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vinodwahi

Member
Hi folks

I am currently busy with writing my flight operating book.
I've received a few from some other RV9a pilots, using these ones as references.

Unfortunately, I don't know if the RV9a should be operated with extended flaps (0'/10'/20') for take off??
And what about short field take off??

Thanks so much!!!
Happy landings
Vinod
 
This thread could go on for pages with debate.

My experience with the RV10 and RV9 is that flaps of 10-20 degrees will help with short field, and once accelerated retracting back to zero flap carefully is an effective short field or soft/rough field.

For 99% of the time flapless is the best option.

I have not done any data collection so I can't help you there, but my experience is based on operations from a grass and at times rough and soft airfields about 50% of the time.
 
The ailerons are typically optimized for max lift and min drag on the "down" side. For maximum L/D, push the stick to one side and align your flaps with the "down" aileron.
This works great for most GA airplanes.

I use flaps for every takeoff. By doing this, I've developed a routine. If you only do it for short or soft fields, you are more likely to forget to raise them after takeoff.
 
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On pavement no flaps are needed.

On grass I always use flaps, as described by Mel; lower them to match a down aileron. Once off the ground, climbing, and clear of obstacles they are retracted.
 
One other thing Vinod, for aborted landings, I found it best to simply leave all the flaps in and add full power, keeping the airspeed below the max flap speed until clear of obstacles and then retract them as needed.

Even when I had the 135 HP engine, at GW, and hot days (96*F/35.5*C) the RV-9 is so over powered that it will easily climb to altitude.
 
a little data point.

I also wondered what i 'should' do....I found the most dramatic answer was thru actual testing, or trial & error!
What I found is that with no flap, whether loaded lite or at gross, with the nose slightly off the runway, it would lift off readily, but then kind of wallow and hunt for a climb attitude ( ok, could be the pilot technique of course!).
With half flap, ( =aileron down angle) when I picked up the nose, it would almost immediately fly, and enter a solid climb, feeling like I was going up in an elevator. Very solid feel, especially in gusty conditions, I was well clear of the ground and climbing steadily.

The airfoil designer was kind enough to respond to an old thread on this; so I'd take that to the bank!


Vx (best angle of climb) is established in flight tests. Because thrust decreases with speed, Vx is always a speed which is close to the stall speed where the thrust is high but the plane is not stalling.

Since you are not concerned with the rate of climb, just the angle, I'd suggest using 20 degrees of flaps. You'll need to establish the stall speed with that setting, then climb at something higher than that until you clear the obstacle. Just be sure you don't stall the airplane!

Hope this helps,

John Roncz
 
I use Mel's technique on grass, short runways, and when loaded heavy. It also worked great for those high density altitude takeoffs in the Idaho mountains.
 
Neal@F14 said:
I use Mel's technique on grass, short runways, and when loaded heavy.
Click to expand...

Me three. On paved runways the Nine climbs like a banshee anyway, and other than at gross, always lifts off quickly. When I'm solo with half fuel, it feels like a STOL. :D
 
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