bevar

My Feedback: (27)

A friend called me today and asked me if Turbo Prop planes need brakes. He felt that since it's a prop plane...no. I said that since it's turbine powered...yes.

What do you guys think?

Beave

trioval00

My Feedback: (17)

For RC fixed wing aircraft: With the exception of hand-launched aircraft which have no undercarriage
and with a flight weight under 7.5 pounds wet, the model shall be able to come to a controlled stop on
command with the engine at idle on a level hard surface


This is from the AMA web site.........510-A

bevar

My Feedback: (27)

Again...is a Turbo Raven a prop plane or a jet aircraft per the regs? It will be turbine powered BTW...

Beave

RUFTER

Beave, you should run a poll on this one.

My 2c, on a Turbo Raven, no. Prop-strike risk too high

Regards, Bart.

bevar

My Feedback: (27)

Bart,

It's an AMA reg question. There are some tail dragger turbo props being built and some are saying they do not need brakes because it's a prop plane. I say they do because it's a turbine powered plane.

It's a legality question. I have been told by the JPO that they do, but some pilots keep saying that they don't.

Beave

Gonzalo38

I don't know about the legal implications, but I wouldn't use brakes on a tail dragger unless is absolutely necessary to stop the plane in a hard surface strip.

A good alternative could be the brakes some IMAC pilots are using in their planes. They are manufactured by www.whiteroseeng.com



As per their website description:

Brakes - These are for those of you that fly from hard surface runways and have a problem keeping your plane taxiing slow enough for safe operation. They will also shorten the landing roll out. The brakes are on all the time, not controllable with the radio. You manually adjust the amount of drag to suit your particular situation.

The brakes are designed to be used with any of our wheels and axles and are a simple bolt on installation. They can be used with other manufacturers axles and wheels with some modification. The weight is less than 1.7 ounces per wheel. If you replace the normal steel axles and plastic/sponge wheels with our wheels and titanium axles you can have the brakes with no additional weight gain. The brakes are only available on the 4 3/4" Five Spoke Wheels.

RUFTER

Thank goodness I don't have to worry about AMA or FAA regulations over here! From reading all the stories here on RCU it looks like you guys are going to need a lawyer as a plane spotter pretty soon.
But if it is written in the regs somewhere, no need to discuss further. I have just never seen a Turbo Raven with brakes before. I think the issue is idle thrust, and I don't think the idle thrust of a turboprop is higher than a IC engine swinging the same size prop.

Bart.

basimpsn

My Feedback: (5)

I remember when Joe did the first flight with his PILATUS PORTER brakes was not install. But after losing ground control on a attempt take off he desided to install brakes and program it also to lock the brakes up if the plane lost signal( failsafe).
http://www.youtube.com/watch?v=H6YruAVK_Xw

Dr Honda

My Feedback: (4)

there really isn't a question about it... the AMA says you got to have brakes. BUT... it doesn't say how many, or on what wheel. Put a little drag brake on the tail wheel.

bevar

My Feedback: (27)

Yep...

invertmast

My Feedback: (23)

But it does say "on command". Their is no commanded control over a drag brake.

but, just because we Have to have them, doesn't mean we Have to use them.

rcjets_63

My Feedback: (4)

I would think that "on command" doesn't mean that you have to have command over the drag brake, it just means that you can stop the plane on command on a hard level surface. That "command" could be pulling the throttle back to idle.

My understanding is that it was recognized that turbines can have a significant amount of thrust, even when at idle, and that the rule was created to make sure that the plane could be stopped on it's own.

Jim

invertmast

My Feedback: (23)

Jim,
That makes sense. Its kinda of one of those rules that is open to interpretation, and in this case that is a good thing!

bevar

My Feedback: (27)

Jim,

A scrubber on the tail wheel, like the Shock Jet has on the nose wheel would work. Trust me...if you fly a Turbo Prop without a brake system of some sort...you have no AMA insurance coverage and you are flying an illegal turbine airplane, per the turbine regs.

