Why did my instructor freak out?

[mhorowit]

OK - on Sunday I'm going for refresher training since I haven't flown in about a year. I'm reviewing landing techniques and understand the physics involved in a 'bounce'.

When I was doing transition training I recall the instructor went bananas when I moved the yoke forward after a bounce.

Was he reacting to the fact I didn't _simultaneously_ advance the throttle?
(In my mind, I was attempting to re-establish the 3-point attitude). - Mike

[Carl Ellis]

Re: Why did my instructor freak out?

Because you lowered your angle of attack. With less lift you'll come down *hard*.

- Carl -

[alwaysoar]

Re: Why did my instructor freak out?

Yes, and it might have been too much forward yoke when you should have just "relaxed" back pressure. Please define a "bounce." Did you clobber in, and did the nose bounce up radically causing a very high angle of attack? What speed do you approach at? I rarely bounce, but I'll do little skip-de-doos down the runway sometimes if I don't finesse the attitude with the speed with the height above the runway, etc. It really wouldn't hurt to get with an instructor. Instruction through the forum leaves a lot be desired since no one here has flown with you--that I know of.

Ed@BTV VT
TF 527

[mhorowit]

Re: Why did my instructor freak out?

It's an AOA problem, and yes, like I said, I'll see an instructor, but for now the answer seems to be: he freaked because I didn't add power when I lessened the AOA. I like the term 'relaxing pressure' vice 'pushing forward' - Mike

[flyguy]

Re: Why did my instructor freak out?

Mike,
A good-sized bounce is more than a just a wheel bounce. It is caused by the push up from the wheel contact rotating the aircraft around it's center of gravity and increasing the angle of attack and causing a baloon. The aircraft pitches up and baloons without any additional control input (backpressure.)
The aircraft is then way nose high for the contol input, airspeed, ect. and will respond by pitching down. If at the same time you reduce the back pressure it will add to the aircraft's normal response of pitching down and your vertical rate down will cause you to hit really hard the second time. Which will cause the airplane to really overrotate, pitching up again and doing the entire process all over again, getting worse each time, until something breaks.

It is a form of PIO (pilot induced oscillation.) That is, control inputs are 180 degrees out of phase with what is needed. Don't feel too bad, even Shuttle Astronauts have been know to do it, (in the roll axis, if I remember correctly.)
I would guess that is why your instructor freaked out .
Darryl

[mhorowit]

Re: Why did my instructor freak out?

Well described- Mike

[paulp]

Re: Why did my instructor freak out?

Howdy Mike,

You didn't say whether you were doing a three point(stall landing) or a wheel landing. On a wheel landing, the yoke is moved forward to stick the gear on the strip. If you encounter a bounce, during the initial contact with the surface, the acft will still be generally level,i.e. little or zero AOA. If you push the yoke forward, after the bounce, you will then be diving at the runway and, as with all conventional geared acft, your cg will be behind you and you will have your hands (and feet) full and with the next contact, you stand a good chance of planting the nose of the acft in the dirt. Remember, landing a Taylorcraft, aeronca, cessna, ect is like having a bowling ball at the end of a pole that is behind you and you have to balance it so that it doesn't get off to the side of you or worst case senerio, in front of you.

A stall landing or three point is a little different. The bowling ball still wants to get ahead of you but now, you have a positive AOA-so, if you have a bounce, just slightly relax the back pressure and add a little power and start again. REMEMBER, if you don't feel good about the landing, ADD POWER AND GO AROUND!!!!!! It is no disgarce and shows good sense. You can make 100 perfect landings and #101 will keep you humble for a month. Of course, #101 will have an audience. And, if they say anything just say "hey fellas, I'm going to give you all thirty minutes to draw a crowd before you kiss my #*@."

Still recommend an hour or two of instruction.

[Richard Boyer]

Re: Why did my instructor freak out?

Howdy Mike,

REMEMBER, if you don't feel good about the landing, ADD POWER AND GO AROUND!!!!!!

