Time Out
27th Jul 2005, 00:51
Summary
The circumstances of this occurrence are consistent with a loss of aircraft directional control during an attempted go-around manoeuvre with reduced right engine power. This is supported by the intention to include asymmetric flight in the training session, and by information related to the go-around. That information included:
• the three previous circuits were concluded by touch and go landings, but on this occasion the pilots initiated a go-around
• the pilots did not conduct a landing as would be expected if they had concerns about any aspect of the aircraft’s serviceability or performance
• the aircraft began to diverge right soon after commencing the go-around and that divergence was not corrected
• the aircraft’s performance deteriorated until it stalled at a height from which recovery was not possible
• at impact both engines were producing significant and comparable power.
However, because the investigation was unable to confirm the configuration of the aircraft during the approach and go-around, the reason the aircraft was not landed or restored to stable flight before control was lost could not be determined.
Findings
Aircraft
1. The aircraft had been fully fuelled with the correct fuel for normal engine operation before the flight.
2. The damage to the propellers indicates that the engines were producing significant and comparable power at impact.
3. Both propellers were assessed as being at their correct relative blade pitch angle for the take-off, go-around or early climb phase of flight.
4. The position of the wing flaps at impact could not be conclusively determined.
5. The position of the landing gear at impact could not be confirmed.
Flight Crew
6. The instructor was appropriately qualified to conduct the flight.
Air traffic control
7. The aerodrome controller saw the landing gear extend and issued a clearance for the pilots to conduct a touch and go landing.
Significant factors
1. The aircraft was not landed, or power restored to the right engine in sufficient time to regain stable flight.
2. The aircraft departed from controlled flight at a height from which recovery was not possible.
ATSB safety action
Following a number of accidents in recent years, involving twin-engine aircraft that incurred a loss of some or all engine power, the ATSB implemented a research project (B2005/0085) into power loss related accidents involving twin-engine aircraft. That report was approved for public release 27 June 2005 and concluded that:
• Power loss accident rates in twin-engine aircraft are almost half the rate in single-engine aircraft. However, a power loss accident in a twin-engine aircraft is more likely to be fatal than a power loss accident in a single-engine aircraft.
• Fatal accidents subsequent to a power loss in twin-engine aircraft are overwhelmingly a result of in-flight loss of control events.
• Just over one-third of power loss accidents in twin-engine aircraft occurred during a non-asymmetric power loss. The majority of these were related to fuel management, and no benefit was derived from the presence of a second engine.
• More accidents (46 per cent) occurred following an asymmetric power loss in the take-off phase than in any other phase of flight.
The research report is available on the Bureau’s website www.atsb.gov.au or from the Bureau on request.
Full Report (http://www.atsb.gov.au/aviation/pdf/200304589.pdf)
The circumstances of this occurrence are consistent with a loss of aircraft directional control during an attempted go-around manoeuvre with reduced right engine power. This is supported by the intention to include asymmetric flight in the training session, and by information related to the go-around. That information included:
• the three previous circuits were concluded by touch and go landings, but on this occasion the pilots initiated a go-around
• the pilots did not conduct a landing as would be expected if they had concerns about any aspect of the aircraft’s serviceability or performance
• the aircraft began to diverge right soon after commencing the go-around and that divergence was not corrected
• the aircraft’s performance deteriorated until it stalled at a height from which recovery was not possible
• at impact both engines were producing significant and comparable power.
However, because the investigation was unable to confirm the configuration of the aircraft during the approach and go-around, the reason the aircraft was not landed or restored to stable flight before control was lost could not be determined.
Findings
Aircraft
1. The aircraft had been fully fuelled with the correct fuel for normal engine operation before the flight.
2. The damage to the propellers indicates that the engines were producing significant and comparable power at impact.
3. Both propellers were assessed as being at their correct relative blade pitch angle for the take-off, go-around or early climb phase of flight.
4. The position of the wing flaps at impact could not be conclusively determined.
5. The position of the landing gear at impact could not be confirmed.
Flight Crew
6. The instructor was appropriately qualified to conduct the flight.
Air traffic control
7. The aerodrome controller saw the landing gear extend and issued a clearance for the pilots to conduct a touch and go landing.
Significant factors
1. The aircraft was not landed, or power restored to the right engine in sufficient time to regain stable flight.
2. The aircraft departed from controlled flight at a height from which recovery was not possible.
ATSB safety action
Following a number of accidents in recent years, involving twin-engine aircraft that incurred a loss of some or all engine power, the ATSB implemented a research project (B2005/0085) into power loss related accidents involving twin-engine aircraft. That report was approved for public release 27 June 2005 and concluded that:
• Power loss accident rates in twin-engine aircraft are almost half the rate in single-engine aircraft. However, a power loss accident in a twin-engine aircraft is more likely to be fatal than a power loss accident in a single-engine aircraft.
• Fatal accidents subsequent to a power loss in twin-engine aircraft are overwhelmingly a result of in-flight loss of control events.
• Just over one-third of power loss accidents in twin-engine aircraft occurred during a non-asymmetric power loss. The majority of these were related to fuel management, and no benefit was derived from the presence of a second engine.
• More accidents (46 per cent) occurred following an asymmetric power loss in the take-off phase than in any other phase of flight.
The research report is available on the Bureau’s website www.atsb.gov.au or from the Bureau on request.
Full Report (http://www.atsb.gov.au/aviation/pdf/200304589.pdf)