I feel like you folks would enjoy reading /u/Admiral_Cloudberg on reddit. About once a week on Saturdays, he posts a well researched and documented aircraft crash article.
Here is the reddit link to his OPs:
He also posts to Medium with the same content but a different format:
Admiral Cloudberg – Medium
I just want to say for the record, the shows I’m referring to like “Mayday/Air Crash Investigations”…don’t seem particularly sensationalized. It’s not “Top Ten Dumb Aircraft ground smashies” by Spike TV.
They’re respectful, the dialogue is straight from the blackboxes. Survivors, pilots actual people who worked on the investigations are involved. If anything, its “Forensic Files of the Airline Industry”
That said, I’m sure there are forensic experts who roll their eyes at Forensic Files. And rightfully so. And in no way am I trying to say anyone in this thread is ‘wrong to have an adverse opinion’ of these shows. Also FTR my faves are the ones which have happy endings, like the guy who was going to ditch in a NOLA canal, and instead effected a perfect landing on grass strip beside the canal.
Thanks, good reading. What about this instance from four years ago - an EVA Air Boeing 777 almost smashed into a mountain near LAX, due to ATC miscommunication - would this have been something AutoGCAS could have solved, or would this be EGPWS’ job to solve? (Since it involves a mountain and not flying downwards, it would be EGPWS?)
Also, could Auto-GCAS have prevented something like the SilkAir185 or EgyptAir crashes where the suicidal pilot deliberately sent the plane downwards (unless AutoGCAS can be disabled manually?)
“Make the seats face back. Crash loads are easier to take on your back than facing forward.”
The problem with rear facing seats is that in a sudden deceleration passengers are more likely to be hit by loose objects flying around the cabin, with forward facing seats the seat back protects them
That was a communication problem. Whether the jet had EGPWS, Auto-GCAS, or anything else, wouldn’t solve the basic issue that there was a breakdown between what the controller wanted them to do and what they thought they were being asked to do.
Right. There’s no point trying to solve safety issues way downstream at the final point of failure. If, instead, you look upstream, you will find a relatively small number of common failures that lead to the multiple end results.
Human failures, machine failures (traceable back to human failures if you wish to dig deep enough), and human/machine interface failures are the big problems facing the industry. Unfortunately it is difficult to improve one area without making another area worse. Obvious example is that increased use of automation has improved safety a tremendous amount but it has also had a detrimental effect on the manual flying skills of the human pilots. The machine makes the whole operation safer and if the machine fails the human can normally fix things without it ever making the headlines, but if the machine fails and the human fails the results are spectacular in their badness.
Also the increase in ability of the machine means that the corresponding decrease in ability of the human is masked and may never be made fully apparent until the human is required to do something they simply don’t have the skills to do.
Back in the 1960s and earlier, pilots were mostly very good because they had to be. Now the machine is so much better but the pilots have a different skill set and may fail at tasks that the pilots of the past would do every day.
If I could do something to improve safety it would be to somehow meld the raw flying and navigating skills of the mid 1900s pilots with the technology of modern aircraft and the systems management skills of today’s pilots.
Rear facing seats, five point harnesses, helmets, there are lots of things that could be done to achieve incremental improvements in crash survivability, but, whether we wish to admit it or not, we have decided that the increased safety is not worth the inconvenience. If we wanted to be “fully safe” we wouldn’t leave our houses, but we do, because we don’t actually want to be “fully safe” we just want to feel “reasonably safe”. The line is apparently somewhere around wearing helmets on motorbikes and bicycles. A significant proportion of people would rather have the freedom of letting their hair blow in the wind rather than wearing a helmet, fair enough I guess.
Personally I look at a guy or gal on a motorbike with shirts and a T-shirt and think they are idiots. Meanwhile I’m quite happy to do 70 kph on a bicycle down a winding road with blind corners wearing the thinnest layer of Lycra between my skin and fresh air because wearing leathers would be hot and uncomfortable, go figure! Perceived safety is complicated.
