J35 Bonanza Power-On Stall / Spin

[Music] flower's going to take a look a quick look at the stall spin loss of control accident of a j35 bonanza i think there's some real important lessons on this one so stick with us on flywire hi i'm scott purdue and today on flywire we're going to look at the stall spin accident of j-35 8255 delta this accident occurred north of helen and montana on june 24 2013 just after noon local so there's no way dsb or anything like that from back then but we have the impact and we have some pictures the aircraft departed helena regional airport about 11 50 from runway 3-4 and the crash site is about 10 miles north of the airport a family member reported in an interview that the pilot was going to out to practice because he hadn't flown in a month and he was planning on a family trip over the july 4th weekend the local weather observed 10 miles south of the airport was calm winds visibility 10 miles temperature 68 degrees 2.44 and the altimeter is 2965. so pretty sounds like a pretty nice day relatively low density altitude the dense land there is about four thousand feet little less than four thousand feet the aircraft impacted the ground in a left wing low nose down attitude on a heading of zero nine zero degrees and the at rest heading was also 090 degrees the aircraft came to rest upright with the impact damage to the cockpit and wings consistent with a near vertical impact and it sat down both fuel tanks were breached as was the aux tanks and what that tells us is the airplane wasn't rotating significantly enough in a flatter attitude the cockpit controls for the mixture propeller and throttle were all observed to be in the full forward position and the landing gear remained in the retracted position inside the wings post-crash inspection of the airframe and the engine revealed no problems were noted that would have prevented normal operation the airplane had an annual inspection on 2013 so about three months prior and then a dual yoke control had been installed at that time in the airplane some interesting comments from witnesses to the accident were recorded in the docket the first witness lived about a mile from the crash site and reported that he first became aware of the airplane when he heard the engine suddenly change pitch and speed up and he looked up and saw the airplane spinning slowly and a nose-down attitude he observed five spins before he lost sight but slowly i'm not sure the second witness who lived about eight tenths of a mile from the crash site observed the airplane and heard the props of a small plane struggling twice this is a quote he thought he heard a bang on impact but he was not certain if there was another airplane in the area prior to the accident that's kind of an usual thing to say but it's important because a third witness who contacted the ntsb himself reported that he lived two miles west of the airport and he was about eight miles south of the crash site he thought it to be the same shape and size as a cessna 180 172 and he watched it as he watched it another airplane larger than the first appeared he thought it was closing on the high wing airplane eventually making an invasive maneuver to avoid a collision and he's overtaken and made a really serious maneuver to avoid a collision and then pressed on the atc controller at at the airport reported that he watched the accident airplane depart to the north and did not observe any other airplane in the vicinity he did say there was a 182 cessna 182 doing touch and goes on runway 2-7 so slightly off off set from the runway 3-4 where the accident airplane took off from notably the airport does not have radar among the ntsb docket files are copies of the pilot logbook and in reviewing that and comparing it with the report i noticed several discrepancies i'm not going to quibble about tens of hours but the report lists 69 hours in make and model and the log book shows 19.4 over a period of two years and three months the only apparent checkout program for the pilot was a 1.0 flight with five landings i'll stipulate the possibility here that the log book in the docket is incomplete and if so i think that's serious because the record is what's in the docket not what somebody left out there's discrepancy on upon the part of investigators i think if this is an incomplete log what else is incomplete additionally in the logs available there is no corresponding flight entry to the flight review or the make and model sign off date this may seem like a minor point but as i said the ntsb docket is an official record and then it should be it is stipulated in in courts of law it's complete and factual repository of the action investigation in a lawsuit these facts could be germane to the case at this point we can't tell whether the fault lies with the ntsb or the pre-verification on part of the pilot and this is important for us to actually piece what happens what happened and and everything be reliable okay so it's plain to see here that the aircraft departed control flight entered into a spin the power was set to full and wonder wonders how these two facts could be true at the same time to spin an airplane must for stall and then yaw to depart control flight with full power the only logical way for that to happen would be in a power on stall i can't think of any other situation i've always thought that a power on that power on stalls were just a thing because well well because we can do them i never really thought it was about a realistic scenario the pitch angle required at full power from takeoff is extremely high for any pilot not experienced in aerobatics i don't know why you'd be doing an airplane that wasn't aerobatic for the average pilot it is unthinkable it isn't an extreme unusual attitude the only time you use full powers for takeoff and the recovery is actually pretty easy you just unload that's what you do and that's what you're taught the faa acs pretty much restricts the power on stall power setting to no less than 65 from a realistic standpoint the only time you'd most likely be able to stall with power on like this is at altitude for a normally aspirated engine the max power you setting you'd likely see is about 75 65 75 power at a density altitude about eight or nine thousand feet like this accident happened at and i've always had a problem so i personally have always had a problem with power on stalls so it's looking to me like this j35 was practicing power on stalls and like i said the density altitude was probably around eight to nine thousand feet and the engine was putting out somewhere around 