rabenschlag
Posts: 1012
Joined: Fri Oct 20, 2000 10:28 pm

The Larger The Engine The Larger The Trouble

Wed Nov 14, 2001 1:30 am

maybe thats a bit off topic. but the crash of the AA A306 made me ask myself whether there is a relation between engine size and the potential damage the engine does to the plane if theres a failiure.

sometimes, blades of the fan come off and damage the plane. take the UA DC-10, in sioux city. there the no2 engines blade came off and damaged hydraulic linings causing the crash landing. the larger the engine the larger the damage?

take vibrations that might be caused by the moving parts getting out of balance. the lager the engine the more damage?

take the case that an engine fails during take off. the force pushing the plane in one direction (the spin) will be the larger if the failing engine is larger.

and, of course, if the whole engine falls off the plane, might it cause more damage if it is larger?

im not sure. could it be that large engines are unsafer than small ones?

regards, rabenschlag


 
AFC_Ajax00
Posts: 740
Joined: Tue Nov 21, 2000 5:33 am

RE: The Larger The Engine The Larger The Trouble

Wed Nov 14, 2001 1:31 am

I do not agree, for newer engines are larger and use techniques aqquired from years of experise so theyare very modern and safe.
Once you have tasted flight, you will walk the earth with your eyes turned skyward; for there you long to return
 
Guest

RE: The Larger The Engine The Larger The Trouble

Wed Nov 14, 2001 1:56 am

Look at the problems GE had with their newly designed GE90 engine for the 777?
 
cfalk
Posts: 10221
Joined: Mon Dec 04, 2000 6:38 pm

RE: The Larger The Engine The Larger The Trouble

Wed Nov 14, 2001 2:17 am

There have been a number of instances of uncontained failures of "small" engines like on DC-9s as well. What HAS changed is engine manufacturers testing the engines to ensure (as much as physically possible) that in case of a complete engine self-destruct, like all the fan blades breaking, that all the pieces remain within the casing. I understand that the 777's engines were designed that way, and that is a huge undertaking, considering the size of the engine.

The A300's engines are of an older generation, so perhaps it wasn't built to contain such failures as well (?)

By the way, the A300 that crashed had CF6-80C2A5 engines. The Sioux City DC-10 that blew the engine had an older version of the same engine, the CF6-6D.

Charles
The only thing you should feel when shooting a terrorist: Recoil.
 
VS744
Posts: 659
Joined: Mon Aug 06, 2001 9:22 pm

RE: The Larger The Engine The Larger The Trouble

Wed Nov 14, 2001 2:22 am

If a blade breaks, and the turbines move off centre - i.e out of balance, surely the momentum of this could have caused the engine (still intact) to shake violently side to side until it either ripped off the safety bolts, or the section of the wing?

Thats my theory from now on.

This would explain why:
a) the engine came off
b) the wing was damaged
c) there was no explosion....
 
b757300
Posts: 3914
Joined: Fri Dec 15, 2000 10:27 pm

RE: The Larger The Engine The Larger The Trouble

Wed Nov 14, 2001 2:26 am

Tedski must really be loving all the anti-GE stuff going around right now.

When I have the time this afternoon, I'll find plenty of incidents involving P&W and RR engines.
"There is no victory at bargain basement prices."
 
MxCtrlr
Posts: 2312
Joined: Tue Nov 13, 2001 11:22 am

RE: The Larger The Engine The Larger The Trouble

Wed Nov 14, 2001 2:28 am

I don't agree. Take the case of the DL MD80 series aircraft a few years back that suffered an uncontained engine failure and a piece of the compressor section perforated the cabin and killed two pax sitting in their seats. Larger engines do NOT necessarily mean larger problems!
DAMN! This SUCKS! I just had to go to the next higher age bracket in my profile! :-(
 
penguinflies
Posts: 932
Joined: Thu Apr 06, 2000 12:00 pm

RE: The Larger The Engine The Larger The Trouble

Wed Nov 14, 2001 11:14 am

IMO, larger engine is better.

GE and PW produced videos where they blew a random blade-at takeoff power-from the root and how it was contained.

the 777 engines are also derated on some, if not all airframes.

Also isn't a engine failure on an MD-80 easier to fly than a Boeing or Airbus due to the fact that the placement of the engines from the lateral axis lessens the yaw?
 
AA737-823
Posts: 4905
Joined: Wed Mar 01, 2000 11:10 am

RE: The Larger The Engine The Larger The Trouble

Wed Nov 14, 2001 2:31 pm

I don't like GE.

But I will say that the NTSB has said that there is NO evidence of Catastrophic Uncontained Engine Failure- CUEF.

If AA would stick with Pratts, we'd all be happier fliers.

Okay, so that is bullcrap.

I really think that the pylon snapped, and the departing engine impacted the fuselage, causing the glued-on tail section to snap off.

Just a theory.

Randy
 
Guest

RE: The Larger The Engine The Larger The Trouble

Wed Nov 14, 2001 4:02 pm

The 777 engines are the largst, and are by far, more safer than anything else out there.