Care to Talk About It?

Jonathan Baron

Jonathan Baron

New member
Hey Folks!

I'm writing an article for the upcoming issue of the newsletter.....hey, stop groaning! This article is on the hydrauic power packs in our 'Masters and early Vikings, referred to by Aviation Consumer as "notoriously balky." Thus I need your stories if you have run afowl of these devices. If you'd rather not discuss this in our forum, send me email at blue.baron@verizon.net. If you have some photos, that would be wonderful as well, but by no means necessary.

The photos of my recent power pack adventure were taken by a reporter working for a local newspaper in Albany, OR, who is on vacation until past my deadline, alas.

Thanks! Yeah, I know you hand crank Cruisaire pilots may be giggling a bit at this notion, but I've heard tell that they can jam up too. If your cabin has inexplicably gotten hotter due to such an event please share your story with me as well :)

Jonathan
 
hey jon!

the only airborne problem i've had (so far) was when my PilotGuide slid under the gear handle and wouldn't allow it to move down far enough to activate the valve. after a few moments of the usual "oh, sh*t" stuff :shock: , i figgured it out and the gear came down fine.

2 anualls ago my IA was concerned that the manual pump didn't have enough ooomph to fully retract the gear without help while on the jacks. said it could be an indication of something else wrong. we never found anything else out of order, so he signed it off and i keep my eye on it.

good topic! hope we get s'more input.

blue skies,
vic & N522A
 
There is nothing really wrong with the powerpaks if they are properly maintained. They have seals and o-rings that eventually go bad due to age or fluid contamination but that can be expected. If you need to see what is inside one and how to overhaul one, replace the components, set pressures, etc. and your overhaul person keeps his manual locked in the safe, get an early Aztec or late Apache manual. Piper puts their own part number on the Aztec one--I seem to remember it to be a 31800-something number--but it is built the same as the "N" and the Apache uses the "N". The big problem with overhauling your own is finding someone who will sell you the "special" valves in the unit but they might be OK in yours and the problem is o-rings. Setting the pressures--very easy. Incidentally, I think the 31,800 would work in a Cruisemaster just fine except that the reservoir on the top is taller and the pressure would have to be reset. Lets not write an "expose" article on the unit. Our friends--We're only here to help you"--already don't like old airplanes and sit around on their ----- looking for something to do. Regards, Ron
 
hey ron!

you're correct that the 14-19-2 and (i think) -3 share the same power pak as the apache/aztek. however the "straight" 14-19 uses an early version, the 750B which is a completely different package on the outside.

due to the differences in mounting schemes between the two, i think it would be major surgery to convert to the later 750N. might have to be done someday, but i'm not ready yet.

a couple of years ago i tried to find documentation on this pak and came up empty handed. AirParts of Lockhaven actually has the manuals and will do the ovh for ~$1500 :shock: but were adamant about NOT releasing any maintainence/ovh information. even tho i offered to pay whatever they wanted for a copy, their remark was something like "...we went thru hell to get that manual, and we're not going to give it away...". i was not happy.

ah, the joys of antique a/c maintainence! :D

blue skies,
vic & N522A
 
:oops: Jonathan, As I mentioned before I had a gear actuator problem July 2004( right hand failed to move the lever) . Actually, I had recently purchased my Cruisemaster in April of that year and had built 25 hr in it up to that fateful Friday afternoon. I was practicing short field three point landings in preparation for a fly in to a grass strip at local flyin community. Typical summer in the south thunder boomers were lurking about and after the 5th or so circuits around KCEU I got concerned about one approaching from the west and as I was on down wind for 25 I said to myself ( read prophetic) "this will be my last landing of the day". Well I had owned a skyhawk for 13 years so shall we say the transition from the trike 145hp spam can to the high performance complex tail dragger was somewhat daunting but I did manage to put the tail wheel down first and right on the center line but boy did it stop short. Say what are those two little red lights for???

Since the prop had a different profile the engine had to be torn down for a peek so while its apart why not go ahead and renew it... and etc. etc $$$$ etc. That included the microswitch on the throttle linkage that was broken. Thats the one that sounds the horn when the gear is not down.

In October I was in the process of circulating over KCEU putting the second hour on the machine and enjoying life and being back in the air. Toward the end of the hour I noticed that my heel was sliding around a bit ... I wonder why. Well again on down wind to 25 I practiced my new GUMP GGUMP Gear, Gas Undercarriage, Mixture Prop, which I do at each radio announcement.

