Bad timing...

[Jay Honeck]

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.

We spent the morning snaking wires for the kids' new DVD players --
the price for a good quality display has FINALLY dropped to $79.95 (at
Radio Shack, of all places), so we bought two -- and generally enjoyed
bumming around the hangar. We were able to clean the windshield for
the first time in over a month, and basically removed a winter's-worth
of debris from the plane.

Gum wrappers, pencil stubs, dead batteries, they all came out, and we
probably gained 3 pounds of useful load by the time we were finished.

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...

Our friend arrived, and we got into the sun-warmed airplane. What is
it about a leather interior baking in the sun that just smells SO
good? Combined with a little gas on the fuel tester, that odor just
screams *airplane* in so many ways... God help me, I love it.

We taxied out to the hold-short line, I applied the brakes, and we
immediately began a pyrhouette to the left. The right brake pedal
went completely to the floor -- nothing at all. Pumping did nothing,
either -- so we taxied back in.

This brake had done this once before, when an O-ring had failed,
causing the brake fluid to dump overboard. At the time, we debated
buying a new brake cylinder housing, because the inside where the O-
ring fits wasn't pristine, leading to speculation that it may have
been cutting the rubber O-ring over time. However, my A&P had said
the failed ring was old, and had been able to insert a new O-ring
without difficulty, so he pronounced it "serviceable" and we'd been
flying it that way ever since.

It was looking like that decision was coming back to haunt us, as I
gingerly taxied back to my A&P's shop. But we wouldn't know till he
took a look.

Luckily, he was able to drop everything and have a look. Brake fluid
was dumping everywhere as I removed the wheel pant (the most God-awful
job on earth, with a zillion easily strippable screws, a couple of
inaccessible nuts, and a lot of places to bang your head), and we all
climbed under the wing for a look.

To our surprise, the brake assembly itself loose. We had virtually NO
brake pads left, and -- without pads -- the backing plates can come
far enough out to allow the cylinder to come completely out, resulting
in a complete loss of fluid.

The metal-on-metal braking had apparently been going on for some time,
because the disk rotor was warped and scored. It was toast, our
flight with our friend was scrubbed, and we would need some new parts.

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.

So, we've ordered the parts to be shipped overnight from Spruce, and
they should be here tomorrow. We *should* still be able to depart for
Texas on Sunday, with luck. And I guess we should say that this was
actually GOOD timing, because this could just as easily have happened
in Fredericksburg, far from home.

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?

Anyone know if it's possible for a brake to hang up and not release,
resulting in advanced wear like this? Or should I keep blaming Mary
for riding the (right) brake?

:-)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Bob Noel]

In article . com>,
"Jay Honeck" > wrote:

[snip]
> Or should I keep blaming Mary
> for riding the (right) brake?

If you didn't say it, I was going to. In fact, as soon as I knew it
was a brake problem, I knew it would be blamed on Mary...

:-)

--
Bob Noel
(let's face it, lawyers won't like ANY sign...)

[Tony]

You just know that brake had been lightly engaged since you last
worked on it, Jay. Did the airplane tend to go to the side when you
were at low speed?

Had take off runs gotten just a little bit longer? A little more P
torque, things like that, sending subtle messages?



