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A Matter of Millimeters: The story of Qantas flight 32

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Re: A Matter of Millimeters: The story of Qantas flight 32

#41

Post by lovemenot »

nradov wrote: post #38
lovemenot wrote: post #37

Earlier quoted context omitted.

Also, let's not completely discount remote pilots

Let's completely discount remote pilots. There is no technology on the horizon which would solve the network latency or sensor fidelity problems that prevent remote piloting from being adequate for handling in-flight emergencies.

I don't claim to be knowledgeable. It's just a hypothetical question.

Surely, it depends on the nature of the emergency. As I understand it, in this Qantas example, the pilots did not need to fly the plane with real-time responses, just to make good decisions.

Let's not completely discount remote pilots, while recognising they are not a universal panacea.

Re: A Matter of Millimeters: The story of Qantas flight 32

#42

Post by sylens »

modernpacifist wrote: post #40

I don't know about others, but I can't help but smile when I read the detailed series of events in aviation postmortems. To be able to zero in on what turned out to be a single faulty part and then trace the entire provenance and environment that led to that defective part entering service speaks to the robustness of the industry. I say that sincerely since mistakes are going to happen and in my view robustness has l…

I think many of us are so used to working with software, with its constant need for adaptation and modification in order to meet an ever growing list of integration requirements, that we forget the benefits of working with a finalized spec with known constants like melting points, air pressure, and gravity.

Re: A Matter of Millimeters: The story of Qantas flight 32

#43

Post by mkl »

lovemenot wrote: post #41
nradov wrote: post #38

Earlier quoted context omitted.

Let's completely discount remote pilots. There is no technology on the horizon which would solve the network latency or sensor fidelity problems that prevent remote piloting from being adequate for handling in-flight emergencies.

I don't claim to be knowledgeable. It's just a hypothetical question. Surely, it depends on the nature of the emergency. As I understand it, in this Qantas example, the pilots did not need to fly the plane with real-time responses, just to make good decisions. Let's not completely discount remote pilots, while recognising they are not a universal panacea.

They needed to make a lot of real-time responses when coming in to land, as they had a very narrow window of viable speeds and limited control.

Re: A Matter of Millimeters: The story of Qantas flight 32

#44

Post by grecy »

aunty_helen wrote: post #35

My first job was working at a mro that overhauled engines a bit smaller than the Trent 900s but same principles apply. I built qa software to digitize the forms and signature process like what’s mentioned in the article as having not correctly been signed off on. I ate lunch with repair engineers that had dark wells of knowledge about the engines they worked on. They could talk so deep on a subject that lunch break w…

> As for Qantas, near the end it mentions the plane was repaired at great cost

Indeed. Qantas has been ranked the safest airline int he world almost every year since forever [1]

I clearly remember when QF32 happened and everyone was utterly shocked. That simply DOES NOT happen to Qantas.

[1] https://www.forbes.com/sites/laurabegleybloom/2023/01/03/ran...

Re: A Matter of Millimeters: The story of Qantas flight 32

#45

Post by stevepeg »

XorNot wrote: post #21

The one thing which sticks out to me is the ECAM system including a baked corrective message of "open fuel transfer valves" due to the imbalance. That seems like an odd message to include in an emergency action system, which by definition is only active in unexpected situations. Is there really no system to confirm if a fuel leak is happening?

A320/330/340/350 driver here (can't get away from Airbus apparently).

Nope, there is no system to confirm a leak apart from a camera around the tail if you're lucky enough to have one, my previous airline had a flight where an engine leak was detected this way. Think about it, how would you design such a system? So this falls on the crew.

The procedure to determine if you have a leak is pretty much the same across types: add the fuel on board (FOB) to the fuel used (FU) and make sure that the number you get is the same as what you started the flight with. If it's less by some margin then you probably have a leak. You can confirm further by looking at tank quantities (but they take time to reduce depending on the size of the hole). If you get an engine or pylon leak then you might also see increased fuel flow on that engine. If the leak is elsewhere in the system then you might notice a smell. If you can't work it out then the procedure (at least on Airbus types) usually involves turning an engine off to see if the leak stops (yep, really).

As for the ECAM "open fuel transfer valves" message, I don't know for sure on the 380 but all the other Airbus types I've flown have something like:

.IF NO FUEL LEAK

FUEL IMBALANCE....MONITOR

So it doesn't really instruct you to open the transfer valves but leads you into the fuel imbalance procedure if you think you need it. The very first line of the fuel imbalance procedure says something like "Don't apply this procedure if fuel leak is suspected".

Re: A Matter of Millimeters: The story of Qantas flight 32

#46

Post by lovemenot »

mkl wrote: post #43
lovemenot wrote: post #41

Earlier quoted context omitted.

