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Thread: Unstable approach and Pilot overload

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    Default Unstable approach and Pilot overload

    http://www.tsb.gc.ca/eng/rapports-re...2/a16a0032.asp

    3.0 Findings

    3.1 Findings as to causes and contributing factors


    1. The pilot's inability to effectively manage the aircraft's energy condition led to an unstable approach.
    2. The pilot "got behind" the aircraft by allowing events to control his actions, and cognitive biases led him to continue the unstable approach.
    3. A loss of control occurred when the pilot rapidly added full power at low airspeed while at low altitude, which caused a power-induced upset and resulted in the aircraft rolling sharply to the right and descending rapidly.
    4. It is likely that the pilot was not prepared for the resulting power-induced upset and, although he managed to level the wings, the aircraft was too low to recover before striking the ground.
    5. The pilot's high workload and reduced time available resulted in a task-saturated condition, which decreased his situational awareness and impaired his decision making.
    6. It is unlikely that the pilot's flight skills and procedures were sufficiently practised to ensure his proficiency as the pilot-in-command for single-pilot operation on the MU-2B for the conditions experienced during the occurrence flight.

    3.2 Findings as to risk


    1. If the weight of an aircraft exceeds the certified maximum take-off weight, there is a risk of aircraft performance being degraded, which may jeopardize the safety of the flight.
    2. If pilots engage in non-essential communication during critical phases of flight, there is an increased risk that they will be distracted, which reduces the time available to complete cockpit activities and increases their workload.
    3. If flight, cockpit, or image/video data recordings are not available to an investigation, the identification and communication of safety deficiencies to advance transportation safety may be precluded.
    4. If pilots do not recognize that changing circumstances require a new plan, then plan continuation bias may lead them to continue with their original plan even though it may not be safe to do so.
    5. If pilots do not apply stable-approach criteria, there is a risk that they will continue an unstable approach to a landing, which can lead to an approach-and-landing accident.
    6. If pilots are not prepared to conduct a go-around on every approach, they risk not responding appropriately to situations that require one.
    7. If a flight plan does not contain search-and-rescue supplementary information, and if that information is not transmitted or readily available, there is a risk that first responders will not have the information they need to respond adequately.

    3.3 Other findings


    1. Transport Canada does not monitor or track the number of days foreign-registered aircraft are in Canada during a given 12-month period.
    2. Turbulence and icing were not considered factors in this occurrence.
    3. Transport Canada considers that the discretionary installation of an angle-of-attack system on normal-category, type-certificated, Canadian-registered aircraft is a major modification that requires a supplemental type certificate approval.
    4. Although the aircraft was not in compliance with Airworthiness Directive 2006-17-05 at the time of the occurrence, there was no indication that it was operating outside of the directive's specifications.
    5. Although not required by regulation, the installation and use of a lightweight flight recording system during the occurrence flight, as well as the successful retrieval of its data during the investigation, permitted a greater understanding of this accident.

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    Senior Member Gabriel's Avatar
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    If the weight of an aircraft exceeds the certified maximum take-off weight, there is a risk of aircraft performance being degraded,
    Does that mean that there is a chance that the performance may NOT be degraded with the weight of an aircraft exceeding the certified maximum take-off weight????

    Take an airplane, load it beyond the MTOW, make it take-off in the same minimum distance, climb at the same max climb rate, and stall at the same 1G stall speed than the same airplane in the same conditions except that with a weight below the MTOW, and there may be a Nobel prize waiting for you for debunking the laws of Physics as we know them today.

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    Senior Member Evan's Avatar
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    Quote Originally Posted by Gabriel View Post
    Does that mean that there is a chance that the performance may NOT be degraded with the weight of an aircraft exceeding the certified maximum take-off weight????

    Take an airplane, load it beyond the MTOW, make it take-off in the same minimum distance, climb at the same max climb rate, and stall at the same 1G stall speed than the same airplane in the same conditions except that with a weight below the MTOW, and there may be a Nobel prize waiting for you for debunking the laws of Physics as we know them today.
    There's a lot of non-commital language going on there.

