The “impossible” turn and the “startle effect”

Discussion in 'Rules and Regulations / Flight Safety / Better Pil' started by BJC, Feb 13, 2019.

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  1. Feb 13, 2019 #1

    BJC

    BJC

    BJC

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    Starting a new thread to discuss the “startle effect” mentioned by TX, and related issues, including the “impossible turn.”

    There are lots of things that could, perhaps, should be different about “standard” takeoff procedures. For starters, why wait to be startled? Why not expect an engine loss of power or total failure on every takeoff? Easy to do; simply focus on the task at hand.

    By altering the flight path, the usable runway ahead can be increased by not flying the centerline. Flying at about a 20 degree angle to the CL keeps traffic relative confined, but, when flown to the down wind side allows for landing ahead by first pitching up to (approximately) minimum sink speed, applying full flaps, and using a maximum slip to get down to the remaining runway with minimum forward speed and forward flight distance. It also allows for a turn-back into the wind once adequate altitude and speed have been attained. It does take practice, but that can be fun. The down side is that actual practice on an airport excites people who strictly adhere to the oft-taught “crash straight ahead” theory.

    By knowing the surrounding terrain, the cross wind turn can be placed to optimize emergency landing options. Last fall I visited I19, and departed on runway 7 with a planned departure to the SSW. No other traffic was in the area. The terrain beyond the departure end looked very inhospitable, but a nice road that crosses near the end of the runway would have been an option. I was near gross weight, so a turn back would have been more difficult. We took off, turned more than the standard 90 degrees to follow the road, turned less than 90 degrees to downwind, then departed to the SSW. We had good landing options at all points in the vacinity of the airport. A more “standard” pattern would have put us over some bad terrain.

    At my home airport, 97FL, my crosswind turns and initial power reductions are positioned not by pattern altitude, but by my position relative to open areas where an emergency landing would be most likely survivable.

    I understand the guidance to student pilots to land straight ahead; they are far from the experience and skill level necessary to do anything differently. But why does the skill and judgement development stop there?

    Please share your thoughts, techniques, and experiences on these subjects.


    BJC
     
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  2. Feb 13, 2019 #2

    Dan Thomas

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    Most pilots get the PPL and stop right there. A few will get a night or IFR or taildragger rating, but most won't continue to build beyond what they picked up from the instructors. They're pilots now, doncha know?

    When I went for the CPL, IFR and instructor tickets, I found out just how little I knew and how some of it was wrong altogether.

    So, for the average PPL, landing straight ahead within 30° is the safe thing to avoid an almost inevitable stall/spin if he tries to turn back. Crashing under control is far preferable. Since our PPL students were going to be going on to the CPL, we taught what you are proposing: expect a failure and have a plan. Know where you'll put it down. A verbally-spoken emergency self-briefing immediately before takeoff.

    Note: in the US an instructor is called a CFI: certified flight instructor. In Canada "CFI" means the Chief Flight Instructor in a flight school, while the rest of us are at one of four stages of instructor, Classes Four (basic) up to One (can teach other instructors). I was a three and never got beyond that due to heavy maintenance responsibilities. One can't do everything. Classes 2 and 1 require extensive hours in teaching experience and numerous successful student checkride recommendations, and more written exams and flight tests to get past.
     
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  3. Feb 13, 2019 #3

    Topaz

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    I think it depends entirely on the airplane involved. Yes, yet another variable.

    But seriously, while I would (and have) done a turn-and-return-to-runway from 250' AGL in an SGS 2-33 (rope break, simulated by pulling the release), I wouldn't think of doing that same maneuver in, say, a Thorp T-18 or a fully-laden Bonanza. Every airplane is a glider when the power is off. Some of them, though, aren't very good ones.

    More to your point, the key takeaway here, IMHO, is that you always assume that every single takeoff is going to end up with the tow-rope broken or the bolted-on towplane going silent, and at the worst possible time. If you take off with the expectation that the tow-rope could break, or the bolted-on towplane will go silent, and either at the worst possible time, you can take ten seconds before takeoff and think, "Okay, if that happens, what am I going to do on this takeoff to stay in the "walked away" category?" Take those ten seconds and you probably will walk away, should something go wrong.
     
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  4. Feb 13, 2019 #4

    Victor Bravo

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    I'm nobody's idea of a high-end test pilot, but I do have a relevant technique I used starting in the R/C model days that is equally valid IMHO in full scale aircraft.