On Mar 8, 6:29 pm, "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.
>
> We spent the morning snaking wires for the kids' new DVD players --
> the price for a good quality display has FINALLY dropped to $79.95 (at
> Radio Shack, of all places), so we bought two -- and generally enjoyed
> bumming around the hangar. We were able to clean the windshield for
> the first time in over a month, and basically removed a winter's-worth
> of debris from the plane.
>
> Gum wrappers, pencil stubs, dead batteries, they all came out, and we
> probably gained 3 pounds of useful load by the time we were finished.
>
> 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...
>
> Our friend arrived, and we got into the sun-warmed airplane. What is
> it about a leather interior baking in the sun that just smells SO
> good? Combined with a little gas on the fuel tester, that odor just
> screams *airplane* in so many ways... God help me, I love it.
>
> We taxied out to the hold-short line, I applied the brakes, and we
> immediately began a pyrhouette to the left. The right brake pedal
> went completely to the floor -- nothing at all. Pumping did nothing,
> either -- so we taxied back in.
>
> This brake had done this once before, when an O-ring had failed,
> causing the brake fluid to dump overboard. At the time, we debated
> buying a new brake cylinder housing, because the inside where the O-
> ring fits wasn't pristine, leading to speculation that it may have
> been cutting the rubber O-ring over time. However, my A&P had said
> the failed ring was old, and had been able to insert a new O-ring
> without difficulty, so he pronounced it "serviceable" and we'd been
> flying it that way ever since.
>
> It was looking like that decision was coming back to haunt us, as I
> gingerly taxied back to my A&P's shop. But we wouldn't know till he
> took a look.
>
> Luckily, he was able to drop everything and have a look. Brake fluid
> was dumping everywhere as I removed the wheel pant (the most God-awful
> job on earth, with a zillion easily strippable screws, a couple of
> inaccessible nuts, and a lot of places to bang your head), and we all
> climbed under the wing for a look.
>
> To our surprise, the brake assembly itself loose. We had virtually NO
> brake pads left, and -- without pads -- the backing plates can come
> far enough out to allow the cylinder to come completely out, resulting
> in a complete loss of fluid.
>
> The metal-on-metal braking had apparently been going on for some time,
> because the disk rotor was warped and scored. It was toast, our
> flight with our friend was scrubbed, and we would need some new parts.
>
> 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.
>
> So, we've ordered the parts to be shipped overnight from Spruce, and
> they should be here tomorrow. We *should* still be able to depart for
> Texas on Sunday, with luck. And I guess we should say that this was
> actually GOOD timing, because this could just as easily have happened
> in Fredericksburg, far from home.
>
> 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?
>
> Anyone know if it's possible for a brake to hang up and not release,
> resulting in advanced wear like this? Or should I keep blaming Mary
> for riding the (right) brake?
>
> :-)
> --
> Jay Honeck
> Iowa City, IA
> Pathfinder N56993www.AlexisParkInn.com
> "Your Aviation Destination"

[Crash Lander[_1_]]

"Jay Honeck" > wrote in message
oups.com...
> Anyone know if it's possible for a brake to hang up and not release,
> resulting in advanced wear like this? Or should I keep blaming Mary
> for riding the (right) brake?
>
> :-)
> --
> Jay Honeck

I'm by no means an expert, but as I was reading this, I was thinking of
possible causes and came up with this possibility.
In my training a/c, full throttle requires some right rudder to keep her
straight. I'm assuming your a/c does this too. Is it possible that when you
are applying this right rudder, you're also inadvertently applying the right
brake at the same time? I'm also assuming your a/c has toe brakes. As you
can see, I know very little about a/c mechanics, but this seemed feasible to
me.
Oz/Crash Lander

[EridanMan]

Ouch...

This is one of those stories that makes me glad that I didn't spend
the extra money (and lost useful load) to install Toe-Brakes in 61J...

Yes it was odd... for the first 5 minutes of taxiing.

After seeing two of my old club's planes go through a set of pads per
100 hour inspection (one of them having a similar catastrophic right
(I believe) break failure... only during a landing... only a VERY good
instructor prevented a ground-loop). And then hear stories like this
from a very experienced pilot no-less...

I can't say I miss them.

[Capt. Geoffrey Thorpe]

"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.

[Newps]

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.

[Matt Whiting]

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

[john smith]

In article . com>,
"Jay Honeck" > wrote:

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

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

[Jim Burns]

"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

[[email protected]]

In rec.aviation.owning Jay Honeck > wrote:
> Anyone know if it's possible for a brake to hang up and not release,
> resulting in advanced wear like this?

Sure. Short answer: Check the flex line (rubber line) on that side.
If OK or not so equipped, see below.

Long answer:

When I got the engine running (for some value of running) in the first
car I've owned that's older than me, I of course had to take it around
the block. I had reasoned that its manual four-wheel drum brakes would
not respond as well as the power-assisted front disc, rear drum brakes
did on nearly every other car I had owned or driven. Still, when I got
to the stop sign just down the block, I was glad it was one of the
optional ones with the white stripe around it, because I got halfway
into the intersection before I stopped. When I let off the pedal and
tried to accelerate again, the car hesitated for a second, then there
was a ping! from one of the front wheels and the hesitation was gone.

At first I wondered if I was simply treading too lightly on the brakes,
so I got the car back up to 15 mph and literally stood on the pedal.
This still produced a rather anemic stop, so I was convinced something
was wrong. Again, as I tried to accelerate away, I was held back until
I heard the ping! from the front wheel. I carefully returned home to
investigate.

