Brakes and the "A" Models

Bob Axsom · #1 02-13-2006, 07:17 PM

I previously noted that one of the advantages of the tail draggers was they could still taxi if they lost their brakes. We flew our RV-6A to St. Augustine and Panama City, Florida this past week and we had a few problems. One was I wore the brakes down on the right main gear to the extent that the piston (puck) came out of the housing enough to leak the fluid out of that side. When I got in the plane to leave Panama City yesterday I saw fluid on the ground but attributed it to fuel venting. I got in to start up and the right pedal flopped forward with no resistance. I pumped it and it seemed like I got some pressure so I started the engine. With over 4,500 hours of flight time I thought I could handle with pumping finese. I had to give it some power to overcome inertia and move the plane then I had to turn left coming out of the spot. Well, it turned to the left alright, all the way around like a pinwheel. My friend J that lives there thought I was demonstrating how maneuverable the plane is. DON'T DO WHAT I DID - THE PLANE IS TOTALLY UNCONTROLABLE ON THE GROUND WITHOUT BOTH BRAKES! I know, anybody that can think ought to know that but it is amazing what you can make yourself think you can do in spite of the physics involved. When that nose gear pivots into a turn there is no way to stop the turn except to shut down, get out and put it where you want it or worse (heaven forbid) hit something.

Bob Axsom

osxuser · #2 02-13-2006, 08:36 PM

You think thats bad? I had ONE wheel on a Tiger lock up when I was trying to taxi it. That made me look like an idiot, fortunitly there were no airplanes parked nearby. I agree, there are some SERIOUS issues with the use of a free-castoring nosewheel if you brakes go wacko.

AntiGravity · #3 02-13-2006, 09:20 PM

Quote:

Originally Posted by osxuser

I agree, there are some SERIOUS issues with the use of a free-castoring nosewheel if you brakes go wacko.

So has anybody designed a steerable nosewheel for the A's at all?

akarmy · #4 02-13-2006, 09:39 PM

Quote:

Originally Posted by Bob Axsom

Well, it turned to the left alright, all the way around like a pinwheel.

Bob Axsom

Neat. 2 years ago I had the same thing happen when I taxied out of the RV corrall at the Arlington airshow. Neat project to lay in the grass and repair a broken brake line at 5pm on Sunday while everyone is tearing down the airshow! You are right, with no brakes you only go quickly in one direction!

Ironflight · #5 02-14-2006, 07:12 AM

....And I am sure there are MANY other former Grumman drivers here in the RV world who do as well! You get very protective of your braking systems when you own a Grumman - can you say "Primary ground control system?!"

Paul
(ex - AA1B-160 owner)

rv6ejguy · #6 02-14-2006, 09:31 AM

Quote:

Originally Posted by Bob Axsom

One was I wore the brakes down on the right main gear to the extent that the piston (puck) came out of the housing enough to leak the fluid out of that side.

Bob Axsom

Not to sound unkind, but don't you do 100 hour checks on the brakes? At my current level of pad wear, I'm looking at over 400 hours before I have to replace mine. (6A)

Hawkeye7A · #7 02-14-2006, 12:13 PM

Sorry if you're already aware of this:
A while back there was a notice(SB maybe?) about some of the Cleveland calipers having been assembled incorrectly by reversing the piston and having the "O" ring groove closer to the puck when in fact it needs to be inserted first into the bore. I met an RV-er at our local airport(he had borrowed the plane) and during his taxi in, he lost some brake fluid from one side. I informed him of this occurance with several other pilots, he found a local A&P to help him out and turned out that that's what happened to his. Replacing the "O" ring, reinstalling the piston ring groove inwards(towards the bleed valve) and reassembly got him on his way.

flyeyes · #8 02-14-2006, 12:30 PM

Quote:

Originally Posted by Hawkeye7A

Sorry if you're already aware of this:
A while back there was a notice(SB maybe?) about some of the Cleveland calipers having been assembled incorrectly by reversing the piston and having the "O" ring groove closer to the puck when in fact it needs to be inserted first into the bore. I met an RV-er at our local airport(he had borrowed the plane) and during his taxi in, he lost some brake fluid from one side. I informed him of this occurance with several other pilots, he found a local A&P to help him out and turned out that that's what happened to his. Replacing the "O" ring, reinstalling the piston ring groove inwards(towards the bleed valve) and reassembly got him on his way.

A thousand word's worth...

you can easily visualized how it's possible to turn the piston around backwards.

gmcjetpilot · #9 02-14-2006, 02:12 PM

That is why T/G's are better. No brake riding, longer brake life and positive gnd steering with the rudder (pedals).

George

Bob Axsom · #10 02-14-2006, 03:40 PM

Mine was correctly assembled I just stretched it too long before replacing the pads. I had them at home - I know, I know - but moving into a new home has been very time consuming. Anyway, the message is don't think you are Superpilot and can move one of these birds under power with questionable brakes - if they are bad it can't be done! One other caution - I probably have worn the right brake pads on takeoff. I conciously try to avoid it but I suspect when I'm standing on the right rudder peddle, I'm getting some brake as well. You can do better I'm sure.
Bob Axsom