    When there is any question of engine reliability, I take off and immediately turn 30 degrees to the right as soon as I have solid control of the aircraft. Then I put the airplane in a very shallow left bank, and climb away, very very slightly turning left (often not even fully coordinated).

    If the engine stops running, I'm in a good position to continue a left turn back to a downwond landing. Importantly, the 30 degree offset results in my not having to make as tight of a turn radius to get back to the runway. This means I can make a little more gentle turn, less bank angle, less G load, less AoA, and I'm already in the early stage of that turn by virtue of having put it into a shallow left bank.

    Basically I put myself into the best possible position to get back to the runway, and instead of thinking about "what if it quits" I am actually positioning the aircraft as if I know it is going to quit.

    Everybody asks me why I turned away from the runway literally upon liftoff, and I have to explain all of this so they don't think I'm flying drunk. Sometimes, if it's a pretty girl asking, I tell a long and lurid story about a model airplane engine called a Webra Speed .61, which had a really wonky carburetor, and the days before model engines had "muffler pressure" pressure taps to improve fuel delivery, and how many times we used to have engines quit in models in the old days when we had to walk uphill in the sleet and mud to fly our models :)

    Even though it looks pretty screwy, I do bellieve this immediate offset maneuver will give me the best possible opportunity to not damage the aircraft (and thus myself) if Ih ave an enginee out on a test flight from a straight runway surrounded by unlandable terrain.
     
  5. Feb 13, 2019 #5

    BJC

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    Nor am I, but this stuff is just common sense.

    Years ago, when I first started turning just after lift-off, I always turned right. Then when I started working on turning back for a landing, the difficulty of getting aligned with the runway for a downwind landing, with even a small crosswing, became clear. A small radius turn into a crosswind works well.


    BJC
     
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  6. Feb 13, 2019 #6

    Pops

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    One of the first things my military instructor taught me was to play "What IF" on every flight. Take-off to landing. Same for switching fuel tanks on a cross country flight. Same for in cruise, same for pattern and landing. Don't just set there dumb and happy. When downwind, read the terrain and the structures upwind of the runway and know where to expect the turbulence and wind shears, etc.
     
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  7. Feb 13, 2019 #7

    Tiger Tim

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    I've always been all for just crashing straight ahead, though to be fair I've flown mostly over flat land with easy options straight ahead. Based on some of the unnecessarily fatal accidents I've seen I've become pretty convinced that as long as you can make it all the way to the ground in a light (low performance) plane under control and with the wings level you'll be close enough to fine. There can always be a replacement airplane. Higher performance airplanes may have different demands but I'll cross that bridge if and when I get to it.
     
  8. Feb 13, 2019 #8

    Dan Thomas

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    That's really hard to change with young folks now. They've grown up with cars that pretty much operate themselves and almost never quit. Push a button to start it, push a lever to get it in gear, push go or stop, and point it where you want to go. Follow the map. If it's slippery the ABS mostly keeps you out of trouble, and some cars will start applying the brakes if the car ahead slows too suddenly. And then there's the Tesla; much more automation.

    If we had airplanes like that we could get a PPL in about five hours. If we had airplanes like Teslas we'd need about ten minutes of dual, mostly about how to tie it down.

    Such technology has dumbed-down the populace, and getting them to start thinking, studying and understanding takes some doing. The aviation accidents we see are often the sort of thing you wouldn't commonly see in the '60s. Accelerated stalls, running out of fuel, engine failures due to carb ice, getting lost. Driving into mountains in poor visibility. Running off the end of the runway or getting blown off the side in a ten-knot wind.

    I have given presentations at pilot-recurrency seminars, and while most of the PPLs present appreciate knowing more, some seem to be befuddled about what's being presented. No frame of reference, see? One has to start right at the most basic level sometimes.
     
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  9. Feb 13, 2019 #9

    Pops

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    You are correct, I see it with some of the people that fly off our grass strip.
     
  10. Feb 13, 2019 #10

    blane.c

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    I think it has a lot to do with how invested you are with the aircraft involved, knowledge, finance, emotion. If you know you can or cannot make the turn act accordingly, if you want to make the turn because of the money or time you have invested, probably not the best reasons. And knowing that it is not a 180 degree turn but a 270 degree turn followed by a opposite 90 degree turn should be basic.
     
