27
$\begingroup$

Are pilots allowed to intentionally crash inside the simulator? It is good for stress relief and seems like a fun way to do something you would never do on an actual aeroplane, with little to no consequence.

If not, why not?

$\endgroup$
15
  • 12
    $\begingroup$ I've done it in the shuttle simulator, when I was testing out a fix for the sim crashing at too high of an altitude on contingency aborts. But I am not a real pilot. $\endgroup$ Jul 27 at 19:29
  • 17
    $\begingroup$ IIRC some C130 simulators in the UK in the late 1970s used a video camera to capture real-time images of a landscape model - seems rather primitive by today’s standards but there you go. If a pilot crashed into something it would cause damage to the camera and landscape, so it was frowned upon. $\endgroup$
    – Frog
    Jul 27 at 19:48
  • 4
    $\begingroup$ What type of simulator are you asking about - Advanced full flight/full motion simulators or lower end Flight training devices? $\endgroup$
    – 757toga
    Jul 27 at 19:59
  • 6
    $\begingroup$ Does this answer your question? Do Flight Simulation Instructors stop the simulator before a simulated crash? $\endgroup$
    – BtureP
    Jul 27 at 20:41
  • 14
    $\begingroup$ As a layperson I'd be concerned if pilots were being conditioned to crash a plane (even a fake one) to "blow off steam". $\endgroup$
    – Joe Sewell
    Jul 28 at 16:05
32
$\begingroup$

I've intentionally crashed Full Flight Simulators, to demonstrate to the instructors that in a modern day FFS, crashing is a non-event. Basically just a stop of the real-time equation computations, a bit of a crash sound, and freeze of the visuals. The instructor then selects a new initial position, the sim resets at this position after the normal time period, and the training continues.

During normal flight training when type rated pilots demonstrate their skills in handling emergencies to prevent a crash, this does not happen of course. Unintentional crashes can take place during the type rating courses, when pilots who just graduated on a propeller plane are getting used to the speed of control and decision making of a passenger jet.

Yes indeed, crashing an older type sim could have lengthy consequences if the computers needed to be re-booted upon a crash. Not anymore.

Note: I'm talking about modern simulators with electric motion and control loading. Any event that kicks a hydraulic system off-line needs fade-in time for the re-engage.

$\endgroup$
6
  • 15
    $\begingroup$ I would also like to state that even in 'very' modern simulators (I work on cutting edge fighter pilot systems), mission computers are re-hosted on PCs. they often don't like being reset. crashing often means a full reset which sometimes can take up to 15 (or more) mins. It happens every day. Sometimes on purpose. But this type of behaviour isn't limited to just "older type sims". Doesn't mean it 'needs' to be that way but it is that way still $\endgroup$
    – g19fanatic
    Jul 28 at 15:56
  • 1
    $\begingroup$ The ones I”m talking about had industrial PC host computers. A crash was handled in the software: detection of a sudden spike in flight path, upon which the flight dynamics computations were frozen, then re-initialised by the instructor. Never did the host need to reboot. $\endgroup$
    – Koyovis
    Jul 28 at 23:43
  • 6
    $\begingroup$ @Koyovis, the problem sometimes happens when the real firmware or complete sub-systems are used in the simulator. They are rarely designed to "understand" crash (or even "pause" for that matter), and might not continue correctly without a reset. $\endgroup$
    – Zeus
    Jul 29 at 2:28
  • 3
    $\begingroup$ I've heard of pilots taking an hour the last day of training practicing crazy engine-out takeoff scenarios where you're lucky to make it back to the runway. Sounds like a fun end of the day energy-management challenge where most people fail. $\endgroup$
    – Nate Lowry
    Jul 29 at 2:43
  • 4
    $\begingroup$ @NateLowry Yeah I did that in the 737NG simulator, crazy scenarios in a steep dive with the engines at idle, then start the pull-up at exactly the right moment for a neat touchdown. Part of a bet that I could get the plane on the ground faster, did so by touching down at the point where I took off, against the take-off direction, which is against standard practice of course. Can only be done in a sim. Exciting rides. $\endgroup$
    – Koyovis
    Jul 29 at 4:13
26
$\begingroup$

One reason to deliberately crash in a simulator is to reconstruct an accident.

This happens once in a while during an accident investigation, as it's less dangerous (obviously) than trying to reconstruct the conditions of the accident in a real aircraft (if possible at all, as the investigators of course can't control the weather outside of the simulator.

But that's not done for fun, to blow off steam, or some other "I feel like it" moment by a pilot.

