Aerobatics Slow Rolls
Thread Starter
Joined: Aug 2009
Posts: 92
Likes: 0
From: Australia
Aerobatics Slow Rolls
Hi,
Not sure if this is the right forum to ask but something has been bothering me recently. The IAC states for aerobatics:
How can you fly the aircraft along a straight line and also keep the longitudinal axis of the aircraft straight. I would have thought that the less efficient fuselage lift in the knife-edge portion of flight would necessitate a higher angle of attack to maintain 1 g lift in the vertical. Thus requiring the longitudinal axis of the airplane to be tilted. Can someone clarify this for me.
J
Not sure if this is the right forum to ask but something has been bothering me recently. The IAC states for aerobatics:
Slow rolls have to be flown normally on a straight line (exception is the avalanche). The roll rate has to be constant and the longitudinal axis of the plane has to go straight.
J
Joined: Dec 1999
Posts: 2,584
Likes: 0
From: UK
You are right, of course, the longitudinal axis of the aeroplane must change during the roll as you've stated. I think what the description means to say is that the axis of the flightpath during the roll must remain straight.
Joined: Apr 1999
Posts: 1,274
Likes: 0
From: Glen Prosen, Scotland
Don't know about IAC, but here's a very good summary of competition aerobatic judging which should tell you all you want to know (slow rolls are on page 9):Judging - Centre of Gravity Track
Joined: Oct 2010
Posts: 3
Likes: 0
From: Dallas, TX
Removing this post after reading Deefer Dog's comments. Thanks for the correct inputs. Maybe one day, you can teach me slow rolls! 
Last edited by Ulysses05; 27th October 2010 at 17:29. Reason: wrong info
Joined: May 2010
Posts: 645
Likes: 0
From: europe
Ulysses, I beg to differ.
First, the manouvre you describe is actually an"aileron roll" which bears only a passing resemblance to a "slow roll." In competition, the slow roll should be flown without gain or loss of altitude, and certainly without any initial pitch up that you mention, or it would be heavily penalised by the judges.
Most types certified for aeerobatics will fly the manouvre, but success depends on piloting skill. As a general rule of thumb, if you can slow roll a Tiger Moth (circa 1930, with almost non existant ailerons, and no inverted fuel system), you can slow roll anything.
DB6's post is good reading on the subject.
First, the manouvre you describe is actually an"aileron roll" which bears only a passing resemblance to a "slow roll." In competition, the slow roll should be flown without gain or loss of altitude, and certainly without any initial pitch up that you mention, or it would be heavily penalised by the judges.
Most types certified for aeerobatics will fly the manouvre, but success depends on piloting skill. As a general rule of thumb, if you can slow roll a Tiger Moth (circa 1930, with almost non existant ailerons, and no inverted fuel system), you can slow roll anything.
DB6's post is good reading on the subject.
Joined: Apr 1999
Posts: 1,274
Likes: 0
From: Glen Prosen, Scotland
Even slower nowdays, Stik. Try a Grob Heron (lower-powered, fixed pitch Tutor) - I keep telling my students to think of them as axial rolls; roll as fast as you can, they'll still be slow in this thing. You Pitts guys have it pitts-easy ! 
Joined: Oct 2010
Posts: 3
Likes: 0
From: Dallas, TX
I stand corrected. Thanks for pointing out the difference between an aileron roll and a slow roll. I guess with the limited power of the trainer I flew, I could never have aimed for a slow roll as flown by the pure aerobats. And yes BOAC, my former students will never win an aerobatic championship.. they're too busy whooping British ass in Exercise Indradhanush back in India.
Per Ardua ad Astraeus
Joined: Mar 2000
Posts: 18,575
Likes: 4
From: UK
I say, I hope you mean 'whopping British arse' old chap. I don't think I've ever whooped an ass of any nationality.
I suspect our Typhoos will wax a few backsides, actually (that's 'kick some asses')
- especially if we can encourage them to fall out of a few slow rolls.....................
I suspect our Typhoos will wax a few backsides, actually (that's 'kick some asses')
- especially if we can encourage them to fall out of a few slow rolls.....................
Joined: Oct 2010
Posts: 3
Likes: 0
From: Dallas, TX
Ah! Language!! I shall concede that to you since you guys taught us the language anyway! I'm looking at the Typhoon with some interest too. Guess they want to sell some to the Indians, that's why they are there.
