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Go-around from Low Airspeed/Low Thrust
|Category:||Loss of Control|
|Content source:||Flight Safety Foundation|
When a go-around is initiated with the aircraft in landing configuration (landing gear, flaps etc. extended) a loss of altitude is inevitable while the engine accelerates and the pitch change and increased power take effect.
However, if a go around is initiated when airspeed is already below the prescribed figure because engine thrust has been and remains too low, then it may already be unstable and recovery from such a situation necessitates careful handling as thrust is added and pitch attitude changed.
Low airspeed and/or thrust means that the altitude loss after selection of go-around thrust is likely to be more than in a normal situation. The illustration below, taken from the Briefing Note on Energy Management produced as part of the FSF ALAR Toolkit, illustrates this point.
This Briefing Note states that deceleration below the applicable final approach speed should occur only during manoeuvres to achieve terrain avoidance, collision-avoidance or recovery from wind shear whilst noting that all three of these require the selection of TO/GA thrust.
A Serious Incident Example
- B733, vicinity Bournemouth UK, 2007: On 23 September 2007, the pilots of a Thomsonfly Boeing 737-300 almost lost control of their aircraft after initiating a go around from an unstable low airspeed and low thrust condition reached progressively but unnoticed during an approach to Bournemouth at night. Mismanagement of the aircraft during the go around attributed to a lack of adequate understanding of the aircraft pitch control system led to extreme pitch and an aerodynamic stall but the crew eventually recovered control of the aircraft followed by an uneventful second approach and a successful landing.
Flight Safety Foundation
- Do you really understand how your trim works? Many do not, and why it matters. - A paper written by Captain Alex Fisher for GAPAN. The paper was presented at the Go-Around Safety Forum (GASF) in Brussels in 2013.