Recreating real life air disasters

[Levkov 8]

The point of flight simulators is to teach pilots to handle situations that are not safe to be taught in a real plane. We can either teach ourselves and wach these situations on our computer monitors or we WILL see them anyway, but on CNN. As far as 9/11 is conserned, it has nothing to do with piloting skills, it was a criminal action aimed against random people and it is completely pointless to reproduce in flight simulators.

[davierosoft 13]

Runway conditions based on weather have been simulated for a while in a few high end payware fs9 & FSX addon's.

FSX manages incorrectly also the dry runway, this thing created a lot of problems to the pmdg team for the autobrake and brake temperature. You can see how wrong it is by making turns. This on dry runways, how wrong it will be on wet runways?

 

As far as 9/11 is conserned, it has nothing to do with piloting skills, it was a criminal action aimed against random people and it is completely pointless to reproduce in flight simulators.

If flight dynamics and structural stress could be correctly reproduced, a bit of pilot ability is required to strike on a target like a tower or like a few floor building, if all is done at overspeed, you can break the plane before the target, you can miss it and so on.

FSX is able only to stop the simulation for overstress.

[OmniAtlas 93]

Engine bird strike anyone? :)

 

I think there is an actual iOS app (x-plane) based on that situation.

[vololiberista 205]

Engine bird strike anyone? :)

 

I think there is an actual iOS app (x-plane) based on that situation.

 

Well there is the VC10 in FS9. It's coded in such a way that it is indeed possible and indeed has happened that either one or two engines can be affected immediately after take-off. ie. upon rotation. Therefore one has to apply the very specific airspeeds required dependent on flap settings and so on, in order to climb out, dump fuel and follow the flight manual's requirements and recommendations as regards to landing procedures. In effect your cockpit work load has just gone through the roof!

 

As mentioned earlier the model also caters for depressurisation. Either due to cockpit mismanagement or due to other unknowns. If you don't follow the checklist and/or forget to don your oxygen mask in the seconds available, then you experience a blackout until the air becomes more dense. When you re-awake you may find that your a/c is in an errect steep dive staring down onto mountain tops! Thereafter or assuming that you did indeed follow the correct procedure and made a Mayday call you have to request a new altitude to stay within FL100 and FL150 for the rest of the flight to your alternate bearing in mind that you only have oxygen for just over 4 hours in total.

 

99.9999% of the time pilots are there just to press the right button at the right time. But, when thing do go wrong they have to be on the ball. And, at least in these cases the sim pilot's ability is tested thoroughly.

vololiberista

[Paul_Smith 92]

You weren't here on 9/11...

No I wasn't, but I do remember exactly where I was, and it is not something I am ever likely to forget. I am not an American and have never even been to New York. However, I have four seperate and unrelated connections to the events of that day, three with positive outcomes. It is sometimes understated or even ignored, but I would like to point out for any who might have forgotten, that was not a day that America changed, that was a day the world changed!

[TheDanger 182]

that was not a day that America changed, that was a day the world changed!

 

For the worse! For reasons that some would have you believe but that may not be true.

[TheGoat 0]

I myself have recreated a couple of situations where in both cases the pilots made navigations errors and ended up lost, one hitting a mountain (AA 757 in sout america), and the other running out of fuel (732 Varig in the amazon). I just wanted to see if I made the exact same errors (with the same payload, fuel, etc), if I would end up at the exact same spots. Since I used the LVLD 763 (diferent aircraft), and the captain sim 732 (not realistic enough) the end result was scary close to the rw data. I never wanted to be disrespectful to the dead, and don't feel I was.

 

So, if I found a NG situation that the crew made a mistake, yes, I will recreate it.

[hopskip 253]

A few months ago I was reading into the Turkish Airways 737NG crash just short of EHAM Amsterdam, where one Radar Altimiter failed and kicked the Autoland mode into FLARE mode prematurely.

 

Tried it with the PMDG NG, and found that the radio altimeters fail differently in the NGX. Not sure, but this may be an update in the NG's (real one's) failure modes, or perhaps that the Turkish 737 failed in an unusual way so as to remove the failsafe the NGX displays.

