Jet engine attachment Options

[AirbusA380]

Why are jet engine attached only with two large pins on the pylons? Apparently, it works, but what is the reasoning which defeats the common sense approach that shouldn't there be more attachment points for such a big piece of hardware?

[flyingcanuck]

One reason I've heard is so that they can just shear away if struck to hard; that way they don't damage anything else. But I've heard that they can do considerable damage while being jettisoned.

[Fluffdoc]

Most jet engines are attached with three bolts - two at the front and one at the rear. The primary purpose of the bolts is attach the engine to the engine mounts which are then attached to the pylon. The mounts themselves transmit most of the thrust and other loads from the engine to the airplane.

The bolts are specially designed for that application and made out of high strenth steel. They are designed to shear off to allow the engine to depart the airplane if it hits a large obstacle or if the engine has a sudden stoppage. This will prevent severe and possibly fatal damage to the airplane.

[dmd747]

Most jet engines are attached with three bolts - two at the front and one at the rear. The primary purpose of the bolts is attach the engine to the engine mounts which are then attached to the pylon. The mounts themselves transmit most of the thrust and other loads from the engine to the airplane.  

The bolts are specially designed for that application and made out of high strenth steel. They are designed to shear off to allow the engine to depart the airplane if it hits a large obstacle or if the engine has a sudden stoppage. This will prevent severe and possibly fatal damage to the airplane.

I've heard the same about landing gear. That they are made to break away after an Eastern Airlines incident quite a few years back. It was a 727 that approached too low and struck a light pole and then flipped upside down. Does anybody know if all landing gear systems are made to break away still? By the way sorry for not remembering the incident details. If anyone remembers it more clearly please advise me. It was a former Eastern Airlines mechanic that told me the story.

[glnflwrs]

No, at least not any that I've seen. In fact they are probably the most well secured part on the plane. On most heavies the gear strut is approx 10 inches or larger in diameter. The dog-bone which is the large horizontal part that the axles go into, is about the same.

The landing gear are designed and built to take a LOT of punishment and extreme loads. Except on Airbus planes. Hehehe!

:D :lol: 8)

[rjb4000]

I've heard the same about landing gear. That they are made to break away after an Eastern Airlines incident quite a few years back. It was a 727 that approached too low and struck a light pole and then flipped upside down.

They probably would have made the lightpoles weaker rather than make the landing gear weaker..

[N5528P]

Why are jet engine attached only with two large pins on the pylons? Apparently, it works, but what is the reasoning which defeats the common sense approach that shouldn't there be more attachment points for such a big piece of hardware?

I think you answered the question yourself: Why having more if it works?

Of course there are other reasons like getting rid of the engines, weight, ... but the essence is: Why strengthen something which works fine?

Regards, Bernhard