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  • Unstable approach and Pilot overload

    Collision with terrain of Mitsubishi MU-2B-60, N246W, 1.4 nm WSW of Îles-de-la-Madeleine Airport, Quebec on 29 March 2016


    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.

  • #2
    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.

    --- 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 ---

    Comment


    • #3
      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?

      Comment


      • #4
        BTW: do you see any way that that a recovery was possible here?

        Comment


        • #5
          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?

          Comment


          • #6
            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.
            Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

            Comment


            • #7
              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.

              Comment


              • #8
                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...
                Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

                Comment


                • #9
                  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.

                  Comment


                  • #10
                    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...
                    Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

                    Comment


                    • #11
                      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.
                      Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

                      Comment


                      • #12
                        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...
                        Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

                        Comment


                        • #13
                          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.

                          Comment


                          • #14
                            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.

                            --- 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 ---

                            Comment


                            • #15
                              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!

                              Comment

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