Online consultation with a group of enthusiasts brought a nearly
unanimous answer: The rubber lines in the brake system tend to
deteriorate on the inside as well as on the outside. Besides causing a
reduced flow of brake fluid and poor braking in general, a flap of
rubber will often form inside the line. This flap acts as a check valve:
when you stomp on the pedal and bring up the pressure in the system, the
fluid is forced past the flap and out to the wheel cylinder or caliper,
applying the brake. When you let off the pedal, the shoes or pads are
pushing back on the piston to return the fluid to the master cylinder,
but this pressure is not as great, and the flap is enough to prevent it
from returning. The result is that the brakes on that wheel stay
engaged. Eventually enough fluid may get back through to release the
brakes on that wheel - probably the ping! that I heard. Many people
said they liked to replace the flex hoses immediately on any old car new
to them, and then on a schedule of every 5 to 10 years thereafter.

After a little further inspection, I decided that although the master
cylinder and wheel cylinders were not original to the car, the flex
lines probably were. I ordered a new set, and when they arrived, I
swapped them out. I did a test on the old lines: with them lying on the
ground, not connected to anything, I hooked up my hand vacuum pump to
them. It should have been like sucking on a brand new soda straw, but
instead it was like sucking on a bottle - I could pull a 25" Hg vacuum
from either end of all the hoses. The brakes were probably only working
as much as they did because the hydraulic pressure in the system was
considerably higher, and could force a little fluid through the old
hoses. A road test with the new hoses proved much more satisfying; I
could reliably stop at both the optional and the mandatory stop signs.

One diagnostic for this problem in a car is to raise the wheels off the
ground and make sure they turn freely by hand. Then stomp on the brakes,
and make sure that the wheels don't turn. Finally, let off the brakes,
and see if the wheels turn freely again. If one of them doesn't, open
the bleeder valve on that wheel cylinder or caliper. If you get a spurt
of fluid from the valve and the wheel suddenly turns freely, then the
problem is probably in the lines or master cylinder. If the wheel is
still stuck, then the problem is probably in the wheel cylinder or
caliper.

An alternative way to see if a brake is dragging lightly is to travel in
a straight line for some distance, stop, then compare the temperatures
of the wheels from side to side. If you're optimizing for cheap, you
can check with a careful hand or wet fingertip. If you're optimizing
for shiny, this is a perfect excuse to buy one of those infrared remote
thermometers. If you can't travel in a straight line, one of the brakes
might be dragging more than lightly, or possibly the vehicle control
system is affected by ethanol.

I know that an airplane, in general, is not a car. On a Cessna 182, the
one airplane that I've been around the most, if you start at the wheels
and work in, the system is similar to a car. There is a pad moved by a
piston at the wheel. Then, there is some combination of hard line and
flex line that goes from the wheel back to the fuselage - the flex line
is there to account for relative motion between the wheel/landing gear
and the fuselage. Then it's hard line back to the master cylinder. The
mechanical linkage to operate the master cylinder is different, but the
principle is the same as in a car.

It could be that your airplane doesn't have any flex lines in its
braking system. In that case, you have to decide whether to go after
the wheel cylinder or the master cylinder next. You might be able to
swap existing parts from side to side to see if the trouble follows the
part or not. Or, tear down the parts from both sides, and play "One Of
These Things Is Not Like The Others."

Disclaimer: This is based on experience with braking systems on ground
vehicles. I don't have an A&P; I don't even have a TG&Y. Some of this
may not be allowable owner maintenance. Your mileage may vary.

Matt Roberds

[Jay Honeck]

> 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"

[Jay Honeck]

> Disclaimer: This is based on experience with braking systems on ground
> vehicles. I don't have an A&P; I don't even have a TG&Y. Some of this
> may not be allowable owner maintenance. Your mileage may vary.

Thanks, Matt -- I appreciate the brake system primer. I will
definitely be checking the flexible lines.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Jay Honeck]

> 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"

[Jack Allison]

Jay Honeck wrote:
> Anyone know if it's possible for a brake to hang up and not release,
> resulting in advanced wear like this? Or should I keep blaming Mary
> for riding the (right) brake?
>

No no no...it's "Hail Mary", not "Blame Mary". :-)


--
Jack Allison
PP-ASEL-Instrument Airplane

"To become a Jedi knight, you must master a single force. To become
a private pilot you must strive to master four of them"
- Rod Machado

(Remove the obvious from address to reply via e-mail)

[Maxwell]

"Jay Honeck" > wrote in message
ps.com...
>
> 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.
>
Where are you having lunch in Oklahoma?

