Thread: Boeing 787
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Old 11-12-2010, 05:41 PM   #30
Marin
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Boeing 787

I don't know if 100% containment of blades is a requirement, but a certain degree of containment strength is. I suppose it's impossible to guarantee 100% containment since things can fail in so many ways. But I'm pretty sure from tests we've seen from the engine manufacturers that the containment of blade separation under "normal" failure modes--- however one defines that--- is a certification requirement.

Guaranteeing no damage to the airframe from a blade departing the engine would be extremely difficult, and would require literally armor-plating the fuselage in the areas where blade penetration could occur. From everything I have seen and worked with from the engine manufacturers, the objective is to retain any pieces that come off within the engine case itself. I have worked with slow-motion footage from GE showing how blades that break or separate do not break through the engine casing.* They severely damage it in some cases, but the case is not penetrated.

As I said earlier, I received an e-mail from someone at work who was sent an initial damage report to the A380 by someone in a position to have it. It is pretty amazing what was done to the plane--- the airframe and systems themselves--- by the blade separation. One thing that received some press was the fact that the #1 engine, the engine outboard of the engine that failed, could not be shut off once the plane was on the ground. What I did not know until I read the damage report was they first tried to shut it off using the fire suppression system for that engine. It did nothing. This meant that for the duration of the flight after the engine failure in #2, the #1 engine had no fire protection at all. The only way they were able to shut the engine off was to spray foam into it with a fire truck. There were photos of this in the press.

-- Edited by Marin on Friday 12th of November 2010 07:43:13 PM
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