OPNLguy From , joined Dec 1969, posts, RR: Reply 4, posted (9 years 3 months 1 week 4 days 16 hours ago) and read 6466 times:
Based upon this photo http://coppermine.luchtzak.be/displayimage.php?album=249&pos=11 showing the aircraft's engine pointing the opposite direction from the aircraft's direction of travel, plus one of the messages mentioning that the engine "fell off in mid-air", I'd say you could be looking a case of a failure of the aft cone bolt, one of three that attaches the engine to the wing. There are two forward, and one, aft, and should the aft fail, there's only a steel cable/restraining strap to keep the aft end of the engine from dropping down too far. If that cable fails as well, the aft end of the engine can drop further and contact the ground, or even separate from the aircraft itself.
There have been numerous 737-200 engine separations caused by aft conebolt failures over the years, mainly in the 1970s, 1980s, and early 1990s. Piedmont (pre-USAir merger) had one at ORD. USAir themselves had one at PHL. Delta had one at DFW. In all of these cases, the aircraft was taking off, and the separated engine impacted on/near the runway used. Southwest had the aft bolt failure on one at DAL, but the strap held and they returned to land with the engine still on the wing. There were others elsewhere, but the aforementioned ones are the only that come immediately to mind.
Tightening up the inspection intervals and replacing all the conebolts more frequently seemed to make these kinds of engine separations pretty rare over here, but of course, maintenance standards can easily vary around the world.
SATL382G From , joined Dec 1969, posts, RR: Reply 7, posted (9 years 3 months 1 week 4 days 11 hours ago) and read 6152 times:
Ordinarily I find your posts well though out, but this time I think you're on good drugs!!
You expect me to believe that the cone bolt fails, engine comes off in midair, takes the starboard gear and half the right horizontal stab with it. Then our pilot, "Aviation Superman", manages a feat of aviation derring do to get the plane back down on the grass, intact, and skids to a stop only 600 meters away!! That's FUNNY!
I think it's more likely that Aviation Superman lost control on takeoff (for reason as yet unknown) and veered off the left side. Right gear and starboard engine come off due to structural overload and remove right horizontal stab in the process. Aircraft skids, loses it's nosegear and comes to a stop.
OPNLguy From , joined Dec 1969, posts, RR: Reply 8, posted (9 years 3 months 1 week 4 days 10 hours ago) and read 6065 times:
>>>You expect me to believe that the cone bolt fails, engine comes off in midair, takes the starboard gear and half the right horizontal stab with it.
No, but I never said nor inferred that a departing engine took out the starboard gear and right horizontal stabilizer, you did.
Based upon (1) the passenger statement that there was a "big boom" and (2) that an engine fell off in mid-air, and (3) that engines -have- separated from other 737-200s at/immediately after takeoff before (see Delta and Piedmont), and (4) the location of the engine's final resting place versus that of the fuselage, all my original message said was that this "could" be a case of an aft cone bolt failure. Not 100% yes. Not 100% no. Just that it "could" have, as in the context of being the initiating event.
To be sure, there are other things that could have caused this accident, lots of them. I don't know conclusively what did, any more than you do, hence my use of the word "could", but if a 737-200 shucks an engine at very low altitude, a cone bolt related failure is something that pops into my mind as a possibility, although it might not to others unfamilar with this 737-related quirk.
SATL382G From , joined Dec 1969, posts, RR: Reply 9, posted (9 years 3 months 1 week 4 days 9 hours ago) and read 5984 times:
You're saying that the cone bolt failure caused the engine to come off. This implies then that the stab and gear coming off are related to the engine situation. You don't have to state it, the pix show engine and starboard gear together. Or are you saying that a second, simultaneous, failure caused the gear to come off?
I'm somewhat familiar with cone bolt failures. I just don't understand how you can explain a cone bolt failure incident by saying that the engine came off in midair, the gear & stab came off for whatever reason, and the pilots gets it back down on the ground, it skids to a stop and it comes out intact.
The gear is sitting in close proximity to the engine and it appears to have a chunk of the stab in it's "teeth". Leads me to conclude engine, gear, and stab came off nearly simultaneously.
OPNLguy From , joined Dec 1969, posts, RR: Reply 10, posted (9 years 3 months 1 week 4 days 7 hours ago) and read 5888 times:
>>>You're saying that the cone bolt failure caused the engine to come off.
I'm saying that it's -possible- that it could have. From the above NTSB links:
From Delta/1992: "ENGINE SEPARATION WAS THE RESULT OF THE FAILURE OF THE AFT CONE BOLT AND THE ENGINE SECONDARY SUPPORT ASSEMBLY."
From Piedmont/1989: "AN EXAM OF ITS WING & SEPARATED ENGINE REVEALED THE AFT CONE (ENG MOUNTING) BOLT HAD FAILED FROM FATIGUE, THEN THE TWO FORWARD CONE BOLTS FAILED FROM DUCTILE OVERSTRESS."
From USAir/1989: "AN EXAM REVEALED THE AFT MOUNT CONE BOLT FOR THE #2 ENG HAD FAILED FM FATIGUE THRU THE THREAD RELIEF UNDERCUT RADIUS. "
From Southwest/1986: "THIS INCIDENT OCCURRED WHEN THE NO. 2 ENGINE EXPERIENCED AN AFT ENGINE MOUNT CONE BOLT FAILURE AND THE SUBSEQUENT FAILURE OF THE SECONDARY SUPPORT LINK (STAINLESS STEEL CABLE). "
Now, is there any remaining doubt that an aft cone bolt failure could easily cause an engine separation? Did that absolutely happen in the Air Guinee case? I have no idea--all I ever said was that it could be a possibility, and in the context that it may have been the first thing to depart the aircraft and initiate the subsequent events.
>>>This guy never got airborne....
I don't know--I wasn't there. I'm only going by the posted statement "Almost immediately after the plane took off and was in mid air, we noticed that the left wing was on fire." I'm taking the statement at face value.
>>>I'm somewhat familiar with cone bolt failures. I just don't understand how you can explain a cone bolt failure incident by saying that the engine came off in midair, the gear & stab came off for whatever reason, and the pilots gets it back down on the ground, it skids to a stop and it comes out intact.
Let's try it this way...
Let's assume the aft cone bolt failed and the engine separated as a result, and that was the first thing that happened in the accident sequence. Here's where the all the other variables come in. What happened next? Were they just feet off the ground? 300 feet? 500 feet? How fast were? Did the crew try to put it back on the ground? How heavy/light were they? Did the main gear hit and fail first, or did the nose gear, or did they bank and a wingtip first contact the ground?
I don't have the foggiest idea as to what the answers are, nor what the precise sequence of events actually was. Whatever particular order you wish to put them in doesn't necessarily eliminate the possibility an engine separation was the -first- thing that happened. Given that some 737-200 engine separations have been associated with takeoffs within a close distance off the ground, I think it remains a POSSIBILITY here.
Now, if I have to explain this again, someone might not conclude that I'm the one on drugs...