Dakotasport From Canada, joined Dec 2000, 227 posts, RR: 0 Posted (9 years 5 months 1 week 6 days 2 hours ago) and read 6043 times:
I was wondering something. The THY incident in the '70s and I believe there was also a AA DC10 that experienced the problem with the cargo door opening in flight. My question is, how is it possible that an un-pressurized section of an a/c (cargo hold) could cause a rapid decompression as in these two incidences when the door comes open during flight????
MD11Engineer From Germany, joined Oct 2003, 13602 posts, RR: 63 Reply 3, posted (9 years 5 months 1 week 5 days 21 hours ago) and read 5823 times:
On the original DC-10 cargo doors it was possible to move the locking lever into the locked position without having the (electrically operated) latches fully engaged.
After the accident the door latching mechanism was redesigned. It is now impossible to push the locking lever down if the latches are not in their end position, due to a cam as part of them, which has to move out of the way for the locking bars. The position of the locking bars can (and has to be checked) through small windows inserted in the cargo door. The same door is in use on the MD-11. There have been no more problems since them.
Since the pressure differetial pulled down the floor over the aft cargo hold and pulled on the control cables, causing the flight crew to loose control over their plane, there have been several blow out panels incorporated in the cargo hold ceiling and sidewall panels, which will permit a controlled equalisation of pressure if there should be a decompressation either in the cabin or cargo holds.
BTW, the 747 had a similar problem with a cargo door opening in flight, killing several people (United Airlines). Only the fact that the control cables of a 747 run above the cabin (due to it´s cockpit in the upper deck), prevented a similar loss as the Turkish Airlines accident. The lock and latch mechanism of the 747 was redesigned as well, with similar inspection windows and a change of the material of the locking cams from aluminium to steel.
Broke From United States of America, joined Apr 2002, 1322 posts, RR: 3 Reply 4, posted (9 years 5 months 1 week 5 days 19 hours ago) and read 5712 times:
On the American DC-10-10 incident. The plane took off out of Detroit and was climbing out over Southern Ontario when the cargo door opened. Due to the transient pressure differential between the cargo compartment and the passenger compartment, the floor partially collapsed, jamming several empennage flight control cables (rudder and elevators) that are routed through the lightening holes in the floor beams.
The crew controlled the airplane by the use of the rudder and elevator trim tabs and the stabilizer trim. One of those incidents, most people never hear of, that could have been a major disaster except for the skill of the flightcrew. The contents of the cargo compartment and the lounge above were lost. At that time there no passenger seats in that area and no serious injuries or fatalities occurred.
A change to the cargo doors was made via service bulletin and a production change on the line. There was an error in the production records and 2 airplanes were registered as being modified and they were not. One was a National Airlines DC-10 and the other was the THY DC-10 that was later lost coming out of Orly. It is still the greatest loss of life by a single airplane crash in aviation history. Hopefully, that is a record that will not be broken.
Jetstar From United States of America, joined May 2003, 1581 posts, RR: 10 Reply 5, posted (9 years 5 months 1 week 5 days 17 hours ago) and read 5685 times:
In the THY incident, and as discovered on the National DC-10 and also another DC-10 after the THY crash, both airplanes had not been modified. The paperwork showed these modifications required after the AA incident had been installed, but in fact were not.
The investigation found that the mechanic who was assigned to install this modification just signed the paperwork off as installed, but never did the work. Also the inspector who was required to inspect the mechanic’s work and sign it off never went out to the airplanes to inspect the job but also signed it off as installed.
Both the mechanic and inspector were arrested and charged with criminal negligent homicide. I do not know of the outcome of the trial.
Dc10guy From United States of America, joined Feb 2000, 2685 posts, RR: 7 Reply 8, posted (9 years 5 months 1 week 3 days 9 hours ago) and read 5301 times:
As has been correctly stated the THY & AA aft bulk cargo doors blew out because of a bad design that was know about and covered up etc. But the reason the THY plane crashed and the AA plane almost crashed was because there was inadequate pressure equalization between the upper and lower compartments. When the door blew out the floor crushed the control cables for the rudder and elevators .... Very sad. If the AA plane was fully loaded like the THY was it most likely would have crashed too.
Next time try the old "dirty Sanchez" She'll love it !!!
Jetstar From United States of America, joined May 2003, 1581 posts, RR: 10 Reply 9, posted (9 years 5 months 1 week 2 days 16 hours ago) and read 5171 times:
IIRC the AA DC-10 was at a lower altitude than the THY DC-10 so the force of the explosive decompression was less. On the AA -10 it severely buckled the floor jamming the control cables.
On the THY –10, the floor above the cargo compartment completely caved in and some passengers sitting above the collapse area were sucked out of the airplane. The found these passengers still strapped into their seats in a field near were the cargo door landed away from the main wreckage area.