    If pilots do not recognize that changing circumstances require a new plan, then plan continuation bias may lead them to continue with their original plan even though it may not be safe to do so.
    Does that mean that plan continuation bias might lead them to go around?

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    Senior Member Evan's Avatar
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    BTW: do you see any way that that a recovery was possible here?

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    Quote Originally Posted by Evan View Post
    BTW: do you see any way that that a recovery was possible here?
    From the point of upset from the throttle?

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    Senior Member 3WE's Avatar
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    So much talk...

    Two guys got behind and distracted-at the worst possible time- when you you need to be closely monitoring airspeed.

    For all of the safety warnings we have, I continue to wonder if speed/stall warnings need bigger buffers?

    Easy to pontificate that Colgan and Hui Theiu Lo and this guy totally sucked...then again...you never know when a momentary attention lapse might happen to any one, and seems like one could be automatically warned before they got 30 knots slow.

    As to recovery, Mitsubishis are supposed to be a bit less forgiving than Cessna 150s...or so I’ve read.
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    Senior Member Evan's Avatar
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    The issue here isn't just getting behind and neglecting airspeed. A smooth application of power would have taken care of that. The fatal move was advancing the throttles to full power so abruptly, which, in turn, exposes the real core issue, low hours and poor understanding of the aircraft itself. This pilot-in-command had 150 hours on a high-performance turboprop.

    Yes, Schwartz, from the moment the throttles were firewalled, which caused the upset. From that point on (allowing a second or two for reaction time), I'm not sure anything could have been done to save them. Pulling back the throttles along with leveling the wings maybe, but with less than 500ft to regain lift and arrest descent, I don't think so. At best perhaps a less violent crash.

    The MU-2B lacks ailerons (to allow for full-wing flaps) and uses wing spoilers instead. These are supposed to remain more effective than ailerons in a stall recovery, which probably explains why the pilot was able to roll back towards level while probably being stalled. But the pitfall here is that roll authority = airspeed - torque (not a real formula Gabe), meaning that as airspeed decays to a critical level, the control surfaces have diminished authority to counter full-power torque and p-factor issues (pitching up as well). This may not have been as much of an issue on the piston twins this pilot was more familiar with. Adding full power on a t-prop like this at very low airspeed and altitude was a fatal move.

    Yes, it comes down to airmanship and never getting into a low-energy situation, but as you say 3WE, this is bound to happen from time to time and therefore it is essential that a revenue pilot, especially PIC, knows (and has a practiced proficiency on) the correct recovery procedures for the type he is flying. What to do and what never to do.

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    Senior Member 3WE's Avatar
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    Quote Originally Posted by Evan View Post
    ...The fatal move was advancing the throttles to full power so abruptly, which, in turn, exposes the real core issue...
    While there is truth in your statement, it’s 70% wrong and we can argue in circles all day long.

    Two guys are flying sloppy to the point of no airspeed and no altitude and oh shit, AND THEN you want them to be keyboard-smart Evan and surgeon-yoke ITS and recover a turboprop with a nasty reputation from a worst-case approach stall?

    No man...this 40% Sloppy fundamentals, 40% gross failure of critical airspeed monitoring (another fundamental) and at most 20% a failure in following the MU-2-236a approach stall checklist...
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    Quote Originally Posted by 3WE
    While there is truth in your statement, it’s 70% wrong and we can argue in circles all day long.

    Two guys are flying sloppy to the point of no airspeed and no altitude and oh shit, AND THEN you want them to be keyboard smart Evan and surgeon-yoke ITS and recover a turboprop with a nasty reputation from a worst-case approach stall?

    No man...this 40% Sloppy fundamentalists 40% gross failure of critical airspeed monitoring (another fundamental) and at most 20% a failure in following the MU-2-236a approach stall checklist...
    So then, your point is that airmen don't need to know the correct recovery procedure for the type they are flying because they should never get into a low-energy situation due to cockpit distractions, workload and continuation bias? Well, let us know when you wish to rejoin the real world.

