Question for our resident pilots..What would cause this engine failure?
- Thread starter loneryder
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edyvw
$50 site donor 2025
Compressor stall. My take.
Bird?
Bird?
@ 36,000 feet?
edyvw
$50 site donor 2025
I missed altitude. I know that it happened and when I saw title I didn’t want to read further bcs. the way it was written.
Idk? Failed blade? Other components? Who knows.
Modern jet engines are WAY more complex than most realize. Because of that, theres more " critical " components than most realize.
Besides what failed and how it failed, just as important to know is the maintance history.
Besides what failed and how it failed, just as important to know is the maintance history.
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The altitude reference is incorrect. This was a common bird strike that occurred on take-off. It was the no. 2 engine (Rolls Royce RB211-535). The reference in some of the news articles that there was a chemical reaction in the combustion section is also poor reporting.
And for the record, the term for bird guts that have ingested into a jet engine is referred to as "Snarge". Look it up.
And for the record, the term for bird guts that have ingested into a jet engine is referred to as "Snarge". Look it up.
The article is too vague to ascribe a cause. “Chemical reaction inside the combustion chamber” doesn’t make any sense to me. I don’t know what is meant by that. I have a lot of time with RB-211s. Never heard of that.
The video shows it compressor stalling - flames from the engine, not the wing, as the article describes.
In general, engines fail because either a control system fails (bad sensor, bad data, processor, etc.) or a mechanical part lets go (compressor blade, turbine blade, bearing). Hard to know what happened in this case from the description.
But compressor stalls happen when the airflow in the engine is disrupted - that can be mechanical, or control system.
If you can’t restart it, it’s most likely mechanical. Typically, a control system has redundancies and will work if the engine is shut down and restarted.
If you hear it “popping” - and I didn’t on the video - then it is still compressor stalling.
The video shows it compressor stalling - flames from the engine, not the wing, as the article describes.
In general, engines fail because either a control system fails (bad sensor, bad data, processor, etc.) or a mechanical part lets go (compressor blade, turbine blade, bearing). Hard to know what happened in this case from the description.
But compressor stalls happen when the airflow in the engine is disrupted - that can be mechanical, or control system.
If you can’t restart it, it’s most likely mechanical. Typically, a control system has redundancies and will work if the engine is shut down and restarted.
If you hear it “popping” - and I didn’t on the video - then it is still compressor stalling.
MolaKule
Staff member
If there was a popping noise, it could be caused by fuel igniting after the combustion chamber or a compressive wave buildup at the last high-pressure stage or both.
There are several videos out there that have a popping sound all throughout the descent. Flames shoot out with each pop.
I haven't seen all of them them - only the article that you linked and on which you solicited commentary.
I've already explained what the popping sound and flames are caused by - it's a compressor stall.
Also - the video linked in the article shows the airplane climbing, not descending. And the flames stop after a few seconds.
So, reckon the crew shut it down fairly quickly.
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4WD
$50 site donor 2025
I am referring to the video in the link with the sound turned up. I really don't know if the plane was going up or down but the entire video shows regular popping. You say that's compressor stall? The flames stop but the popping continues.
Yes. It is a compressor stall.
MolaKule
Staff member
A bit of research explains this phenomenon: "...The following, if severe enough, can cause stalling or surging.
- Ingestion of foreign objects which results in damage, as well as sand and dirt erosion, can lower the surge line.
- Dirt build-up in the compressor and wear that increases compressor tip clearances or seal leakages all tend to raise the operating line.
- Complete loss of surge margin with violent surging can occur with a bird strike. Taxiing on the ground, taking off, low level flying (military) and approaching to land all take place where bird strikes are a hazard. When a bird is ingested by a compressor the resultant blockage and airfoil damage causes compressor surging. Examples of debris on a runway or aircraft carrier flight deck that can cause damage are pieces of tire rubber, litter and nuts and bolts. A specific example is a metal piece dropped from another plane.<a href="https://en.wikipedia.org/wiki/Compressor_stall#cite_note-3"><span>[</span>3<span>]</span></a> Runways and aircraft carrier flight decks are cleaned frequently in an attempt to preclude ingestion of foreign objects.
- Aircraft operation outside its design envelope; e.g., extreme flight manoeuvres resulting in airflow separations within the engine intake, flight in icing conditions where ice can build up in the intake or compressor, flight at excessive altitudes.<a href="https://en.wikipedia.org/wiki/Compressor_stall#cite_note-4"><span>[</span>4<span>]</span></a>
- Engine operation outside its flight manual procedures; e.g., on early jet engines abrupt throttle movements (slam acceleration) when pilot's notes specified slow throttle movements. The excessive over-fuelling raised the operating line until it met the surge line. (Fuel control capability was extended to automatically limit the over-fuelling to prevent surging.)
- Turbulent or hot airflow into the engine intake, e.g., use of reverse thrust at low forward speed, resulting in re-ingestion of hot turbulent air or, for military aircraft, ingestion of hot exhaust gases from missile firing.
- Hot gases from gun firing which may produce inlet distortion; e.g., Mikoyan MiG-27.
Effects
Compressor axially-symmetric stalls, or compressor surges, are immediately identifiable, because they produce one or more extremely loud bangs from the engine. Reports of jets of flame emanating from the engine are common during this type of compressor stall. These stalls may be accompanied by an increased exhaust gas temperature, an increase in rotor speed due to the large reduction in work done by the stalled compressor and – in the case of multi-engine aircraft – yawing in the direction of the affected engine due to the loss of thrust." WIKI.and
https://simpleflying.com/jet-engine-compressor-stalls-guide/
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The plane is in the distance. Sound travels slower than light. The popping continuing after the last flash is the sound corresponding to earlier flashes.
Ed