Engine Mount

[Jakemaster]

Yes, the DC-10 had one of the bolts holding the engine snap and it fotated around the front bolt, burst into flame, then broke of and ripped away

[Ivan]

1991 el al crash had the front pins go before the rear ones... causing the engines to crash into the flaps before coming loose

[Fly2e]

As the DC-10 was heading down the runway, the engine actually disconnected and lurched forward then up and over the wing releasing all the hydraulic fluid.

The plane had already committed to take off and as it climbed, hydraulic fluid poured out of the system rendering control surfaces useless!!

As the pilots struggled to control the plane, with the loss of hydraulic fluid, it was a lost cause.

Here is a shot of that DC-10 moments before crashing...

[Bubblehead]

I understand that anything can happen to an engine that will cause excessive damage including mistakes by people on the ground. I'm mainly curious about what would happen, in your opinion, to an engine running at full RPM (what's the RPM on takefoff?) if for some reason, it sucked in a large object such as a geese causing blade damage?

I'm not a degreed engineer but from what I know about rotor imbalance, three criterias come into play: RPM, amount of imblance and distance of the imbalance from the center. For example, with the RPM constant, an ounce of imbalance, one inch from the center increases by a mathematical series of factors
as the distance from the center is increased.

Lots of ineteresting information I've learned from this thread.

Bubblehead

[Fly2e]

I'm mainly curious about what would happen, in your opinion, to an engine running at full RPM (what's the RPM on takefoff?) if for some reason, it sucked in a large object such as a geese causing blade damage?

THIS!

[Hagar]

Yes, the DC-10 had one of the bolts holding the engine snap and it fotated around the front bolt, burst into flame, then broke of and ripped away

I understood it was the mounting itself that fractured & not the pin or bolt.

I'm mainly curious about what would happen, in your opinion, to an engine running at full RPM (what's the RPM on takefoff?) if for some reason, it sucked in a large object such as a geese causing blade damage?

I think it's most likely the engine would shake itself to pieces & some of these pieces could easily damage the aircraft or passengers in the vicinity of it. This was demonstrated in the case of United Flight 232.

United Flight 232, a McDonnell Douglas DC-10-10. While cruising at 37,000 feet, the aircraft suffered a catastrophic engine failure. The uncontained disintegration of the number two engine's fan rotor caused the loss of all three of the aircraft's redundant hydraulic flight control systems and made the aircraft almost uncontrollable.

Captain Haynes and his crew, augmented by a DC-10 instructor pilot who was aboard as a passenger, were able to navigate to the municipal airport at Sioux City, Iowa, U.S., where the aircraft was crash-landed approximately 45 minutes after the hydraulic failure. Of the 285 passengers and 11 crew members aboard, 174 passengers and 10 crew members survived.

http://www.airdisaster.com/eyewitness/ua232.shtml

The cause of the engine breaking up was later discovered to be a fatigue crack in the fan disk. Possibly this flaw had been present since manufacture.

[Craig.]

Depends on how bad the blade damage is. I hate the fact my baby is being used in the examples But 232 is a testiment to the punishment the Dc10 can take and still fly with a capable crew.

[Nexus]

Depends on how bad the blade damage is. I hate the fact my baby is being used in the examples But 232 is a testiment to the punishment the Dc10 can take and still fly with a capable crew.

If the same thing would've happened to a Tristar, if would still have what? Tripple redundancy in the hydraulics, because of the way the hydralic system was set-up? I don't think the UAL DC10 even had hydraulic fusings (One-way check valves, to prevent total hyd. fluid loss)
Needless to say, the L1011 had that designed in from the beginning.

I'm not saying the DC10 had a design flaw, but once again proves how technically superior the L1011 was:
SYSTEM REDUNDANCY

The Lockheed TriStar also had a flap-disagreement system, so the slats wouldn't have been retracted on the engine-less wing.
Would that have been enough to save the aircraft, who knows

[Nexus]

[quote]I seriously doubt it.

[Hagar]

Well, contraire to popular belief, the Dc10 would still be abel to land, despite lacking an engine. The reason why it rolled over was becuase of the extensive hydraulic leakage. With no hydraulic fluid to keep the slats extended...the slats simply retracted causing that wing to go into a stall.

That might be true Nexus but one part of Jake's statement is very important. A jet engine or the remains of it jettisoned from an aircraft could cause a lot of damage & possible caualties on the ground. I don't think this would ever be considered, especially in these days of compensation culture.

[myshelf]

That might be true Nexus but one part of Jake's statement is very important. A jet engine or the remains of it jettisoned from an aircraft could cause a lot of damage & possible caualties on the ground. I don't think this would ever be considered, especially in these days of compensation culture.

sheer bolts are very common. they are there to let the structure fail at the point where it does the least damage. like, better the engine departs, than rips half the wing off trying to.

by and large it will always be better the engine falls off, at least halfway controlled, and let the plane make an emergency landing than having the plane coming down.

[Bubblehead]

Would a fly-by-wire aircraft such as the B777 suffer the same fate if it had lost an engine the same way?

Bubblehead

[elite marksman]

Yes. The system only separates the cockpit from the controls. The control surfaces are still controlled by hydroulics, so if you lose pressure, you're screwed. Although, if the system has check valves you may retain enough pressure to get the aircraft back to the runway.

[Nexus]

I dont know about the 777 FBW protections, but let's examine what would've happened to an Airbus A330 with FBW.

If everything works as it should you have bank angle protections at 67 degrees aswell as pitch protection 30degrees up and 15 degrees down.
High angle of attack (alpha) protection is also offered which makes it impossible to stall the Airbus. The Alpha max cannot be exceeded even though the pilot have full aft deflection of the sidestick. This is called Normal law

But what if you lose thean entire engine, like the DC10 we've been talking about?

In theory the damage would be so severe so all protections would likely be lost, the aircraft would probably be in Direct law
This means ZERO protections for bank, pitch and stall.
Autotrimming is unavailable.
The deflections of the sidestick is now a direct relationship between sidestick and control surface. No signals are augmented via the flight computers.

But the slats on the engine less wing would not retract, since the Airbus has "wing tip brakes", which prevents slat/flap movement in cause of a runaway or hydraulic failure. Also keep in mind that the hydraulic systems in an Airbus are VERY segregated.

So I think the Airbus crew would have a better chance...
But your question is too complicated to give a correct answer, even for a professional pilot, so an amateur like me can only specualate, really.

Edit: Just talked to a former A330 captain. And listen to this...this is just incredible. He said that aslong as you have ONE functional hydraulic system, the aircraft can still be flown normally ie: in NORMAL LAW.
Sounds too good to be true actually.

[Bubblehead]

Nexus:

The ex-AB330 captain must know what he's talking about. Does the Boeing fleet of similar design (B737,757,767, 777 and the latest 787) have comparable capabilities?

Bubblehead