    By the way, from the time the pilot began ignoring airspeed to the time he noticed it again and took action, this wasn't a situation requiring an upset recovery. All he needed to do was add moderate power and possibly decrease pitch slightly. Worst case scenario: a missed approach (which it should have been even before this point). It was the error in firewalling the throttles that got him into an unrecoverable upset.

    And what do you mean by "a turboprop with a nasty reputation"? The MU-2 has a nasty reputation for pilot error because it has characteristics that differ somewhat from the piston aircraft that often preceded it. That reputation came from inadequate training and familiarization with those procedures. It actually has beneficial qualities in stall recovery, such as effective roll authority even in a stall.

    Your one-size-fits-all idea of airmanship is what is getting people killed.

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    Senior Member 3WE's Avatar
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    Quote Originally Posted by Evan View Post
    Well, let us know when you wish to rejoin the real world.
    The real world where you instantly wake up from distraction and execute a successful stall recovery on short final...

    The real world where we routinely survive 150 stall recoveries on short final?

    You ARE correct that I will never deliberately ever do such things except on MSFS...
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    Quote Originally Posted by Evan View Post
    So then, your point is that airmen don't need to know the correct recovery procedure...
    Nope...it’s that no procedure nor fundamental nor genius, practiced skill works particularly well when you SUDDENLY realize you are out of airspeed, AND altitude...

    IF you know it’s coming and aren’t literally at stall with no meaningful altitude to burn, sure, but that’s not the case here.
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    By the way...years ago scientific engineers suggested that training should focus on almost never ever ever ever ever ever getting CLOSE to stall, as opposed to actually practice so stalling an airplane...

    I worried that this outstanding (and often type specific) training might lead to a pilot not remembering that sometimes, slight, measured nose down inputs might possibly occasionally rarely maybe be valid to think about...breifly...

    ...even though it IS better to recover at or before the first stall warning...
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    Quote Originally Posted by 3WE View Post
    Nope...it’s that no procedure nor fundamental nor genius, practiced skill works particularly well when you SUDDENLY realize you are out of airspeed, AND altitude...

    IF you know it’s coming and aren’t literally at stall with no meaningful altitude to burn, sure, but that’s not the case here.
    I think that WAS the case here. There was no mention of a stall warning. The pilot added power when he realized he was a few knots above and approaching stall (top of the barberpole I think) and added power incorrectly, excessively. It might have been a panic reaction but I don't think so. The extreme uncommanded roll beyond 70° brought on the (accelerated?) stall.

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    Senior Member Gabriel's Avatar
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    A pilot with low hours in the type and class of plane + a pilot even less qualified initiated an approach where the reported ceiling was 1/2 of the minimums without ever considering a missed approach (they briefed the approach for 12 minutes and didn't mention the missed approach). They were way higher and faster than required but they continued the approach. They crossed the localizer like 3 or 4 times and were never established on it. Even then, I will admit that I am fine with that, but you have to say "if I don;t have this thing stable on slope and on speed by X I will go around". This approach was never ever stable, since the point they started the descent to the crash. They had so much workload trying to correct the over corrections that they didn't have time to run the approach or landing checklist. And you are discussing if the problem was the sudden addition of power or the stall recovery? These guys were not dead on arrival, they were dead on approach. And it had been a very lousy display of airmanship even if they had added power smoothly or recovered expertly from the stall. Probably the approach should have never been attempted to begin with, and if you do it, in solid IMC, you absolutely have to have a stabilized approach gate so they should had gone around at it. Or what about going around at the minimums without the runway on sight at least? You have a person drunk and high doing 120 MPH in a school zone with a car with no brakes and then focus on how he didn't the right thing to recover from the overturn.