I’m by no means an expert in the field, I just find accident reports interesting. I’ve noticed in the last year or two several good examples of the above - where the pilots have entered incorrect information into the flight computer, resulting in not enough thrust being applied for take-off. So far (in the UK at least) this has resulted in nothing worse than planes brushing the lights at the end of the runway with their landing gear as they fail to reach an adequate altitude quickly enough. But it is slightly scary to think such a thing can happen in this day and age - in fact, it is precisely this day and age (of automation) that is behind such incidents.
Regarding the above, I wonder if the professional pilots here could explain why automated take-off, as a whole, is a good idea? I can see how automated landing can make things a lot easier in terms of the computer getting the plane lined up with the runway, but for take-off, why not just have the pilots in full manual control?
PIlots DO have full manual control during takeoff. You missed a nuance.
As part of the departure planning process, we compute a power setting for the engines. Then during takeoff we set the throttles to produce that much power. We don’t (generally) “just floor it” and take off with maximum possible power. Why we do that is a separate post.
About 12 factors go into the computation of the correct thrust setting for the current situation.
When I was a newbie, we manually looked that data up in a very complicated set of tables, wrote it on a piece of paper, then another pilot manually turned a knob to set pointers on the engine gauges to the desired value. Then at takeoff we manually pushed/pulled the throttles until the engine gauges’ needles settled down aligned with their pointers. In fact that was flight engineer work; the pilots didn’t set the initial power. There are lots of opportunities to screw that 100% manual process up.
What’s changed in 30 years is now a computer at HQ does the computations, the settings are downloaded to the airplane, and a computer puts the little marker (we call them “bugs”) on the vid screen depiction of engine gauges. And for takeoff we push/pull the throttles until the vid screen depiction of needles on those gauges aligns with the bugs.
No real difference.
Sometimes the download doesn’t happen and now we need to figure out the calcs just like before or else look them up on an HQ-generated piece of paper and instead of twiddling a knob to set the bugs to “1.85”, we keystroke “1.85” into a computer.
Again no real difference.
One small difference has crept in. Above I said that
Then at takeoff we manually pushed/pulled the throttles until the engine gauges’ needles settled down aligned with their pointers.
Nowadays on most aircraft we push the power up about halfway, wait for the engines to catch up, then push a button and an automated system (“autothrottle”) adjusts the engines up to the preset correct thrust setting then disconnects itself. All the takeoff calcs assume full thrust level is achieved real early in the takeoff roll. In fact the original setting are only valid at fairly low speeds. Autothrottle can do that work quicker and more accurately than the pilots can. More precisely, the flight engineer’s knob push/pulling to align needles with bugs has been replaced by the autothrottles knob push/pulling to align needles with bugs.
Autothrottle is exactly as prone to GIGO errors as a human would be. Once the bugs are wrong due to an upstream error, the takeoff will be wrong.
I mentioned that the autothrottle disconnects as soon as the power is set correctly. Why? So it can’t malfunction later in the takeoff roll, liftoff, or early stages of the climb and stupidly retard the power. Pilots are 100% running the throttles after that disconnect.
There;s more on the topic of automated takeoffs, but I have to leave for an appointment and this is long enough.
This. Exactly this.
If the industry could fix this, the perplexing modern sort of confused / startled / bad piloting crashes would all but disappear just as the old-fashioned aircraft failures and poor weather or nav crashes have largely already been banished to the history books.
You were right, I did enjoy that - thank you very much.
I didn’t see this point addressed. IANAP but my understanding is that planes can fly without all four engines running. I don’t know how often all four engines fail, but it’s not common enough to justify the costs of an extra engine. Airlines have been known to remove fuselage paint to save fuel.
I have heard of one highly publicized case of this where volcanic ash was fouling the engines and they all stalled (engine stall, not flight stall). In such a case a fifth engine would stall too. (They were able to restart the engines when they descended below the ash layer but at the time they did not know what was causing it. Meantime they were gliding–planes don’t suddenly drop with no engines.)