Gear...Gear ... GGG. Hey the red light are still on. And the pins on teh wing dont look right. OH... Clemson unicom can you look at my wheels. Oh they really are not down.

I tried to recylce still no luck. I tried to use the hand pump... no resistance.. now I know why my heel was slipping. My white socks are red and oily. One final try. Slow to 60 wheel lever down. make sure flap lever is in neutral position. Hold 60 .... Wow I ve got two greens and wheels are down.

Seems like the hydraulic hose connection at the reservior had come loose. My mechanic breathed when I landed and Ive been bragging about the landing gear redundancy ever since, but your experience has spooked me.
 
Dave,
In my old P-3 sqdr, we had a "rule" that after 5 T&G, you had to leave the pattern and regroup, even though there was a three person flight crew! This came about after two of our senior pilots (one was an IP) actually hit the #2 prop on the ground, went around as they FOD'ed the #1 engine and fuselage (looked almost like it got hit with a machine gun!). They came around on the two st'bd engines and the plane never flew again.
As a result of that, I do not cycle the gear when I am in the bounce pattern. That helped me some, but unfortunately it didn't help last year when my rt LG retracted on rollout at PDX (with an Airbus on short final behind me!). Pretty strange looking out the rt window, sitting 90 deg to the runway and watching landing lts coming at you. Wonder how much that go-around cost them?

Ah yes, really is true..."time to spare - go by air"!
 
Wow - thanks guys!

No expose' intended - just useful information to pass along, and I wish to heck I had a broken hydraulic line at the time. It would have allowed the gear to drop. Still I think the *last* thing we need is a device to dump the fluid in an emergency. Pressure is supposed to be handled by the pack itself. Pulling out the right seat and breaking the lines was, as I think I noted, the final suggestion but I rejected it given the conditions at the time (low fuel, choppy air, and the sheer maneuverability of our airplanes).

Ron:

For those, such as I, who are mechanically challenged, can you think of a method short of pulling and bench testing the pack that we or our mechanics can employ during annuals? Or should we view this as we do aviation's most fundamental mechanical risk mitigation strategy, the TBO?

Larry:

Reminds me of Hitchcock's North by Northwest :)

Jonathan
 
ok guys, please dont laugh too hard here. I'm just the newbie on the block...haven't even gotten my 260C 's new wing on yet (long story). I work in the commercial flight control segment of an aerospace company as a hydraulic tester. This is pure theory, but when we want to check a manifold or pressure source for flow and pressure, we just T in an inline pressure gauge and run a flow meter. Since from what I've read, the system works on a 1,ooo psi basis, I would order a gauge from someplace like McMasterCarr or similar industrial catalogue, T in at the outlet side of the power pack, run the pressure up (retract and hold) and watch to see that the required pressure developes, and check to see if it leaks down on the gauge. Should tell you what shape the o'rings\checkvalves are in. I wouldnt think that the unit developes much flow due to the size of the reservoir I have seen in mine, so shouldnt be an issue. This can be done to any outlet of the power pack to help isolate any weak points. Now I havent done this yet myself, but it looks as though there should be enough room to do this in the aircraft, especially if I use a flex line as I plan to. The gauges I am thinking of are about 2" in dia, and a little plumbing is needed to t in. When done, just remove from inline and replace fittings as usual. I will be doing this in a week or so to check all my hydraulic systems prior to my first anual. My A&P is all interested in watching...will let you know in shorter form :mrgreen:
 
Walter:

I hope you can get your 260 in the air soon! One of the things I love about this virtual place is that people don't trash one another - hard to find on the internet, believe me.

Your bench-test-on-the-airplane method would seem to me to be a good way to find wear symptoms, beyond the typical pumping the gear up and down with the handle method. The pressure source is something I may have missed, as the in-the-air source is the hydraulic pump mounted as an accessory on the engine. My mechanic has tried running the pump apart from the engine employing an air drill but he can't get the rpm he needs. We can't run engines while they're up on blocks.

My case involved a valve or the like jamming the pack in a gear up mode. Hand pumping seemed tied into the same snafu. Issues of magazines for our type, dated back forever that I purchased from the club when I purchased my 'Master refer to people, now long gone alas, who rebuilt the equipment but failure modes were not discussed. I think we understand why :oops:

What can't be tested, I fear, is whether the fluid will be routed properly when next the system is employed. How the heck can that problem been detected prior to failure <sigh>.

Oh, and as an aside, David, you sure looked happy with your 'Master in those Sun-N-Fun photos in the last issue. Post some color snaps on PopAv if you get the chance, will you?

