Archer main strut sticking

G

guardrail

Pre-takeoff checklist
Joined
Sep 5, 2012
Messages
364
Location
Jacksonville, FL
Display Name
Display name:
guardrail
I tried to do some googling and found one thread on the Piper forums but it turned out to be a bashing. Not much else on this issue, so I thought I'd see if PoA had some experience to share.

Flew the club's Archer II yesterday and on the last landing I noticed it landed 'firmer' than normal. I chocked this up to my poor handling of the approach but as I was taxing back it felt like the right side was sitting taller than the left. Sure enough when going to tie down I could see the right side strut appeared to be fully extended and that side of the plane is a good bit taller than the other. Doing a little wing push up from underneath there was no give, the thing seemed stuck at full extension. The club manager did not seem all too concerned about it, I was concerned I messed something up and he really was nonchalant. Given I've not flown this particular plane much and haven't experienced this before on any of the other Piper's I've flown I thought I'd try and find out what's the deal?

Do the Piper oleo's stick from time to time? Is there a way to un-stick them without maintenance? I hate to return the plane in any less condition than I took it and would feel terrible impacting someone elses planned flight. Am I being over sensitive?
 
yes it seems to be a design fault in as much as it's pretty common.

probably needs a bushing and seal kit.
 
guardrail said:
Do the Piper oleo's stick from time to time? Is there a way to un-stick them without maintenance? I hate to return the plane in any less condition than I took it and would feel terrible impacting someone elses planned flight. Am I being over sensitive?
Click to expand...
I've had this happen in a Cherokee once. It's (generally) not a pilot issue, it's a maintenance issue. If you break the airplane, you can feel bad about it. If the airplane breaks through no fault of yours while you're flying it, then don't.
 
This is not uncommon with Pipers. Cessna is a "spring" gear that deforms (correctly deforms we hope!) during takeoff and landing. Pipers on the other hand have an oleo or hydraulic type of gear. Check the fluid in the reservoir - should be in a small black can on the engine side of the firewall when you open the cowl. In fact, it should always be part of your pre-flight, to make sure there's brake fluid.

Because the cherokee uses this type of gear, the visible strut needs to be clean. It picks up dirt & dust & crud and this jams against the O-ring seal, as Tom pointed out. It can result in the wing-high.

I have this all the time on the cherokee, it really isn't a big deal. Most of the time as you taxi back the strut will release and the wing will clunk down, surprising any passengers you have on board.

I clean the struts after most flights (the advantage or disadvantage of owning). Red brake fluid (use NOTHING else!) and a rag or paper towel, and wipe down the struts.

Since you're in a club, talk to whoever is in charge of maintenance. You have a great opportunity to learn something new about the airplane. And if you're interested, offer to help with the maintenance in the club. I don't know how your club is set up, but providing assistance in any area may be required or it may result in "benefits" such as reduced rental rate or similar.
 
Common issue, the Archers I used to fly would have at least one strut hangup and it wouldn't release till I made the turn onto the taxiway.
 
Mine haven't stuck since the re-bush/re-seal that Tom mentioned.
 
Yea it is somewhat normal for that to happen. Usually a jiggle of the wing or some bumps in the taxiway seem to settle it back out. I seem to have seen them on newly sealed struts. The tighter, not broken in struts seem to stick more. I think most of the Cherokee series is just not heavy enough for the struts. Just my 2 cents.
murphey said:
Check the fluid in the reservoir - should be in a small black can on the engine side of the firewall when you open the cowl. In fact, it should always be part of your pre-flight, to make sure there's brake fluid.
Click to expand...

I don't know if that is going to help the strut issue, but still a good idea to check.
 
Thanks for the feedback, I feel a lot more at ease now. Also the club manager and maintenance guy hasn't called me screaming so that's a good sign haha.
 
murphey said:
This is not uncommon with Pipers. Cessna is a "spring" gear that deforms (correctly deforms we hope!) during takeoff and landing. Pipers on the other hand have an oleo or hydraulic type of gear. Check the fluid in the reservoir - should be in a small black can on the engine side of the firewall when you open the cowl. In fact, it should always be part of your pre-flight, to make sure there's brake fluid. .
Click to expand...
Brake fluid and strut fluid two different reservoirs.

each strut is its own self contained system and has no connections to any other system in the aircraft.
 
