Crash of Jeju Air 737 at Muan International Airport, 29/12/2024

Yes, today we should be able to mandate a safe wireless backup safety system to make for the cables redundancy some military planes have used.
The question isn't so much would this be useful as a backup, but would it be secure against hacking by a state level actor? That should be the case with a physical cut-out, but only 'should', not 'will'. After the number of errors found in Boeing's analysis of the safety case for MCAS on the Max, I'm really not sure that's a 1x10^-9 bet.
 
The question isn't so much would this be useful as a backup, but would it be secure against hacking by a state level actor? That should be the case with a physical cut-out, but only 'should', not 'will'. After the number of errors found in Boeing's analysis of the safety case for MCAS on the Max, I'm really not sure that's a 1x10^-9 bet.
No, there's no "oni"/nine 9s bets left.
 
Jeju Air also significantly outpaced other LCCs, such as T'way Air, Jin Air and Air Busan, which recorded 315, 243 and 227 delays, respectively.

The rate of delays due to maintenance for Jeju Air stood at 1.01 percent, exceeding the overall industry average of 0.64 percent during the period.

For 2023, Jeju Air had 943 delays due to maintenance issues. The rate of maintenance-related delays for the year was at 0.97 percent, also higher than the industry average of 0.59 percent for the year.

[...]

The plane involved in the crash was found to have operated 13 flights in the 48 hours prior to the incident.


Hastened maintenance would bring such results potentially (you devoid less time to it but have more frequent occurrence of flight delays due to the increased severity of it).
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Their aircraft were spending 10% more time in the air each month than their rival low cost South Korean carriers, if that resulted in only 0.45% more delay incidences of which 0.38% more flights were delayed due to aircraft maintenance than the national average I am actually impressed considering the average age of their fleet is 15 years old with only a couple of the MAX that were ordered for a complete fleet replacement having been delivered (they also have a small batch of 2018 vintage 737-800's).
 
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Their aircraft were spending 10% more time in the air each month than their rival low cost South Korean carriers, if that resulted in only 0.45% more delay incidences of which 0.38% more flights were delayed due to aircraft maintenance than the national average I am actually impressed considering the average age of their fleet is 15 years old with only a couple of the MAX that were ordered for a complete fleet replacement having been delivered (they also have a small batch of 2018 vintage 737-800's).
Holy crap!!!

Yes, that's a heck of a lot of extra time in the air.
 
@Scott Kenny : seems they are holding back on the number of flights to catchup with maintenance.

 
Or it was just much less distance to get to the ground? Pilot aborted landing and instead of a full circle around the airport following traffic pattern went for an immediate 180 to land.

GA folks call that "the impossible turn" when you're talking about engine failure on takeoff, mostly because it's the only engine and you don't have enough speed/altitude/energy to safely do a 180 and line back up on the runway.

In this case, Pilot had one mostly-working engine but unknown levels of damage to flaps and gear (or hydraulics), so staying in the air wasn't impossible but you sure as hell do NOT want to spend any more time in the air than you have to.

I think I'd end up doing the same, opting for an immediate 180 instead of following traffic pattern.

This is where I think the opinion of a commercial pilot would be of interest.

I've has some training in accident response and doctrine for high consequence accidents though not directly involved in aviation, and one of the key things I've seen is a doctrine of deliberate response. A common theme in historic incidents is operators taking actions that were incorrect or sub-optimal believing that they were taking the right actions, and these actions actually making the casualty worse. Generally this is a result of perceived time criticality, when almost invariably a more delayed but better considered action would have been better.

To mitigate this, doctrine emphasizes controlled considered response with appropriate resource management. Immediate actions are still taken as needed, but once in and interim stable situation, operators should then pause for evaluation and planning follow on actions.

Applied to this case, I would expect them to have been trained to put the aircraft in a stable position (shut down failed engine, increase power to a slow climb rate, declare emergency, etc.) and then to execute a deliberate pause for evaluation and discussion before attempting landing. There is no reason to think they wouldn't have had sufficient fuel for a decent amount of flight time, and all evidence indicates the remaining engine and control systems were functioning correctly and there was no fire, injury or structural damage that would necessitate an immediate landing.

To me, once the situation was stable, remaining in the air was the safest option for the near term. Conversely, trying for an immediate landing has considerable risk. This assumes there's no known problem that would cause progressive loss of airworthiness - fire, hydraulic leak, 2nd engine damage, etc.

Looking at it from the pilot's perspective, they knew, or should have known they were landing in a really poor configuration, and that this was likely to result in something like what actually happened. The only way this seems justified is if they had reason to believe the aircraft was going to fall out of the sky if they didn't land right now, and it's difficult to reconcile that with the apparent aircraft condition and indication they should have had (i.e., controllable, one engine works, no apparent structural damage or evidence of fire).
 
