant hydraulic systems. The Bell Jet Ranger/ Long Ranger and the Robinson R44 have boosted controls with mechanical backup. There are multiple ways such hydraulic systems can fail, but basically you can either have a failure where the entire system stops working or a failure where a part of the system stops working.
1.16.2 Information below is extracted from the Pilot’s Operating Handbook R44 Raven II. Hydraulic system failure is indicated by heavy or stiff cyclic and collective controls. The controls will be normal except for the increase in stick forces. However, in this case the hydraulic did not fail; it was an induced failure.
1.17 Organisational and Management Information 1.17.1 The training school had a valid ATO (aviation training organisation) approval (no.
CAA 0012). 1.17.2 The aircraft was maintained by aircraft maintenance organization (AMO) No. 1018,
which was in possession of a valid AMO approval certificate. 1.17.3 The Regulator allowed the use of this helicopter for training, although it does not
have a complete dual hydraulic control system. Furthermore, this control can only be accessed by the student and not by both pilots.
1.18 Additional Information 1.18.1 None. 1.19 Useful or Effective Investigation Techniques 1.19.1 None. 2. ANALYSIS 2.1 Man 2.1.1 The SP was undergoing conversion training into a Robinson R44 helicopter when
the accident occurred. The training required that the hydraulic switch be deactivated or switched off. Following the deactivation of the hydraulic system, the SP informed the IP of the stiffness of the controls. The IP explained the need to have the hydraulic system off. The SP then managed to get the helicopter on to a hover and held a steady hover for a short period before losing control. The instructor pilot instructed the student pilot to activate the hydraulic switch, which is situated only on
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the student’s side of the cyclic control. The student did not activate the hydraulic switch timeously, resulting in the helicopter impacting the ground hard.
2.2 Machine 2.2.1 According to available records, the helicopter was properly maintained and
according to available documentation the helicopter had no recorded defect or malfunction that could have contributed to or caused the accident. Because the exercise being carried out required that the hydraulic switch be turned off, the pilot lost control as the controls became hard to manipulate.
2.2.2 The helicopter is used for training, although it does not have a dual hydraulic switch
for both instructor and student. This switch was only on the SP cyclic control and in a position where the instructor could not reach it.
2.3 Environment 2.3.1 The available information revealed that fine weather conditions prevailed in the area
at the time of the flight and subsequent accident. Therefore it is concluded that weather was not a contributory factor to the accident.
2.3.2 The Regulator allowed the use of this helicopter for training although it does not
have a complete dual hydraulic control system. Furthermore, this control can only be accessed by the student and not by both pilots.
3. CONCLUSION 3.1 Findings 3.1.1 The instructor pilot had a valid commercial pilot licence (helicopter) and was properly
rated at the time of accident. 3.1.2 The student pilot had a valid private pilot licence (helicopter and fixed wing) at the
time of the accident. 3.1.3 According to available information the aircraft was properly maintained. 3.1.4 Weather was not a contributory factor to the accident. 3.1.5 The hydraulic switch was deactivated. 3.1.6 The student reported hardness of the controls 3.1.7 The student pilot lost control of the helicopter. 3.1.8 The helicopter vertically impacted the ground hard, resulting in the helicopter being
destroyed. 3.1.9 The helicopter had the hydraulic switch only on the SP cyclic control and not on the
instructor's cyclic or in a position were both pilots could access it.
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3.2 Probable Cause/s 3.2.1 Helicopter vertically impacted the ground hard following the pilot's loss of control
during hover. 3.2.2 Contributory 3.2.2.1 The failure of the instructor to react by taking over control of the helicopter as it can be flown with the hydraulic switch in the off position. 4. SAFETY RECOMMENDATIONS 4.1 None 5. APPENDICES 5.1 None.
Report reviewed and amended by the Advisory Safety Panel on 16 March 2010 -END-