Comment by maxbond
2 days ago
I just want to call out that, whatever the facts of this case, pilot heroism is way more common than pilot murder. This is off the top of my head, so don't quote me on the precise details, I'm probably misremembering some things. But a few of my favorite examples:
- British Airways 5390: An incorrect repair causes the windshield of a plane to be blown out mid flight. A pilot is nearly sucked out. The head flight attendant holds onto his legs to keep him in the plane. The copilot and flight attendant think he is dead, but they keep the situation under control and land the plane.
Everyone survives - including the pilot.
https://www.youtube.com/watch?v=rGwHWNFdOvg
- United 232: An engine explodes in the tail of an MD-10. Due to rotten luck and weaknesses in the design, it takes out all three of the redundant hydraulic systems, rendering the control surfaces inoperable.
There's a pilot onboard as a passenger who, it just so happens, has read about similar incidents in other aircraft and trained for this scenario on his own initiative. He joins the other pilots in the cockpit and they figure out how to use the engines to establish rudimentary control.
They crash just short of the runway. 112 people die, but 184 people survive.
https://www.youtube.com/watch?v=pT7CgWvD-x4
- Pinnacle 3701: Two pilots mess around with an empty plane. They take it up to it's operational ceiling. While they're goofing off, they don't realize they're losing momentum. They try to correct too late and cannot land safely.
In their last moments they decide to sacrifice any chance they have to survive by not deploying their landing gear. They choose to glide for the maximum distance to avoid hitting houses, rather than maximizing how much impact is absorbed. They do hit a house but no one else is killed.
> British Airways 5390: An incorrect repair causes the windshield of a plane to be blown out mid flight. A pilot is nearly sucked out.
This one is a good illustration of how better design can help prevent accidents or make them less severe.
The error the maintenance people made was that when they replaced the window and the 90 screws that hold it on 84 of the screws they used were were 0.66 mm smaller in diameter than they should have been.
The window on that model plane was fitted from the outside, so the job of the screws was to hold it there against the force of the pressure difference at altitude. The smaller screws were too weak to do that.
If instead the designers of the plane had used plug type windows which are fitted from the inside then the pressure difference at altitude works to hold the window in place. Even with no screws it would be fine at altitude. Instead the job of the screws would be to keep gravity from making the window fall in when the plane is not high enough for the pressure difference to keep it in place.
My vague memory of the Air Emergency episode on this (AKA Air Crash Investigation, Air Disasters, Mayday, and maybe others depending on what country and channel you are watching it on) is that after this accident many aircraft companies switched to mostly using plug windows on new designs.
Aviation is full of those design choices. Similar to how a multi-engine propeller plane will use oil pressure to keep the props in the flying angle, which means that when oil pressure is lost (catastrophic engine failure) it will feather giving the other engine the best chances of keeping the plane flying with the least amount of drag. While on a single-engine plane it's installed exactly opposite, in case of oil pressure loss the prop goes to fine pitch giving you the best hope of creating some trust in case the engine may still be working.
Most of these things were figured out over 100 years of carefully analysing accidents and near accidents to continuously improve safety.
> the pressure difference at altitude works to hold the window in place
Curious, is the pressure difference actually greater than the force of 800km/h wind pushing on the window? Or is it just for side windows?
Dynamic pressure of wind is 1/2 p v^2 where p is the air density and v is the velocity.
At sea level p = 1.225 kg/m^3. It goes down as altitude goes up. At sea level the dynamic pressure at 800 km/hr would be about 4.4 PSI.
At 20000 ft the air density is about half that of sea level, so around 2.2 PSI wind pressure. It would be around 1.4 PSI at 35k ft.
At cruising altitude planes are typically about 8 PSI above the outside pressure.
It would be maybe an interesting project for someone more ambitious then me to get a speed vs altitude profile of a typical airline flight and an altitude vs cabin pressure profile and figure at what part of a typical flight the screws on a plug window are resisting the most force.
The outward pressure is about 5-6x greater than the force of air resistance at cruising altitude
> plug windows
Surprisingly hard to search for this phrase
This article covers the topic though:
https://www.witpress.com/elibrary/wit-transactions-on-the-bu...
Here's another one:
Air Canada 143
- Pilot calculated incorrect fuel due to metric/imperial unit mixup, and ran out of fuel midair.
- Said pilot performed an impossible glider-sideslip maneuver to rapidly bleed airspeed just-in-time for an emergency landing at an abandoned airfield, having to completely rely on eyeballing the approach.
- No fatalties or serious injuries.
https://www.youtube.com/watch?v=jVvt7hP5a-0
It was a series of events and failures rather than simply “pilot calculated incorrect”. And it was a bit more nuanced than metric/imperial conversion.
Via wiki (but accident section is more detailed):
“ The accident was caused by a series of issues, starting with a failed fuel-quantity indicator sensor (FQIS). These had high failure rates in the 767, and the only available replacement was also nonfunctional. The problem was logged, but later, the maintenance crew misunderstood the problem and turned off the backup FQIS. This required the volume of fuel to be manually measured using a dripstick. The navigational computer required the fuel to be entered in kilograms; however, an incorrect conversion from volume to mass was applied, which led the pilots and ground crew to agree that it was carrying enough fuel for the remaining trip. ”
https://en.m.wikipedia.org/wiki/Gimli_Glider
It's not an impossible maneuver. Glider pilots do this all the time especially if they don't have spoilers
Also with additional control difficulty due to reduced hydraulic pressure.
