Mesabah

This is about stalls, not about float, that's just a secondary aspect of a significantly better system.

Engineers are constantly looking to improve systems. A better system would have prevented the Colgan accident. Whether captain Renslow was qualified is a completely different topic.

JohnBurke

Renslow's qualification and ability is not a different topic at all; it's key to the loss of the aircraft and the mishap, and the outcome.

A better system would absolutely not have prevented the flight. The crew had ample warning and indication and in fact upon receiving a stick shaker continued to increase AoA and progressed deeper into the stall, failed to provide more than partial power, and maintained back pressure and a high AoA all the way to impact.

Mesabah

Neither crew member recognized the stall, and their inputs were consistent with confusion, and sudden reaction. This actually happens more than it should in this business. The Q-Alpha system clearly warns pilots in spoken language of an approaching low energy state. The aircraft would have been barking at them to increase power several seconds before the shaker activation. The shaker is engineered to prevent false activation, every pilot needs to understand they can be in a stall, or parts of the wing can be stalling before the shaker activates.

JohnBurke

Again, ample warning was given. In fact, because of the selectable stall speed input on the Dash 8, early warning was given, with a greater-than-normal cushion of AoA and airspeed prior to the stall; the crew had adequate notice: enough so that crew who were doing their jobs could have and would have reacted with plenty of time to not only avert a stall but entirely avoid a departure from controlled flight.

This was NOT a lack of cockpit data. This was NOT a lack of warning. This was NOT a lack of reaction time. This was NOT an insufficient margin of energy, AoA, or any other metric regarding lift reserve or capability. This was simply a matter of incompetence.

The aircraft manufacturer could have had flashing windows the color of the rainbow with peach, kiwi bubblegum, and Fantastic Fatfinger Freddy Pink thrown in for good measure, and it wouldn't have mattered. And it didn't matter. It didn't matter that aerodynamic buffeting occurred, that the stick shaker occurred, that the pusher occurred, that cockpit instrument indication warned of the stall, or the fact that the crew had calculated the speeds and knew them and had briefed them, because despite the plethora of warning in the cockpit from visual to tactile to airframe buffet, the crew still failed to act, still failed to increase power adequately, still failed to reduce AoA, still failed to do the most basic requirement and tenet of airmanship:

Fly the damn airplane.

Adding gee-which gizmos, light, reserve lift indicators, PLI's, and all the other wonder gimmicks for the modern cockpit wouldn't have made one iota of difference when the crew didn't do their most basic, core job. Fly the damn airplane.

Mesabah

Q-Alpha or similar system is NOT a gee-whiz gizmo. It takes the same philosophical approach to warning the crew in the same fashion as GPWS, TCAS, depressurization, etc. This would have absolutely reduced the element of confusion in this accident. If you think the crash would have still happened, with both pilot knowing the aircraft state, then we agree to disagree.

I think, that had the FO or the airplane warned the captain to check airspeed, this crash would have been prevented. I mean, what do you do as PM when you see the other pilot making a mistake, say nothing because they should know better?

ptarmigan

I agree with you. Q-alpha would have made a big difference. Those who are arguing against you in this thread are indicating a lot of hindsight bias. It is easy to see what YOU would have done differently with the benefit of hindsight, and it makes us feel good to think that a particular accident would not have happened to us, but it is almost always wrong. The reason is that such thinking ignores the actual contextual factors occurring at the time. If you cherry pick what you are perceiving or should be perceiving in hindsight it is obvious. In real time there are all sorts of other aspects. Put yourself, as Dr. Sidney Dekker says, "in the tunnel", knowing ONLY what they knew at the time, and having ONLY the training and experience that they had then, plus with any other fatigue, experience, etc.

JohnBurke

It would have made no difference whatsoever.

Your dismissive viewpoint abandons decades of experience that the commenters here have, individually, and the centuries, collectively. Call nearly four decades of doing it, teaching it, observing it, studying it, etc, mere bias (and an objective view of a mishap that's been picked apart every which way from sunday) a "feel good" biased view if you like (and you do), but it's wrong, and such dismissiveness is hardly beneficial.

Yes, we can view the mishap based on hindsight, because very clearly we cannot view it with foresight. It existed in time, and exists now as a detailed mass of data. We know that the participants were minimally experienced, the F/O woefully so, and the captain one who bought his job, had numerous failures in his training and past, and who bragged on the transcribed cockpit conversation of shortcutting his career by buying his job with Gulfstream. The F/O made uncommanded changes in configuration.