[Steve Foley]

"Maxwell" > wrote in message
...

>>
> Where are you having lunch in Oklahoma?

My choice would be Durant, and grab a ride to Chucks BBQ.

[Maxwell]

"Steve Foley" > wrote in message
news:AScIh.7993$pi.2627@trndny09...
> "Maxwell" > wrote in message
> ...
>
>>>
>> Where are you having lunch in Oklahoma?
>
> My choice would be Durant, and grab a ride to Chucks BBQ.
>
Indeed. But I was going to recommend Ponca City. Excellent mexican food
located right on the field.

[NW_Pilot]

"EridanMan" > wrote in message
ps.com...
> Ouch...
>
> This is one of those stories that makes me glad that I didn't spend
> the extra money (and lost useful load) to install Toe-Brakes in 61J...
>
> Yes it was odd... for the first 5 minutes of taxiing.
>
> After seeing two of my old club's planes go through a set of pads per
> 100 hour inspection (one of them having a similar catastrophic right
> (I believe) break failure... only during a landing... only a VERY good
> instructor prevented a ground-loop). And then hear stories like this
> from a very experienced pilot no-less...
>
> I can't say I miss them.
>

I have had a right break failure in a piper with toe brakes also right brake
stuck upon applying them.

[David Lesher]

"Jay Honeck" > writes:


>Anyone know if it's possible for a brake to hang up and not release,
>resulting in advanced wear like this? Or should I keep blaming Mary
>for riding the (right) brake?


Yes. In cars, this is often caused by the caliper rusting.
That's caused by a) road salt b) water in the brake fluid.
Hence the recommendation to flush the fluid every 2 years.

I've read both the 'rotor runout' and seal material explanations
for retraction; I suspect there's some of each. In any case, with
no pressure/drag - i.e pads skipping along; there's very little if
any braking action.

The constricted hose IS a known problem if a rare one. I think
newer hoses/neopreme may have solved the issue.

Do NOT overlook master cylinder/pedal issues. One of those
old batttries wedged under the pedal and.......

--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

[Jay Honeck]

> No no no...it's "Hail Mary", not "Blame Mary". :-)

Now Jack here is obviously a successfully married man...

;-)

Well, the parts arrived from Spruce by 10 AM this morning, and the
brakes were fixed by lunch. Atlas is tucked safely back in his hangar,
fully fueled and ready to go.

All we need now is some nice weather on Sunday. It's 35 degrees and
raining, right now -- ain't nuthin' flying around Iowa City...

Prog charts show a big chunk of (argh!) thunderstorms moving into
Oklahoma and Texas on Sunday morning...

:-(
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Peter Dohm]

> > Ouch...
> >
> > This is one of those stories that makes me glad that I didn't spend
> > the extra money (and lost useful load) to install Toe-Brakes in 61J...
> >
> > Yes it was odd... for the first 5 minutes of taxiing.
> >
> > After seeing two of my old club's planes go through a set of pads per
> > 100 hour inspection (one of them having a similar catastrophic right
> > (I believe) break failure... only during a landing... only a VERY good
> > instructor prevented a ground-loop). And then hear stories like this
> > from a very experienced pilot no-less...
> >
> > I can't say I miss them.
> >
>
> I have had a right break failure in a piper with toe brakes also right
brake
> stuck upon applying them.
>
>
This makes me just a little curious.

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

My reason for asking is that, if hydraulic, the same culd happen with the
handbrake--although the possiblility of inadvertantly dragging the right
brake while applying rudder would be eliminated.

Peter

[Peter Dohm]

> >Anyone know if it's possible for a brake to hang up and not release,
> >resulting in advanced wear like this? Or should I keep blaming Mary
> >for riding the (right) brake?
>
>
> Yes. In cars, this is often caused by the caliper rusting.
> That's caused by a) road salt b) water in the brake fluid.
> Hence the recommendation to flush the fluid every 2 years.
>
> I've read both the 'rotor runout' and seal material explanations
> for retraction; I suspect there's some of each. In any case, with
> no pressure/drag - i.e pads skipping along; there's very little if
> any braking action.
>
And a few cars, such as Corvettes in the middle 1960s, were reputed to have
springs inside the calipers so that the pads would not retract. This was
supposed to keep the pads and disks cleaner and drier, with only a very
slight increase in the rate of wear.