Tom-D said:
Brake fluid and strut fluid two different reservoirs.

each strut is its own self contained system and has no connections to any other system in the aircraft.
Click to expand...


Argh....my bad. My shop told me to use the brake fluid to clean the struts, so I was confused.
 
murphey said:
Argh....my bad. My shop told me to use the brake fluid to clean the struts, so I was confused.
Click to expand...
It is the same fluid. Hydraulic fluid (Mil-H-5606)

and is used several places in the piper line.
 
You can use brake fluid (5606) to clean with. Its just that the reservoir is not connected to the struts so it won't help the sticking problem. :)
 
Oh crud, that's a brake fluid reservoir? I though it was just a bottle of strut cleaning fluid! No wonder I have such a b!&%^ of a time stopping.
 
You are telling me they are not supposed to limp off the runway crooked ?

It is as common as drafty doors. I have only found this a problem when landing on iced over runways. Just like the drafty doors, this can be fixed by application of money.
 
DaleB said:
Oh crud, that's a brake fluid reservoir? I though it was just a bottle of strut cleaning fluid! No wonder I have such a b!&%^ of a time stopping.
Click to expand...

Now now - no need to stomp on Murph while she's down...
 
My Piper 235 had the nose strut get stuck up the other day. I had the strut resealed and now seems to be working fine.
 
Definitely not uncommon....usually an indicator of a really GOOD landing! :-)
 
as everyone else said, the oleo strut can require maintenance periodically. Especially if it's a rental and gets landed hard often.
 
tmyers said:
I must have always landed great on the right side then LOL
Click to expand...

There was a cross wind so I did touch down on the left main first, I wouldn't have called it my finest landing by any stretch of the imagination though. The first two in the day were beauts!
 
DaleB said:
Oh, totally not my intent. It was completely self-deprecating.
Click to expand...

Well then, stopping a Cherokee is a totally different topic...bleed the five master cylinders and try again.
 
I spent some effort and money trying to fix it a while ago (left main strut for the most part). New seals helped a little, but it still sticks from time to time. It doesn't seem to affect the performance of the plane (they extend on take off anyway).
 
Granville's Strut Seal does seem to help a bit with sticky PA28 struts even though many consider it to be "snake oil". It worked for me in my old Cherokee.
 
Clark1961 said:
Well then, stopping a Cherokee is a totally different topic...bleed the five master cylinders and try again.
Click to expand...

You got that right!!! Lots of dynamic braking with the nose up. I don't think I have ever been able to get enough braking to chirp the tires on a Cherokee like the Cessna would do.
 
Neal Howard said:
Granville's Strut Seal does seem to help a bit with sticky PA28 struts even though many consider it to be "snake oil". It worked for me in my old Cherokee.
Click to expand...

it will not fix a rolled seal, the major factor causing the stuck strut.
 
tmyers said:
You got that right!!! Lots of dynamic braking with the nose up. I don't think I have ever been able to get enough braking to chirp the tires on a Cherokee like the Cessna would do.
Click to expand...

I've been through it all on Cherokee brakes. The final fix was to redress all cylinders, checks, and renew all hoses. Of course all the brake pads are renewed when needed. The brakes are just undersized. A Cherokee will not stop like a Skyhawk.

Just something for owners to think about if they haven't already: how long have the hoses been in place? If it is forever and the hoses are hard as rocks then just maybe it's time for new ones. Oil lines, brake lines, fuel lines,...
 
tmyers said:
You got that right!!! Lots of dynamic braking with the nose up. I don't think I have ever been able to get enough braking to chirp the tires on a Cherokee like the Cessna would do.
Click to expand...

Too many hoses in the Piper brake system. Rubber hose liners will expand under pressure and absorb fluid displacement, allowing the master cylinders to bottom out before adequate pressure is reached. Piper should have used much smaller hoses instead of the 1/4" ID hoses they have; Cessna uses mostly 3/16 or 1/4" aluminum tubing that's much smaller inside and really rigid and so it works just fine.

Bleeding the air out of Pipers is also a real pain. Lots of high spots where air is difficult to push out without aggressive power bleeding.

Dan
 
You must log in or register to reply here.
Back
Top