AT43, vicinity Stansted UK, 2007

Summary

On 18 January 2007 an ATR 42-300 freighter developed a control difficulty just after a night take off from Stansted UK, which led the flight crew to declare an emergency and undertake an immediate return to land. The landing was uneventful but the approach flown was unstable, with EGPWS warnings, and the origin of the handling difficulty was considered to be, in part, due to inappropriate control inputs by one of the pilots.

Event Details
When	January 2007
Actual or Potential Event Type	Human Factors, Loss of Control
Day/Night	Night
Flight Conditions	On Ground - Normal Visibility

Flight Details
Aircraft	ATR ATR-42-300/320
Operator	Not Recorded
Type of Flight	Public Transport (Cargo)
Origin	London Stansted Airport
Intended Destination	Dublin Airport
Actual Destination	London Stansted Airport
Take off Commenced	Yes
Flight Airborne	Yes
Flight Completed	Yes
Flight Phase	Climb
	ICL / ENR

Location - Airport
Airport vicinity	London Stansted Airport

General
Tag(s)	Approach not stabilised

HF
Tag(s)	Ineffective Monitoring, Manual Handling, Inappropriate crew response (automatics)

LOC

Tag(s)

Flight Control Error"Flight Control Error" is not in the list (Airframe Structural Failure, Significant Systems or Systems Control Failure, Degraded flight instrument display, Uncommanded AP disconnect, AP Status Awareness, Non-normal FBW flight control status, Loss of Engine Power, Flight Management Error, Environmental Factors, Bird or Animal Strike, ...) of allowed values for the "LOC" property., Temporary Control Loss, Extreme Bank, Take off Trim Setting

EPR
Tag(s)	“Emergency” declaration

Safety Net Mitigations
Malfunction of Relevant Safety Net	No
GPWS	Partially effective

Outcome
Damage or injury	No

Causal Factor Group(s)
Group(s)	Aircraft Operation

Safety Recommendation(s)
Group(s)	Aircraft Airworthiness

Investigation Type
Type	Independent

Description

On 18 January 2007 an ATR 42-300 freighter developed a control difficulty just after a night take off from Stansted UK, which led the flight crew to declare an emergency and undertake an immediate return to land. The landing was uneventful but the approach flown was unstable, with Terrain Avoidance and Warning System (TAWS) warnings, and the origin of the handling difficulty was considered to be, in part, due to inappropriate control inputs by one of the pilots.

Synopsis

This is an extract from the report published by the Aircraft Accident Investigation Branch (UK) (AAIB), UK:

"Soon after takeoff from London Stansted Airport the aircraft developed a yawing motion which persisted as a yawing/rolling motion of varying severity. The yaw damper could not be engaged. An emergency was declared and the aircraft returned to Stansted. No mechanical fault was found which would have caused the motion, although an undetected and intermittent fault affecting components within the rudder control system could have degraded the aircraft’s handling characteristics with the yaw damper not engaged, as could a takeoff with the rudder control system incorrectly configured. The nature of the motion and observed control deflections were such that an inadvertent and inappropriate rudder input by a pilot would have been required for the oscillations to persist.

Four Safety Recommendations were made, concerning operational advice to flight crews and ongoing serviceability checks for Flight Data Recorders (FDRs)."

Related Articles

LOC

• Loss of Control

Further Reading

For further information see the full report published by the AAIB (UK).