Takeoff (climb)

Detailed investigation and analyses of the examinable evidence confirmed that the aircraft had developed some problem with its Engine No.2 (Right) immediately after takeoff which was observed by the cockpit crew as propeller feathering on its own. No concrete evidence could be found which would have led to the engine’s propeller malfunction as observed. The only probable cause of propeller feathering on its own could be the wear & tear of the beta valve leading to beta system malfunction. However, this anomaly at the most could have led to the non availability of one engine and making a safe landing with a single engine since the aircraft was capable of landing with a single engine operation. Some of the actions by the cockpit crew before takeoff and subsequent to the observed anomaly in the Engine No.2 were not according to the QRH / FCOM which aggravated the situation and resulted into the catastrophic accident.
The following factors contributed to the accident:
The aircraft accident took place as a result of combination of various factors which directly and indirectly contributed towards the causation of accident.
The primary cause of accident includes, inappropriate skill level of Captain to handle abnormal operation of engine No 2 just after takeoff, failure of cockpit crew to raise the landing gears after experiencing the engine anomaly, execution of remedial actions by FO before the attainment of minimum safe altitude of 400 ft AGL resulted in non conformance and non compliance of cockpit crew to OEM recommended procedures to handle such situations.
The lack of situational awareness and CRM failure directly contributed towards ineffective management of the flight deck by the cockpit crew.
The contributory factors include inadequate cockpit crew simulator training monitoring mechanism both at operator and CAA Pakistan levels in respect of correlation of previous / current performance and skill level of cockpit crew during the simulator training sessions along with absence of conduct of recurrent / refresher simulator training between two annual simulator checks in accordance with ICAO Annex-6 guidelines and CAA Pakistan (applicable ANOs) requirements for specific type of aircraft in a year.

The total loss of engine power for undetermined reasons because examination of the airframe and engine did not reveal any anomalies that would have contributed to the loss of engine power.

It is believed that the accident was the consequence of an engine failure.

The following findings were identified:
1. Acklins Blue Air Charter was advertising and operating as a Bahamas air taxi operator without having undergone the certification process in contravention of Bahamas Civil Aviation (Safety) Regulations Schedule 12.
2. The airplane was issued a Certificate of Airworthiness on May 19, 2010, by the Bahamas Flight Standards Inspectorate, and was being operated by Acklins Blue Air Charter.
3. The Cessna 402C aircraft is classified in the performance Group C. This requires rapid feathering of the propeller of a failed engine and the raising of flap and the landing gear in order to achieve maximum climb performance.
4. The airplane maintenance records were not located; therefore, no determination could be made whether the airplane was being maintained in accordance with Bahamas Civil Aviation Regulations.
5. The 12,000 hour pilot and second pilot were not qualified to operate in Bahamas commercial air taxi operations.
6. No determination could be made whether the pilot or second pilot had completed required training and had accomplished a satisfactory recurrent flight check of their flying ability as required by CASR Schedule 12 and 14 for aircraft operating in commercial air transportation as well as the stipulation by the insurance policy.
7. Post-accident weight and balance calculations indicate the airplane was being operated approximately 523 pounds over maximum certificated takeoff weight (6,850 lb)
8. The pilot was advised by an air traffic controller that white smoke was trailing the left engine during takeoff; the pilot did not declare an emergency or advise the controller of any engine failure or mechanical abnormality.
9. The airplane's left engine could not produce rated shaft horsepower during takeoff.
10. Several factors contributing to the degradation of the airplane's performance and its inability to maintain flight include the wind-milling propeller, the pilot's intentional initiation of a steep turn to return to the departure airport, and his intentional lowering of the landing gear during the turn to return.
11. While turning to return, the airplane stalled, pitched nose down, and impacted in a lake.
12. The search and rescue efforts were timely and appropriate; however, the lack of accurate information on the pilot submitted flight plan delayed recovery of all victims.
13. The left propeller was not feathered.
14. The No. 2 cylinder of the left engine failed due to fatigue that originated in the root of the cylinder head thread that was engaged with the first thread on the barrel.
15. Post-accident inspection of the cockpit revealed several switches for the right engine were secured; however, no determination could be made when the switches were placed / moved in those positions.
16. No evidence of failure of the airplane's structures or flight control system contributed to the accident.
17. Existing regulations did not require the aircraft to be fitted with flight recorders. The lack of any recorded data about the aircraft's performance or the flight crew conversations deprived the investigation team of essential factual information.
18. Current Civil Aviation Department personnel and budget resources may not be sufficient to ensure that the quality of surveillance for certified as well as uncertified air carrier operations will improve.
19. Airside access procedures are inadequate at Fixed Base Operators. Access to the secure airside occurring without any check of individuals to challenge whether they have a legitimate reason for accessing the secure airside. FBO door to access airside is not secured or locked continuously; persons observed walking in and out without being challenged.
20. Flight Plan Forms are being accepted and transmitted to ATC with incomplete information. This information is vital for search and rescue purposes.
21. Weather was not a factor in the accident.
22. ATC was not a factor in the accident.
23. Currently flight plans for private flights are only required for international operations.
24. The pilot was aware of discrepancy associated with the manifold pressure reading of the left engine prior to takeoff. This discrepancy was brought to his attention by a client from the flight immediately preceding the accident flight.
25. The exact center of gravity of the accident airplane could not be calculated accurately as no indication of what seat each passenger occupied in the airplane and no indication of where luggage or equipment were placed on the aircraft could be determined. However, due to the exceedance of weight limits the aircraft was already outside the allowable center of gravity envelope developed by the manufacturer.
26. The pilot had insufficient time to prepare for the approach to runway 27 before beginning the approach. The airplane pitched up quickly into a stall, after extension of gear, recovery before ground impact was unlikely once the stall began.
27. Post accident inspection did not reveal any mechanical evidence or problems with the right hand engine.
28. The pilot's decision to return to the airfield was reasonable. Once the aircraft began to lose height a return to the airfield became impractical and a forced landing in the direction of flight should have been attempted.
29. The right propeller was never recovered from the lake.
The following causal factors were identified:
1. The left engine suffered a mechanical failure of the #2 cylinder, and therefore could not produce rated shaft horsepower. No indication of total loss of power with the left engine reported.
2. Right Engine electrical and engine control switches were found in the “OFF” position, therefore the aircraft was incapable of climbing on the power of one engine alone.
3. The excess weight above the maximum weight allowed for takeoff may have been an important factor in the aircraft's inability to gain adequate altitude after takeoff.
4. The pilot secured the right engine which was mechanically capable of producing power resulting in a total loss of thrust. He then sometime thereafter initiated a steep turn with gear down and the left engine already not developing sufficient shaft horsepower to sustain lift.
5. The pilot attempted to return to the departure airfield but lost control of the aircraft during a turn to the left.

