Philippine Airlines Flight 113 operated by a Boeing 777 bound for Manila suffered a compressor stall and engine fire.

I wonder why the pilot didn't dump fuel from the left-side prior to the landing to meet the maximum landing mass (MLM) required and to avoid damaging the undercarriage as seen in pictures?

I assume that, when I have an engine fire, I shut it down and crank the remaining fuel residual until it is put out. Any idea?

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    $\begingroup$ For reference, the incident is avherald.com/h?article=4cf94f2d&opt=0. No mention of landing gear damage. $\endgroup$ – Jan Hudec Nov 23 '19 at 10:53
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    $\begingroup$ … note that deflated tires and burnt brake pads, which are common consequence of brake overheat, the main issue in overweight landings, are no big deal, because these things don't last that long in regular operation either. $\endgroup$ – Jan Hudec Nov 23 '19 at 11:13
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    $\begingroup$ @JanHudec: that sounds like a good answer: it didn't damage anything serious or expensive, and probably the pilots anticipated that. So the cost downside to an overweight landing is low. That's a nice complement to John K's answer about the possible safety upside. $\endgroup$ – Peter Cordes Nov 23 '19 at 19:20
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    $\begingroup$ Dumping all the fuel on the left side would cause catastrophic imbalance leading to loss of control and a crash. It would likely lead to a crash much faster than "simply" having an engine on fire. $\endgroup$ – FreeMan Nov 25 '19 at 19:44
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    $\begingroup$ I have to disagree Freeman, jettison nozzles dumps only for 15 minutes and its purpose to reduce fuel volume not emptying the tank, plus you can always cross feed from the others tanks to regain the balance instantly as you are dumping for weight reduction yet you maintaining stable balance $\endgroup$ – Adham Nov 25 '19 at 20:49

If you had an engine fire, even though it may be "out", you want your airplane on the ground as soon as you possibly can. You don't know what structural damage is lurking as a result of the fire. Dumping fuel would take a fair amount time to get rid of any significant amount.

So it's "Screw the landing gear. We're landing overweight".

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    $\begingroup$ I also wonder if dumping fuel while engine is on fire would not create a dramatic fire hazard. $\endgroup$ – Léa Gris Nov 23 '19 at 14:49
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    $\begingroup$ @LéaGris it is actually allowed. The fuel jettison nozzles are located further outwards on the wing for exactly this reason. $\endgroup$ – Bianfable Nov 23 '19 at 16:21
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    $\begingroup$ @LéaGris Nah, mostly it just looks cool. $\endgroup$ – David Richerby Nov 26 '19 at 10:34

On twin-engined aircraft the standard procedure for engine failure is to land as soon as possible. Since it is possible to land overweight—and aircraft are designed so that it is—delay to dump fuel is not considered acceptable, and no reasonable pilot would delay the landing when they can land already.

Landing overweight is not really a big issue. The limiting factor for maximum landing weight is the kinetic energy of the aircraft that will be dissipated on the brakes as heat. If the aircraft is overweight on landing, the brakes will probably overheat. But:

  • Since they had engine fire, the fire engines were on stand-by anyway, they can deal with hot brakes too.
  • The heat often causes tires to deflate and the brake pads might be burned, but those need to be replaced quite often anyway, so it's not a big loss.
  • The aircraft can't depart again until the brakes cool down, but it's not flying anywhere until they replace the failed engine anyway.

So it's safer to just land overweight than spend longer in the air with only one engine.

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    $\begingroup$ The only real fallout, unless the crew lands hard and breaks things, is an overweight landing inspection, basically a visual inspection looking for deformed or cracked structure. $\endgroup$ – John K Nov 24 '19 at 21:28
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    $\begingroup$ Basically this: Engine Fire > other problems from overweight landing. $\endgroup$ – Nelson Nov 25 '19 at 2:47
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    $\begingroup$ It should be noted that all the tires deflated upon landing $\endgroup$ – Machavity Nov 25 '19 at 14:46
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    $\begingroup$ @Machavity, all tires deflated, but most probably after landing. It is kind of expected result. The brakes heat up to white hot (900°C is quite expected) and that starts to heat the tires and the air within expands. There are fuse plugs that will melt and release the pressure before it could cause explosive decompression. By that time the aircraft has turned off the runway (if possible), is surrounded by firefighters, and if there was still active fire on landing, it is already evacuated. $\endgroup$ – Jan Hudec Nov 25 '19 at 14:53
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    $\begingroup$ If you are landing overweight and single engine, you are almost gauranteed to blow tire fuses because a lot of airliners (I think the 777 included) land with half flaps when single engine so the Vref is considerably higher. More weight than normal, and more kinetic velocity to cope with as well. $\endgroup$ – John K Nov 26 '19 at 4:06

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