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    Quote Originally Posted by Gabriel View Post
    A pilot with low hours in the type and class of plane + a pilot even less qualified initiated an approach where the reported ceiling was 1/2 of the minimums without ever considering a missed approach (they briefed the approach for 12 minutes and didn't mention the missed approach). They were way higher and faster than required but they continued the approach. They crossed the localizer like 3 or 4 times and were never established on it. Even then, I will admit that I am fine with that, but you have to say "if I don;t have this thing stable on slope and on speed by X I will go around". This approach was never ever stable, since the point they started the descent to the crash. They had so much workload trying to correct the over corrections that they didn't have time to run the approach or landing checklist. And you are discussing if the problem was the sudden addition of power or the stall recovery? These guys were not dead on arrival, they were dead on approach. And it had been a very lousy display of airmanship even if they had added power smoothly or recovered expertly from the stall. Probably the approach should have never been attempted to begin with, and if you do it, in solid IMC, you absolutely have to have a stabilized approach gate so they should had gone around at it. Or what about going around at the minimums without the runway on sight at least? You have a person drunk and high doing 120 MPH in a school zone with a car with no brakes and then focus on how he didn't the right thing to recover from the overturn.
    Very well said Gabe!

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    Quote Originally Posted by Evan View Post
    The extreme uncommanded roll beyond 70° brought on the (accelerated?) stall.
    Interesting cause & effect there...
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    Quote Originally Posted by Gabriel View Post
    And you are discussing if the problem was the sudden addition of power or the stall recovery?
    Yes, because this shouldn't just be about 'these guys'. There are going to be guys like this continuing unstable approaches, suffering from continuation bias and landing successfully over and over again, until they don't. You don't have to be ok with that to accept it. I'm not ok with it but I have accepted that it is going to persist.

    But steps can be taken to assure that a piston-twin pilot transitioning to a high-performance t-prop KNOWS the correct go-around and approach-to-stall procedures, KNOWS the reasons for them and DEMONSTRATES proficiency on them before getting that certification. As 3WE pointed out, the MU-2 had a nasty reputation early on because pilots were not being properly trained on the vital differences between piston procedure and t-prop operation. Examples:

    Because the MU-2 offers very high performance at a relatively low cost, some of its operators lack sufficient training and experience for such an advanced aircraft. The MU-2 has performance similar to a small jet, yet early pilot certification required only a simple endorsement from pilot certificates for much slower twin piston-engine aircraft. The fact that numerous MU-2 pilots were inexperienced at high speeds and high altitudes seems to have resulted in the high crash rate. Once type-specific training was required for MU-2 pilots, the accident rate dropped to normal levels.

    Some fatal accidents have occurred because normal engine-out procedures for light twin aircraft are not effective when flying the MU-2. The commonly taught procedure of reducing flap following an engine failure on take off leads to a critical reduction in lift in the MU-2 due to the highly effective double-slotted flaps. When pilots were taught to retain take-off flap and to reduce climb rate in the event of an engine failure, MU-2 accident rates were reduced to almost nil.
    Steps were taken in 2008:

    In early 2008, the FAA issued a Special Federal Air Regulation (SFAR) directed at MU-2B operations. Pilots flying this aircraft after that date (current MU-2 pilots would have a year to come into compliance) were required to receive type-specific initial training, as well as recurrent training. The agency also required that a fully functional autopilot be available for single-pilot operations, and that FAA-approved checklists and operating manuals be on board at all times. Unusual for this SFAR, pilot experience in other aircraft types cannot be used to comply with MU-2 operational requirements. For instance, the requirement to perform landings within the preceding 90 calendar days before carrying passengers is altered by this SFAR to require those landings be made in the MU-2.
    Yet, this pilot didn't seem to have an essential understanding of throttle handling as low airspeed. So something is broken there.

    The industry can and should continue all efforts to impress the requirement for stable approach criteria. But that cannot preclude giving pilots the knowledge they need to save themselves (and their passengers) from themselves when they fall prey to human factors. Or should we just eliminate stall warnings and procedures altogether and rely on perfect airmanship at all times?

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    Quote Originally Posted by Evan View Post
    Yes, Schwartz, from the moment the throttles were firewalled, which caused the upset. From that point on (allowing a second or two for reaction time), I'm not sure anything could have been done to save them. Pulling back the throttles along with leveling the wings maybe, but with less than 500ft to regain lift and arrest descent, I don't think so. At best perhaps a less violent crash.
    Yeah, the report indicates the pilot did everything correctly to right the aircraft and it hit the ground almost level, nose up a bit. The aircraft bounced once (uphill) and then skidded. It sounds like the pilot did indeed correct the upset properly, but didn't have enough altitude left and that once the upset happened to that degree it was over at that altitude. Reading the report, I came away that they implied he could have advanced the throttles quickly had he been prepared for the response of the aircraft. They implied he wasn't practiced enough on that aircraft and was caught by surprise which means to me, he knew what to do once it happened, but there was a delay in response due to surprise. I think he had very little margin for error at that altitude and airspeed.

