Originally Posted by JammedStab
I'm no sim expert but I believe the more unusual things like actual stalls and other things that the simulator were not certified for may not be very realistic at all. Especially in an old DC-8.
But we have to make do with what we have I suppose. Based on this reality combined with your post, there is not much that we should be doing in the sim.
While I continue to offer recommendations regarding simulator use, let me be perfectly clear … in today’s environment there is NO, absolutely NO, training that is better conducted than that accomplished through the proper use of simulation equipment under the supervision of a properly, completely, and competently trained instructor. The cautions I offer are to help ensure that the instructor/evaluator conducting the training (or administering the evaluation) knows if, what, and where the simulator being used may provide less than optimum cueing for use by the pilot being trained or checked. As some of the “older” heads would recognize, simulation has come a
very long way over the last 30+ years … to the extent that we now have several “levels” of simulation … where each level is designed to provide appropriately differing levels of simulation accuracy … and only the top levels authorize complete training and checking capabilities – e.g., Level D has essentially no training/checking restrictions (even though it is not perfect) – Level C provides the same capability, but only IF the applicant meets certain prerequisite requirements – and Level B provides for complete
recurrent training/checking, including the takeoffs and landings required for recurrent training or checking. In the US there are essentially 4 levels of full flight simulators (FFS at levels A, B, C and D) and 4 levels of flight training device (FTD at levels 6, 5, 4, and 3) … with a 5th level of FTD likely available with the next update of the regulation dealing with simulation equipment (Part 60) which will likely be a new Level 7 FTD. All of these devices are under the purview of the Air Transportation Division, while the General Aviation Division is currently responsible for the devices used in general aviation activities, called BATD (Basic Aviation Training Device) and AATD (Advanced Aviation Training Device) … although there are factions at work that would recommend the FAA “get its act together” and put all devices into a continuum of device levels such as advocated by ICAO, and eliminate the confusion that inevitably creeps into the mix without such standardized oversight. The various levels of FTD can be, and ARE, regularly used to provide excellent training – provided such training remains within the verified performance envelope of the specific device being used – AND is conducted under the direct supervision of a competently trained and validated instructor and/or evaluator – regardless of the level of simulation used - again, recognizing the existing authorizations and/or limitations for each specific device.
As I’ve mentioned in earlier posts, there is an international activity currently underway, sponsored by the UK’s Royal Aeronautical Society (RAeS) and the International Air Transportation Association (IATA) called the International Training and Qualification Initiative (ITQI) where the focus is aimed at establishing the minimum standards that should be applicable for the training and evaluation of Pilots, Instructors, and Evaluators – I think this is a very important activity and that it should be participated in by all who have an interest in seeing that such standards are developed and incorporated into the training and testing of airline crews anywhere and everywhere.
Other than the obvious reasons for having such internationally accepted standards, this would better ensure that any use of “older” simulation equipment (like that older DC-8 simulator) could be effectively used for teaching the kinds of things that had been taken for granted – Yes, I said effectively used. For example, while the particular simulator used by ABX for stall recovery training could still be used for that training, there would be a CONDITION applied (and this is a huge deal!!) that the instructor would be trained on the content and limitations of the simulator and on the best way to ensure that whatever is being taught or tested is thoroughly understood by the instructor or evaluator, including any and all simulation deficiencies and the best way to ensure that proper and effective training (or testing) can be accomplished in THAT simulator … requiring that the instructor be on his/her toes to ensure that the crew members being trained are carefully observed with respect to what the pilot flying is actually doing and correct any inappropriate action – on the spot – with an explanation of the reason for the correction. For example, if the pilot is attempting to maintain altitude through the use of nose-up elevator pressure while adding power to “fly out of the top of the stall (and I’ve always hated that particular reference) the instructor would correct those inappropriate actions and explain why it would be necessary to allow the nose to approach or go below the horizon WHILE full power is added – explaining that the higher the altitude this task is begun, the higher the gross weight of the simulated aircraft, and the slower the airspeed at the time of the initiation, the greater the probability will be for getting the nose closer to, or further below, that horizon, WHILE full power is added (and I mean full power, which, depending on the existing altitude, could mean “bend-the-throttles-over-the-forward-limits” – and then IF the pilot not flying (the pilot monitoring) notices the EGT climbing into the red, he might consider advising the pilot flying to “pull ‘em back a bit” … but just to keep the temperatures within bounds) to ensure the minimum amount of time to regain flying speed – AND the instructor must be able to explain, and effectively teach, that operation
within the mid-range of the stick-shaker is not necessarily something that
must be completely avoided – and CAN be used to better ensure the capability of the airplane to remain airborne and lessen the possibility of ground contact IF the potential for ground contact is more than remote… AND, in the event that ground contact cannot be avoided, at least that contact will be at the minimum rate of descent possible. The instructor should explain that in at least in some simulators (and was true in that old ABX-used DC-8 simulator) the “thrust” value could well be provided on the basis of simple throttle position instead of the computed value of fuel flow, fuel density, fuel temperature, airflow direction into the engine intake (usually skewed with nose pitched up, interrupting direct airflow down the axis of the engine), and similar issues. There are very few currently operating simulators that are equipped with programming that will provide a close approximation to what is likely to happen in a real airplane in a fully developed aerodynamic stall – although there IS currently underway, a focused international effort to determine how to best acquire, use, gather, formulate, extrapolate, program, test, etc., etc., methodologies that can provide the most realistic simulation of such an aerodynamic stall possible – AND, just for your information … that effort has been realizing quite a bit of success over the past year, or so – and I fully expect that to be an extremely valuable addition to simulator qualification requirements – once any “bugs” are ironed out.
