Parking Brake DOES work

[TheTurtle]

feeling kind of dumb.  Was going to fiddle with my non working parking brake this weekend.  I dont ever use it but figured it would be something to tinker with.

Come to find out if I push on the brakes and then set the parking brake it works fine....  DUUUuuuuhhh.

To be fair I dont push my brakes in my car to set the parking brake...

Is that the way most hydraulic airplane parking brakes work?  Now im wondering if all those cessna parking brakes actually worked as well.

[PaulM]

Yes, if you look at the diagram in the POH the Mooney parking brake is a valve between the rudder pistons and the brakes, so it holds the pressure that has already been applied.   

Cessna's current pull and turn system works differently and pulls the rudder pedals forward via a cable.. and the turn just locks it into place.    I just checked and older Cessna systems were just hydro locks like our mooney..   I seem to remember that the 172N we had (1982) was the newer system. 

[DXB]

I had the identical experience when I got my plane and so am honored to be a fellow member of the Parking Brake Bozo Club.  I was annoyed the he MSC didn't catch something so basic at prebuy until I figured out that it was just fine a few weeks later.  

[bradp]

How about the opposite bozo club where I tried to taxi with my parking brake set. I'm a member.


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[201er]

Just now, bradp said:

How about the opposite bozo club where I tried to taxi with my parking brake set. I'm a member.


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Who hasn't? Then again the parking brake isn't firm enough not to let you start rolling with even a slight bit of power!

[Skates97]

22 minutes ago, DXB said:

I had the identical experience when I got my plane and so am honored to be a fellow member of the Parking Brake Bozo Club.  I was annoyed the he MSC didn't catch something so basic at prebuy until I figured out that it was just fine a few weeks later.  

Another member of the club here. I was just not going to worry about it, the only time I ever use it is when starting the engine and during run-up, but I always have the brakes on then as well because I don't trust the parking brake to do the job. Then I was reading and realized it just holds the pressure already applied like others said here and what do you know, it actually does work.

[cctsurf]

I find it interesting that a number of you are saying that the parking brake is not solid.  Mine is amazingly so.  I can run up to full power and not move...  I wonder what the difference is.

[MooneyBob]

3 minutes ago, cctsurf said:

I find it interesting that a number of you are saying that the parking brake is not solid.  Mine is amazingly so.  I can run up to full power and not move...  I wonder what the difference is.

Same here. After last annual they did something to it and it is really solid. 

[MHemperly]

POH.... haha

[Bartman]

My parking brake did not work well when I got the plane 10 years ago. At the first annual the guys drained what they described as fluid that had turned to gel, flushed the system, and refilled with fresh fluid. 

Although it works well, I rarely use it. 

[Marauder]

What? We got parking brakes on these planes?!

[Yetti]

Mine is a valve on the firewall below the reservoir up in front of the pilots feet.  You can see the knob move the cable and close the valve.

[Bob_Belville]

Hum, my Start Engine and Before Take Off check lists both start with Set Parking Brake.

Start Engine & Taxi:

BAGGAGE DOOR: LATCHED

SEAT/SHOULDER BELTS: ON       

PASSENGER BRIEF: DONE

GEAR HANDLE: CHECK LOCKED   

BRAKES: SET
RADIO MASTERS: OFF

CBS & ELECT SWITCHES: CHECK

POWER BOOST: CLOSED

COWL FLAPS: OPEN

FUEL SELECTOR: FULLEST TANK

MIXTURE/THROTTLE/PROP: COLD START: ALL FULL FORWARD

MASTER: ON      VACUUM: CHECK CLOCK/TIMER: SET JPI: SET

FUEL BOOST PUMP: 5 SEC. (COLD)

MIXTURE: CUT OFF    THROTTLE 1/4” PROP: “CLEAR”
STARTER: ENGAGE MIXTURE: ADVANCE THROTTLE: 1200 RPM OIL PRESSURE: GREEN MIXTURE: LEAN – SHORT OF ROUGH

RADIO/ASPEN MASTERS: ON    

NAV LIGHTS/ STROBES: SET
XPONDER: SET

GPS: SET

BOTH GEAR ALERT/GEAR LIGHTS: TEST

FLAPS: PUMP FULL DOWN AND RELEASE

ATIS/AWOS/RADIOS: CHECK,

SET ALTIMETERS: SET BOTH

AUTOPILOT: TEST, SET READY

Before Take Off:

BRAKES: SET FLIGHT

CONTROLS: FULL TRAVEL

COWL FLAPS: OPEN

SPEED BRKS: RETRACT

PITCH TRIM: TEST ELECTRIC & MANUAL SET FOR TAKEOFF

FLAPS: 15⁰ NORMAL TAKE OFF

THROTTLE: 1800 RPM

MAGS CHECK–TACH MODE: (DROP <125 RPM)

PROP: EXERCISE

JPI ENGINE INSTUMENTS: CHECK THROTTLE: IDLE
ASPEN HSI HEADING: CHECK RUNWAY

IFR: CLEARANCE LIMITROUTEALTITUDE DEPARTUREFREQUENCYTRANSPONDER

COMM/NAVS/GPS: SET

TRANSPONDER: STBY TO ON
LIGHTS & PITOT HEAT: SET AS REQUIRED

DOOR/LUGGAGE DOOR/ WINDOW: LOCKED

FLOOR AREA FOR GEAR LEVER: CLEAR

FUEL BOOST: ON MIXTURE: FULL RICH (EXCEPT @HIGH PRESS. ALT.)

