Aircraft Brakes

[Brett]

Would it be generally expected of an aircraft braking system to hold the plane in situ under Full power ? Static rpm test .

 

 

[Tex]

Not a tail dragger, you would likely nose over

 

 

[Guernsey]

Generally speaking...Yes....but some taildraggers where the engine is mounted level or higher than the wings and fuselage the engine would pull the aircraft onto its nose.

 

An aircraft where the engine is mounted on the nose which is lower than the wing and in line with the fuselage and tailplane would not nose over if rear stick (up elevator) was applied as the airflow from the prop would force the tail down.

 

Seems a long winded reply but I think you get my drift.

 

Alan.

 

 

[facthunter]

Some aircraft will move forward with wheels locked, on full power. It all depends on the thrust/weight. Some brakes will only just hold. Full power runs really should chock the wheels. and some aircraft have been known to "jump" chocks.

 

Another often forgotten thing to watch is other traffic behind or in hangars behind. Be courteous and considerate. Nev

 

 

[Ultralights]

100Hp in a 280kg empty aircraft will easily drag the wheels across the tarmac while the brakes are still locked.

 

 

[Yenn]

You shouldn't need that much braking power. In a taildragger you will almost certainly nose over if your brakes are that good and you use tham at speed, and I would guess that a nose leg would get a lot of compression loading in the same situation.

 

 

[kaz3g]

Would it be generally expected of an aircraft braking system to hold the plane in situ under Full power ? Static rpm test .

Hi Brett

 

Depends on the brakes that are fitted and why.

 

My Auster starts to creep once I get more than about 1800 rpm on the dial so I do my ordinary runups at 1600 rpm. The brakes are cable operated drums and they are really only designed to assist taxiing rather than for pulling the aircraft up from speed.

 

Modern hydraulic discs will obviously do a lot better.

 

I did my static rpm test with the tail tied down but, as others have said, if you are doing it on the brakes or chocks make sure you have full back stick and open the throttle slowly until you get to full power in case things get exciting.

 

kaz

 

 

[robinsm]

My Xair holds on the drum brakes to about 5000rpm then gets the creeps. I do run ups at 4000 so all ok there. Initiall installation runs on the new motor at 6500 rpm were done with the aircraft tied to a very solid object buried in the ground. and the stick pulled as far back as possible. The ride was still interesting, like riding a wild horse only more fun.

 

 

[Brett]

cheers for the replies,,, The brakes seem to hold ok to about 2200-2300 rpm also with stick back. I just tied it to a car via a long rope again to get the full power rev's required to tune the aerocarb via there manual. Its seems at full noise it would be quite a of an ask for them to hold. It taxi's well with the individual brakes and turns on a dime so I guess they will be acceptable. Actually I think I'd be more than a bit nervous at full noise if it wasn't tied back the way it buffets around and so on. Nosing it over while running I'm sure wouldn't make my day.