Findings As To Causes and Contributing Factors:
The bird strike occurred on take-off at an altitude of less than 50 feet. Gulls were ingested in the left engine, which then lost power.
After the loss of engine power, the flight crew had difficulty controlling the aircraft. The aircraft touched the ground, forcing the pilot flying to abort the take-off when the runway remaining was insufficient to stop the aircraft, resulting in the runway overrun.
Findings As To Risks:
Although a cannon was in place, it was not working on the day of the accident, which increased the risk of a bird strike.
The presence of a goose and duck farm outside the airport perimeter but near a runway increases the risk of attracting gulls.
Operators subject to Canadian Aviation Regulations Subpart 703 are not prohibited from having an aircraft take off from a runway that is shorter than the accelerate-stop distance of that aircraft as determined from the performance diagrams. Consequently, travellers carried by these operators are exposed to the risks associated with a runway overrun when a take-off is aborted.
The absence of a CVR makes it harder to ascertain material facts. Consequently, investigations can take more time, resulting in delays which compromise public safety.

Findings:
- There were no technical defects identified that may have contributed to the accident and the aeroplane was considered controllable during the take-off roll, with the engine able to deliver power during the short flight.
- The aeroplane’s centre of gravity was at least 0.122m rear of the maximum permissible limit, which created a tendency for the nose to pitch up. The most likely reason for the crash was the aeroplane being excessively out of balance. In addition, the aeroplane probably became airborne early and at too low an airspeed to prevent uncontrollable nose-up pitch.
- The aeroplane reached a pitch angle that would have made it highly improbable for the unrestrained parachutists to prevent themselves sliding back towards the tail. Any shift in weight rearward would have made the aeroplane more unstable.
- The engineering company that modified ZK-EUF for parachuting operations did not follow proper processes required by civil aviation rules and guidance. Two of the modifications had been approved for a different aircraft type, one modification belonged to another design holder and a fourth was not referred to in the aircraft maintenance logbook.
- The flight manual for ZK-EUF had not been updated to reflect the new role of the aeroplane and was limited in its usefulness to the aeroplane owner for calculating weight and balance.
- Regardless of the procedural issues with the project to modify ZK-EUF, the engineering work conducted on ZK-EUF to convert it from agricultural to parachuting operations in the standard category was by all accounts appropriately carried out.
- The weight and balance of the aeroplane, with its centre of gravity at least 0.122m outside the maximum aft limit, would have caused serious handling issues for the pilot and was the most significant factor contributing to the accident.
- ZK-EUF was 17 kg over its maximum permissible weight on the accident flight, but was still 242 kg lighter than the maximum all-up weight for which the aeroplane was certified in its previous agricultural role. Had the aeroplane not been out of balance it is considered the excess weight in itself would have been unlikely to cause the accident. Nevertheless, the pilots should have made a full weight and balance calculation before each flight.
- The aeroplane owner and their pilots did not comply with civil aviation rules and did not follow good, sound aviation practice by failing to conduct weight and balance calculations on the aeroplane. This resulted in the aeroplane being routinely flown overweight and outside the aft centre of gravity allowable limit whenever it carried 8 parachutists.
- The empty weight and balance for ZK-EUF was properly recorded in the flight manual, but the stability information in that manual had not been appropriately amended to reflect its new role of a parachute aeroplane. Nevertheless, it was still possible for the aeroplane operator to initially have calculated the weight and balance of the aeroplane for the predicted operational loads before entering the aeroplane into service.
- The aeroplane owner did not comply with civil aviation rules and did not follow good, sound aviation practice when they: used the incorrect amount of fuel reserves; removed the flight manual from the aeroplane; and did not formulate their own standard operating procedures before using the aeroplane for commercial parachuting operations.