PARK BRAKES: RELEASE

[Brandontwalker]

So... that's how it works. I'll have to give it a try next time I'm at the airport. Another bozo I guess.


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[Hank]

11 hours ago, Marauder said:

What? We got parking brakes on these planes?! 


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Had my C  nearly 10 years, never touched the Parking Brake knob. I have no idea if it works or not, but the brakes are fine. I did have to press harder than for a normal runup when checking dynamic balance at full power vs. normal 1700 RPM runup, though.  

Bob, like my own,  yours above says, "Brakes--Set" which to me means both feet forward. It does not say "Parking Brake--Set" or I would have done so from my first time through the checklist. 

Edited February 14, 2017 by Hank

[Bob_Belville]

8 hours ago, Hank said:

Had my C  nearly 10 years, never touched the Parking Brake knob. I have no idea if it works or not, but the brakes are fine. I did have to press harder than for a normal runup when checking dynamic balance at full power vs. normal 1700 RPM runup, though.  

Bob, like my own,  yours above says, "Brakes--Set" which to me means both feet forward. It does not say "Parking Brake--Set" or I would have done so from my first time through the checklist. 

Wow, just wow.

The knob on the dash closes a valve that holds the hydraulic pressure you've applied to the calipers with the toe brake pedals. I'm surprised some of you folks were not shown this as about the first item of Mooney transition training. While it is possible to go through everything on the check list while holding pressure on the brakes, it sure is safer to lock the brakes on. Stuff happens.

So now you've shut down on the ramp away from your hangar. What do you guys do when that ramp that has a slope or in a strong wind? Maybe you're alone at the self serve pump. Don't you wonder why the ramp "boy" asked you if your brakes were off so that he can move the plane?

[Brandontwalker]

1 hour ago, Bob_Belville said:

Wow, just wow.

The knob on the dash closes a valve that holds the hydraulic pressure you've applied to the calipers with the toe brake pedals. I'm surprised some of you folks were not shown this as about the first item of Mooney transition training. While it is possible to go through everything on the check list while holding pressure on the brakes, it sure is safer to lock the brakes on. Stuff happens.

So now you've shut down on the ramp away from your hangar. What do you guys do when that ramp that has a slope or in a strong wind? Maybe you're alone at the self serve pump. Don't you wonder why the ramp "boy" asked you if your brakes were off so that he can move the plane?

Hmmm...  Chocks and ropes always seem to manage just fine.  Haven't ever had the need to use the parking brake personally.  As to the checklist/run up, I have always just held the brakes.  Maybe I'm simple minded (you know us southerners).  If holding the brakes doesn't work, I would proceed back to the hangar until the brakes and/or pilot is checked out.

Edited February 14, 2017 by Brandontwalker

[Bob_Belville]

Just now, Brandontwalker said:

Hmmm...  Chocks and ropes always seem to manage just fine.  Haven't ever had the need to use the parking brake personally.  As to the checklist/run up, I have always just held the brakes.  Maybe I'm simple minded (you know us southerners).  If holding the brakes doesn't work, I would proceed back to the hangar until the brakes and/or pilot is checked out.

• You've never parked where the plane started rolling as you exited?! You frequent self serve pumps with tie downs? The one at Minute Man (6B6) is on the top of a hill, I would never deplane there without setting the brakes. My avionic shop's ramp, Twin Lakes, (8A7), is also on the top of a hill so steep that unless Robbie trusts your airmanship he'll ask you to park on the main ramp and he'll bring the plane in with his tug. 
• The parking brakes only hold on to what you've done with the toe brakes. If the plane want to move when you run up for Mag check, the parking brakes won't help.
• I'll be interested to hear from one or two of our Master Mooney CFIs. I would not be surprised to hear a war story or two. To quote myself, stuff happens.
• Try them, you'll like them.

Now I'll concede that our Mooneys do not roll easily, wind is less a factor than for most makes in our category, and the wheel nuts are tightened to only spin one rev or less, but I think it is bad form to leave a plane, especially on a crowded ramp where jet and turbo blasts might occur without setting the brakes. Think a C172 getting blown into your pretty bird.

[carusoam]

1) My C's parking brake never worked... the valve wouldn't hold the pressure.  Same as every flight school plane I flew...

2) It would have been nice if Craig got MS up and running in y2k!

3) No, I don't trust the parking brake to hold my plane while I do a run-up.  That would be ill-advised.  It can move pretty far before your feet get back on the brakes...

