Cirrus Trim Runaway Fatality

at the end of every day there's something that you wished you knew earlier the closing price of the stock market the Bad Coffee Lid destined to spoil your virgin white shirt their silly inconveniences when compared to getting home safely to your family when tragedy strikes it's easy to wonder about the butterfly's effect if you took the time to give your kids an extra kiss your wife an extra hug if those few seconds would put you on a path that would preserve your life if it's possible in other words to kill destruction by sparing a few seconds Aviation accidents can be like that add a second subtract a second sometimes it's the difference between living and dying there's a striking picture of the pilot sitting on a Lamborghini in front of a cirrus a companion to a watermark of a bowl climbing the stock market ladder life can be full of paradoxes described as a man of Faith he was happily married with three daughters the names of his father and brother were prefixed with the honorific doctor which means that education ran deep in his family the pilot apparently followed a slightly more Meandering path a high school athlete who was honorably discharged from the Marine Corps he eventually matriculated to Computer Engineering with Amazon on his CV he wasn't done he got an MBA along the way to becoming an entrepreneurial CEO he flew his first airplane at the age of 15 though apparently he hadn't done much beyond that still he loved Aviation he loved his family and he loved God it was a cirrus sr-20 predecessor and little brother to the SR-22 the best-selling piston of the new millennium the sr-20 was the first general aviation aircraft to be equipped with the full airframe parachute you have two options when it comes to redundancy pay a bundle a la a second engine or get a cirrus that can float to the ground there's a funny thing that happens in GA with redundancy though it can simultaneously reduce the accident rate while also leading to more fatalities general aviation twins have suffered from this the second engine theoretically will keep the plane flying until it can safely land in the event of an engine failure but it comes at a particular risk asymmetric thrust creates tricky handling characteristics which all too often results in the aircraft rolling uncontrollably and entering a dive an event which is almost always fatal and almost always the Pilot's fault you might wonder what this has to do with the single engine airplane with the parachute a lot of people are surprised how often the pilot forgets to deploy the shoot in the heated moments preceding the loss of aircraft control perhaps redundancy is overrated or maybe like a lot of other things in aviation it's only good if you insufferably drill yourself to use it in 2011 the sr-20 and SR-22 had a better overall accident rate than most of the ga Fleet while also proving more deadly at 1.6 fatal accidents per 100 000 flight hours it eclipsed the leading Diamond da40 by a factor of five even the Cessna 182 a more relevant comparison had a fatal accident rate less than half of the Cirrus confronted by this Cirrus launched an aggressive training program which focused on the deployment of the ballistic parachute system by 2014 the fatal accident rate was reduced by 74 percent nearly matching the performance of the class-leaning da40 which benefited from a slower much more benign Wing a parachute doesn't do you any good if you don't use it but that wasn't the only problem on the accident flight it was a busy day in the pattern that Montgomery Gibbs Executive Airport in San Diego I go for without delay traffic is short final four to eight left all right Montgomery charity again right you were stepping on me say you're full call signs your papa Montgomery shower standby 2540 Papa Montgomery you're following a series number a fun make right traffic Runway could take us let's take off the accident airplane had been around the pattern several times with repeated practice Landings first to Runway 2-8 left before transitioning to a right-hand pattern for 2-8 right the pilot was performing stop and goes which are generally used by a student pilot on a solo flight around the pattern more experienced Pilots or students with flight instructors on board will often perform touch and goes which allow for many more Landings in a given period of time at the cost of being more demanding there are a few things that you need to know for the rest of this to make sense November 700 Yankee Zulu was a sixth generation SR20 equipped with a technologically advanced avionics Suite it's a dual use aircraft that is used both for training and is a relatively capable cross-country platform if you're thinking about a relatively high performance and economical aircraft to use on business trips and is going to be your first airplane it's hard to beat the sr-20 if you can afford the half million dollar price tag the Air Force Academy bought 25 of them in 2011. they designated them as t-53as and used them for initial Flight Training November 700 Yankee Zulu was built in 2020 at which time it was registered to a corporation it was a sixth generation sr-20 equipped with cirrus's perspective plus avionics Suite that Suite includes the GFC 700 autopilot with an option for garmin's electronic stability and protection system ESP for short the system is designed to provide both bank and Pitch protection with the autopilot off by applying restorative forces on the side stick in the event that the aircraft exceeds 45 degrees a bank or 17 and a half degrees of nose up Pitch it will also apply nose down forces in the event the stall warning system is active or during low but non-stall speeds when the autopilot is engaged the aircraft as most aircraft do comes installed with a pitch trim system this alleviates the need for persistent control forces to be applied when the aircraft operates at various speeds along its roughly 70 knot in-flight AirSpeed range on the serious it's electronically controlled via hat switch on top of the side stick in the event of a pitch trim runaway the only way to disrupt trim commands is to pull a circuit breaker on a light single with a relatively small operating AirSpeed window this isn't a problem serious details in the sr-20 pilot operating handbook that even full deflection of