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  #1  
Old 06-26-2020, 07:22 PM
Tankerpilot75's Avatar
Tankerpilot75 Tankerpilot75 is offline
 
Join Date: Jan 2015
Location: Oklahoma City, OK
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Default Aileron rolls ?

As an “old“ military pilot I thought I knew a few things about gentle aerobatics. Unfortunately I’ve either totally lost those skills or I’m not doing something right (I suspect the later).

Here’s the situation: I entered the aileron roll at 125kts and 20 degrees nose high. Full left aileron deflection and the roll began as expected. After a full 360 degree rotation I found myself approximately 50 degrees nose down and doing a “nose low” unusual attitude recovery (felt like the bottom half of a low g loop) - not what I expected. Roll rate did seem a little slow. No rudder input was used for the roll since it was an “aileron roll!” Second and third attempts - same results.

I’m thinking maybe a little rudder is required to speed up the roll rate. Am I correct? Obviously, the slower the roll rate the lower the nose is at a return to wings level. Suggestions from those with better RV flying skills?

The T38 would do two full deflection 360 degree aileron rolls in about one second (could give you a real headache if the other pilot caught you off guard). The T37 was slower. However neither aircraft required rudder input for the aileron roll. It’s only been 45 years since I flew those aircraft but the memories are precious!
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  #2  
Old 06-26-2020, 07:29 PM
PCHunt PCHunt is offline
 
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Location: San Diego, CA
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My guess is that you are not fully releasing back pressure on the stick when you are rolling.

Pull up to 20 degrees, then STOP pulling up by releasing all back pressure on the stick. Pause for a split second to make sure all back pressure has been released, THEN do the roll.

If you are pulling back on the stick, the nose will drop as you describe.

You should end the roll at about 10 degrees nose low with the above procedure.
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  #3  
Old 06-26-2020, 07:31 PM
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catmandu catmandu is offline
 
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I like 140 KIAS, nose up for a potato, unload, deflect aileron, use rudder to help nose through the roll depending on magnitude of aileron deflection. Unload after nose up is key, as Pete said.
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Last edited by catmandu : 06-26-2020 at 07:32 PM. Reason: Pete beat me to it.
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  #4  
Old 06-26-2020, 07:45 PM
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rswalden rswalden is offline
 
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Quote:
Originally Posted by Tankerpilot75 View Post
.... I entered the aileron roll at 125kts and 20 degrees nose high. Full left aileron deflection and the roll began as expected. After a full 360 degree rotation I found myself approximately 50 degrees nose down and doing a ?nose low? unusual attitude recovery (felt like the bottom half of a low g loop) - not what I expected. Roll rate did seem a little slow. No rudder input was used for the roll since it was an ?aileron roll!? Second and third attempts - same results......
Try 145-150 KIAS with nose well above the horizon. That's plenty of smash.... I do all of my "gentlemanly" aerobatics at this speed with power set at 24/2400 for loops/cuban 8/rolls/cloverleafs etc... with about a 3.5 g entry pull. At that power setting I can do over the tops all day long without losing entry altitude.

Depends on your engine/prop, of course.
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  #5  
Old 06-26-2020, 08:32 PM
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jliltd jliltd is online now
 
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I too am thinking you have some pull on the stick. And the speed sounds low. After pitching to 20-30 nose up by positively neutralizing and keeping the pitch at or forward of that point during the maneuver will yield much better results.
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  #6  
Old 06-26-2020, 08:46 PM
jrs14855 jrs14855 is offline
 
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Location: Lake Havasu City AZ
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Default Rolls

I would normally respond by telling the OP to get some aerobatic instruction.
When I was instructing in the Pitts I would introduce a trainee to aerobatics with aileron rolls. I would not demonstrate the maneuver but would lead up to the first attempt as follows: Roll the airplane from 30 degree left bank to 30 degrees right bank with a touch of coordinated rudder. Gradually increase bank angle to 60 degrees. Then a 30 degree climb angle, hands momentarily off the stick at 30 degrees. When comfortable with this pull up to 30 degrees, hand off the stick, a touch of left rudder and push the stick to the left with finger pressure applied to right side of stick.
In two years of doing this I never had to take control and while the results were not always pretty they were always successful.
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  #7  
Old 06-26-2020, 09:00 PM
Scott Hersha Scott Hersha is offline
 
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Location: Cincinnati, OH
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Here?s how I did my first few rolls, trying to do as Van advised in an early version of the RVator.....

At 140-150 KIAS level flight, maintaining your power setting throughout, pull the nose up to 30* nose up. Let go of the back pressure for a couple seconds, wings level (the nose will stay there, briefly), then just push the stick to the left (or right) with your feet flat on the floor. Don?t push or pull on the stick, don?t use your rudder, just apply aileron movement. Watch the world go around, and when you come out at the end of it, you should be about where you were when you started. Your nose will be pitched down maybe 15*, but your airspeed won?t be excessive, and you can recover to level flight without much G force. You might notice a little wallowing on the top because your airspeed is decaying, and you aren?t using your feet, but there is very little adverse aileron yaw in these airplanes, so until you get comfortable, don?t worry about using rudder input. A little later, rudder input will make the roll a little quicker and crisper, but it is just as fun to do it the way I suggested.
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  #8  
Old 06-26-2020, 09:01 PM
sandifer sandifer is offline
 
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Location: NC
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I agree with the comment about it being likely that you were holding some aft stick during the roll, which caused you to "dish" out low. 20 degrees nose high at 125KT in an RV-7 is just fine if you return the stick to the 1G position before rolling (and keep it there), and use full aileron, rudder or no rudder. RVs have differential ailerons which vastly reduce (but don't entirely eliminate) adverse yaw. Rudder use will not greatly affect what happened here.

Regarding the urban legend of the 720 deg/sec T-38 roll rate, I have it on good authority that it's pure BS trolling by those who wrote the flight manual. Somehow the A-4 has the exact same max roll rate. There's zero evidence of the existence of this roll rate. TWO hundred and seventy deg/sec is more likely the reality, which would FEEL like 720 to those who'd never experienced anything more than the lethargic roll rate of the T-37. To put this in context, RVs generally roll <110 deg/sec at VA.

Last edited by sandifer : 06-26-2020 at 09:16 PM.
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  #9  
Old 06-26-2020, 09:31 PM
sandifer sandifer is offline
 
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Location: NC
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If you'll indulge a little thread drift, here's a video I made a few weeks ago on what 720 deg/sec ACTUALLY looks like. It's an epic Facebook topic among certain circles.

https://www.youtube.com/watch?v=9TeZOyJ17RU
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  #10  
Old 06-27-2020, 03:53 AM
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ronschreck ronschreck is offline
 
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Here's a great video from my friend Gordon Penner. Lot's of great tips!

https://www.youtube.com/watch?v=eLJaqWYYeRw
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