It's a turbine powered aircraft that weighs over 7.5 pounds and is not hand launched, so it must have brakes.

Beave

PS. The AMA safety committee also says a Turbo Prop mush have brakes on it.

rcjets_63

My Feedback: (4)

Hi Thomas, HNY to you

Don't get me wrong, I'll still always install brakes on any of my jets, turbine-powered or otherwise). Even if they would stop on their own on a hard level surface. Brakes just gives that extra measure of safety. Besides, when I want my jet to stop, typically I want it to stop as quickly as possible.

Jim

invertmast

My Feedback: (23)

HNY?

I agree with you completely!

RCISFUN

My Feedback: (44)

I hope it means Happy New Year

The other possibilities in the Google search are disturbing [X(]

invertmast

My Feedback: (23)

Oh,
well now i feel Dumm (yes i know its spelled Dumb).

But in that case
Happy New Year to you as well Jim

pilott28

My Feedback: (27)

I have been down this road a couple of times with the AMA on behalf of the JPO and while the language could be clearer, I have been told that "on command" means brakes. I asked why not just use the word "brakes" and was told that the authors of the wording wanted to leave room for thrust reversing systems. How true this really is, I don't know as I was getting the info second hand.

Does anyone have any good data on turbine prop RPMs at idle as opposed to normal 2 cycle engines? I am thinking that if the data shows similar thrust at idle between recip and turbine prop aircraft, that would almost be a defacto argument to get the rule changed.

Boli, you have both ... do you think it would be worth your time doing a little data gathering?

invertmast

My Feedback: (23)

Keith,
But doesn't the AMA regs say something about no thrust reverser unless they are from a manufacturer? If that is the case, and their are no turbine manufacturers currently offering thrust reversing systems (that i know of), why wouldn't it be best to just put "brakes" until the latter happens and then update the wording if and when a manuf. does offer a thrust reversing system?

causeitflies

An adjustable pitch prop could provide reverse thrust...

BaldEagel

A piece of fuel tubing on the axle pushed up against the wheel with a collet and washer provides just enough drag to prevent my IMAC size Yak from rolling forward on tick over, as someone said above to bring to a commanded stop just close the throttle to tick over, or cut the engine.

Mike

gsoav8r

My Feedback: (6)

I think this is actually a well crafted sentence. I dont see were it allows for drag brakes at all as they are not capable of being used on command.

To me "with the engine at idle on a level hard surface" is a qualifying statement that describes the state of the model Before brakes are applied. The statement can be used at the beginning or end of a sentence. For example..

with the engine at idle on a level hard surface the model shall be able to come to a controlled stop on
command

Fun stuff.

Cheers,
James

Nhalyn

For me the statement is simple : the aircraft should be able to stop by it own when the pilot want to, and should be able to stay stoped with engine set at idle. What ever meanings you use.

That's the same problem with all big prop engined airplanes : the idle thrust of those big propellerssometimes is too much to stay stopped. As on Imac planes, or warbirds, or othergiants planes, it's very simple and currentto put some stuff like fuel tubing to ensure an constant brake effect that help for landing and ensure that the plane don't move at idle.

It is not a commanded brake, but I can stop my plane where and when I want simply by putting power to idle. For me that answer the question for AMA. If not, that mean that we have to put some brakes on all our giant scale propelled planes, turbine or IC engined ! (For "AMA ruled" flights in US)

The problem for "non-propelled" jet is that the take-off need no brake at all (permanent brakes should be burned by the high speed of take off) and we even put ballbearings on the wheels to ensure good working of that stuff...

It's very rare to see commanded brakes even on giant scale RCplanes with twice (or more !)the weight of common turbine engined planes.

gsoav8r

My Feedback: (6)

The rule is specific to Turbine powered aircraft. It has no bearing on electric, gas or glow powered models.