$\endgroup$
5
  • 4
    $\begingroup$ It certainly might be useful and justified to find the conditions that led to a crash, but even then, I doubt that someone would deliberately crash it. It would be at most one more case of "this might have caused the crash". As far as crashing "for the hell of it", I'm sure that whoever is paying for your time on the simulator (i.e., your airline employer) would not be amused. I suspect that the licensing authorities would not look kindly on the mental stability of a pilot who appears to be possibly suicidal (see GermanWings crash). $\endgroup$
    – Phil Perry
    Jul 28 at 14:49
  • 3
    $\begingroup$ @PhilPerry deliberately recreating the exact conditions that caused a previous crash is IMO deliberately crashing. As the people doing it have good reason to do so their mental state won't be questioned if they do it in the context of investigating that previous crash. $\endgroup$
    – jwenting
    Jul 29 at 6:15
  • $\begingroup$ jwenting, my point is that investigating why a crash happened may well result in a crash (as in real life), but hopefully the tester can work their way out of it ("it might have been avoided if the pilot had done X"). That's NOT deliberately crashing. As for doing it deliberately, I would hope that the simulator operator would report to the authorities anyone who seems to be crashing for no real cause, as they are obviously mentally ill. Note that's different from pushing the envelope or practicing in unsafe conditions. $\endgroup$
    – Phil Perry
    Jul 29 at 14:37
  • 2
    $\begingroup$ @PhilPerry the investigators will run the scenario several times. First using the exact inputs they found the actual pilots used (if known) and then trying different things that might have prevented the accident. $\endgroup$
    – jwenting
    Jul 29 at 14:57
  • 1
    $\begingroup$ I think I read that during the final real airworthiness test flights of the 737-Max, post-fixes, the pilots attempted to recreate a situation similar to the fatal crashes. $\endgroup$ Jul 29 at 17:27
23
$\begingroup$

Advanced full flight/ full motion simulators are extremely expensive (can be in the Millions $$) and are very expensive to operate. In an Air Carrier ( or similar) training and testing environment these Sims can be scheduled 20 hours (or more) a day. Usually training and testing procedures/profiles are so packed with maneuvers there is little time for random activities outside of the mandatory syllabus or testing requirements.

Often, when one of these simulators crashes in the course of training or checking (which in my experience is not common) it goes "off motion" abruptly causing some stress to the hydraulic components and requires a reboot of its systems that utilizes valuable time.

Likely people have crashed these types of simulators on purpose, but for the reasons I note above, I doubt it is done very often.

$\endgroup$
13
  • 5
    $\begingroup$ Good answer. A couple nights ago I had a hard landing on a no-flap approach and it dumped the motion. It's tough on the machinery... crashing wouldn't be something you would do for fun, although I have flown under bridges in military simulators, so you can have some fun occasionally. $\endgroup$ Jul 28 at 5:06
  • 14
    $\begingroup$ If such machinery is so expensive, then why didn't they install any failsafe to protect the machinery from damage, in such cases. Why should it stop "abruptly"? It could be designed to limit acceleration and deceleration to safe values. $\endgroup$
    – vsz
    Jul 28 at 9:49
  • 5
    $\begingroup$ @vsz The few seconds before a crash are extremely important. There could still be a way to save the plane and passengers, so the simulation should be as faithful as possible. When would you begin to limit acceleration and deceleration? $\endgroup$ Jul 28 at 10:06
  • 11
    $\begingroup$ @Tim they could also choose to simulate the crash without any physics: the screens could go dark and the simulator could continue simulating perfectly straight and level flight (or whatever the last attitude was) through the ground, until it's turned off or reset. If it can simulate straight and level flight above the ground without damage, it can also simulate it below the ground without damage, since the ground level is just a computer fiction. $\endgroup$
    – user253751
    Jul 28 at 10:46
  • 4
    $\begingroup$ @EricDuminil: At all times, the simulator could determine--given the present state of hydraulic valves and the positions and velocities of all parts of the real-world system, some combinations of motion actions would be able to safely bring the mechanics to a stop without hitting any mechanical limits if the mechanical action requested by the physics simulation were performed. If no such sequence would exists, check the list of "escape action sequences" that exist from the current state and perform the first action of one of them (preferably the one that would best match the physics). $\endgroup$
    – supercat
    Jul 28 at 17:30
5
$\begingroup$

For a specific example where multiple tests were done in a simulator that resulted in "crashes", see the Miracle on the Hudson:

From Wikipedia (which has references to NTSB and other reports), emphasis added:

The NTSB used flight simulators to test the possibility that the flight could have returned safely to LaGuardia or diverted to Teterboro; only seven of the thirteen simulated returns to La Guardia succeeded, and only one of the two to Teterboro. Furthermore, the NTSB report called these simulations unrealistic: "The immediate turn made by the pilots during the simulations did not reflect or account for real-world considerations, such as the time delay required to recognize the bird strike and decide on a course of action." A further simulation, in which a 35-second delay was inserted to allow for those, crashed.