- The Director of Civil Aviation delegated the task of assessing and overseeing major modifications to Rule Part 146 design organisations and individual holders of “inspection authorisations”. The delegations did not absolve the Director of his responsibility to monitor compliance with civil aviation rules and guidance.
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- The delegations increased the risk that unless properly managed the CAA could lose control of 2 safety-critical functions: design and inspection. The Director had not appropriately managed that risk with the current oversight programme.
- The CAA had adhered strictly to its normal practice and was acting in accordance with civil aviation rules when approving the change in airworthiness category from special to standard. However, knowing the scope, size and complexity of the modifications required to change ZK-EUF from an agricultural to a parachuting aeroplane, it should have had greater participation in the process to help ensure there were no safety implications.
- There was a flaw in the regulatory system that allowed an engineering company undertaking major modification work on an aircraft to have little or no CAA involvement by using an internal or contracted design delegation holder and a person with the inspection authorisation to oversee and sign off the work.
- The level of parachuting activity in New Zealand warranted a stronger level of regulatory oversight than had been applied in recent years.
- The CAA’s oversight and surveillance of commercial parachuting were not adequate to ensure that operators were functioning in a safe manner.
- The CAA had mechanisms through the Director’s powers under the Civil Aviation Act and his designated powers under the HSE Act to effectively regulate the parachuting industry pending the introduction of Rule Part 115.
- An alcohol and drug testing regime needs to be initiated for persons performing activities critical to flight safety, to detect and deter the use of performance-impairing substances.
- In this case the impact was not survivable and the passengers wearing safety restraints would not have prevented their deaths, but in other circumstances the wearing of safety restraints might reduce injuries and save lives.
- Safety harnesses or restraints would help to prevent passengers sliding rearward and altering the centre of gravity of the aircraft. It could not be established if this was a factor in this accident.

The pilot's delayed application of full power during a soft/wet field takeoff, resulting in a collision with trees during takeoff.

A loss of power in the right engine for undetermined reasons and the pilot’s subsequent failure to maintain adequate airspeed, which resulted in a loss of control. Contributing to the loss of control was the regulatory certification basis of the airplane that does not require airspeed indicator markings that are critical to maintaining airplane control with one engine inoperative.

The investigation determined the inadequate action of the flight engineer, consisting in early and uncommanded landing gear retraction, as a cause of the accident.
Contributing factors to the accident were:
1. Inadequate crew recourse management and insufficient experience in cooperation and coordination between crewmembers.
2. Start of aircraft rotation at low speed and with fast elevator movement to 17˚, which resulted in:
Lifting the aircraft sufficiently to close the WOW switch and allow the retraction of the landing gear at the speed not sufficient for the climb.
Providing misleading information to FE about the aerodynamic status of the aircraft.
3. Inadequate adjustment of the WOW switch, which allowed the gear retraction to be activated before the aircraft was airborne. The position of the landing gear selector on the central console is not considered as a contributing factor to the accident. However, investigation finds necessary to point it out as a safety concern, specifically in situations, where crewmembers are trained and/or used to operate the aircrafts with gear selector location according to the EASA Certification Standards CS-25. Positioning of the gear lever to the location which is compliant to EASA document CS-25, would create additional safety barrier to avoid similar occurrences, specifically in aircrafts where landing gear is operated by FE.