Parking Brake

[ghostflyer]

Russ Farris ,I totally support your ideas as we can all change hats if we are all so inclined. Most car mechanics have drivers license dont they? Being able to appreciate all facets of aviation makes it a more exciting job,hobby,interest etc. Now back to brakes.I wasnt aware of the hand brake issue so a inspection of our aircraft system was top priorty. Our 170A [serial no 19006] has a different brake system so far discussed. Our system is similar to Page 44 fig 25 L/h bubble inset of the Cesna parts manual. A cable attaches to the top of each brake piston/rudder pedal attach point and then routes around a pulley and joins mechanically to a single cable which then joins to a ratching T handle . The handle must be pulled and brake pedals depressed for park brake to be deployed. I am very interested to know if any other owners have had trouble with this system.

[GAHorn]

The "L/H bubble"??? The bubble which applies to SN19200 and on? (despite the fact your serial is 19006?) With the brake pedals depressed, the cable lifts the lever which locks the master operating rod in the down/applied position. If so, that is the type which is troublesome.

[ghostflyer]

The "L/H bubble"??? The bubble which applies to SN19200 and on? (despite the fact your serial is 19006?) With the brake pedals depressed, the cable lifts the lever which locks the master operating rod in the down/applied position. If so, that is the type which is troublesome.

Thankyou for answering so soon.Its a very important subject. On my page 44 on the L/H "bubble" it states "Serials from 18003 to 19200". We have no locking lever on the master Cylinder but only a cable which pulls down the master operating rod and this holds the brake cylinder in the pressure mode by the ratchet lock on the T handle. However I have concern regarding the sloopy cable with brakes off with full rudder deflection of either pedal.

[GAHorn]

Regardless of which "bubble" if your airplane conforms to the IPC illustration for your serial number, then to my knowlege that parking brake has not had any failures of the type we have been discussing. The type brake we have seen troubles with are those which apply the brakes via the pilot-operated pedals, which are locked into the applied position via "plates" or "locking levers" which are lifted into the locked position via cable.

[Indopilot]

Ghostflier, It sounds like you have the later style sometimes refered to as "cane handle" Put in most newer A/C. I am not aware of any problems with that style, except that the handle can crack at the notches. I just installed one in our 171 to replace the self starter parking brake.

[GAHorn]

Ghostflier, It sounds like you have the later style sometimes refered to as "cane handle" Put in most newer A/C. I am not aware of any problems with that style, except that the handle can crack at the notches. I just installed one in our 171 to replace the self starter parking brake.

He does not have the "later" style you are thinking of, Ghostflier. (The type you are thinking of was used in latemodel 172/182/etc.) He has the earlier Cessna 170 type which does not use lifted levers.

[bagarre]

OK. I've read all the posts and I fully understand the problem with the parking brake.

And it concerns me because 81D only had the cables disconnected.
My tailwheel instructor wants to re-connect the parking brake and he's not without a whole lot of experience in 170s.

He also brings up a good point. If you have no parking brake, how do you secure the airplane at the pumps or any other place you need to step away for a second and chocks might not be available? A quick gust of wind in that case could wreck your day.

Does everyone carry around two sets of wheel chocks to prevent their plane from swinging one way or the other?
Just curious.

Thanks.

[Bruce Fenstermacher]

I wonder how I will secure my J3 which has no parking brake? Lots of airplanes have no parking brake. SOME airplanes have no brakes at all. Imagine that.

Yes I carry two sets of chocks in my 170 which I've operated for more than ten years without a parking brake and no problems. In fact to be honest I carry 4 sets of chocks but two are readily available. Could there be a circumstance were it is a small challenge to figure out exactly how to accomplish getting out and chocking the airplane or parking the airplane so it doesn't roll before it's chocked. Of course.

Ask your instructor how your going to disengage a brake, that is jammed on, that you don't know about, at the moment your wheel touches the ground AND your immediately heading for the runway edge. Answer, apply the brakes, which your not going to do. Your going to be buying a new plane at worst or a new pair of underwear at best.

I would rather tackle the extremely remote issue of climbing out and chocking the aircraft, which BTW does not happen with a blink of any eye as a stuck brake ground loop will, rather than worry at each wheel touch down whether the wheels are going to roll free.