Originally Posted by JammedStab
To be honest, I have flown 5 types with sims(and one other sim for a job interview) and not one flies like the real aircraft. Most had at least one characteristic that was appeared to be really off. Things such as extreme sensitivity in more than one type to strange visuals on V1 cuts to a really large pull force required to rotate.
In most cases, the majority of any “sensitivity” such as what you describe (and I’m assuming you are referring to the “sensitivity” of the simulated airplane’s response to your control inputs) is attributable to inaccuracies of the motion system. Of course, no FTD is required to have a motion system – and the first two levels of FFS require only a 3-axis motion system … it’s only the highest 2 levels of FFS that require a fully functional 6-axis motion system. But, it is absolutely necessary for that motion cueing (all of it) to be kept (as much as can be provided with the technology – the newer the better) within the appropriate values mandated for that specific simulator. Humans operate in a 3-dimensional world and are subject to external forces – most noticed when free to move both along AND around an axis in each of those three directions … that is 2 motions in each of 3 axes (along
AND around the longitudinal, the lateral, and the vertical axes), meaning 6 degrees of freedom – which is where the “6DOF” reference is derived. If you have a simulator with only 3 degrees of freedom – the motion cannot be recognized as “realistic,” and of course, with NO motion – the result is more than obvious – and tends to skew the pilot’s recognition of the effect of his/her control inputs. But input cueing is not limited to motion – there are also visual cues, sound cues, and control feedback cues – where visual cues include BOTH outside the cockpit (runways, airports, etc.) and inside the cockpit (instrument response times and magnitudes, just to name 2 of the very many) – sound cues from the engines (steady and changing), audible warnings and reminders, slip-stream noise, etc. – and control feed-back, sometimes referred to as control “feel” – the amount of effort you have to exert on the control wheel to make a turn or how much column force is necessary to rotate for takeoff, etc. The most misunderstood factor about these input cues – is that there are very few persons who are even aware of what they use for cueing stimuli on which they make their control application decisions – conscious AND subconscious decisions.
Originally Posted by JammedStab
Oh well, I did my first flight on the line with no touch and goes for the last type despite the reality the fact that what I was seeing, hearing and feeling in the aircraft were not exactly the same as the sim. So, I think I'll try pushing the TOGA switch next time under the proper circumstances in the sim and take my chances of the potential future consequences.
Ouch – if you operate under the US regulations, I certainly hope that your simulator training was done in either a Level D, or at least a Level C, simulator with your having had the appropriate prerequisite experience requirements. I know of a relatively new airline that had gone into business not terribly long ago with a desire to type rate ALL of their crew members – left seat and right seat. Fine with me … but when it came time to begin “line operating experience,” the airline was erroneously told they could begin doing so without any seat dependent training for the right seat guys in the right seat. That generated a set of serious issues that resulted in the airline’s certificate being moved to another district and there were some persons within and outside of the airline and the FAA who lost their jobs!
Originally Posted by JammedStab
While a little off topic but I do remember reading that DC-8 crash report many years ago that you have mentioned. Improper stall recovery is what I remember. I believe they were in a nose down attitude but still stalled. Pulling on the control column were they not? Not very conducive to a recovery. Good point on the misleading sim stuff they experienced but a stall recovery is fairly straight forward. I'm sure Douglas has written down procedures, just like Boeing does as earlier mentioned by me. Somebody didn't follow them it appears.
As is true in almost any/every accident … there were a lot of errors made … and I’m not trying to point out anything OTHER THAN it is apparent that these
very experienced pilots attempted to do what they were trained to do … and whether they realized it or not, I would argue that they were doing what they had seen done, had practiced doing and at each practice they had achieved the result they desired – but those times were in the simulator.
NTSB Accident Report ABX DC-8
The National Transportation Safety Board determines that the probable causes of this accident were:
•the inappropriate control inputs applied by the flying pilot during a stall recovery attempt;
•the failure of the nonflying pilot-in-command to recognize, address, and correct these inappropriate control inputs; and
•the failure of ABX to establish a formal functional evaluation flight program that included adequate program guidelines, requirements and pilot training for performance of these flights.
Contributing to the causes of the accident was the ABX DC-8 flight training simulator’s inadequate fidelity in reproducing the airplane’s stall characteristics.
If you were to review the Flight Data recordings of this accident (which are available, by the way) I believe you would see that the pitch attitude did, in fact, achieve a nose-down position on more than one occasion … but at each time as I recall there was an apparently deliberate attempt to either reduce the amount of nose-down or return to a nose-up. In fact, if memory serves, there was never a time when the control column pressure was toward a nose-down position (i.e., a nose down control column pressure) … in fact, again, if memory serves, there were times, well after the initiation of the stall buffet, where the control column back pressure was at or above 30 pounds of pull. I don’t remember the charted range of this parameter – but I remember the “nose-up” pressure being almost to the end of the charted range. And, as a correction … I think I had said they were at 17,000 feet and on further thought, I don’t think that is correct … it seems to me after considerable attempts to recall some of the specifics (but … you should know that there are times when I can’t tell you what I had for breakfast that morning!) I think the altitude was more in the range of 12 to 14 thousand feet – but I don’t recall if that was MSL or AGL – probably MSL … and I think that the report (at least the report available to the pubic) contains FDR information for only the last couple of minutes of the flight.