I call that a "Hit and Run". I still get to log it as a landing! After all, my logbook doesn't have a "bad landing" column....thank goodness!!

Richard Boyer
N95791
Georgetown, TX

[paulp]

Re: Why did my instructor freak out?

Richard,

Just remember, any landing that you walk away from is a GOOD landing-any landing that you walk away from AND the airplane is still flyable should be considered to be an OUTSTANDING landing!!!

[flyguy]

Re: Why did my instructor freak out?

Does that mean I can log each bounce as a takeoff and a landing?
Darryl

[paulp]

Re: Why did my instructor freak out?

Darryl,

Yes, you can log each bounce as a landing. It ain't kosher and the logs won't be correct but you can.

[VictorBravo]

Re: Why did my instructor freak out?

I am NOT an instructor and not a high time pilot...but I do have to say that the crucial matter is WHEN he pushed the yoke forward and how fast the airplane is flying at the time of the bounce.

If you bounce and apply forward pressure immediately after the bounce, what that does is stop the excessive climb rate and lower the AOA back into the "flying" range. This should prevent you from heading towards a stall five feet above the runway. It also keeps the speed from deteriorating as fast, so you don't lose control and flying speed as fast. This in turn allows you to still have some lift available to cushion the "second" landing and hit softer.

If you were at or near full stall when it bounced the first time, then pulling back on the yoke as the airplane soars upward below stall speed is a guarantee of a very hard secondary landing, with not enough lift to cushion it.

What I do is if I bounce I want to keep the height of the bounce as low as possible. So I would indeed push the yoke forward as soon as it came back off the ground, and try to keep it from rising up away from the runway. Then when it started back down I would "flare" again using back pressure on the yoke to maximize the lift just at the second arrival. This requires good timing to do it right.

In my opinion, the LAST thing you want to do is let the airplane bounce upwards any distance on a botched full stall 3 point landing.

Bill Berle

[flyguy]

Re: Why did my instructor freak out?

Bill,
If my reflexes were that fast I wouldn't be bouncing in the first place. Man if I tried that I would dribble the airplane all the way down the runway like a basketball . And if I could do it-- I would be in training for the International Aerobatics competition or flying SR71's.
In all fairness I have to say that most of my bounces are pretty anemic. If it's a resonable day when I come over the fence there isn't much flying stuff left. I'm much more likely to drop it in from a foot up than to bounce.
I use to come in a little faster and let her slide along the top of ground affect and when she fell through I would catch it with what I had left in the elevator, kinda plop on the deck, but I'm getting too old for that kind of stuff now.
Darryl

[matsuthunder200]

Re: Why did my instructor freak out?

I like this thread it reminds me of when i first started geting checked out in a tail dragger. At first i was always bouncing down the runway and when i did my instructor always made me go around. what i was doing wrong was i was looking right in front of the airplane instead of way down the runway. what he made me do was a normal appr, and during the flair he would tell me not to land but fly down the entire runway a foot off the ground nine out of about the 10 times i did that i never made it a hundred feet or so before i would touch down on the runway and have the smothest landings i had ever made up untill then. After that i might have a bounce once in fifty and for some reason i still go around. I think you did the right thing if the nose comes up during a bounce and you are at stall speed you haft to push forwards on the yoke and apply power if you dont you may stall and then you might brake somthing. I think go aronds are a wonderful thing. when you start doing off airport landings short gravel bars, 600 ft ruways and the like if you bounce or come in 5 mph to fast or it dosnt feal right for any reason i always go around.

[mhorowit]

Re: Why did my instructor freak out?

Howdy Mike,

You didn't say whether you were doing a three point(stall landing) or a wheel landing. And, if they say anything just say "hey fellas, I'm going to give you all thirty minutes to draw a crowd before you kiss my #*@."

Still recommend an hour or two of instruction.

It was a 3pointer

I have to remember that phrase

No question - lesson set up for Sun afternoon - Mike