Looking at it from the pilot's perspective, they knew, or should have known they were landing in a really poor configuration, and that this was likely to result in something like what actually happened. The only way this seems justified is if they had reason to believe the aircraft was going to fall out of the sky if they didn't land right now, and it's difficult to reconcile that with the apparent aircraft condition and indication they should have had (i.e., controllable, one engine works, no apparent structural damage or evidence of fire).

The CVR should shed light on that.
 
This is where I think the opinion of a commercial pilot would be of interest.

I've has some training in accident response and doctrine for high consequence accidents though not directly involved in aviation, and one of the key things I've seen is a doctrine of deliberate response. A common theme in historic incidents is operators taking actions that were incorrect or sub-optimal believing that they were taking the right actions, and these actions actually making the casualty worse. Generally this is a result of perceived time criticality, when almost invariably a more delayed but better considered action would have been better.

To mitigate this, doctrine emphasizes controlled considered response with appropriate resource management. Immediate actions are still taken as needed, but once in and interim stable situation, operators should then pause for evaluation and planning follow on actions.
Yes, been there done that on subs myself.

Stern planes stuck full dive at any speed? You have 8 seconds to have run through the Immediate Actions (trying the other hydraulic source, telling the Officer of the Deck alternatives have failed, OOD ordering all back emergency, and ordering an Emergency Blow of the forward ballast tanks before you go into an outside loop underwater. And in the midst of said outside loop, go way, way past test depth. Had several simulator runs where we breached design crush depth, and one time where the Chief of the Watch pulled the EMBT blow valves without orders saying "court-martial me on the surface, sir").

Once your immediate actions are done, you get to watch someone jockey ahead and astern bells to try to keep the ship at a reasonably level attitude as you float upwards and send A division aft to see what failed. Probably the packing at one end of the hydraulic ram that pushes the planes around, so there's also a good 20-50 gallons of hydraulic fluid atomized in the engine room for fun. Rig ship for fire!


Looking at it from the pilot's perspective, they knew, or should have known they were landing in a really poor configuration, and that this was likely to result in something like what actually happened. The only way this seems justified is if they had reason to believe the aircraft was going to fall out of the sky if they didn't land right now, and it's difficult to reconcile that with the apparent aircraft condition and indication they should have had (i.e., controllable, one engine works, no apparent structural damage or evidence of fire).
I've heard/read claims that in the event of a bird strike to the engines, you can get a lot of smoke in the cabin. Supposedly there's no damper between the engine and the air chillers for pressurization air?

That would suggest to the flight crew that they had a fire onboard, and might explain their hurry to get that plane on the ground.

But we need the CVR to confirm that.
 
The CVR should shed light on that.
I thought that but there’s a bit of a problem developing.


I was sure they were on DC essential bus. There was a proposal to put them on internal battery but I think that was pretty recent and not sure how it progressed.
 
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Yeah, IMO I think that the CVR and FDR units should have their own internal emergency batteries in case their external power-supply are interrupted.
 
I thought that but there’s a bit of a problem developing.


I was sure they were on DC emergency bus. There was a proposal to put them on internal battery but I think that was pretty recent and not sure how it progressed.
Dafuq? I could have sworn those had internal batteries, not just the ones powering the pingers.
 
They could have not have performed the teardrop maneuver required to circle back to the runway and still land with a high airspeed if they had no thrust for 4 minutes. This lends credence to the theory that in the heat of the moment the crew might have mistakenly shut off the wrong engine.
 
Dafuq? I could have sworn those had internal batteries, not just the ones powering the pingers.

Same! In fact, if it turns out their power supply is configured in a way which leads them to trip out in a situation such as this, you'd have thought the issue would've come up before. I mean, if this becomes the accident we'll come to remember as the one that exposed the problem, I'm a bit surprised it took until 2024 to happen. Seems like an obvious flaw to have a piece of emergency equipment depend on power that may go off-line as part of the emergency, so a kind of issue that you'd think would be preempted without needing a crash to draw attention to it...
 
It seems loss of CVR and FDR on the 737 is a known issue;-


They’re only powered by AC from either left or right engine or APU generators with a power transfer between systems (manually selected?) so not connected to the battery power DC essential inverter. I’ve seen comments that this changed in 2010 but the incident aircraft was delivered in 2009.

If it’s Boeing it may not tell you how it’s going.
 
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It seems loss of CVR and FDR on the 737 is a known issue;-


They’re only powered by AC from either left or right engine or APU generators with a power transfer between systems (manually selected?) so not connected to the battery power DC essential inverter. I’ve seen comments that this changed in 2010 but the incident aircraft was delivered in 2009.

I can see the FAA issuing a first priority urgent directive to all B737 operators and to Boeing to fix this design flaw in pre-2010 B737s.
 

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