Valve type parking brake mod?

[jrenwick]

Hi,

Has anyone ever looked at replacing the Cessna parking brake mechanism with a cable-actuated dual valve, such as Cleveland P/N 60-5 or MATCO P/N 06-17200? See http://www.aircraftspruce.com/catalog/l ... valves.php .

John

[blueldr]

How about installing one of the cane handle type parking brake systems as in the C-182. The handle latches when pulled out and the cables hold the pedals down and the brakes on. The handle is turned one quarter of a turn to release it.

[Jr.CubBuilder]

Just a Super Wild Ass Thought (SWAT) but I've looked at mine, which should be coming off in a week, and thought that if the locking latches were shortened so that they didn't extend beyond the circumrence of the master cylinder and had a stronger return spring the problem of accidental locking might be eliminated completely.

[GAHorn]

The "cane handle" solution is what convinces me that Cessna knew they had a problem. It would be a better solution (and maybe an easier-to-approve one.) I like the idea of hydraulic parking brake valves also, but I don't think I'll spend any money on the issue. I've been operating my 170 now for over 5 years and only occasionally missed a parking brake, usually when parking on a slope and needing to get out of the airplane. It's been a simple matter to just taxi/turn the airplane sideways and get some chocks.
Jr.CubBuilder, that idea might work, but you'd still be dealing with an unapproved modification that would have questionable results. How often do you really need a parking brake? (As a flight instructor, I sometimes give Bi-annual flight reviews and observe some pilots that use the parking brake during run-ups. I try to discourage that because of their intent. Their intent is usually to relieve themselves of the responsibility to watch outside the aircraft for unintended movement during the run-up. (I believe this is the most common useage of the parking brake.) The result is that if the parking brake does not hold (as it frequently doesn't) then they don't notice the aircraft movement. (This resulted in a prop strike in the most egregious case I've ever heard of. The pilot of a Baron told me he once used his hydraulic-valve type parking brake to hold the aircraft during run-up. Unnoticed by him while he had his head way down in the cockpit, the aircraft moved about 20 feet! (I know) until it was in the direct engine blast of a B-737 taxying into position. It picked up the Baron, tipped it and dropped it onto it's right gear hard enough cause the right prop to strike the pavement.) Reliance on a parking brake is a poor habit anyways, IMHO. I always try to discourage the use of parking brakes if the intent is to relieve the pilot of responsibility to observe outside the cockpit. It's easier to notice movement from insufficient braking through the tactile feeling of your feet if you use them to hold the brakes, again IMHO.

Then of course, there are the issues of ongoing maintenance, adjustments, and the never-to-be forgotten times the brakes are locked on, and will not release, and meanwhile you're blocking the progress of those behind you.... KISS

[zero.one.victor]

A friend of mine who used to own an A model (now owned by another friend) insisted on using his parking brake instead of chocking the wheels. Even after several instances of the parking brake bleeding down, allowing the airplane to roll. Either gravity induced (parked on a slope) or prop blast induced. he never bothered to make sure the tailwheel was back in it's straight-ahead detent either. IMHO he really lucked out not having incurrd any airplane damage due to his laziness. I ALWAYS chock mine, & always make sure the tailwheel's locked straight, too.

Eric

[jrenwick]

I fully appreciate that parking brakes have to be used with caution. That doesn't diminish their value for me. The situation where I really want them is at the fuel pump, when the wind is up enough that the airplane is threatening to jump out of the chocks. Parking brakes can really help a set of chocks to do their job.

Mostly I just wanted to know if anyone had worked on a hydraulic valve solution to replace Cessna's mechanical device, because that looks to me like it would be fairly easy to install, even using the existing cable. I guess the answer is no, nobody's done that on a 170. Thanks for the feedback!

Best Regards,

John

[thammer]

I'm kinda curious about the legality of removing the parking brake. 120/140's have the same problem. It seems the guys who usually are first to bring up unauthorized changes are generally silent on this one. (That's not a barb guys, just an observation.) Is there something about this that makes it ok to do? If the FAA guy happens to sneak up on you and look at your parking brake cables in the cabin and sees them cut off, what can he say?

[zero.one.victor]

I'd scratch off the "parking brake" placard above the knob, disconnect it, & call it good. How many FAA inspector types are up enough on our old airplanes to even notice the discrepancy? The few that are probably own their own 170 (or 120/140 or 180 or 190/195), & have their parking brake disconnected too!

Eric

[Metal Master]

Hi,

Has anyone ever looked at replacing the Cessna parking brake mechanism with a cable-actuated dual valve, such as Cleveland P/N 60-5 or MATCO P/N 06-17200? See http://www.aircraftspruce.com/catalog/l ... valves.php .

John

I have never performed this mod on a 170 however I did perform it on a Cessna A152 aerobat. It was a rental and training airplane and the pilots whenever they would fly aerobatics would jam on the brakes and get the parking brake locked on the shaft of one of the master cylinders during flight. This occurred multiple times. With the result that the aircraft would be landed with the parking brake locked. At the least the aircraft would not be able to be taxied. In the worse case they would blow a tire. I imagine in a 170 the results could be much worse. We used the Cleveland hydraulic parking valve. A similar installation was used in Mooney M20J's and K's. We had to get a field approval to do the mod. But with the evidence of several blown tires at the exits to the runway being blocked at towered airport it was easy to get the FAA rep to field approve the installation.

[N2865C]

I'm kinda curious about the legality of removing the parking brake.

Since it is not required equipment, I see no reason it can't be removed. I removed mine and my AI made a log book entry to the effect of = Removed parking brake assembly from master cylinder and labeled control knob inoperative.

[thammer]

I'm kinda curious about the legality of removing the parking brake.

Since it is not required equipment, I see no reason it can't be removed. I removed mine and my AI made a log book entry to the effect of = Removed parking brake assembly from master cylinder and labeled control knob inoperative.

That sounds pretty straight forward and makes sense. Thanks.