    On final approach, the aircraft slowed to within a few knots of the stall speed before this was recognized by the pilot. The sudden addition of high power at low airspeed in the MU-2B produces a right-rolling tendency, which can lead to loss of control if not anticipated and corrected. The pilot was surprised by the right roll and delayed correcting it, which permitted the aircraft to roll more than 70° before returning to a near wings-level attitude at impact. A loss of control occurred when the pilot rapidly added full power at low airspeed while at low altitude, which caused a power-induced upset and resulted in the aircraft rolling sharply to the right and descending rapidly.

    Although information was available to explain the aircraft's characteristics when high power is applied at low airspeeds, it is unlikely that the pilot was familiar with this situation, based on his reaction during the occurrence. The pilot had about 2500 total flight hours and had held an airline transport pilot licence for about 6 years, but his flying experience was primarily on non–high performance single-engine and multi-engine aircraft. During the 20 months that the pilot had flown the occurrence aircraft, he had accumulated about 125 flight hours, of which at least 100 hours were flown under the supervision of a qualified and experienced pilot. In the previous 3 months, he had logged only about 19 flight hours and, in the previous 30 days, only 4 flight hours. The investigation could not determine how many pilot-in-command (PIC) hours the pilot had flown with another pilot accompanying him.


    It is interesting that someone had installed a light weight video/audio recorder which is how they were able to do such a good analysis.

    The data and audio retrieved from the Wi-Flight was critical to understanding the events that led to the accident. Although not required by regulation, the installation and use of a lightweight flight recording system during the occurrence flight, as well as the successful retrieval of its data during the investigation, permitted a greater understanding of this accident.

    During the approach to Runway 07, the aircraft struck the base of a hill in a left-wing-low, nose-high attitude, 1.4 nm west and 1000 feet south of the runway centreline (Figure 4). The aircraft momentarily became airborne again, then struck the ground and slid for about 100 feet before coming to rest.

    Propeller strikes were found in the ground on both sides of the initial impact site: 3 strikes on the left side and 2 on the right side. Measurements of these strikes indicated that the engines were driving both propellers and producing power at impact. Based on the analysis of the propeller strikes and the flight data, the investigation determined that the aircraft struck the ground at a ground speed of about 100 knots and a descent rate of approximately 4000 fpm.


    Unfortunately, the descent rate was too fast to be survivable even thought the aircraft appears to have protected the occupants.

    The aircraft had 2 distinct ground impacts. The investigation calculated the peak vertical acceleration, which was reached during the first impact, to be about 78g for 0.06 seconds. Research has established that a vertical g force of this magnitude causes severe injuries even if the aircraft structure and restraints provide maximum attenuation of impact forces.Footnote 39

    All occupants had been wearing the available seatbelts.

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    Senior Member Evan's Avatar
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    Quote Originally Posted by Schwartz View Post
    Reading the report, I came away that they implied he could have advanced the throttles quickly had he been prepared for the response of the aircraft.
    I'm not so sure about that. At minimal airspeed those wing spoilers might lack the authority to overcome so much torque-induced roll, so even a well-prepared pilot might get into some roll excursion when firewalling the throttles at that speed. I suspect the low-energy recovery procedure involves advancing the levers more carefully AND being prepared to counter the roll it might cause.

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    Senior Member Gabriel's Avatar
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    Superior pilots use their superior judgement to avoid using their superior flying skills.

    I agree with 3WE that a pilot that had been so sloppy and doesn't know its airspeed and altitude and is sitting 2 miles behind the airplane he's flying will doubtfully suddenly recover all his wits the moment that the fit hits the sham. If the pilot had the proper training and attitude he would not have been in that position to begin with, and if he is then he doesn't have the proper training, knowledge or attitude, so again, it is unlikely that he will react brilliantly to the upset (physical after the yaw/roll or "psychological" the moment that the stick shaker shakes).