I never owned one and don't know how well it worked.

Peter
(Anticipating the obvious question)

[[email protected]]

On Mar 9, 8:47 pm, "Jay Honeck" > wrote:
> Prog charts show a big chunk of (argh!) thunderstorms moving into
> Oklahoma and Texas on Sunday morning...

Yep, low ceilings, crappy visibility, possibly rain and thundershowers
from west of Wichita Falls all along the Red River all the way to Lake
Texoma forecast for most of the day Sunday. MVFR at best, probably
actually gonna be IMC though.

Might be a better idea to try again Monday. Or if you can, leave
Saturday morning. It's supposed to be very clear and almost no winds
all day Saturday across the local region here.

[Jay Honeck]

> Might be a better idea to try again Monday. Or if you can, leave
> Saturday morning. It's supposed to be very clear and almost no winds
> all day Saturday across the local region here.

Yeah, we'll probably only make it half-way down Sunday anyway...so
flying in to Fredericksburg on Monday is no biggie.

Can't leave today, dang it. Got a million loose ends to tie before we
can leave the hotel for a week...
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[EridanMan]

Yes its hydraulic (Single Cylinder)... so yes, it could definitely
still fail.

The whole system is much simpler (And lighter, by about 8 lbs) than
the toe-brake system though, and according to my mechanic at least,
its basically bullet-proof...

This is simply according to him - but apparently fried right wheels/
brakes are a reasonably common (especially on Grummans and training
aircraft)... he attributes it simply to the subconscious dragging on
takeoff/taxi... At the very least, the right pads wear faster than the
left on most planes he looks at, even with experienced pilots.

The only planes he doesn't see it on are the few that don't have toe
brakes. That was enough for me... (Disclaimer, I am a young, low-time
pilot with ABSOLUTELY no experience in this matter, other than I
learned in a few toe-brake planes before I bought 61J, and I adapted
to no toe-brakes in about 5 minutes...)

I do tend to trust the opinion of a mechanic who tells me not to give
him money for things though...

-Scott

[Dylan Smith]

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.

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

[Dylan Smith]

On 2007-03-10, Jay Honeck > wrote:
> Prog charts show a big chunk of (argh!) thunderstorms moving into
> Oklahoma and Texas on Sunday morning...

In my experience of (around 800 or 900 hours of) flying around Texas -
prog charts showing possible thunderstorms are not necessarily doom to a
trip.

My usual strategy was to look again at the radar just before departure,
and pick a point where I could stop and re-check the radar to see how it
was progressing. Around 70% of the time, the entire trip was a 'go'
because the thunderstorms turned out to be very widely scattered.

It also depends what the thunderstorms were associated with.
Thunderstorms embedded in a front, with low IMC? I'm not going to even
bother going to the airport. But basically reasonable VMC conditions,
and an area of widely scattered storms? Flight watch, and a stop at a
nearby airport to get a full update on the weather would usually prove
useful. About half the time, thunderstorms in the prog charts wouldn't
even materialise on the day of the trip and it was obvious from just
looking out of the window or calling Flight Watch that there was no need
to stop.

Of course, it's wise to exercise caution if you've no experience flying
in the area (because you don't get that gut feel whether they are
airplane-eating monsters or easily avoidable airmass storms), and the
usual advice to have an 'out' is something that can't be ignored.

But isn't it funny that on the day of a trip, all this weather always
seems to show up? I've done the Houston to Pinckneyville trip about half
a dozen times, and I can predict years in advance that there will be a
cold front lined up such that it lies right over the middle of Arkansas
on the Friday afternoon just when I'm passing. It's _always_ there on
that particular Friday, like a big cosmic meterological taunt!

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

[Steve Foley]

"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.

[Peter Dohm]

> > 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

[Peter Dohm]

> Yes its hydraulic (Single Cylinder)... so yes, it could definitely
> still fail.
>
> The whole system is much simpler (And lighter, by about 8 lbs) than
> the toe-brake system though, and according to my mechanic at least,
> its basically bullet-proof...
>
> This is simply according to him - but apparently fried right wheels/
> brakes are a reasonably common (especially on Grummans and training
> aircraft)... he attributes it simply to the subconscious dragging on
> takeoff/taxi... At the very least, the right pads wear faster than the
> left on most planes he looks at, even with experienced pilots.
>
> The only planes he doesn't see it on are the few that don't have toe
> brakes. That was enough for me... (Disclaimer, I am a young, low-time
> pilot with ABSOLUTELY no experience in this matter, other than I
> learned in a few toe-brake planes before I bought 61J, and I adapted
> to no toe-brakes in about 5 minutes...)
>
> I do tend to trust the opinion of a mechanic who tells me not to give
> him money for things though...
>
> -Scott
>
>
Thanks.