See also United 232.

$\endgroup$
5
  • 1
    $\begingroup$ But they didn't "intentionally crash" in the simulators, did they? $\endgroup$
    – Bianfable
    Jul 28 at 19:48
  • 4
    $\begingroup$ Not truly "intentionally crash". But my impression is that they went into the simulation knowing there was a high probability of crashing. Not exactly what the question asked, but similar to jwenting's answer, with specifics. $\endgroup$ Jul 28 at 19:55
  • 5
    $\begingroup$ Welcome to Av.SE. That's a good example of a case when the pilots were entirely willing to "crash the simulator" for an entirely valid reason. I agree that it's a good answer to the question. $\endgroup$
    – Ralph J
    Jul 28 at 21:18
  • 2
    $\begingroup$ Crashed, in this case meaning: did not make the runway. $\endgroup$
    – Koyovis
    Jul 28 at 23:52
  • 3
    $\begingroup$ @Koyovis In the case of the Hudson, the real pilots did not make the runway, but they didn't crash, they performed a controlled ditching. But the simulations mostly resulted in (simulated) crashes. $\endgroup$ Jul 28 at 23:53
5
$\begingroup$

I work in a company that builds simulators. Our customers have a lot of expectations, so we work hard to make the simulation adequate. The precision of the simulation of a crash is not, by far, what is most expected from our simulators. So we do not waste our time making it somewhat realistic. Moreover, to check that a simulation is realistic, it is compared to real aircraft behaviour. We do not find easily data for crashes to compare with, hopefully. So, for our sims, this non-realistic feature is just here to inform that the aircraft can't fly anymore and that the lesson should be resumed.

$\endgroup$
4
  • 1
    $\begingroup$ I agree that professional flight simulators don't focus on "post-crash" simulation like fancy explosions and other animations that might be considered as "fun", but on "pre-crash" simulation (events that lead to a crash). Maybe those simulators even abort before the pane (or parts of it) hit the ground. Also I think it's a very hard part to simulate equipment failures is great detail. Maybe have a look at X-Plane: It may be some fun to do a "power slide" on the runway with an airliner, but it's most likely not realistic (as the tyres would be pulled off, I guess). $\endgroup$
    – U. Windl
    Jul 29 at 10:13
  • 1
    $\begingroup$ Why would a professional flight simulator (or the company that builds one) want to reproduce game like effects (ala xplane). That's not what those simulators are for. $\endgroup$
    – CGCampbell
    Jul 29 at 14:21
  • 2
    $\begingroup$ While most simulators don't try and specifically replicate crashes, I have seen both developers and customers decide they need to "just see what happens when the plane crashes". It is one of those things a lot of people will want to try. $\endgroup$
    – Dragonel
    Jul 29 at 18:23
  • 1
    $\begingroup$ Landed a sim of an aeroplane type I had not flown before a couple of months ago. My touchdown would have been too impactful on the landing gear, the sim conveyed this by freezing the visual and playing a crash sound. Then I could re-initiate to the glide slope to try again. The sim was built in 1993 - it had no problems with a hard landing crash, it only showed me that my landing skills need to be improved on this AC type. $\endgroup$
    – Koyovis
    Jul 30 at 7:05
3
$\begingroup$

Not aviation, but simulator related. In the 1960s the UK railways were transitioning from steam traction to electric and diesel. A lot of steam drivers needed retraining. They had to unlearn a lot of things to do with the 'feel' of the train in motion. A simulator was built, with a replica locomotive cab, with a movie screen in front. On this was projected a film of the route being trained. A mainframe computer was programmed to read the cab controls (speed and brake) to control the film speed, show appropriate readings on the dials in the cab (speed, brake air pressure, motor amps, etc) and also move the cab via hydraulic actuators in accordance with the calculated motions expected due to acceleration, deceleration, rounding curves, passing over switches, etc.

One driver, allegedly, braked too late at the end of a run in a terminal station with buffer stops, and the computer faithfully moved the cab in accordance with the deceleration, breaking the driver's nose against the windscreen.

$\endgroup$
3
  • $\begingroup$ It can't have moved the cab exactly in accordance with the acceleration and deceleration of a real locomotive - if it did then it would be a real locomotive. $\endgroup$
    – bdsl
    Jul 30 at 9:11
  • $\begingroup$ @bdsl of course it didn't mimic exactly to the extent of replicating a collision authentically. That would be pointless, and if it did, a trainee driver might seriously injured or killed. $\endgroup$ Jul 30 at 22:59
  • $\begingroup$ I wasn't so much thinking about not mimic to the extent of a collision - I was more just thinking not mimicking the acceleration to the extent of actually travelling from one end of the UK to the other. $\endgroup$
    – bdsl
    Jul 30 at 23:25

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.