  11. Feb 13, 2019 #11

    don january

    don january

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    In cropdusting your runways can change 2 or 3 times a day and usually its a new area with many unknowns. It's hard to know where the next field is until your off the ground and you hope you've been in it before. Like all runways the wind direction and speed is the first thing I consider. I like after leaving the ground is to let the plane find what the rudder is doing for you and let the plane slid down wind until airspeed is good and then roll into the upwind side watching what the extra weight is doing to the controls and airspeed. Pilots can get into problems in the headwind picking up lift but not airspeed and that's were a stall can catch you. If you find yourself in that predicament there is little to no choice other then dropping your nose and flying until it stops regardless of whats in front. Its great to know the area around a airfield and have that image of worst case in your thoughts but in many cases that can't be done.
     
  12. Feb 13, 2019 #12

    Turd Ferguson

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    engine stoppage between liftoff and 200 ft and most pilot's are gonna stall.
     
  13. Feb 14, 2019 #13

    BJC

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    Not disagreeing, but why is that so?


    BJC
     
  14. Feb 14, 2019 #14

    Dana

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    Not if they're expecting, no, planning for the engine to quit.

    I always start drifting downwind once I'm too high to get it back down on the remaining runway. My home field is tough; there's nothing around it but trees. When I was flying 2-strokes or the single ignition half VW, I always did a circuit of the field to gain altitude before setting out over the forest. I've always made it a point to practice the maneuver and know how much altitude I need to turn back in every plane I've owned.
     
  15. Feb 14, 2019 #15

    Monty

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    They have never practiced a 100ft rope break in a glider. Seriously. Or Practiced a 100 ft engine failure. Or practiced a 200 ft failure, or even know what altitude is needed for a 180 degree turn in THEIR aircraft.. It's just not taught. Most instructors would be terrified of full slip nose down at 100 ft right at the end of the runway.. I'd be terrified of most of them demonstrating it....Can you imagine doing a 300ish foot turn with a 45 degree angle of bank back to the runway with most people??? Pull a little too hard and things get really bad, really fast....The 180 degree turn to downwind is entirely possible if practiced with proper decision points for altitude and knowledge of the aircraft....so is the 100 ft failure........but given the fact that a simulated engine failure can often turn into an actual one, that close to the ground....I wouldn't want to do that with the average student.....and that is where we are. This might actually be a good thing to do in a simulator first to learn numbers and such. Then maybe practice at altitude with simulated conditions....then maybe I'd be comfortable with someone who nailed all of that closer to the ground.

    Monty
     
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  16. Feb 14, 2019 #16

    Turd Ferguson

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    As Beryl Markham would say: “Success breeds confidence.” I would add, more success breeds overconfidence.

    In FAA hazardous attitude lingo it would be a combination of Macho and Invulnerability.
     
  17. Feb 14, 2019 #17

    radfordc

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    I find it interesting that everyone here is fully confident that they could handle this situation safely...and that they are sure that most everyone else couldn't.

    I have had an engine stoppage below 400 AGL on takeoff.
     
  18. Feb 14, 2019 #18

    Monty

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    Glider pilots have the advantage of instantly knowing the rope has failed and making a clean decision. They practice for this. They don't have a choice. If you don't know how to do it you WILL crash when it happens. And ropes break all the time. Feeling invulnerable would mean thinking it won't ever happen to me. Not a good bet statistically.

    Statistically thinking it won't fail is a good bet with most engines. It probably won't fail. It also usually won't fail all at once cleanly. This leads to scrambled, uncertain decisions. So the best advice is to land straight ahead unless you have trained for engine failure and a 180 degree turn at gross, high density altitude and a sizeable downwind component.....most of us, me included, have not done that regularly. If we did....it would be possible to deal with the situation. The question is, would the training lead to more accidents than happen from actual engine failure, considering the average pilot? Especially if the unambiguous advice is to land straight ahead...

    People test flying experimental aircraft with experimental engines might want to find an old SAC base.....

    Monty
     
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  19. Feb 14, 2019 #19

    BJC

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    The first actual-altitude turnback and land that I did in my then new Sportsman was to a 2,500 ft runway, with an uphill far end. The Sportsman wing is so much better that the A152 wing that I needed the entire runway to get stopped.


    BJC
     
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  20. Feb 14, 2019 #20

    Turd Ferguson

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    That's because pilot world is analogous to Garrison Keillor's Lake Wobegon, "where all the women are strong, all the men are good-looking, and all the children are above average." If you are in a room full of pilots and ask who is above average, 90% will raise their hand which shows pilots in general have a pretty high opinion of themselves. If you want to disperse those same pilots faster than opening a can of tear gas, just ask who is up for a proficiency check.

    I have too and I've never thought for a minute the subsequent successful landing back on the runway was anything more than sheer luck.
     
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