And while we are talking about the parking brake. Recently I've meet a lot of new folks with 170s. Some knew the parking brake issue and just had the cable disconnected. That is not enough in most cases. It is my opinion that removing the cable may help the situation but not eliminate it. You must remove the tab that the cable connects to as well. In most cases that I've seen this tab is just as capable of being activated by the firewall environment and locking the brakes.

To remove this tab you must disconnect the peddle from the master cylinder rod. Remove the fork from the end of the master cylinder rod in order to slip the tab off. It is not all that complex of a job but a bit of a pain in the back because of the location and the contortions required to get there. Short of removing the tabs, I'd safety wire them down in some fashion so they can not be set.

[flat country pilot]

Does everyone carry around two sets of wheel chocks to prevent their plane from swinging one way or the other?
Just curious.

Yep,

and tie downs too.

[GAHorn]

OK. I've read all the posts and I fully understand the problem with the parking brake.

And it concerns me because 81D only had the cables disconnected.
My tailwheel instructor wants to re-connect the parking brake and he's not without a whole lot of experience in 170s.

He also brings up a good point. If you have no parking brake, how do you secure the airplane at the pumps or any other place you need to step away for a second and chocks might not be available? A quick gust of wind in that case could wreck your day.

Does everyone carry around two sets of wheel chocks to prevent their plane from swinging one way or the other?
Just curious.

Thanks.

Ask your instructor if he's going to be happy with the accident report blaming HIM for not preventing YOU from groundlooping....and ask him if it's too much trouble for him to hold the brakes at the pump while you get out and
get some chocks. Ask him also, if all the experience he has in 170's.... included any with the brakes enabled or disabled....or did he know anything about this issue at all before you brought it to his attention.

It's YOUR airplane. It's YOUR choice. It can be YOUR wreckage.

PS: Disconnecting the cables does NOT remove the problem. The only way to prevent the accident chain is to remove the locking levers atop the brake cyls.

[jrenwick]

I used to worry keeping the airplane still at the pump without parking brakes, but it really hasn't come up since I disabled the brakes a few years ago. I made a pair of chocks out of 2" PVC pipe (a squared-off "U" shape), which I keep under the back seat -- one on each side. It's very quick to step out, reach for one of these, and slide it around the tire. Much less fussy than a pair of regular chocks with a cord tieing them together.

[Bruce Fenstermacher]

OK now that I've vented a bit this is what I'd tell your instructor.

In the 60 years 170s have been around it has only been a relatively new idea of 15 years or so that the parking brake is a problem. It has always been there but the data just not collected. The last 15 years and the advent of computerized communication has allowed the collection of this information.

I know we have a few long time members who also have lots of 170 experience. And at convention when they hear us talk about the parking brake they get this deer in the head lights look and say. "That is exactly what happen to me 8 years ago when I touched down in ol Betsy". "Never knew what happen, we just touched down and next thing no matter what I did we were going left for the trees".

So tell your instructor that the problem isn't new but the fact we've collected the stories over the years and come to this conclusion is relatively new in 170 history. We're just trying to get the word out.

[mit]

I bought my first 170 in 1981 and heard about the Goodyear brake problems and the parking brake problem from old timers around here that flew and worked on them when they where NEW in the 50's.

[4583C]

OK now that I've vented a bit this is what I'd tell your instructor.

In the 60 years 170s have been around it has only been a relatively new idea of 15 years or so that the parking brake is a problem. It has always been there but the data just not collected. The last 15 years and the advent of computerized communication has allowed the collection of this information..

Actually this knowledge goes back to at least the early eighties. Cleo Bickford was the 170 mentor for the previous owner of 4583C and Cleo had advised him to unhook the parking brake before I bought it in 82 . The levers however weren't removed until I did it. Apparently it is a common mistake to disconnect the cable and not to remove the locking levers.

[mit]

OK now that I've vented a bit this is what I'd tell your instructor.

In the 60 years 170s have been around it has only been a relatively new idea of 15 years or so that the parking brake is a problem. It has always been there but the data just not collected. The last 15 years and the advent of computerized communication has allowed the collection of this information..

Actually this knowledge goes back to at least the early eighties. Cleo Bickford was the 170 mentor for the previous owner of 4583C and Cleo had advised him to unhook the parking brake before I bought it in 82 . The levers however weren't removed until I did it. Apparently it is a common mistake to disconnect the cable and not to remove the locking levers.

With all this info we have, in the computer era. How many accidents incidents have happened when just the cable was removed?