    That said, Evan, you also are right in one thing (that you don;t even mention, but it is there hidden in what you said, even if you don't know it). But first some background.

    First of all, you don't need to evangelize me on the problems and importance of correct low speed management (not that you are trying). My "stall rant" thread is the main document that the FAA and EASA and the aviation industry at great reverted to when they designed the new stall and approach to stall recovery principles (not really, but my "document" came first, and is still better than the industry's).

    2nd, the reason why the MU is better than aileron-fitted planes in stall is mainly because the spoilers don't have adverse yaw (that couples into adverse roll with the dihedral effect) so precise rudder coordination is less critical. Neither ailerons or spoilers are effective if that portion of the wing is stalled (spoilers basically stall part of the wing, so doing that in a stalled part will hardly have any effect), and all planes are designed so as the root of the wings stall first so in incipient stall the tips (and the ailerons or spoilers in the MU) remain unstalled. Another problem with ailerons is that, at a critical point, a down-going aileron can promote a stall in that part of the wing that you are truing to push up, with a net reduction of lift in that zone and hence adverse roll. That's why the new standards based on my paper call for first unloading the wing (euphemism for reduce the angle of attack) before rolling wings level. But the reduction of effectiveness of the roll control surface due to reduced speed and increased AoA as well as the almost elimination of the roll damping (main component in roll stability) is common to aileron and spoilers. So the advise to reduce AoA FIRST and level wings first is till, well, advisable.

    Talking from a "generic skills common sense" and not MU specific procedures or characteristics, the moment the pilot had the stickshaker he should have reduced AoA FIRST (and we are talking about a split-second first). Then the roll due to addition of torque would have been reduced somehow by the improved roll damping and the spoilers would have been more effective to control roll. We will never know what happened up there, but I suspect that when this pilot saw the nose going down he freaked out and pulled up, and that the plane had more that a stickshaker but rather a real stall at some point. Was the plane still recoverable after the initial roll upset caused by the sudden addition of power 1 knot above the official stall speed? Almost sure yes, with a near-perfect use of stick and rudder that no pilot is likely to pull out at that point.

    None of the above is MU specific, and is all very important. Regarding the MU specific or "high performance twin turboprops" specifics, the sudden yaw and roll caused by the sudden addition of power, this is also a known situation in high-power piston singles and everything in the middle.

    After flying planes like the Cessna 152 and the Piper Tomahawk with 112 HP, one day I flew (with an instructor of course) a 230 HP Cessna 182. Because we had taken off from a somehow busy airport, we went to practice touch-and-goes in a nearby 600m-long grass field. IT was my first time in a plane with constant-speed propeller and (spoiler alert) rudder trim (why would you want a rudder trim in a single?). I was impressed with my own performance managing the throttle, RPM, airspeed, flaps and descent path towards the landing. Touch (with the stall warning just starting to sound).. and go!!! And there does the nose go to the left. It took me completely by surprise. The plane yawed waaaay to the left and was rolling too. I quickly reacted both with rudder and aileron inputs. The aileron inputs were effective (much similar reaction than say a Cessna 152) but the rudder didn't seem to do much. Of course, it was me who was not doing much. Suddenly I felt the the rudder pedal have an "automatic" input that felt like all the way to the right (it was not), something that I would have never dreamed of doing in the Tomahawk unless unless I was doing an agressive sideslip. Of course, it was the instructor. Then I said to the instructor "oh, so that's what the rudder was there for". Next landing was equally perfect but its subsequent go around was quite better, but I was still shy on the rudder. There is a very nice video out there in YouTube where you have a Cessna 1820 doing a touch and go in a dirt runway and the moment that they apply power and go up the plane yaws like 20 degrees to the left and the people on the ground starts to scream "right rudder, right rudder!!!", it was very similar to what happened to me.
    Consider that we are much more sensible to roll than yaw. In VMC we are naturally much better at keeping the wings level than the ball centered. That explains why in my case and in the video there was no significant roll. In IMC, however, it is possible that the roll takes more time to identify and hence the correction is delayed. Probably this was a factor too.

