Chippie Question
 

Could the guru's answer a pub question about Chipmunk operating procedures please?

Take off and/or landing..........Brakes OFF or a couple of notches on?

Ta

A

I was fortunate enough to own a share in a Chipmunk for 5 years.

Normal procedure for us was to leave the brakes off for both take off and landings.

The only exception was for a take off with a significant crosswind from the starboard side. In this scenario, it is possible to "run out" of left rudder due to the combined effects of gyroscopic precession, propwash and crosswind all conspiring to turn the aircraft to the right (Gypsy Major runs the opposite way to Lycomings and Continentals).

The couple of notches of brake is so that the left brake is just binding at full left rudder deflection, helping to keep her straight.

Generally, correct and copious use of into-wind aileron was more effective than using the brakes.

WP.

I was taught brakes always off. However, if you start to run out of rudder authority on landing, gently apply brake to keep it straight.

The RAF instruction manual that I had, says brakes on 3 clicks.

The bloke who let me fly his always recommended no clicks.

Stik

I was tought that before starting the engine you sould release the brakes and then apply full rudder. Then pull on the brake lever and count the clicks until you feel pressure on the rudder pedal from the brake system. It might or might not be three clicks :).
Then as before, no brake for take off or landing except in a crosswind when you apply the amount found above.

I've been flying one for 26 years and it's most certainly NO brake for t/o or landing. If the rudder runs out of authority in a crosswind, either at the start of t/o run or (more likely) at end of landing roll, just reach down with your left hand and apply a bit of brake (the rudder will already be hard over, so only the approriate main gear brake will be applied).

Landing with brake already applied limits rudder movement and runs the risk of locking a wheel and groundlooping when you run out of that limited rudder authority. Much better to have all the rudder movement available, then only apply the brake if it become neccessary so to do.

It all works very well - you just need to curl your little finger around the brake lever as you slow, and gently pull as required contolling direction by how much 'pull' you apply - it don't take much effort.

SSD

The RAF teaching in 1973 at UAS's was exactly as Flap40 has stated. It was known as "setting minimum differential brake".

SSD Is that the reason why "brakes off" is part of the pre-spinning & pre-aeros checks?

DubTrub:

YES!

There's a good AAN (?) that explains the reason behind this and the long chord rudder and the strakes.

Chippie, such a lovely aeroplane to fly, learn on them and they'll give you a sound training in aeroplane (and tailwheel) handling.

Enjoy!

Yup, brakes off is an essential pre-aeros check on a Chippy. Even a bit of wheel brake left on will limit rudder travel.

It's an essential pre-flight check as well, to ensure that the rudder, brakes off, will move freely from stop to stop. If the brakes are incorrectly adjusted, they will come on at extremes of rudder travel even with the brake lever 'off' - and therefore will limit rudder travel.


SSD

OFF

Taxi with thre notches - if set up correctly. Ours isnt and even with no notches the brakes come on at the extremes of the rudder travel. An absolute pig in a cross wind. Try to use rudeer and you slow down!

Note self - must get sorted.

I fly 3 Chipmunks, and they all have different brake settings. One needs 3 notches, another none, so I guess it depends on the individual aeroplane!:O If you set three notches when it doesnt really need them (i.e brakes not adjusted correctly), the brakes wear out faster!

On an airplane like mine that has dispensed with the Dunlop brakes in favo(u)r of the Clevelands definitely NO brake on T/O or landing.

I was told to always do 4 clicks on the brake during my conversation. But this apparently differs from Chippie to Chippie.

For taxying, perhaps, though 4 clicks sound like a lot. But yes, it does vary from Chippy to Chippy - should be as little as you can get away with while retaining steering authority. Don't put too much on, since it'll restrict rudder movement and overheat or even wear out the brakes especially during a long cross wind taxy. If you suddenly feel you need a tad more - just yank the lever a couple more notches! Better to have too little and know that more is available should you need it. ;)

And none at all for take off and landing. Part of the pre-take off and pre-landing checks should be to pull the lever back and let it go (it'll fly forward), to ensure the brakes are fully off.

SSD