65 to 75 percent horsepower the airplane was in a spin with the power all the way up and given the accident profile i think this is what this pilot was led down the primrose path and so to speak okay and here's why the recovery from a power on stall is to unload if you stay coordinated meaning you use the rudder you will accelerate out of a stall condition fairly quickly that becomes the standard however if you screw it up what happens don't forget that the faa position is that we stay away from spins that's the best practice we avoid them we talk about them but we avoid them the power on stall is the worst case scenario for the bad that can happen in this situation okay so imagine if you will put yourself in the seat you're at the stall break with full power and the nose perhaps 20 to 30 degrees nose high the airplane breaks to one wing and begins to spin your recovery plan is to unload so you do that and what happens the spin accelerates it doesn't stop you don't recover from the stall your spin accelerates damn that's unexpected yeah here's what's happening first off power is a pro-spin input meaning that when you add power the airplane tends to flatten out torque and p-factor and essentially it digs into the spin y'all rate increases the odds of recovering a spin with power on is small add to that if you push the stick forward well you just added another pro spin input the airplane tends to flatten out a little more and yaw faster still okay you might have seen a flat spin at an air show the routine is to add out aileron full power and forward stick that's how you do a flat spin and you increase your yaw rate and a bonanza it's not going to be a flat spin it's going to be still pretty significantly nose down it's not an extra you can recover you cannot recover the airplane from a flat spin you have to reduce power neutralize controls but that's not what we teach in this situation power on stall unload remember we don't teach spin recovery and i suspect that this pilot really had no idea what to do next and he was so confused by the situation that pulling the power to idle just didn't occur to him that's the stress of a few seconds and i'm a really unusual situation what do i do and the recovery from an unused in the recover from an unusual attitude world more power is effective in a very small narrow range of upsets very controlled very coordinated let's look at the airplane now and see what i'm talking about the thing we want to do when a spin happens is is basically have to stabilize the airplane there's a real popular mnemonic out there p-a-r-e that's power aileron rudder elevator okay i personally am not a big fan of mnemonics i don't like cigar i don't like you know all the different uh mnemonics out there to remind you of what to do i'm more of a flow kind of a person and i like to do actions that's what i think of in a flow as i do actions and for me that extra step of remembering what the word is and then remembering what the letter stands for there's actually two extra steps there to me that's just i don't like it you may be different and that's fine i don't care but i don't like p-a-r-e because of this because of this situation all right what you have to do first is you have to stabilize the airplane okay you have to neutralize you have to take out the pro-spin inputs i've done several action investigations when i was in the iac as a interested party and in particular pits spin accidents where the power remained up during the spin and that is a pro spin action and people had trouble recovering from the spin so when i i didn't invent this stuff i'm not saying that i'm you know god's gift to aviation here but in my pilot training in the air force what i learned was is that the the bold face essentially is this is and i'm going to paraphrase it idle neutral aft okay so you pull the power to idle and you neutralize the ailerons because those are pro spin even in a jet uh that you have pro spin because there is torque and p factor from the spinning uh disc inside the engine and i've experienced that when you get really really slow you get a little bit of torque okay so it's kind of weird but uh so idle neutral left power to idle ailerons to neutral and you won't go full left on the stick the reason you go full aft on the stick like this is you want to stabilize the airplane in the spin okay to maximize your ability to use the rudder to stop the yaw okay idle neutral f stable you're stabilizing the airplane that's the first step in spin recovery and you're doing this so we think about this is the relative wind is basically going up this way okay so what i'm doing is is i'm allowing as much relative wind to go across the rudder here as possible and this is the effective part of the rudder that's that's going to stop my yaw so if i did something like this or if i had forward stick that is minimal now there's about this much rudder that's exposed to the relative wind it isn't going to work and that's one of those reasons why you know is the forward stick is should not be forward okay because it blanks the rotor out so idle neutral aft is the first thing we do and then we've got to figure out what direction we're spinning and frankly you can be pretty easy about that you can push on either one and if you push on one rudder and there's no resistance it's the wrong rudder push on the other rudder and it's the hard rotor okay to push that's the correct rudder because you have a stalled condition here and if you pull it push it the other way you've actually got airflow on that other side and so that's in a spin left that's what's going to happen here this would be the easy rudder this would be the hard rudder so it's also if i'm in a left spin the ground is going to the right my perception is i'm in a frame of reference here so the ground is going to the right i step on where the ground is going that's the hard rudder and that's how i figure that out so idle neutral aft rudder opposite the spin okay that's it now the next thing you have to do is as the yaw starts i mean this is a this is a very a fraction of a second it's not you know well i'm waiting for 30 seconds you know i'm going to get some coffee or something when the yaw starts slows down you go forward on the stick because you want to break the stall on the wings and i'm going to show you we're going to go look at the bonanza here real quick because i got some real interesting tough video and a spin we're going to look at but the spin left the this wing is stalled that wing is not okay and maybe partially stalled but i think after we see the tough video