Eight pounds is quite a weight saving, especially since Pipers have very
positive nose wheel steering, so the toe brakes provide only dedundancy. My
personal prejudice favors the greatest theoretical redundancy, meaning nose
wheel steering plus toe brakes, but I don't have the experience either--so
it is just opinion, and worth slightly less than you paid for it.

BTW, the Gruman Cheetah and Tiger models, and many of the newer training
aircraft, have castoring nosewheels--so steering is accomplished by
differential braking until the rudder becomes effective. That should cause
them to have faster right side brake wear than Cessna trainers, which have
spring steering which allows the nose wheel to lock straight ahead in flight
and which can become a little problematic; especially if the nose strut and
the springs are not maintained.

Peter

[EridanMan]

> Eight pounds is quite a weight saving, especially since Pipers have very
> positive nose wheel steering, so the toe brakes provide only redundancy. My
> personal prejudice favors the greatest theoretical redundancy, meaning nose
> wheel steering plus toe brakes

Yes, but then you also might argue that toe brakes (requiring two
cylinders, two pressurized lines, etc) have twice as many failure
points for the same mission-critical system (Braking)... so while you
get redundant steering, you get it at the cost of more mission
critical parts to fail;)

I'm stirring the pot of course, I would gladly step up to a newer
aircraft with toe brakes if given the opportunity, I'm just saying I
don't miss them on my current bird;)

For me the 2k labor + 8lbs was the primary deciding factor (funny how
that works;))

> BTW, the Gruman Cheetah and Tiger models, and many of the newer training
> aircraft, have castoring nosewheels--so steering is accomplished by
> differential braking until the rudder becomes effective.

I've flown a friends cheetah... Going from my direct-drive, simple
rudder pedal steering too a toe-brake-only system was... interesting,
to say the least.

My biggest issue in that plane however was it was simply too small for
me... I could not get into a position where I could manipulate the
pedals comfortably... (same with most toe-brake equipped planes (I'm
6'4, 240), but the grumman was particularly bad)

Shame, because otherwise I love the grummans... great view and fun to
fly.

> That should cause them to have faster right side brake wear than Cessna trainers, which
> have spring steering which allows the nose wheel to lock straight ahead in flight.

I think the issue Any training airplane has is simply... trainees...
even aircraft Pipers and Cessnas... it takes a few flights to get in
the hang of keeping your foot off the brakes and on the rudder at
takeoff... for some (like me) its rather uncomfortable even;)

> and which can become a little problematic; especially if the nose strut and
> the springs are not maintained.

I read somewhere that Cessna Milked that patent for all it was worth
and despite the MX issues, I think its a smarter system... I still
live in fear (especially when fighting particularly gusty x-winds) of
touching down sooner than I anticipate with a nice heavily cocked
front nose wheel and hearing the control line go *SNAP*...

> Peter

[Drew Dalgleish]

On 12 Mar 2007 15:30:12 -0700, "EridanMan" >
wrote:

>> Eight pounds is quite a weight saving, especially since Pipers have very
>> positive nose wheel steering, so the toe brakes provide only redundancy. My
>> personal prejudice favors the greatest theoretical redundancy, meaning nose
>> wheel steering plus toe brakes
>
>Yes, but then you also might argue that toe brakes (requiring two
>cylinders, two pressurized lines, etc) have twice as many failure
>points for the same mission-critical system (Braking)... so while you
>get redundant steering, you get it at the cost of more mission
>critical parts to fail;)
>
>I'm stirring the pot of course, I would gladly step up to a newer
>aircraft with toe brakes if given the opportunity, I'm just saying I
>don't miss them on my current bird;)

>> Peter
>
NA stirring the pot would be to suggest that with the training wheel
on the front, long wide paved runways having one wheel brake is way
more than whats needed for safe operation.

