Bad timing...

"Dylan Smith" wrote in message
...
On 2007-03-10, Peter Dohm wrote:
This makes me just a little curious.

Is the handbrake on a Piper (without toe brakes) mechanical or hydraulic?

I presume you're meaning on aircraft like the TriPacer which has the
hand brake, but no toe brakes.

My Cherokee 140 has a handbrake with no toe brakes. It's hydraulic.

This makes me just a little curious.

Is the handbrake on a Piper (without toe brakes) mechanical or
hydraulic?

I presume you're meaning on aircraft like the TriPacer which has the
hand brake, but no toe brakes.

In the TriPacer, a cable goes from the hand brake, around a few pulleys,
and ultimately it ends up under the pilot's seat. Under the pilot's seat
(and I'm not joking) you will find a Piper Cub heel brake, with a hole
in the back of the heel brake, where the cable connects.

The heel brake is hydraulic and applies both wheel brakes
simultaneously. The diaphragm has a habit of splitting just when you
really need the brakes, leaving you with nothing!

--
Yes, the Reply-To email address is valid.
Oolite-Linux: an Elite tribute: http://oolite-linux.berlios.de

Yes, that was the question.

BTW, your description of the TriPacer hand brake is a great example of the
way existing inventory happens to find an additional use. It reminds me of
a conversation I witnessed a few years ago at a combination picnic and
hangar-invasion. One of the members was in the process of building a Pitts
Special from plans--and lamented the difficulty of fabricating the elevator
linkage adaptor (for want of better nomenclature) which attached to the
control stick. Another member took one glance and said "that ol' son of a
gun just cut the top off [of] a cow bell".

Peter

In the TriPacer, a cable goes from the hand brake, around a few pulleys,
and ultimately it ends up under the pilot's seat. Under the pilot's seat
(and I'm not joking) you will find a Piper Cub heel brake, with a hole
in the back of the heel brake, where the cable connects.

The heel brake is hydraulic and applies both wheel brakes
simultaneously. The diaphragm has a habit of splitting just when you
really need the brakes, leaving you with nothing!

--


Unless you put in an STC'd booster from Steve's Aircraft Then you really
have brakes whenever you really need them. :-)

Cheers:

Paul
N1431A

"Jay Honeck" wrote in message
oups.com...
...
During the preflight I spotted a wet mark under the right wheel pant.
Pointing this out to Mary, we both figured that it was the slush and
ice from inside the wheel pant melting in the 40-degree sunshine. We
had heard an "ice ball" bouncing around in the wheel pant after our
last landing, so I "hmph'd" and moved on...

Your first problem is that you drive decent cars. If you always drove junk,
you would know that step 1 for _any_ puddle is to stick a finger in it to
see what it is - water, oil, etc. Touch, color, and smell will nearly always
identify the fluid. One rarely has to resort to taste.

...
Strangely, we had changed that O-ring maybe six months ago, and the
pads were fine, then, so we now have a mystery. How did the brake
pads wear completely away so fast? To be safe, we removed the OTHER
wheel pant (more screws, nuts, banged heads) and inspected the left
brakes, and they are fine. Tons of pad left in them.

Disk brakes rely on rotor runout to push the pads back just a bit do you
don't have the pads in constant contact. If the new O ring was a bit on the
tight side, and the piston was sticking (the O ring could have worked like a
spring) then the pad would drag all the time the wheel was turning and wear
out quite quickly.

Your second problem is that you fly too much. Airplanes sitting in the
hanger don't wear out.

...
But we're still wondering what/how this happened, especially since the
ONLY time we lock the brakes to make a turn is at our hangar, and that
would be a hard LEFT turn. We NEVER turn hard right, so why should
that brake wear so quickly?

Hard, brake locked, turns won't wear the inside pads - they are locked. No
movement, no wear.

Anyone know if it's possible for a brake to hang up and not release,
resulting in advanced wear like this?

As noted above.

Or should I keep blaming Mary
for riding the (right) brake?

That is likely to work as well as me denying that I snore at night.

Your third problem is that your wife (like most) is smarter than you and
blaming her generally backfires.

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

Capt. Geoffrey Thorpe wrote:
"Jay Honeck" wrote in message
oups.com...

Strangely, we had changed that O-ring maybe six months ago, and the
pads were fine, then, so we now have a mystery. How did the brake
pads wear completely away so fast? To be safe, we removed the OTHER
wheel pant (more screws, nuts, banged heads) and inspected the left
brakes, and they are fine. Tons of pad left in them.

Disk brakes rely on rotor runout to push the pads back just a bit do you
don't have the pads in constant contact. If the new O ring was a bit on the
tight side, and the piston was sticking (the O ring could have worked like a
spring) then the pad would drag all the time the wheel was turning and wear
out quite quickly.

Actually, disk brakes are designed such that the deformation of the
seals causes the pads to slightly retract when pressure is released. I
suspect that the seals on Jay's brakes had hardened to the point that
they didn't deform when the brakes were applied and thus could not
"spring back" to pull back the pads.

Rotor run-out will certainly help push the pads back in, but that isn't
how they are designed to operate. Disk brakes will work just fine even
if the rotor is completely true with no run-out.


Matt

Didn't you just have an annual? When I had my 182, while camping at
Johnson Creek, I was landing at McCall, Idaho and had the same thing
happen. No left brake, all the fluid squirted past the window on
landing. Luckily there was a shop on the field. We taxiied up and
asked if he could fix it. He said not til tomorrow, he had to catch up
on his paperwork. You're ****tin' me I thought. So we called the guy
in Cascade, just down the lake from McCall. He said fly it over. So we
did, paying more attention to wind direction than normal. We left the
plane with him, took his car and went and got something to eat. $50 and
a short new section of brake line and we were on our way.




Jay Honeck wrote:
As is apparent from my other recent thread, we're planning to fly to
Texas Sunday afternoon. Well, today was a beautiful day here in Iowa,
and we agreed to fly a good friend to a nearby airport, where he was
supposed to pick up his new (to him) Cessna 172, and take his biennial
flight review.

Didn't you just have an annual?

Nope. We're doing the annual as soon as we get back from Texas, cuz
we suspect it's gonna be a long one. (Still gotta find that fuel seep
in the right wing, which could turn into a hunting expedition, which
-- usually -- means lots of time, parts, waiting, waiting,
waiting....)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

In article .com,
"Jay Honeck" wrote:

Or should I keep blaming Mary for riding the (right) brake?

That was going to be my suggestion. ;-))

"Jay Honeck" wrote
Or should I keep blaming Mary
for riding the (right) brake?

You haven't been reading that suicide thread again have you? From how I
think Mary's been feeling, I think I'd blame ANYTHING or ANYBODY BUT Mary!
lol

Sorry about the brake deal. Things like that suck almost as bad as having
them happen "on the road".

Jim

Sorry about the brake deal. Things like that suck almost as bad as having
them happen "on the road".

I'm incredibly thankful that this happened at home, and not at some
little podunk airport in Oklahoma, where we had stopped for lunch next
Sunday.

Ever try to find emergency repair service on a Sunday? Oh,
wait...we'll always have Dalhart...

:-)

Okay, anywhere OTHER than Dalhart, Texas, losing a brake would have
been a real mess. We'd have been stuck for days, waiting for parts,
and listening to an ever-growing crescendo of whining from the
chitlins...

This worked out as well as could be expected -- as long as Spruce gets
those parts to me tomorrow morning...
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"