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Loss of Control In Flight (LOC-I) Accidents

6 investigationsFrom the official reportsUpdated Sep 2026

Loss of control in flight, abbreviated LOC-I in the taxonomy shared by ICAO and the Commercial Aviation Safety Team, is an accident in which the crew could not keep the aircraft within its normal flight envelope. For more than a decade it has been the largest single cause of fatalities in commercial air transport, according to the safety reports of IATA and ICAO.

The trigger varies: an aerodynamic stall, spatial disorientation, a system failure that was mishandled, a flight control malfunction, severe turbulence or icing. What the accidents share is an unexpected aircraft state that the crew did not recognise in time, followed by a recovery that was late, incorrect or impossible from the height available. After a series of such accidents, the regulators made upset prevention and recovery training (UPRT) part of airline pilot training; the FAA has required extended envelope training in the simulator since March 2019. The investigations below show how each upset developed, why the crew did not recover, and what the investigators recommended.

The investigations

The Boeing 767 freighter N1217A.
NTSB · 2019

Atlas Air Flight 3591

· Boeing 767-375BCF (converted freighter)
A 767 freighter's go-around mode engaged by accident in turbulence; the first officer, disoriented, pushed the aeroplane into a steep dive, and 32 seconds after the mode change it struck the bay.
Loss of controlSpatial disorientationAutomationCRMHuman factors
An Air France Airbus A330-200, registration F-GZCP, on the ground at Paris Charles de Gaulle airport.
BEA · 2009

Air France Flight 447

· Airbus A330-203
A temporary loss of airspeed indications at FL350 led to inappropriate control inputs, a stall that the crew never identified and the loss of all 228 people on board.
Loss of controlStallAir dataAutomationCRM
A Bombardier Dash 8 Q400 twin turboprop airliner, registration N208WQ, in Continental Connection colours.
NTSB · 2009

Colgan Air Flight 3407

· Bombardier DHC-8-402 (Q400)
A Q400 slowed into its stick shaker on a night approach in icing conditions; the captain's aft column inputs stalled the wing and he pulled against the stick pusher.
Loss of controlStallIcingFatigueCRM
The recovered vertical stabiliser of American Airlines Flight 587 being lifted by a crane beside a US Army Corps of Engineers vessel.
NTSB · 2001

American Airlines Flight 587

· Airbus A300-605R (A300B4-605R)
An A300-600's fin broke off in the climb when repeated full rudder reversals after a minor wake encounter built loads beyond the ultimate design load.
Structural failureFlight controlsLoss of controlHuman factors
The Alaska Airlines McDonnell Douglas MD-83 registered N963AS at an airport.
NTSB · 2000

Alaska Airlines Flight 261

· McDonnell Douglas MD-83
An MD-83's stabiliser trim jackscrew lost its nut threads through lack of grease, and extended check intervals let the wear go undetected until pitch control was lost.
MaintenanceFlight controlsLoss of control
The Swissair McDonnell Douglas MD-11 HB-IWF at Zurich airport.
TSB · 1998

Swissair Flight 111

· McDonnell Douglas MD-11
A fire hidden above the cockpit ceiling of a Swissair MD-11 spread through flammable insulation during a diversion to Halifax, degrading the aircraft's systems until control was lost and it struck the sea.
FireHuman factorsLoss of control

The theory in the Library

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Picture credits

  1. Atlas Air Flight 3591: Orlando Suarez · CC BY-SA 4.0 · Wikimedia Commons
  2. Air France Flight 447: Pawel Kierzkowski · CC BY-SA 3.0 · Wikimedia Commons
  3. Colgan Air Flight 3407: DearEdward from New York, NY, USA · CC BY 2.0 · Wikimedia Commons
  4. American Airlines Flight 587: NTSB · Public domain · Wikimedia Commons
  5. Alaska Airlines Flight 261: Frank Jäger · CC BY-SA 2.0 · Wikimedia Commons
  6. Swissair Flight 111: Aero Icarus from Zürich, Switzerland · CC BY-SA 2.0 · Wikimedia Commons

Crash Investigations pages summarise official investigation reports for study and exam preparation. The investigating body's report is the authoritative account and prevails wherever it differs from this page. Under ICAO Annex 13, an investigation exists to prevent accidents, not to apportion blame or liability.