Takeoff abort

[johnm]

A theoretical .........

 

If you were taking off with say 1 notch of flap (or no flap) - lets say grass runway - plane has brakes - fixed undercart

 

And you had to stop takeoff - lets say loss of power - no groundloops or deviation from runway is possible

 

The remaining strip distance is minimal - what would be the best way to stop ?

 

.............. i'd go for full flap and brakes ?

 

 

[rgmwa]

Full flap would increase lift (likely more than drag) and reduce brake effectiveness? I'd go for no flap, brakes and back elevator below flying speed to increase drag. Happy to be corrected.

 

rgmwa

 

 

[Downunder]

Hitting full flap, from no flap may "jump" you off the deck?

 

Perhaps brakes and gradual flap if possible.

 

 

[Downunder]

Full flap would increase lift (likely more than drag) and reduce brake effectiveness? I'd go for no flap, brakes and back elevator below flying speed to increase drag. Happy to be corrected.rgmwa

"Up" elevator would be countered by the brakes pulling the nose down?

 

 

[rgmwa]

"Up" elevator would be countered by the brakes pulling the nose down?

Up elevator would push the tail down and add load on the main wheels (by taking load off the nose wheel) as well as producing drag.

rgmwa

 

 

[ian00798]

I would probably use whatever technique the POH for that aircraft recommends for a short field landing. It's always going to be a compromise, for example a Cessna with 40 degrees of flap will give great aerodynamic braking which probably outweighs the penalty of less mechanical breaking. Something with less flap extension would produce a different effect. Ultimately this scenario doesn't sound like a fun time to become a test pilot, use the technique mentioned in the book.

 

 

[kaz3g]

Full flap when landing will allow you to land the aircraft at a low ground speed which is good. Deploying full flaps when at speed on the ground will reduce the weight on the ground due increased lift and reduce the effectiveness of braking which is bad.

 

Even an AUSTER can lock a wheel with zealous brake application sometimes So my thought is maximum traction is the best answer...no flaps, nearest to zero thrust, maximum braking without skidding (or tipping a TD on its nose), and stick back. Ground loop before hitting the fence.

 

Kaz

 

 

[howe]

Well if you are still on the ground with minimal strip left get another aircraft.

 

 

[facthunter]

The general view is get it on the ground with out delay, use spoilers or other technique to get max weight on the main wheels, apply brakes and use them hard if you have a critical field length. This assumes you have a good braking surface. Aquaplaning can happen at high(er) speeds with visible water on the strip/runway. Wet grass may have little grip. Same with black Pilliga soil with rain on it or any similar.. If you have a STOL type and any sort of headwind you are going to touch down very slowly in any case. They have long legs and can tip forward easily wthout power blowing over the tailplane if you brake hard, so watch this with any tailwheel type as you slow up. The technique you use will vary with the characteristics of individual planes. If you have a tricycle U/C having it sit nose down is better than tail down, prop clearance permitting as the wing will produce less lift. Light aircraft brakes are not like race car brakes. They are often pretty basic and inadequate and only an aid to turning when taxiing. Tiger Moths didn't have them at all originally on the australian version.

 

As an add on make sure your throttle is FULLY closed and your idle setting is not too high as it will make the plane float and also counter the brakes to some extent, in the landing roll .Nev

 

 

[johnm]

.............. just for the conversation - good variation in answers

 

I suspect most ultralight planes suffer from brake fade quickly, so how you stop best, needs to be thought about (or read)

 

 

[Jaba-who]

There are other things that no one has mentioned.

 

Turn off the engine! It's amazing how much thrust even an idling engine produces.

 

Lazy s turns down the runway as wide as your speed will allow without ground looping.

 

Brake handling - especially Jabiru brakes ( prior to the mark 3 s) Repeated apply and release. Don't hold them on - they'll fade then you have nothing.

 

Slower firm application on Wet surface esp grass. - resist all urge to jam em on hard - you'll aquaplan.

 

Learn what your aircraft does with respect to flaps lift vs flaps drag. This is different for different aircraft and where one will jump into the air others will just drop onto the ground more firmly.

 

Pre-plan every take off roll so that if you hit your mark and you aren't flying you'll have plenty of time to pull up. Don't ever go beyond your mark hoping it'll fly. Better to go back and start again.