> On the Boeing 767, the control surfaces are so large that the pilots cannot move them with muscle power alone. Instead, hydraulic systems are used to multiply the forces applied by the pilots. Since the engines supply power for the hydraulic systems, in the case of a complete power outage, the aircraft was designed with a ram air turbine that swings out from a compartment located beneath the bottom of the 767,[10] and drives a hydraulic pump to supply power to hydraulic systems.
> As the aircraft slowed on approach to landing, the reduced power generated by the ram air turbine rendered the aircraft increasingly difficult to control.[16]
> The forward slip disrupted airflow past the ram air turbine, which decreased the hydraulic power available; the pilots were surprised to find the aircraft slow to respond when straightening after the forward slip.
Yes. On a plane which is designed to be a good glider. I highly doubt a 767 is designed to be a glider. It's definitely not impossible (after all, it was done successfully!), but certainly a very difficult (and undocumented) one on such a plane.
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I would say it is much much harder. The wing configuration of an aircraft dictates the minimum glide speed. The more angled (for a better word) the wing, the higher the speed it needs to be at to be able to glide and not stall.
Mentour Pilot is a fantastic channel.
Anyone who does on-call should look into aviation disasters. Crew resource management, the aviate-navigate-communicate loop, it's all very applicable. ('WalterBright is an excellent source of commentary on applying lessons from the airline industry to software.)
But I did burn out on Mentour Pilot after a while, I just had my fill of tragedy.
A long time ago I had a colleague turn me on to Sidney Dekker’s “Drift Into Failure”, which in many ways covers system design taking into account the “human” element. You could think of it as the “realists” approach to system safety.
At the time we operated some industry specific, but national scale, critical systems and were discussing the balance of the crucial business importance of agility and rapid release cycles (in our industry) against system fragility and reliability.
Turns out (and I take no credit for the underlying architecture of this specific system, though I’ve been a strong advocate for this model of operating) if you design systems around humans who can rapidly identify and diagnose what has failed, and what the up stream and down stream impacts are, and you make these failures predictable in their scope and nature, and the recovery method simple, with a solid technical operations group you can limit the mean-time-to-resolution of incidents to <60s without having to invest significant development effort into software that provides automated system recovery.
The issue with both methods (human or technical recovery) is that both are dependent on maintaining an organizational culture that fosters a deep understanding of how the system fails, and what the various predictable upstream and downstream impacts are. The more you permit the culture to decay the more you increase the likelihood that an outage will go from benign and “normal” to absolutely catastrophic and potentially company ending.
In my experience companies who operate under this model eventually sacrifice the flexibility of rapid deployment for an environment where no failure is acceptable, largely because of an lack of appreciation for how much of the system’s design is dependent on an expectation of the fostering of the “appropriate” human element.
(Which leads to further discussion about absolutely critical systems like aviation or nuclear where you absolutely cannot accept catastrophic failure because it results in loss of life)
Extremely long story short, I completely agree. Aviation (more accurately aerospace) disasters, nuclear disasters, medical failures (typically emergency care or surgical), power generation, and the military (especially aircraft carrier flight decks) are all phenomenal areas to look for examples of how systems can be designed to account for where people may fail in the critical path.
Something I love about Mentour pilot is that he’s started doing videos on incidents where there was a near miss but no tragedy. Just as much to learn but without the ghoulish rubbernecking aspect.
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Also green dot aviation has some great videos. Excellent animations. A calmer style. Both are great.
Eh. His older videos are indeed phenomenal, but newer ones are "you won't believe what happened, right after this sponsor break"
In the particular case of his channel's subject matter, I actually kind of like the dramatic cliffhanger effect that (un)intentionally heightens the narrative's tension, since his video is telling a story. Compare to doing that for informational videos where there's no need for manufactured drama.
FUD. His videos are just as consistently good as they always have been. The sponsor sections can be easily skipped (hint: SponsorBlock).
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If you're focused on whether or not the pilot cares (or is even alive), you've lost the plot. The point is to keep passengers alive regardless of the pilot.
There's no real point to considering what happens if the pilot wants to murder people on board. Of course they will succeed....
The thing is, people always want something to be done. And politicians want to do something. No matter what kind of action it is, someone knifed a kid on the street, we must ban knives of a certain length. A pilot downs a plane while the other leaves the cockpit - we must mandate two pilots always present. Someone hides explosives in his shoe - we must X-ray all shoes of all passengers forever. Etc.
The human brain can't take the idea that yeah an exceedingly rare thing happened and we're not going to do anything, because rare things do happen sometimes. And the medicine can be worse than the disease. We just accept that yeah, despite best efforts, some pilots will be hostile for whatever mental reasons. Not saying that is what happened in this case, but just saying that IF that happened.
We need more tradeoff thinking, instead of do something! thinking.