I don't claim to be knowledgeable. It's just a hypothetical question. Surely, it depends on the nature of the emergency. As I understand it, in this Qantas example, the pilots did not need to fly the plane with real-time responses, just to make good decisions. Let's not completely discount remote pilots, while recognising they are not a universal panacea.

They needed to make a lot of real-time responses when coming in to land, as they had a very narrow window of viable speeds and limited control.

That seems to be correct.

A partial mitigation of these issues could be high bandwidth / low latency networks just in take-off / landing corridors?

Re: A Matter of Millimeters: The story of Qantas flight 32

#47

Post by foobazgt »

lovemenot wrote: post #41
nradov wrote: post #38

Earlier quoted context omitted.

Let's completely discount remote pilots. There is no technology on the horizon which would solve the network latency or sensor fidelity problems that prevent remote piloting from being adequate for handling in-flight emergencies.

I don't claim to be knowledgeable. It's just a hypothetical question. Surely, it depends on the nature of the emergency. As I understand it, in this Qantas example, the pilots did not need to fly the plane with real-time responses, just to make good decisions. Let's not completely discount remote pilots, while recognising they are not a universal panacea.

There are probably hundreds of ways a plane could fail that would require constant low latency supervision by a pilot. For example, in this specific circumstance, the pilots had to manually maintain speed within a narrow range of 3-4 knots with a bunch of blown control surfaces.

Let's do completely discount remote pilots, please.

Re: A Matter of Millimeters: The story of Qantas flight 32

#48

Post by wkipling »

RetroTechie wrote: post #22
Cyberdog wrote: post #6

Reading articles and seeing videos about airline disasters tends to increase my faith in flying rather than making me more afraid of it. Terrorism or sabotage aside, so many failures have to compound to put a modern airliner in a truly irrecoverable state that it's effectively impossible to happen and not worth my time to even worry about. What times we live in that we can hurtle ourselves across oceans at hundreds o…

That assumes the environment the aircraft flies in, behaves predictable. Sometimes it does not. Turbulence is an obvious one. Downdrafts another. You can have a perfectly functional aircraft, but if the whole air column it's in goes down faster than the aircraft can climb, the aircraft will go down with the air column no matter what. Reminds me of an Air Crash Investigation episode: some volcano had erupted, ash was…

Today we have VA monitoring satellites and aircraft aren't routed through VA.

Re: A Matter of Millimeters: The story of Qantas flight 32

#49

Post by abid786 »

sylens wrote: post #42
modernpacifist wrote: post #40

I don't know about others, but I can't help but smile when I read the detailed series of events in aviation postmortems. To be able to zero in on what turned out to be a single faulty part and then trace the entire provenance and environment that led to that defective part entering service speaks to the robustness of the industry. I say that sincerely since mistakes are going to happen and in my view robustness has l…

I think many of us are so used to working with software, with its constant need for adaptation and modification in order to meet an ever growing list of integration requirements, that we forget the benefits of working with a finalized spec with known constants like melting points, air pressure, and gravity.

Completely agree - I think it can go one of two ways. Software is more malleable than airplanes are and that also comes with downsides (like how much time and effort it takes to bring a new plane to the market)

Re: A Matter of Millimeters: The story of Qantas flight 32

#50

Post by RetroTechie »

Cyberdog wrote: post #28
RetroTechie wrote: post #22

Earlier quoted context omitted.

That assumes the environment the aircraft flies in, behaves predictable. Sometimes it does not. Turbulence is an obvious one. Downdrafts another. You can have a perfectly functional aircraft, but if the whole air column it's in goes down faster than the aircraft can climb, the aircraft will go down with the air column no matter what. Reminds me of an Air Crash Investigation episode: some volcano had erupted, ash was…

I'm not familiar with the volcano incident you referred to, but a bit of searching seems to indicate it was British Airways Flight 009 in 1982, where a 747-200 had all four engines fail due to volcanic ash… then glided safely out of the ash cloud and was able to restart three of the engines and land safely at a major airport. From a complete loss of power to all engines to on the ground with zero deaths, zero injurie…

Sounds like the one! Engine after engine going out. Without (at first) any obvious cause.

> From a complete loss of power to all engines to on the ground with zero deaths, zero injuries. That's exactly the kind of story I'm talking about that gives me such faith in flying!

Understood (and agreed). But you missed my point: fate of that flight didn't result from safety engineering. It depended entirely upon the ash-laden air it flew into, and its effect on the aircraft & its engines. No amount of systems redundancy could have made it a safe flight.

So yes: flying is very safe these days. But there are limits to what safety engineering can provide.

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