F900, en-route, South of Bucharest Romania, 1999
F900, en-route, South of Bucharest Romania, 1999
Summary
On 14 September 1999, a F900 was subjected to rapid and violent vertical load oscillations, which killed most of the passengers, after incorrect crew response to a minor pitch control malfunction.
Flight Details
Aircraft
Operator
Type of Flight
Military/State
Flight Origin
Intended Destination
Take-off Commenced
Yes
Flight Airborne
Yes
Flight Completed
Yes
Phase of Flight
Descent
Location
General
Tag(s)
Inadequate Aircraft Operator Procedures
HF
Tag(s)
Inappropriate crew response - skills deficiency,
Inappropriate crew response (technical fault),
Ineffective Monitoring,
Manual Handling
LOC
Tag(s)
AP Status Awareness,
Temporary Control Loss,
Extreme Pitch
EPR
Tag(s)
“Emergency” declaration
AW
System(s)
Flight Controls
Contributor(s)
Inadequate QRH Drills
Outcome
Damage or injury
Yes
Aircraft damage
Major
Non-aircraft damage
No
Non-occupant Casualties
No
Occupant Injuries
Few occupants
Occupant Fatalities
Most or all occupants
Number of Occupant Fatalities
7
Off Airport Landing
No
Ditching
No
Causal Factor Group(s)
Group(s)
Aircraft Operation
Aircraft Technical
Safety Recommendation(s)
Group(s)
Aircraft Operation
Aircraft Airworthiness
Investigation Type
Type
Independent
Description
On 14 September 1999, a DASSAULT Falcon 900 was subjected to rapid and violent vertical load oscillations, which killed most of the passengers, after incorrect crew response to a minor pitch control malfunction. The incident occurred south of Bucharest, Romania.
Greece's Deputy Foreign Minister, who was standing at the time of the accident, was one of the passengers killed.
Synopsis
This is an extract from the Accident Report published by the Romanian Ministry of Transport Civil Aviation Inspectorate:
"The aircraft performed the flight OAL3838, from Athens to Bucharest as a government flight.
During climb after flap and slats were retracted, the flight crew noticed, on the warning panel, the "PITCH FEEL" light came on. The "PITCH FEEL" warning light, remained continuously ON, during cruise and descent until SLATS were extended.
During descent the Indicated Air Speed (IAS) increased from 240 kts to 332 kts.
Approaching FL150, the F/O had a request for a further descent.
Just before FL150 the ATC re-cleared OAL3838 to continue descent to FL50, while PIC briefed F/A about ETA. One second later, A/P disengaged and for the next 1 minute and 36 seconds the aircraft was manually flown by the PIC.
Between FL150 and FL140, for approximately 24 seconds, the aircraft experienced 10 oscillations in pitch axis which exceeded the limit manoeuvring load factor. Maximum recorded values of the vertical accelerations recorded by an accelerometer located in the landing gear bay were: +4.7 g and -3.26 g.
The impact of the unfastened passengers with cabin ceiling and aircraft furniture, due to accelerations occurring during the pitch oscillations caused fatal injuries to 7 passengers, serious injuries to 1 crew member and 1 passenger and minor injuries to 2 passengers.
The investigation identified following causal factors:
- Inadequate risk assessments of the PITCH FEEL malfunctions.
- Overriding of the A/P on the pitch channel by the crew.
- Inappropriate inputs on the control column at high speed and with Arthur unit failed in “low-speed” position leading to Pilot Induced Oscillations.
- Seat-belts not fastened during descent flight phase."
Related Articles
LOC
Further Reading
For further information see the full Report published by the Romanian Ministry of Transport Civil Aviation Inspectorate.
- Aviation Safety and Pilot Control: Understanding and Preventing Unfavorable Pilot-Vehicle Interactions, by the US National Academy of Sciences, 1997