    So, you are right, adding sudden power in a high-power propeller airplane is problematic, but it is not something exclusive of the MU or "high performance turboprops".

    Now going back to the part that I agree with what you didn't say "There is no "engine stall recovery during go around" procedure. Procedures, especially abnormal or emergency procedures, typically assume that you have ONE problem. And that is a problem because, sometimes, the problem X that you are reacting too was triggered by by a predeceasing problem Y that has an influence on how you need to react to problem X.

    The go-around on the 737 goes something like arrest descent, TOGA, flaps 15, with positive climb gear up.
    Following exactly that procedure almost killed everybody.

    There were an incident in a 737, that could have easily been a tragedy, where the AT had a failure and kept the throttles retarded while the AP kept the glide slope in a deteriorating speed trend (very much Turkish style). The pilots eventually noted that the speed was WAAAAY below Vref and called go-around, arrest descent, TOGA, flaps 15, which immediately triggered the stickshaker. The pilot applied nose-down input to the stops and the airplane's speed did increase first, but the plane kept pitching up, and up, and up, against the full nose-down input, until it eventually fully stalled (despite the TOGA), the nose dropped and the plane started to fall. During the fall the airspeed increased enough that the elevator gained more authority and finally, they were able to recover from the stall, arrest the descent and climb, but the plane started to pitch up uncontrollably again and at that point they had the clarity of mind to apply nose-down trim, which finally allowed a full recovery of normal flight.

    There SHOULD BE (but there isn't) and the pilots SHOULD BE trained for (but they aren't) procedures for go-around that are sensitive to the reason that originated the go-around. If you are in a very slow speed situation, arresting the descent, selecting flaps 15 and applying TOGA are all very bad ideas. Better apply some intermediate thrust (climb?), keep descending, let the speed recover to Vref, and then execute the "normal" go-around.

    It is very possible that, in the MU, pilots are trained to execute a go-around applying full thrust quickly. And it is possible that this is not a big issue if you are flying at the approach speed of 125 knots, or "never below 120" (as the pilot himself was recorded saying, and as he asked the other pilot to keep an eye on the ASI to ensure), but when you are flying 1 knot above stall, the situation can be different. At 120 knots you have 40% more dynamic pressure than at 100 kts, which means 40% more effective fin in yaw damping and anti-yaw moment that will reduce the natural yaw on the same asymmetric thrust (even without using the rudder), the rudder will be more effective, the wings will have more roll damping (even without using the roll spoilers, because of the higher speed but also the lower AoA), the roll spoilers will be more effective, the thrust (and hence the asymmetric thrust) will be lower, and the P-factor will be lower both due to the lower AoA and the lower thrust. So 120 vs 100 are two total different animals (totally different plan e behaviors). And I doubt very much that there is "go-around when you are 1 knot above stall speed" procedure in the MU (or any other plane). And there should? How many combinations of factors are you going to procedurize and train for? n! grows VERY quickly (more than exponentially quickly) as n increases.

    Now, good airmanship dictates that preservation of AoA is priority one in ANY situation, NOTHING goes first other than that, under NO circumstances. Airspeed/energy comes as a close second (in part because it is so related with AoA). So, both in the 737 incident and in the MU accident the pilots should have first controlled the AoA and speed and then execute the go-around, or at least execute the go around while minding the AoA and speed as first priority over climbing (and airspeed is not increased only with thrust but with pitch, since simply adding thrust will have only a temporary and non-sustainable airspeed gain (see the 737 incident above). But yes, you need to teach, learn and practice these things. That are NOT MU specific. And I am not neglecting the importance of knowing your plane and its behaviors, but trying to rescue (from you) the importance of good general understanding, theoretical and practical, of these concepts independently of the airplane type).

    (Again, "watch your speed, especially in an approach in IMC" and "establish a stabilized approach gate" would have worked much better than all that: Superior pilots use their superior judgement to avoid using their superior flying skills.)

    --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
    --- Defend what you say with arguments, not by imposing your credentials ---

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