4) brakes are great for parking in hilly areas, but chocks are still the permanent keep from rolling answer.

5) read your POH because car e-brakes and parking brakes are different in purpose and construction, where a cable operates the rear brakes in place of the primary hydraulic system.

Best regards,

-a-

Edited February 14, 2017 by carusoam

[Bob_Belville]

6 minutes ago, carusoam said:

1) My C's parking brake never worked... the valve wouldn't hold the pressure.  Same as every flight school plane I flew...

2) It would have been nice if Craig got MS up and running in y2k!

3) No, I don't trust the parking brake to hold my plane while I do a run-up.  That would be ill-advised.  It can move pretty far before your feet get back on the brakes...

4) brakes are great for parking in hilly areas, but chocks are still the permanent keep from rolling answer.

5) read your POH because car e-brakes and parking brakes are different in purpose and construction, where a cable operates the rear brakes in place of the primary hydraulic system.

Best regards,

-a-

Anthony, I agree that I keep my feet on the rudders when doing MAG check/prop exercise, for one thing, the brake might not have been set tight enough. And I agree that a car's mechanical "emergency" (bad term) brake is different from the Mooney system where the braking is the same. I do not suggest that brakes are a substitute for chocks or lines.

If my parking brake did not work I would get it fixed. It might not be an airworthy item but it's close, IMNSHO.

[Lance Keve]

I'll share a parking brake scare.  I was at an away airport and pulled to a pump that had a slight decline leaving my nose pointing to the up side as the pump was off to my left.  I pushed the toe brakes, pulled the parking brake, got out and proceeded to get things ready to refuel.  It was a very windy day....and there was nobody around.

Just as I was pulling the fuel line out I noticed the plane starting to creep backwards.  There was maybe 120 feet before the tail would strike a line of parked aircraft.  It was picking up speed and there was no way I could get to a loose chock and back to throw it under a wheel before it would be too late.  If there was an Olympic sport for speed of starting at the front of your plane, while it is rolling backwards, and getting into the left seat and with feet to brakes, I would have earned the gold.  Launched up on to the wing front, pirouetted around the door, and shot myself into the cockpit like a Duke boy expeditiously getting into the General Lee as if Rosco P. Coltrane was coming.

Full force on the brakes slowed the plane to a stop over 10 more feet leaving roughly 25 feet before impact with another plane.  Phew.  Started plane, pulled up to the pumps a bit further, brakes, parking brake, got out and chocked immediately.  Was all fine after that.

The plane had new brake pads at annual and they seemed stiffer in actuation but didn't hold as well as before replacement.  Re-bleeding was the cure.  Parking brake had always worked well before that.

Got lucky that day.

 

[Hank]

Whenever the ramp is such that I worry about rolling, I remove my travel chocks from the hatrack before stepping off of the wing. Sometimes I only put one down when the tilt is pronounced, as I've yet to see a plane roll uphill when starting at rest. My travel chocks started out as a piece of 2" x 2" aluminum angle in the trash can at work . . . Cut to length, filed smooth and sanded until they shine, with rope holes drilled in them. Now they've even been laser etched.

Remove the chock(s) immediately prior to boarding, and apply brakes as necessary [a rare event prior to engine start].

[Guest]

Setting the parking brake on a warm set of brakes is a disaster waiting to happen.  Many years ago a King Air 200 stopped at the hangar up the hill from my old shop. The crew set the brake and went inside to wait on the passengers, the brakes cooled and released, and the plane started rolling.  It came to rest against at lamp post and a Piper Cherokee, just feet from my office window.

The crew learned that chocks were a great invention.

Clarence

[neilpilot]

21 minutes ago, M20Doc said:

Setting the parking brake on a warm set of brakes is a disaster waiting to happen.  Many years ago a King Air 200 stopped at the hangar up the hill from my old shop. The crew set the brake and went inside to wait on the passengers, the brakes cooled and released, and the plane started rolling.  It came to rest against at lamp post and a Piper Cherokee, just feet from my office window.

The crew learned that chocks were a great invention.

Clarence

Setting the parking brake on a cold set of breaks, in hot weather, can result in high pressure locked up leading to a blown hydraulic seal.  Moral of the story, use the parking brake only for a brief period, i.e. during a run up or when deplaning, just long enough to find those chocks.

[Bob_Belville]

27 minutes ago, M20Doc said:

Setting the parking brake on a warm set of brakes is a disaster waiting to happen.  Many years ago a King Air 200 stopped at the hangar up the hill from my old shop. The crew set the brake and went inside to wait on the passengers, the brakes cooled and released, and the plane started rolling.  It came to rest against at lamp post and a Piper Cherokee, just feet from my office window.

The crew learned that chocks were a great invention.

Clarence

A big heavy King Air! That must be quite an incline. Is the brake system the same as our Mooneys? It's easier to image Neil's scenario of a build in pressure than the opposite.