[Peter Dohm]

> > Eight pounds is quite a weight saving, especially since Pipers have very
> > positive nose wheel steering, so the toe brakes provide only redundancy.
My
> > personal prejudice favors the greatest theoretical redundancy, meaning
nose
> > wheel steering plus toe brakes
>
> Yes, but then you also might argue that toe brakes (requiring two
> cylinders, two pressurized lines, etc) have twice as many failure
> points for the same mission-critical system (Braking)... so while you
> get redundant steering, you get it at the cost of more mission
> critical parts to fail;)
>
> I'm stirring the pot of course, I would gladly step up to a newer
> aircraft with toe brakes if given the opportunity, I'm just saying I
> don't miss them on my current bird;)
>
> For me the 2k labor + 8lbs was the primary deciding factor (funny how
> that works;))
>
This is a common topic of hangar flying sessions, and I am not really a
strong advocate either way. I only have a preference, if faced with two
otherwise equal airplanes at essentially the same price.

> > BTW, the Gruman Cheetah and Tiger models, and many of the newer training
> > aircraft, have castoring nosewheels--so steering is accomplished by
> > differential braking until the rudder becomes effective.
>
> I've flown a friends cheetah... Going from my direct-drive, simple
> rudder pedal steering too a toe-brake-only system was... interesting,
> to say the least.
>
I can't argue with you there, although the only plane with toe-brake only
steering that I ever had occasion to taxi was an an Aero Commender.
Interestingly, the rudder was reasonably effective at a much lower speed
than I would have supposed. (I no longer recall the speed--or the wind
conditions)

Actually, the size of the rudder and its relationship to the vertical
stabilizer plays a major role in the need for toe brakes, nosewheel
steering, or even tailwheel steering. I have read that the Supermarine
Spitfire had no tail wheel lock and also no tailwheel steering--and I am
confident that some here will correct me if I am mistaken.

> My biggest issue in that plane however was it was simply too small for
> me... I could not get into a position where I could manipulate the
> pedals comfortably... (same with most toe-brake equipped planes (I'm
> 6'4, 240), but the grumman was particularly bad)
>
> Shame, because otherwise I love the grummans... great view and fun to
> fly.
>
I've never gotten to try one on, but should find it a little easier. I'm a
little guy by comparison--6'1", 200#--and intending to lose 20#.

> > That should cause them to have faster right side brake wear than Cessna
trainers, which
> > have spring steering which allows the nose wheel to lock straight ahead
in flight.
>
> I think the issue Any training airplane has is simply... trainees...
> even aircraft Pipers and Cessnas... it takes a few flights to get in
> the hang of keeping your foot off the brakes and on the rudder at
> takeoff... for some (like me) its rather uncomfortable even;)
>
No argument there. In my case, it was simply a matter of putting my feet as
low a practical on the pedals. However, in the case of something like the
Gruman it would be a little more complicated, a lot would depend on whether
there was sufficient rudder authority just from the prop blast--if not, it
should be a matter of keeping my toes off of the left brake on the take off
roll.

> > and which can become a little problematic; especially if the nose strut
and
> > the springs are not maintained.
>
> I read somewhere that Cessna Milked that patent for all it was worth
> and despite the MX issues, I think its a smarter system... I still
> live in fear (especially when fighting particularly gusty x-winds) of
> touching down sooner than I anticipate with a nice heavily cocked
> front nose wheel and hearing the control line go *SNAP*...
>
I flew Tomahawks in crosswinds while I was still plenty ham fisted (or is
that ham footed) and that was never a problem. The airplane's response was
so non-memorable that I have no recollection of it.

I suppose I should add that I was taught to hold the nose off untill a good
bit of speed was lost, rather than actively derotating. Actually, in the
worst case, I doubt that a nosewheel still cocked would do more than make me
appear clumsy--unless it was combined with a worse error.

Peter

[Tri-Pacer]

>
> 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

[EridanMan]

> NA stirring the pot would be to suggest that with the training wheel
> on the front, long wide paved runways having one wheel brake is way
> more than whats needed for safe operation.

I suddenly got an amusing mental image of an aircraft doing pirouettes
in the run-up area while the flight crew non-nonchalantly went through
their checks...

;)

[Peter Dohm]

> > NA stirring the pot would be to suggest that with the training wheel
> > on the front, long wide paved runways having one wheel brake is way
> > more than whats needed for safe operation.
>
> I suddenly got an amusing mental image of an aircraft doing pirouettes
> in the run-up area while the flight crew non-nonchalantly went through
> their checks...
>
> ;)
>
LOL :-)