Finally a name-that-tune for Lynn:

------------------------------------
Ive decide to do what I can
To find the kind of man I really am

I can see the world from here
And it sometimes makes me want to disappear
Back to nature where we belong
And with just one truth I find you can't go wrong

Wherever you go, what whatever you do
Whatever you say,
Say, say, say, say it with love
------------------------------

A forgotten now, but not an obscure band back when.....:)

Jonathan
 
Jonathan,

ok, I'm hooked now. Doesn't sound as if the engine driven pump is the questionable weak link, so now my focus will be to determine a secondary source a hyd. pressure. I will also discuss the overall scheme of things with some hyd. design engineers at work to see what a plan of action can be formed to test these units for integrety and function. A schematic is indeed needed, but reverse engineering is possible, although time consuming and involving a tear down of a power pack (probably an old unit). This may take some time, but its right up my ally of interest (and employment). As soon as I have more info, I will indeed post it for all to see.

Walt
 
Cruisairs have their troubles too. I found in my airframe logbook an interesting incident.
Apparently in 1961, the starboard chain jumped off the gear causing the gear to lock up. The belly landing resulted in the bottom engine cowl getting trashed and a broken belly stringer.

Gear problems aren't limited to you hydraulic guys.

Still wondering if I shouldn't install the hydraulic hand pump in 392... :D
 
Yes, Dave, I know that the hand crank gear do occasionally fail due to the sort of problems you mentioned. I've heard of an electric gear actuation option for Cruisaires, but I don't recall where. I don't know how the hand pump is set-up unless a power pack is employed, cut off from any pump other than the hand operated one. We all know of folks who stuck O435s in Cruisemasters....with mixed results, and they have an accessory pad for a pump...a hard to find pump.

It would be awfully off-topic to bring up O435s here, of course. Some have gone with a 220hp Franklin (Mike Grimes comes to mind), but it's a pain. O435s are easy to "hop up" to that HP range, but they have other problems. If I had a Cruisaire I think I'd stick with the 150 or 165hp Franklins and make sure the bicycle chain gear system was checked frequently and thoroughly. Simplicity is a GOOD thing :)

Okay, Lynn, the answer to the above is the Moody Blues. They were a wonderful but corney band in the '60s and '70s and proved a good defense against Carol King's Tapestry during the wild oats sewing days :wink:

Jonathan
 
Oh yes Knights in White Satin. We Bellanca Boys all wear the Blue Max. I have had no hydraulic trouble with my crate. I do have the breakdown for the gear actuating cylinders but not the hydraulic pack. Airparts of Lock Haven is a great shop and they do good work. I have been there when Penna. has a blue sky which is rare and these guys know there S--t! Singin the Blues :P :P LYNN N9818B
 
Dave I have the hydrlic hand pump on my 14-13-2 For emergency's it will free fall and the over center springs will help. It was all install about 30 yrs ago. For those talking about toe in and toe out, I was just at Millers in Plainview and they talked about that for the Viking ( same gear setup and wing angle) You should have no more than 3/8 inch difference from the front of the tires measuring across to the rear of the tires measuring across. toe in only. I have tried every way you could and found that almost perfictly straight works best. I used 2 ten foot peceis of extruded alumanum. Good luck :lol: :lol: :lol:
 
"Cold, hard orb that rules the night
Removes the color from our sight.
Red is grey and yellow white,
But we decide which is right."

or

"You run and you run to catch up with the sun but it's sinking.
Racing around to come up behind you again.
The sun is the same in a relative way but you're older;
Shorter of breath and one day closer to death."

Just proving you need adequate ventilation when using Poly-Brush :roll:

The hydraulic hand pump I have and hesitate to install is apparently out of a Cruisemaster. I't s a straight bolt-in job between the seats with a drain to handle drippage through the bottom skin. Only problem is, you have to cut the hand crank tube off the spar carry-thru to install the hand pump. I also have the two hydraulic actuators that run from the spar to the drag strut, but would have to modify the Cruisair drag strut per a drawing provided by Harvey Leydecker. I just don't feel much like cutting my classic up to make way for hydraulics. :? If I wanted that, I shoulda' bought a 'Master :D
 
My power pack has been working well the last 17 years. Every few years it leaks and is corrected by replacing the big reservoir O ring and the smaller ones at the filler ports top washer. A messy job even after pumping out the reservoir through a flap or gear line first.

O ring part numbers mostly from the PA23 parts manual? My notes are sketchy but for removing and resealing the reservoir O rings required may be 1 ea MS28775-258, 2 ea MS28775-112, 1 ea MS28775-010.
 
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