we'll see probably and i have tufted this swing in the steerman but that wing is going to be mostly flying and that's the auto rotational moment so we go forward on the stick to break the stall now we neutralize the rudder okay and we're faced with the dive now we have to recover from the dive so that's the the actions that we take idle neutral aft rudder opposite the spin stick forward just forward to neutral okay to break the aoa and get the airplane flying again neutralize the rudder and then recover from the dive so reason why you only go forward just forward to neutral is the more forward you go the more you're to pitch over negative okay and if you don't if you don't take the rudder out when you do this and i've been with students that do this is they leave the rudder in and they pitch forward really because they're really nervous way far forward the airplane pitches up inverted and starts spinning the opposite direction that's what's going to happen so that's not what we want to have happen idle neutral aft okay rotor opposite the spin stick forward to break the aoa and get the airplane flying again neutralize the rotor recover from the dive now let's go look at the uh some of the airflow on a more modern conventional design all right here's the uh the we'll talk about the steerman so the airflow is a little bit different on this airplane as you can see when i go idle neutral aft this is what happens here uh again the relative wind is about like this uh in this direction across the rudder okay so i'm not exposing very much of the rudder to uh to the relative wind in this situation but the interesting thing is is this rudder is really really effective so i'm not talking about the v-tail i'm not sure exactly what there are dynamics of the v-tail is i'm not going to uh i'm not going to spin one to find out so we're just talking about spins in any any general aviation airplane so idle neutral aft you have the airflow going across uh on the inside of the spin say we're spinning left again this is a very turbulent area but the other side has got pretty good flow so when what happens is is when you release the pro-spin control and that's how we get one into a spin to practice one is as we use for a lesbian use left rudder at the stall to generate a left spin okay when that happens and i uh we're spinning and then uh when i neutralize the rudder when i just let it go then there's enough airflow on this other side that it generates uh lift because this is another lifting body right here it just happens to be vertical when that happens it generates enough lift that it zeros out the auto rotational moment there's another thing happening and we're going to talk about that here in a second but um that's what's happening it's a little bit different than the rudder configuration in the in the steering wheel take a look at the tufted video for the wing on this and as we can see in the full stall uh the both wings are stalled but then once the airplane has started auto rotation then the the inside wing to use the fa diagram says more stalled and the outside wing is less stalled well what i'll tell what i see in the tufted video is is that yes the inside wing is stalled i'd say fully stalled the outside wing is almost fully flying and what that does is that creates a auto-rotational moment this way so it's trying to it's it's in a couple of axes here so you have this wings not producing any lift at all so it has a tendency to go down anyway the outside wing is flying and it wants to generate lift and roll and that roll translates into yaw like that and that's why you get an auto rotational moment and it wants to keep doing that there's more there's more to say about the design of this wing and that vg that that sticks out on the leading edge and i did a short video several months ago about that i'm going to do another one it's not it's not germaine to this stall spin video right now so the what i want you to take away from this is is that a power on stall is as close to where you're going to get i think in a departure in a training situation is that what happened in this in this airplane i don't know if this is what's happened in the j-35 because we didn't have any witnesses say oh yeah he was doing stall practice we just had somebody say that he pushed the power up and then when he looked at the airplane he saw saw the airplane so there was some delay uh he saw that it was spinning okay so to spin an airplane with full power you had to be doing something else okay you got to stall it and it's pretty hard to actually stall the airplane an accelerated stall i've demoed that in this airplane it's pretty hard to do that you know and then drop into a spin so what i want you to take away here is that in a power install you have to be very very careful it's the unload is the way to recover from a power on stall but if you uh get beyond the stall and you start to slice the nose starts slicing in other words it's not straight we stall we push it over we're good but if the nose starts slicing left or right that means that you have a departure happening and the airplane is going to be into a spin power is a pro spin input and you gotta pull the engine to idle you have you have to absolutely right now no delay pull that engine to idle and then neutralize your controls and recover from the spin okay uh that's what you have to do you have to use a rotor to do that and uh if you haven't had training well you got to be really really careful getting into that power on stall situation because i think you're right there on the on the fine feathered edge of uh getting into an accelerated stall and spin in that situation so uh my suggestion is you go out do a little bit of uprt so we can you can understand what uh what's happening in this situation so that's my nickel on the grass i hope you enjoy the video i hope you learned something especially about doing power on stalls and well thanks for watching and we'll see you next time on flywire

Channel: FlyWire- scott perdue

Views: 29,340

Keywords: J35 Bonanza Power-On Stall / Spin, general aviation, beechcraft bonanza, a36 bonanza, J35 Bonanza, power-on stall recovery, power-on stall, Stall / Spin, Flywire, flywire online, flywire youtube, scott perdue, F33C, F33 Bonanza, V35 Bonanza, Aerobatic Bonanza, flight training, bonanza, commercial pilot, pilot, travel by plane, flying an airplane, airplane spin, spinning a GA airplane, departure, controlled flight, recover from a spin, Spin a Bonanza, spinning a bonanza

Id: 65vAwiM4YkI

Length: 21min 32sec (1292 seconds)

Published: Wed Apr 20 2022