Date: March 3rd, 1974
Type: DC-10-10
Registration: TC-JAV
Operator: THY (Turkish Air)
Where: Bois d' Ermenonville, France
Report No.: Not Available
Report Date: -
Pages: -
This is not an accident investigation report.
On Sunday 3rd March 1974 THY Turkish Airlines DC-10 flight 981, which
had taken off from Orly airport Paris and had been in the air for about
10 minutes dived into the forest of Ermenonville north of Paris killing all
346 people on board. Among the jet's passengers were about 200 English
rugby supports flying home from an France-England match.
The reason for the disaster was that a cargo door, which had been
improperly latched by a cargo baggage handler, flew open and the hull
of the aircraft simply disintegrated under the strain of the sudden
depressurisation. Normally aircraft doors are "PLUG" doors opening
inwards, cargo doors have to open outwards due to space limitations. The
elaborate system of latches on this type of door ensure that the door
cannot be shut until a manually operated lever is all the way down in
its slot. However the locking system was not infallible and the
operating lever was not pushed into its proper position causing the
door to fly open during the flight.
When the door blew open this caused damage to the aircrafts floor which
contained the vital control cables and hydraulics which control the aircraft
in flight.
TC-JAV (46704/29) Turk Hava Yollari - THY
346 fatalities / 346 occupants +
Phase: Climb from: Paris-Orly to: London-Heathrow APT Flightnr.: TK981
PROBABLE CAUSE: "The accident was the result of the ejection in flight of
the aft cargo door on the left-hand side: the sudden depressurization which
followed led to the disruption of the floor structure, causing six
passengers and parts of the aircraft to be ejected, rendering No.2 engine
inoperative and impairing the flight controls (tail surfaces) so that it
was impossible for the crew to regain control of the aircraft.
The underlying factor in the sequence of events leading to the accident was
the incorrect engagement of the door latching mechanism before take-off.
The characteristics of the design of the mechanism made it impossible for
the vent door to be apparently closed and the cargo door apparently locked
when in fact the latches were not fully closed and the lock pins were not
in place.
It should be noted, however that a view port was provided so that there
could be a visual check of the engagement of the lock pins.
This defective closing of the door resulted from a combination of various
factors:
- incomplete application of Service Bulletin 52-37;
- incorrect modifications and adjustments which led, in particular, to
insufficient protrusion of the lock pins and to the switching off of the
flight deck visual warning light before the door was locked;
- the circumstances of the closure of the door during the stop at Orly,
and, in paticular, the absence of any visual inspection, through the
viewport to verify that the lock pins were effectively engaged, although at
the time of the accident inspection was rendered difficult by te inadequate
diameter of the view port.
Finally, although there was apparent redundancy of the flight control
systems, the fact that the pressure relief vents between the cargo
compartment and the passenger cabin were inadequate and that all the flight
control cables were routed beneath the floor placed the aircraft in grave
danger in the case of any sudden depressurization causing substantial
damage to that part of the structure.
All these risks had already become evident, nineteen months earlier, at the
time of the Windsor accident, but no efficacious corrective action had
followed." (Aircraft Accident Report 8/76)
Link to similar incident on June 12, 1972