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The engines are designed so that a detached fan blade stays contained within the cowling. Here's a video of a fan blade containment test on a Rolls Royce Trent

The engines are designed so that a detached fan blade stays contained within the cowling. Here's a video of a fan blade containment test on a Rolls Royce Trent 500: https://youtu.be/RIOWjhjC1jM https://youtu.be/RIOWjhjC1jM

KGIII 9y ago
I guess they use really, really precise timing and explosives to knock one blade loose in order to do the containment tests. They want it to come loose at a specific point in the revolution. The documentary didn't say why they wanted it to be at such a specific place, only that they did. I've long since forgotten the margin of error, but it was very small. You probably noticed that the individual blade is painted a different color and is different colors. My recollection is that they use the multiple colors because they do very high definition recording and the colors are all in different areas of the spectrum, so they can observe it better as the thing tends to be quickly obscured by fire and smoke. I probably do watch too many documentaries.
- dba7dba 9y ago
  > I probably do watch too many documentaries. You are not alone. I actually watch more and more documentaries than movies or TV series. Reality is even stranger than fiction often.
  - KGIII 9y ago
    It has been great to see the proliferation of documentaries on the web. Streaming services have been a great thing for me. I watch documentaries pretty much to the exclusion of all other genres, except American football. Even if I'm not actively paying attention, I'll frequently have a documentary playing in the background. It's not a scholastic pursuit. It is purely entertainment. I watch them because I enjoy them. Learning is incidental and not the objective. I like to queue up playlists of documentaries and let them play through. The 'net has been excellent at facilitating this.
    - woodandsteel 9y ago
      One reason I love documentaries is the people in them are often truly intelligent and knowledgeable, where as tv and the movies are full of people who are supposed to be that but don't talk and act like it. And even if the people in the documentaries are not particularly intelligent, at least they are real human beings confronting real situations, instead of phony imitations.
kogepathic 9y ago
> The engines are designed so that a detached fan blade stays contained within the cowling. Yes, but uncontained failures can and do happen. Qantas Flight 32 is an example of an uncontained engine failure on an A380, though with a Rolls Royce engine instead of Engine Alliance (GE + P&W). [0] I do think they're very lucky that this uncontained engine failure didn't cause more damage. QF32 was heavily damaged by debris coming out of the engine, so the fact that this seems to be relatively contained to the engine itself is fortunate. [0] https://en.wikipedia.org/wiki/Qantas_Flight_32 https://en.wikipedia.org/wiki/Qantas_Flight_32
- gmueckl 9y ago
  As far as I have picked up on that subject, passenger aircraft have multiple layers of protection against blades separating from the engine. The cowling is supposed to contain it. If that does not work, the fuselage in the area of the wings is hardened to prevent the separating part(s) from entering the passenger compartment and doing damage there. This is typically implemented using a Kevlar lining on the hull. The Quantas flight is remarkable in that engine parts were not contained successfully and managed to damage critical systems inside the wing not related to the engine itself. Some reports say that the flight crew was overwhelmed by over 50 individual failure reports resulting from this damage. I was actually quite surprised when I learned that it was so easy to damage that many major systems with a seemingly small puncture in a wing.
  - JumpCrisscross 9y ago
    Keep in mind that the Quantas failure, while horrible, resulted in zero fatalities.
    - bdamm 9y ago
      Very remarkable indeed, considering the damage to the landing gear, flaps, fuel tanks, and engine controls. The airplane at the time it landed was way out into the experimental flying zone. When people talk of pilot-less airliners I have to think of incidents like this. Pilots do make mistakes and people die as a result, but when equipment fails and nobody dies because a pilot does what is needed to land safely despite the issue, it rarely makes news. Sometimes people on board don't even know.

KGIII 9y ago

I guess they use really, really precise timing and explosives to knock one blade loose in order to do the containment tests. They want it to come loose at a specific point in the revolution. The documentary didn't say why they wanted it to be at such a specific place, only that they did. I've long since forgotten the margin of error, but it was very small. You probably noticed that the individual blade is painted a different color and is different colors. My recollection is that they use the multiple colors because they do very high definition recording and the colors are all in different areas of the spectrum, so they can observe it better as the thing tends to be quickly obscured by fire and smoke. I probably do watch too many documentaries.

dba7dba 9y ago
> I probably do watch too many documentaries. You are not alone. I actually watch more and more documentaries than movies or TV series. Reality is even stranger than fiction often.
- KGIII 9y ago
  It has been great to see the proliferation of documentaries on the web. Streaming services have been a great thing for me. I watch documentaries pretty much to the exclusion of all other genres, except American football. Even if I'm not actively paying attention, I'll frequently have a documentary playing in the background. It's not a scholastic pursuit. It is purely entertainment. I watch them because I enjoy them. Learning is incidental and not the objective. I like to queue up playlists of documentaries and let them play through. The 'net has been excellent at facilitating this.
  - woodandsteel 9y ago
    One reason I love documentaries is the people in them are often truly intelligent and knowledgeable, where as tv and the movies are full of people who are supposed to be that but don't talk and act like it. And even if the people in the documentaries are not particularly intelligent, at least they are real human beings confronting real situations, instead of phony imitations.

kogepathic 9y ago

> The engines are designed so that a detached fan blade stays contained within the cowling. Yes, but uncontained failures can and do happen. Qantas Flight 32 is an example of an uncontained engine failure on an A380, though with a Rolls Royce engine instead of Engine Alliance (GE + P&W). [0] I do think they're very lucky that this uncontained engine failure didn't cause more damage. QF32 was heavily damaged by debris coming out of the engine, so the fact that this seems to be relatively contained to the engine itself is fortunate. [0] https://en.wikipedia.org/wiki/Qantas_Flight_32 https://en.wikipedia.org/wiki/Qantas_Flight_32

gmueckl 9y ago
As far as I have picked up on that subject, passenger aircraft have multiple layers of protection against blades separating from the engine. The cowling is supposed to contain it. If that does not work, the fuselage in the area of the wings is hardened to prevent the separating part(s) from entering the passenger compartment and doing damage there. This is typically implemented using a Kevlar lining on the hull. The Quantas flight is remarkable in that engine parts were not contained successfully and managed to damage critical systems inside the wing not related to the engine itself. Some reports say that the flight crew was overwhelmed by over 50 individual failure reports resulting from this damage. I was actually quite surprised when I learned that it was so easy to damage that many major systems with a seemingly small puncture in a wing.
- JumpCrisscross 9y ago
  Keep in mind that the Quantas failure, while horrible, resulted in zero fatalities.
  - bdamm 9y ago
    Very remarkable indeed, considering the damage to the landing gear, flaps, fuel tanks, and engine controls. The airplane at the time it landed was way out into the experimental flying zone. When people talk of pilot-less airliners I have to think of incidents like this. Pilots do make mistakes and people die as a result, but when equipment fails and nobody dies because a pilot does what is needed to land safely despite the issue, it rarely makes news. Sometimes people on board don't even know.