Thanks for yet another clear and insightful post. You are right, I had missed that nuance, though as you go on to say, it still amounts to similar problems with similar outcomes. I guess the thrust (heh) of my question really was - say the wrong inputs are given, through whatever system - shouldn’t the pilots recognise, halfway down the runway, that they aren’t accelerating nearly fast enough to reach V2 (apologies if that’s the wrong term) comfortably before the end of the runway and at that point push the throttle levers to maximum manually? Or is that just not a realistic expectation (unless perhaps the pilot is very familiar with both aircraft and airport, which it probably isn’t practical to always be the case)?
The EVA Air event is exactly in the wheelhouse of both EGPWS & auto-GCAS. Simplifying mightily …
As they were mistakenly flying towards the mountains their nav screens would have been horrifying to anyone paying attention. Eventually the crew responded to the EGPWS warnings as designed and maneuvered to avoid the terrain.
Auto-GCAS would have done mostly the same thing with different specifics as to timing & track taken. With the potential advantage that it would have worked even if the pilots had been complacent, distracted, or stuck in the rut of “always follow ATC instructions unquestioningly no matter what.” Which last issue relates to the cultural problems I’ve written about in other threads.
Assuming EVA Air was IMC then had EGPWS not been installed the first warning the crew would have had would have been old fashioned basic GPWS. Which isn’t intended to protect from intersecting mountains and would almost certainly have been far too little warning far too late to prevent terrain impact.
On airplanes with pilots’ controls connected directly to the hydraulics with only limited computerised tweaks available, there’s not a practical way to cut out the pilot’s inputs. It would require very deep-seated redesign of the aircraft to do that, as well as deep-seated redesign of the government standards for traditional non-FBW aircraft design. That’s a tall order.
The 737 MAX MCAS is an example of the sort of half-baked tweaks necessary to retrofit computerized control tweaking into fundamentally noncomputerized flight control systems.
In Boeing’s current product line the 737, 747, & 767 have this limitation while the 777 & 787 do not.
Beyond the FBW issue, remember the bad guy(s) can kill everybody lots of ways besides pointing the airplane at the ground. Turn off all the engines and auto-GCAS won’t save you. Turn off all the electrics and auto-GCAS won’t save you. Turn off all the pressurization and auto-GCAS won’t save you. Turn off all the hydraulics and auto-GCAS won’t save you. Run it out of fuel and auto-GCAS won’t save you. etc.
So it’s no cure-all. But it would probably sand off some remaining fraction of the healthy-airplane-hits-terrain mishaps.
To expand on this a bit, the main cost is probably not so much the purchase price and installation of the extra engine, but the redundant weight you are then carrying on every single flight. Also, where the hell are you going to put the fifth engine? As already stated, I believe any multi-engine plane is already more than capable of flying and landing safely with only one engine operating (maybe not taking off, but even the most reckless pilots don’t take off without an engine working - in fact even a catastrophic engine failure during takeoff is usually recoverable if you still have at least one other working engine). As for single engine planes, they tend to be made such that they already have little capacity for extra payload. And again you have the problem of where to put the spare.
That’s real insightful.
Now that the airplanes are so heavily instrumented and every flight is monitored after the fact for anomalies, the industry have data on how often these takeoff GIGO screw-ups occur. Or at least we have data on the ones that get real critical. The industry has found that it’s statistically pretty rare for the pilots to twig to the problem and go for max thrust. And if they do, it tends to be real late in the process after (almost) too much runway has been consumed. E.g. going full power 3 seconds before liftoff won’t materially alter the liftoff point. The same change 30 seconds earlier would be far more effective. But back then the shortfall just isn’t obvious enough.
The need to be suspicious of performance and go full power at the first inkling of “this ain’t right” has become a training emphasis item.
This emphasis change is due to lots of data from non-crashes. Which is how modern air safety makes improvements. We can now detect many, by no means all, close calls and react to reduce / eliminate their root causes and react by introducing mitigations into the response procedures when the glitch does occur. Which statistically, it will continue to do occasionally.