 

In the real incident, the Radio Altimeter read -8ft during the approach(the same altitude as if the aircraft had all tyres on the ground). In the NGX, the Radio altimeter becomes flagged inop and removes itself from usage. If you fail both of the Radio Altimeters, then APP/autoland becomes unavailable.

 

So perhaps this is an updated configuration, and I wouldn't be surprised if the update was made specifically to address the failure that caused the incident near Amsterdam and retroactivley applied to the aircraft as an airworthyness directive or similar.

 

Alternitavley it could be that there were 2 failures, a failure of the Radio Altimiter, and a second failure of the thing that monitors for failures of the Radio Altimiter. Combined with the late reading of the approach and Landing Checklist, failure to monitor airspeed due to doing the Landing Checklist well after Glideslope Capture, and late application of thrust due to the crew being behind the aircraft... holes in the cheese.

 

IF the Radio Altimeter hadn't failed they would have been fine.

If the Radio Altimeter had failed, but gone into inop mode (as the NGX did when I tried it) then they would have been fine, and would have been notified of the inavailability of Autoland.

If both had failed, but they had completed all their checklists before reaching they may have noticed the speed decay.

Even if all that had happened and they'd just been that much quicker on the checklists they may have noticed the speed before the stall set in.

And even not changing any of the above, if theyd been directed to intercept glideslope from below instead of above, they may have noticed the power change at Glideslope intercept and become more aware of the reduced thrust, in comparison to what happened (where they were at idle thrust to decend and never left idle after pitching UP and REDUCING decent rate on glideslope capture.)

 

As it happened the throttles remained at idle thrust all the way down to 83kts.

 

A factor was a new pilot doing a line check to FO, possibly cockpit conversation delayed the Checklists. We do know from CVR that they started their approach checklist after glideslope capture, which was (as noted) from above glideslope (ATC factor) and quite possibly fast. (as we know from experience in the NGX, it can be a tough bird to slow down.)

 

THY1951 is the flight.

 

As noted above, my attempt at a recreation ended up with the NGX preventing the incident by triggering a failsafe in the Radio Altimeter. This caused Autoland to become unavailable, and the incident became a normal (manual control) landing, and at worst case would have been a go around. However if the failsafe didn't work out (as in the incident flight) and you had 3 people in the cockpit with all the CRM stuff that adds to the complexity of the incident, AND add to the fact that you are not expecting the failure because it's a standard line flight and not a sim checkride... The only way to save yourself from the incident is to think about the factors at play.

 

ie: Captains side Radio Altimeter acting odd. ... Should we use APP mode? What will this do to the Autothrottle? What does Radio Altimeter have to do with Autothrottle holding 142kts as commanded on the MCP in SPD or FLCH mode with APP mode selected as you decend onto a Glideslope?

 

Maybe we are just going to select APP mode till it is stabilized on the ILS/Glideslope on speed and then manually land anyway? Can you do that with a radio altimiter reading randomly wrong or different altitudes (left side/right side). What are the factors?

Can you fly the APP mode with the Autopilot on but Autothrottle off with this error? Will maintaining speed by holding/pushing the throttles up to maintain speed work? Even with FLARE mode becoming active at 1500ft? What will the Flight Director do in this configuration and will it's directions be reliable?

 

These are questions that can be looked at in a practacle - hands-on manner by 'recreating' the incident. Change one factor here and there, see how that effects the outcome.

 

Trent Hopkinson

[aerhead1 5]

I don't think real pilot training and fsx pilots are the same breed, and what real pilots may learn from running a sim of a past mistake shouldn't be something an armchair enthusiast should be concerned with. You may find recreating the crash interesting for some reason, but people lost their lives. Remember, "as real as it gets" is just a slogan. I think if you're too bored to be happy with getting the plane from one place to the other without crashing it, maybe the combat games are for you.

[hopskip 253]

If we're talking about 737NG's (which, considering us being in the PMDG 737NGX forum, we probably are) then why bring up 9/11, which, apart from having nothing to do with aircraft systems and CRM and pilot errors, also have nothing to do with 737's (767's and 757's are the incident aircraft in this case).