the pitch trim system can be easily overrode by nominal control forces they don't provide a specific number let's call it less than 20 pounds of maximum pressure on the side stick to maintain aircraft attitude with the pitch trim rolled All the Way Forward nose down any more than that and you'd have to question the legitimacy of cirrus's phrase easy override we'll make right traffic reminds us to take off okay Tower series foreign as a pilot you know the pattern's full when the tower controller tells you that they'll call your base leg they don't do that to add workload to themselves they do it because they need to provide separation for a myriad of arrival and departures on the same Runway looking forward to it's the right base over the golf course 1 2004 series insane 539 seconds Runway right line up in weight traffic one and a half mile finals here right lineup of weight five three United traffic off your left is for the South Runway 4-0 possible base approved is throwing a series to be me right now a pilot's ears will perk up when they hear someone say my trim is activating by itself that's a flight control issue an emergency condition every single time the tower controller was non-plussed you don't have to be a pilot to work in ATC most controllers know just a little bit more about aircraft systems than your third grade teacher trim is a thing that beautifies the side of a house it would be easy to blame her that's not my point here but it's fair to say that she wasn't much help and her defense the pilot failed to identify his aircraft designation it's such a standard requirement that it becomes reflexive for anyone who has spent any significant amount of time at the controls of an airplane for a student in the midst of a mechanical abnormality it can become an unnecessary inconvenience for the pattern departure does having a trim problem you have a stuck mic on one two five point seven so significant takeoff the pilot used a magic word emergency but it appears as though the transmission was Stepped On by both the tower and another aircraft who was cleared for takeoff the controller was able to extract that someone was having an issue with their trim but clearly did not hear the phrase emergency which though an example of clear communication is itself not the prescribed way for a pilot to communicate a critical situation to air traffic controllers if we're being precise and this is going to be a good example of why a pilot should be the appropriate phrase is mayday mayday mayday there's a reason why you're supposed to repeat it three times if you're stepped on or mumbling it increases the chances that the controller will immediately give you their full attention the pilot was stressed confused and alone even more he was ignored the controller had a packed pattern and was ignorant of how serious a trim issue could be at first she brushed him off then she loaded him up go around hearing because they were offset to the right the cause of a quick go around command is not clear but it had fatal implications maybe zero Yankee Zulu was high and in no position to land maybe the controller hadn't provided enough separation between the Cirrus and assessna that was taking off whatever their cause she added fuel to a spark the pilot was fighting aircraft pitch and she told him to add power and climb she also needed him to offset from Runway Center Line in order to avoid the potential collision with the departing Cessna in other words she loaded him up with tasks when he was already saturated pitch oscillations are clear in the video combined with the Pilot's utterance of a trim runaway it's clear that he had encountered abnormal flight control forces there are four possible causes two more likely than the others garmin's ESP doesn't read minds but it's also a well-designed robust system unless it was malfunctioning it would not have introduced elevator forces which could have been potentially mistaken for a pitch trim runaway unless the stall warning system was already active that warning includes oral alerts that are hard to miss and which were absent in the Pilot's Transmissions another unlikely initiator is a pilot himself over control of an aircraft option results in oscillatory wave patterns as the aircraft is displaced from stable parameters the pilot overreacts with excessive control inputs resulting in exceeding stable parameters in the opposite direction and continues on in this manner until the aircraft departs controlled flight or they let go of the controls or they settle down it's better to take him at his word though that doesn't require that he was 100 correct he clearly identified his belief that the trim was running by itself it's unclear if he identified it on instrumentation or via control forces which were acting against him there are three things that could have caused a resistance that he experienced the first is as he identified in himself runaway trim going against this is a crash itself his final Panic maneuver belies a state of mind in which the pilot did not believe that he could control the aircraft if cirrus's poh is correct and it's hard to believe that it isn't the maximum control forces that he would have experienced would have been mild easy for a former Marine to overpower but you can underestimate startle Factor especially when dealing with an inexperienced student overreactions are natural training and experience are the antidote but you must survive long enough in order to learn the lesson that last part comes down to luck the pilot appeared to be fighting several battles simultaneously he had little experience he was operating in congested airspace he experienced a mechanical issue and he was vectored too closely in the pattern requiring a go around at the worst possible moment the activation of autopilot servos is another potential source for the initial pitch upset garmin's ESP system utilizes those servos but it is an unlikely culprit given the programming architecture it's designed with yet there's also this going for it the maximum downforce that ESP produces is 60 pounds grab a stick and let your four-year-old pull for all his worth you're going to notice it in an airplane you won't have much hope of keeping the nose up which as it relates to a stall is a point ESP stall protection is essentially a stick