Some aircraft are starting to be delivered with a takeoff acceleration monitor system that would compute in real time acceleration rate vs distance remaining, etc., and sound an alarm for low acceleration. With the response being to either stop or to apply max thrust & continue depending on how early/late the warning occurred. That won’t stop GIGO but it will address the late-recognition problem.
Which in turn ties back to my echoing of @Richard_Pearse’s excellent post above. Namely that modern pilots face extreme situations so rarely that hair-trigger preparedness is increasingly hard to achieve. My Dad blew several engines on takeoff in his career. I’ve had zero (so far) in almost the same number of years and nowadays it’s about 1 in 50 pilots who ever has one quit anywhere in flight, much less on takeoff.
Thanks again, though I’m not entirely sure whether your opening line (“That’s real insightful”) is a compliment or heavily sarcastic - knowing you (insofar as one can know anyone via the sole medium of message board posts) it’s the former, but as a layperson I’m not offended if it’s the latter!
The other thing authorities and airlines do of course is try to improve the training and protocols to reduce the incidence of incorrect inputs in the first place. Recent ones I’ve read about included things like the manual not being easy to refer to, and even the difficulty of operating a tablet screen in rainy weather (I think that was some issue with a pushback tug rather than takeoff inputs, but same principle).
It was only in reading the Admiral Cloudberg article about the Russian Yak-42 crash (Last Flight of Lokomotiv: The crash of Yak-Service flight 9633 | by Admiral Cloudberg | Medium) that I learned pilots are only supposed to be certified on one type of aircraft at a time, so perhaps relative unfamiliarity with an aircraft’s handling characteristics shouldn’t be an excuse. But I can certainly see that you might not realise acceleration is inadequate until it’s too late to do much about it - I guess the variances I’m talking about are pretty minor, given that in most cases the aircraft does get airborne, it just uses more runway than it should have to do so. It’s not like people are trying to take off from Denver using figures calculated for La Guardia.
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Airspace complications is part of it. But the big issue at LGA & DCA is the airfield is simply too small. Each runway is too short is the biggee. Their layout is contrary to modern design practice is next. Significant compromises in routings in and out are made for noise abatement and other non-aviation concerns is the next.
A hefty chunk of the safety margin built into ops at e.g. ORD or MEM or DEN is squandered by these compromises. That leaves LGA & DCA “safe enough.” Until a couple more things go wrong and then it isn’t “safe enough” anymore & we bend some metal. Metal that wouldn’t have been bent in the exact same situation at a more spacious uncompromised airfield.
Just like 707s were safe enough in their heyday but aren’t now, LGA was safe enough in it’s heyday but IMO isn’t now.
Airplane manufacturers and airline operators and ATC have been continuously improving their game for decades. And newer airports reflect improvements in the airfield design game. But the old legacy airports just haven’t been able to get past “It’s too hard to expand and too popular to shut down and too hard to build a replacement elsewhere.” So there they sit, a turd in our collective safety punchbowl. Such is politics.
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I don’t know that I could explain the physiology behind it, but as someone who tends to get carsick if I am not sitting facing forward, just reading the idea of sitting backwards on a flight gave me a bit of nausea.
I try hard to avoid sarcasm; what I write usually means what the words say. You correctly found the nub of the problem. That’s insight. Good job!
Wow, I had no idea they were only 7K in length. Even at sea level, do density altitude issues mean you guys sometimes have to fly with less fuel, fewer pax/cargo, than you’d like, or both? Is it mainly an issue for 767/A330-sized aircraft? My own city’s second airport only has max runway lengths of 7600 feet, and I’d not read of issues with its size, but they mainly fly A319/737s types out of it.
Given the congestion of the NYC and DC areas, I can see why there’s pressure to ‘make do’, rather than spend the truly epic amounts it would take to put another Dulles or JFK sized airport into those areas.