How I Stalled on The Base Turn (And Got Away With It)

[Music] unless you live in some kind of fantasy world and maybe even if you don't flying an airplane is just not that hard pull the stick back the houses get smaller push a stick forward they get larger the rest of it is air space rules and maybe a little bit of weather theory yet we still manage to wreck 1200 airplanes a year three or four a day give or take that allows people like me to write about airplane wrecks airplane wrecks we're right another airplane rex we write some more one of the things we have love to write about is stalls and stall spins stahls first appeared in the literature more than 120 years ago written by no less than wilbur wright in the intervening years we have chopped down entire forests printing articles about how to avoid stalls and i'm not sure we've even dented the stall rate what all that shakes out to is this you are unlikely to stall if you keep your head out of your ass yeah well sometimes that's not so easy because a few months ago i stalled the cub in the worst possible place the turn from downwind to base well worse would have been in the turn to final but either way cub patterns tend to be tight and kind of low so let's call it 300 feet clearly i didn't die but i think i might have gained some sense of how inadvertent stalls catch pilots by surprise and do result in fatalities i'm not arrogant enough or even good enough to consider myself stall proof but i always figured i was still savvy enough to at least avoid one i'm rethinking that so here's the setup i was out shooting the video and the camera batteries died so i was planning to install fresh ones the airport i often use for this is a little grass strip south of venice rarely any traffic there but there are a few of these nested there this is a red-tailed hawk it's a common species throughout north america and definitely here in florida if you've ever seen one in the wild you have seen a superb flyer in my experience these birds really like to buzz low-flying airplanes and that's exactly what happened to me but this wasn't a bird strike risk more like an unauthorized surprise formation flight as i was floating through that turn from downwind to base this hawk approached from the inside of the turn and as navy violets might say he dropped anchor 10 feet off my left wing staring right at me as if to say let's see what you got dude i was so mesmerized by this bird that i kept doing what i had been doing without thinking about it slowing the airplane down in a bank you can imagine where this is going but before i go on let's just review stalls the right way to think about stalls has always been an angle of attack terms not airspeed terms we use airspeed because it's a practical surrogate for angle of attack now new airplanes and a lot of legacy aircraft are getting after market angle of attack indicators of various designs an improvement maybe but i'm not so sure they're much better than airspeed indicators at helping pilots avoid inadvertent stalls they're just another thing to look at that you didn't have to look at before and if you're not disciplined about it they're just another gym crack in the panel and now they even have voices and chimes however they are really good for maximum performance landings at the slowest possible speed so there's that stall angle of attack varies with airfoil design but it's typically between 16 and 20 degrees let's use 17 degrees when the wing aoa reaches that angle the flow departs and the wing stalls and as you know or should know that happens independent of air speed if you can install a wing at 38 knots you can stall it at 58 knots if you get the aoa high enough you can do that with pitch or with bank angle load factor really or some combination of the two and that's a typical scenario for a lot of approach phase accidents takeoff phase accidents which are actually more common often involve non-turning stalls sometimes following an engine failure there are a lot of moving parts here when you tug the stick back to increase pitch you've departed steady state flight and put the airplane into a transition the pitch is increasing and so is the angle of attack lift is momentarily increasing and so is drag air speed is decreasing and especially if you're in a turn load factor is also increasing the thrust vector points uphill and the lift vector angles from the vertical to affect the turn kind of busy when you think about it this way in my case and this is the real light bulb moment for me i had the airplane in a transition as happens to many pilots tail dragger or not my landings had turned to crap because i was just flying them too fast i'd gotten lazy in the cub 55 miles per hour or a little less on short final works well it will tolerate 48 over the fence at that speed in a three-pointer it touches down with minimum energy and no bounce and no need to bleed off speed and ground effect waiting for all this to happen so in my stall scenario when mr hawk showed up i had the airplane in an increasing bank and i was feeding in pitch to bleed off speed so the bank was increasing slightly the angle of attack was increasing and so was the load factor the airspeed was doing what i wanted to decreasing in other words everything was in motion and all this is going on while i'm blissfully playing john james autobahn in the pilot seat now i'm not saying it was the bird's fault i said i'm blaming the bird cubs are actually kind of hard to stall that fat airfoil wants to do nothing but fly and it takes a determined pull to get a break out of it if you can get a break at all usually it just mushes along if you're really brain dead about it the wake up call is that the stick gets soft and the lower door floats up off the full open position although it doesn't always do that in this case i never got that far since the instant i felt the mushy stick i unloaded the wing and added a little power it recovers instantly had i persisted in my rapturous admiration of the hawk i'm sure his look would have said hey way to go einstein as i must into the trees this was of course a turning stall or a turning incipient stall if you prefer so doesn't that increase the risk of a spin well it would if the turn were uncoordinated with yaw toward the inside but even with hands of stone i can still fly a coordinated turn and anyway just as stalls take work in a cub so do spins remember that a spin is stabilized auto rotation and the main wing has to be stalled for it to begin and there has to be yaw in the direction of the spin and not just yaw but rate of yaw it's the rate that imparts the momentum to get the rotation going in some airplanes it even takes a little pulse of power over the rudder to get a spin started for all the writing i've done about stalls and spins the eye opener here is that distraction caused this not an engine failure not over banking and not real loss of control it makes me wonder if other pilots have been bitten by this by having their attention diverted to another airplane in the pattern or something on the runway or even a bird just as they have the airplane in a transition from steady state flight to something else in a transition where load factor is increasing along with angle of attack a moment's lapse is all it takes and a cirrus or a cessna might not be so forgiving as a cub i wish i could somehow honor those acres of trees we've mowed down trying to clarify these concepts which are in the end really pretty simple i got nothing i'd be the last guy to dis panel gadgets or training tricks to burn this into the reptile brain but in the end you just have to accept that a piloting mistake might not be prevented by some mind trick training thing we just somehow haven't thought of yet but by the habitual discipline of paying attention to what the hell you're doing it's another way of saying that if you can just figure out a way to keep your head out of your ass everything will be just fine brad webb i'm paul bertarelli thanks for watching he had it coming

Channel: AVweb

Views: 108,219

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Id: -2mzsjXn88Y

Length: 10min 3sec (603 seconds)

Published: Thu Oct 21 2021