The response to the events, which had ample margin from the stall and were not close to the critical AoA at the time of initial warning, was wholly inadequate, despite considerable warning and data providing information about the aircraft state. Upon recognition of the problem, the crew's response was similar to a tailplane icing encounter, though the airline taught no such response, and the procedure didn't exist for the airframe. It was the opposite of what was required, both increasing AoA to the stall and use of partial power, and far worse, was continued from an altitude that allowed far more than enough time for recovery, right to impact.

Numerous cues were available, active, and presenting, from shaker to pusher to airframe buffeting to visual cockpit indications and stall warnings, airspeed indications, power indications, configuration indications, and the event is one trained for at every initial, every recurrent, and one emphasized on every checkride from the time of a student pilot onward. None of this was new, none of this was deceptive or subtle. Further, the crew had misset the stall warning switch, allowing an additional 20 knot margin above the usual alerts; the crew received this warning and continued through that gate all the way to a stall by using partial power and an increasing AoA and then held it.

To suggest that it might or might not have happened to us is a straw-man argument which holds no merit. It's irrelevant. It DID happen to them. We know exactly what happened. We know their state of mind, their background, their personal and professional history, their rest history, their family situation, everything, including training records and cockpit conversation leading up to and throughout the event, as we do with most transport category mishaps. We have all the CVR transcript, the report, and the FDR information to provide us excruciating detail on control inputs, responses, and aircraft behavior, second by second, through the entire event.

This is not a matter of making ourselves feel good. This crew unquestionably had an ample plethora of data giving good, solid indications of the aircraft state, airspeed, and flight condition throughout the entire event, and far more than enough warning that it was coming, impending, happening, and continuing to happen. Physics are the same before, during, and after. The correct responses before, during, and after remain the same, and the crew simply followed their standardized training, they'd have been okay. There was nothing at any time wrong with the aircraft. There was no unrecoverable situation. This was not a challenging event. This was not hard to decipher, nor were the clues vague or easy to misinterpret.

The same clues, in fact the same hard data, the same warnings and progression that the crew in question received are handled and used by tens of thousands of pilots working in the field today; the same that we all train with and use on a daily basis and which still work very effecitvely. Stall recognition is not a murky, mysterious, unfathomable phenomena, particularly a straight ahead, unaccelerated stall as the Colgan crew not only experienced, but caused.

To suggest that the crew suffered from a lack of warning, a lack of flight data, a lack of useful, easily interpreted information, is ridiculous and far misses the mark. There are many things that can be taken from that event, but insufficient cockpit data is NOT one of them.

Certainly the issue of proper stall recovery has been addressed as a result of this mishap: the long-taught, ill-conceived concept of no altitude loss and powering out of a high AoA situation might have merit to prevent ground contact in a windshear situation at extremely low altitudes, but a reduction in AoA has always been and remains the only way to preclude the stall, and the drawn-out process of holding pitch, holding altitude and using power for recovery (especially in this case of partial power) was a poor and inappropriate concept propagated in the industry for far too long. That, fortunately, has been mitigated somewhat by alleviating the hard line for minimal altitude loss in the recovery in training.

The crew might be in part absolved by the problematic training standard of minimal altitude loss and no manual AoA reduction (beyond pusher) in training, except that despite all the warning received, the crew did NOT follow their training.

Be dismissive all you want, but gimmicks and fresh display formats wouldn't have fixed this. This was a human error, not the result of the lack of data.

ptarmigan

Quite frankly, John, I think you are the one being dismissive here. You are ignoring that some of us also have many decades of experience both as a pilot, as well as investigating major accidents. Your experience is certainly valuable, but you are also not looking past your bias here.

I am not sure you understand what q-alpha does at all either. If you do it is not evident from your post. While I am only an acquaintance with the creator of it, Andy Skow, he has done something of real value. If you ever knew Pete Reynolds before he passed (google the name and "learjet") you should know that Pete strongly agreed with what I am writing here. For the record, I have no connection to the system or company aside from being aware of what it does.

Your view, and your response, clearly indicate hindsight bias, whether or not you want to admit it. It is right in your words. I would suggest you attend MIT's workshop coming up. It might be of interest to you. Partnership for Systems Approaches to Safety and Security (PSASS)

Best regards-

Mesabah

JohnBurke

I'm familiar with it. It may have some merit for the lowest hanging fruit that can't fly an aircraft or maintain situational awareness or do their job at the most basic level...but such really ought not be in the cockpit in the first place. Renslow, for example. Given his wholly inappropriate response to impact, there is no reason to believe an annoying voice or additional flashing light would have made any difference. Everything he needed was already in front of him.

[QUOTE=ptarmigan;2777113]
I would suggest you attend MIT's workshop coming up. It might be of interest to you. [/url]

Not remotely of interest, thanks.