Pusher it doesn't take an inexperienced pilot to respond incorrectly to its inputs the captain and pilot flying on Colgan Air flight 3407 had 3 400 hours of pilot time he experienced a stick Pusher of men and what can only be described as a startle response he failed to recognize that the stick forces were associated with the stall protection system he yanked back instead of letting the nose drop and accelerating here's the adsb data 112 knots downwind 77 knots approaching the turn of final at a pressure altitude of 1000ft feet after clubbing the throttle he accelerated to 106 knots and climbed to 1175 feet he descended to the runway while keeping the power in he had accelerated to 132 knots at 875 feet he maintained that speed until short final this explains the loss of separation between zero Yankee Zulu and the Cessna that the tower controller intended to depart prior to his arrival the Cirrus was 40 knots fast on Final the 77 knots during the base leg is one not below Cirrus has published 78 knots for a short field Landing with full flaps and even that speed is only meant for crossing the runway thresholds the lower limit of the green arc on the sr-20 is 71 knots and represents the stall speed with flaps up and Max Wade in a forward center of gravity with only one occupant the Cirrus would have been well below max weight which means that the stall speed would have been a couple of knots slower a few things about stall speed the published numbers are governed by far part 23 which dictates airworthiness standards for manufacturers it gets a little confusing here because stalls and airplanes occur not at a speed but at an angle of attack which is the angle between the wing and the slipstream most straight Wings stall around 17 degrees stalling air speeds are specified as a matter of convenience if the aircraft is maintaining one G One Time's A force of gravity it'll stall its specified air speed in the specified condition if the aircraft is maintaining more than one G which it will in a level turn it'll stall at a higher air speed it'll also stall at a higher AirSpeed if the pilot buries the stick aft an angle of attack indicator is much more reliable as it takes all this into account one instrument but they're not installed in most light singles the use of wing flaps lower stall speed 87 knots is a recommended threshold Crossing AirSpeed in a zero flaps configuration it's 10 knots slower than the pilot was maintaining on base it's quite possible that the flaps are up during the turn post-axis and video footage displays retracted flaps it's possible that the pilot retracted them as a part of the go-around but given the circumstances it's probably not very likely similarly an introvertent activation of the autopilot system is unlikely but not impossible if the servos were alternately fighting against and with pilot inputs it could explain the oscillatory pitch patterns down the runway in either event pressing and holding the red autopilot disconnect switch on the side stick would have de-energized the servos that works on pretty much any aircraft out there if something weird is happening to pitch control forces push and hold that red button it's not going to do you any harm the final potential cause is that the elevator was jammed it doesn't happen very often but it does happen in this case control forces would have been abnormal and unresponsive possibly causing the pilot to misdiagnose it as a trim issue the upside of this theory is that it explains why the pilot may have become fixated on immediately getting the aircraft on the ground even though it had to have been clear that doing so in a controlled fashion was next to Impossible still this Theory contradicts witness testimony and surveillance video which depicted the aircraft oscillating as it overflow the runway an aircraft with a jammed elevator will inevitably experience a fugoid causing the nose to oscillate up and down but the period of these oscillations is generally closer to a minute than to the seconds witnessed in this case some hit big plume of Dust Till Grand this is Rich Pickett and I need to go to the site they said you're clear to go when I got to the crash site there was fuel being spilled so I was worried about fire but went and tried to help the pilots a sole occupant so it took a while for our fire department to get there one of the issues is they couldn't get through the gates they cut the lock made it through the gate there's a lot of the fire departments They Don't Know About Airplanes they don't know about fuel types they don't know about wings they don't know about the Rockets and the Cirrus the parachute had not deployed if the firefighters here at the base of the tower are on frequency if you guys want to head out that way to help it's approved now all aircraft just stand by we have Personnel all over the airport right now I don't want anything else happening whatever the cause the pilot didn't have much time to figure it out but he also had an escape hatch the serious parachute system comes with only one requirement for deployment 133 knot speed limit and even that is an absolute this doesn't mean that altitude is not a factor Sirius recommends making the decision to activate the parachute at or above 2000 feet but also notes that altitude laws prior to full deployment has been demonstrated at less than 400 feet vertically for this reason there's no published minimum for deployment in the event of a spin deployment is required regardless of altitude in theory if he had activated the system while porpoising down the runway he would have drifted to the ground at a much more survivable rate perhaps the equivocations in the Cirrus poh led him to believe that deployment at 100 feet was a death sentence nevertheless it's hard to Envision a scenario that would have prevented the aircraft from climbing if he had retained enough control to gain altitude you had a bot time to assess the severity of the malfunction and find a safe place to deploy the parachute if needed easy to say with all the Time in the World to think about it a man of Faith a father a son and brother a husband regardless of who's at fault don't blame him God bless

Channel: Flying for Money

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Length: 18min 53sec (1133 seconds)

Published: Wed Sep 27 2023