 

I can't see any further lessons from 9/11 for the Pilot perspective either other than the things we already know, and there's no simulator training that can be used to practice techniques to avoid future occurences. It's not like "When bla bla happens this might affect *other system* in *certain ways* therefore be careful when *doing certain actions* otherwise *symptom of error* may occur leading to *potential incident*". which is the kind of thing (good quality) Simulators are good at - showing the relationships between systems which may not appear related at first glance.

[hopskip 253]

I don't think real pilot training and fsx pilots are the same breed, and what real pilots may learn from running a sim of a past mistake shouldn't be something an armchair enthusiast should be concerned with. You may find recreating the crash interesting for some reason, but people lost their lives. Remember, "as real as it gets" is just a slogan. I think if you're too bored to be happy with getting the plane from one place to the other without crashing it, maybe the combat games are for you.

 

The PMDG 737NGX has lots of interesting failure modes where the failure of one system can effect other systems. The Turkish Airlines incident is one example where this may lead to a crash through the interesting failure of a Radio Altimeter causing an erroneous mode-change in the Autothrottle leading to a Stall on approach. It may also lead to further exploration of this failure. In the incident the failure changed the Flight director/FPA mode from GS/LOC to FLARE. Another interesting question is that in FLARE mode, would the Flight Director indicate correctly to follow the Glideslope? Would Autopilot AutoLand work ok if the pilots held the Throttle with their hands to maintain speed? Would it fly the flare attitude correctly even though it thought it was on the ground all the way from Glideslope intercept? Doubt it?

 

If we shouldn't be asking these questions, then why have the 737NGX with all these things simulated anyway? If the aircraft never fails or has system malfunctions, then surely emulating perfectly-functioning aircraft with systems that don't neciccarily interlink would be easier. Sure a failure of the Radio Altimeter won't cause the Autothrottle to reduce to idle thrust when the Autopilot/Flight Director is in APP mode, but then if the Radio Altimeter never fails... who's gonna notice?

 

Trent Hopkinson

[Guest dlrk]

Simulating failures and adverse events is part of the fun of flight simulation. And it's educational too!

 

I think it's fascinating that people are upset and concerned about the moral implications of simulating aviation accidents, yet think nothing of the mass killing of military games.

[Chock 17,769]

I think what you have to bear in mind, is that it is a hell of a lot different when something goes wrong in a real aeroplane as opposed to doing it sat in front of a PC with a nice cup of tea and a plate of biscuits. I can promise you that you react differently in real life. Two examples which happened to me personally illustrate that:

 

I once pushed forward a bit too much on the stick when on short finals at about 150 feet AGL, and of course got a bit of neg G, which felt exactly the same as when the aircraft drops away from you in a stall, and for about two seconds I damn near c****** myself, knowing that a stall at that altitude would probably be fatal. Of course it was not a stall and the aircraft simply continued down toward the runway, but those were the longest two seconds of my life, and just I sat there and did nothing while they passed by, although I did of course land the aircraft after that. This was before I'd done any aerobatics, and I didn't have many hours either, so I wasn't hugely familiar with neg G at the time, but I can still remember how pathetic my complete lack of an attempt to do anything other than sit there thinking 'oh sh**', when that occured. That was of course not going to cause a crash, or I would not be here to relate the tale, but the fact is that you just can't replicate that kind of reaction in a simulator - the fear isn't there.

 

I once took off and got a sympathetic vibration on the instrument panel, which was making a weird buzzing noise (probably just a loose screw on the panel), and on the climb out I was p***ing about trying to figure out what was causing the noise instead of concentrating on what I should have been doing. When I looked up, I was about fifteen knots away from the stall speed, in a climb, with the ASI dropping. That was a lesson learned - fly the goddam plane.

 

Both of the above happened when I was pretty new to flying, so they are to some extent understandable, but the fact is that there have undoubtedly been pilots who made mistakes no worse than those two who ended up not being so lucky. People are often astonished when they read that incidents such as that can be the cause of a crash, but it happened with Eastern Air Lines Flight 401, which was an L-1011 Tristar - the two pilots and the flight engineer were all messing about with a failed nose landing gear indicator light bulb, and whilst they did that, the aircraft flew into the Florida Everglades, killing over half the passengers on board, and seriously injuring the vast majority of those who survived. And the only thing wrong with the aircraft, was that light bulb, the landing gear was fine, and even if it had not been fine, it could have been cranked down manually. This is exactly the same kind of stupid thing I did when that panel was making a buzzing noise, the only difference is, I looked up at the ASI and noticed something was wrong in time to do something about it.

 

You simply can't replicate that kind of thing in a simulator, they are lessons which people either learn from by reading about, or lessons which you might be unlucky enough to make for yourself and then be lucky enough get away with. Turkish Airlines Flight 1951 - i.e. the B737 undershoot crash at Schiphol - was another example of three people on the flight deck being distracted and not watching what they should have been watching. Yes there were some systems out, but they should not have caused a crash.

 

Ultimately, I am glad that the incidents I related happened to me, as they have made me a better pilot, but I know that there will have been some pilots who have not been quite so lucky, and who probably did nothing worse than I did.

 

Al

[hopskip 253]

Turkish Airlines Flight 1951 - i.e. the B737 undershoot crash at Schiphol - was another example of three people on the flight deck being distracted and not watching what they should have been watching. Yes there were some systems out, but they should not have caused a crash.

 

While there were some systems out, it's interesting (to me at least) how systems affect other systems, ie the Radio Altimeter being out will cause a specific problem with the Autothrottle in the specific configuration of the Flight Director/MCP having APP mode selected.

 

It would not be a problem out of APP mode.

 

The question then is if we can use PMDG's 737NGX to explore what systems would be effected in this case.

 

While most of these situations in themselves are not neccicarily going to lead to a crash, in that specific example it did (pilots distracted and/or at the limits of their task workload, doing other things, 3 pilots all concentrating on 1 task and nobody noticing speed/altitude/out the window picture.)

 

In this case the "Crash" was caused by inattention or CRM problems, but the reason they let themselves into the situation is because they expected a different outcome. They expected an Autothrottle to maintain the speed they wanted, because that's what it normally does. They relied on a saftey net which had been taken away due to a failure of an apparently unrelated system. (Most of us think of the Radio Altimiter as the little voice that sais "fifty, fourty thirty twenty ten" at the end of a flight, and not neccicarily anything to do with the autothrottle maintaining speed.)

 

The little intricacies of system relationships is, to me, the most interesting thing about flight, and seeing how they might cause unexpected problems is quite rewarding, and while it's probably possible to study these relationships in other ways, having an "Air Crash" that happens due to a misunderstanding of these relationships or perhaps direction of attention to one task to the neglect of other tasks is a useful learning tool. "Learning from other people's mistakes" as such. And while some may argue "FSX simmers don't need to learn", the fact is that learning for it's own sake can be a pleasant experience.

 

 

you also bought up the L1011 incident. While the "All 3 pilots concentrating on the lightbulb instead of their altitude" is the biggest factor, the reversion of the Autopilot from Altitude hold to CWS is also a factor. We'v seen this CWS mode factor into other incidents too, the Aeroflot A310 where the captain put his young son in the captains seat. When the yoke was knocked, it too reverted to CWS mode.

 

CWS mode is something available to us in the 737NGX too, and I'v seen at least a couple of people posting on this very forum thinking it was a bug or error (usually related to LNAV or VNAV dropping out).

 

Trent Hopkinson

[vololiberista 205]

When I first started my flight training incipient spins were not on the menu. Real spin recovery however, was!! forget scary roller coaster rides. In order to pass that part of the flight test we had to recover within 10deg of the original heading! A real spin is really disorientating and requires instinctive reations. You loose thousands of feet in seconds.

 

The above post also raises a good point in that real simulators are used to test system failures. Trains of events and when or if the pilot is in or out of the loop what his reaction and input should be.

When the Qantas A380 had the engine disintegration they spent two hours just checking computer error messages. This is now a major problem with all modern a/c. The computer systems do not allow a pilot to fly by the seat of his pants.when it becomes necessary. The pilots instead are totally distracted by ambiguous warnings.

Look at the Helios accident. Instead of having a cabin height gauge they had instead "Master Caution". Assuming that they were compus mentus at the time they would have spent too much time going through the list of error messages to find the real cause by which time they would have lost conciousness from hypoxia anyway! Had they had a cabin height gauge it would have been part of their scan and would immediately have been noticed.

vololiberista