Piper cherokee nose gear issue?

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jmarine225

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Jmarine225
IMG_4977.jpegTook my aircraft up today on first flight post annual. It sis a 1969 Piper Cherokee. I did some night flying and my perception was off especially in landings. I figured because I haven’t flown at night in a bit. I get back to the FBO and it feels like the plane is angled back, I can’t fully see over the dash which is odd. I get out and notice the nose gear which is extended quite a bit more than normal. It’s normal extended approx 4 fingers wide now it is twice as much, like fully extended out. Any suggestions on the issue and what may have caused this?
 
Was it serviced or recharged during annual? Can you pull it down with the prop or by lifting up just in front of tie down ring? Probably very slightly overcharged with nitrogen if you can't get it to come down. It can be quite finicky as it doesn't take much to let too much out.

If you are able to get it down or if getting on the wing to get out made it extend, then that would be more a lack of 5606.

Off of memory (look in your poh to confirm) it was 3.25 inches on the nose strut exposed and 4.5 on the mains.

If it wasn't serviced at annual it could be just be a little sticky and needs a little help after it was on jacks. Make sure the chrome is clean, no dust bugs or debris during pre flight.

Look through logs and see when the last time the strut was re sealed. It could be time. But I'd start with the easy stuff first.
 
Likely it was overserviced with air/nitrogen or fluid or both.

Easy to address but I suggest you have whoever did the Annual address it.

It’s a simple matter to just let a little “ air” out of the valve on top of

the Strut. Usually folks let too much out and it bottoms. The pressure

is likey higher than what you have on hand. Suggest you watch and learn for

the next time.


This will not affect you in flight and your wheels will touch at the usual

manner. It’s just that it won’t settle back down.


When servicing I like to set them a little high as it’s easier to let it

out than put it in.
 
Racerx said:
... Off of memory (look in your poh to confirm) it was 3.25 inches on the nose strut exposed and 4.5 on the mains. ..
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Yes, your memory serves.
- Nose 3.25 ± 0.25 in
- Main 4.50 ± 0.50 in.

From my experience:
• Nose inflation pressure (approx psi) unloaded: 120 (Nose wheel off the ground)
• Main inflation pressure (approx psi) unloaded: 120 (Main gear off the ground)
 
Magman said:
This will not affect you in flight and your wheels will touch at the usual

manner. It’s just that it won’t settle back down.
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That oleo is designed to absorb shock to protect the airframe. When it's overinflated---or worse, overfilled with oil---it cannot do that and sooner or later damage will result.
 
I've experienced a few times that the strut may be 'sticky' - on taxi, apply the brake firmly and the nose will dip down, back to ~about where it should be.
 
As others have said, it is overserviced. It takes a "puff" to get it where it is in limits. It's fine to fly but eventually can cause damage.
 
40YearDream said:
I've experienced a few times that the strut may be 'sticky' - on taxi, apply the brake firmly and the nose will dip down, back to ~about where it should be.
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For a while during the life of my plane, I used that nose gear behavior as justification to claim that my landing was "smooth"--the nosegear wouldn't "drop" until I somewhat aggressively hit the brakes.

At some point, the nose gear was serviced such that it now behaves more properly and I no longer get that validation for "smooth" landings.
 
Jim_R said:
For a while during the life of my plane, I used that nose gear behavior as justification to claim that my landing was "smooth"--the nosegear wouldn't "drop" until I somewhat aggressively hit the brakes.

At some point, the nose gear was serviced such that it now behaves more properly and I no longer get that validation for "smooth" landings.
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I do the same thing for my mains. They are serviced correctly, just a little sticky.
 
Domenick said:
Yes, your memory serves.
- Nose 3.25 ± 0.25 in
- Main 4.50 ± 0.50 in.

From my experience:
• Nose inflation pressure (approx psi) unloaded: 120 (Nose wheel off the ground)
• Main inflation pressure (approx psi) unloaded: 120 (Main gear off the ground)
Click to expand...
Just a caution for the OP...those pressures are wheels off the ground as mentioned. The pressure rapidly increases when there's weight on the strut. With the plane on the ground it's more like 250-300 psi. I agree it's likely just overcharged. Takes very little gas to make a big difference in that small of a volume. It's likely they added N until it got to the prescribed height without moving it up and down to overcome the stiction and make sure it would return to the correct height. It's be worth taking it back to them if it's not too far, if only to show them that they're doing it wrong.
 
Thanks for all the replies. As silly as it is, I went to my plane and slowly let some air out and pulled down on the prop a bit. Strut was stuck and dropped down to the normal position.
 
Lama1125 said:
As others have said, it is overserviced. It takes a "puff" to get it where it is in limits. It's fine to fly but eventually can cause damage.
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And, as I found out when mine was overfilled, letting out a "puff" will empty it, and you gotta have the guys with the nitrogen tank shame you.
 
A little 5606 ragged on the chrome every once in a while will help cut down on the stickyness. Just need to remember to wipe it clean first, then lube the chrome.

If you are regular about doing it, the Strut-Wipes are quite handy. We've gone completely to them at work, so no more 5606 bottles in our fire cabinets.
 
Craig said:
A little 5606 ragged on the chrome every once in a while will help cut down on the stickyness. Just need to remember to wipe it clean first, then lube the chrome.

If you are regular about doing it, the Strut-Wipes are quite handy. We've gone completely to them at work, so no more 5606 bottles in our fire cabinets.
Click to expand...
5606 ??
 
luvflyin said:
5606 ??
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Long ingrained habit to use shop verbal shortcuts... We use so many different chemicals at work, that no one can remember all the prefixes on everything. Good example is the touch up paints we use... There are about 18 different spec numbers, but we just call for them by the area of use....Hole primer, tank prime, primer, white, cockpit black...and so on. It's only when something oddball gets called out that we call for it with the full spec number or ask for the approved alternate material.
 
Craig said:
A little 5606 ragged on the chrome every once in a while will help cut down on the stickyness. Just need to remember to wipe it clean first, then lube the chrome.

If you are regular about doing it, the Strut-Wipes are quite handy. We've gone completely to them at work, so no more 5606 bottles in our fire cabinets.
Click to expand...
5606 dries to a sticky film. That sticky film attracts dust and windblown grit, which then gets dragged into the oleo where it cuts the seals and abrades the bushings and the chrome layer. Gets expensive.

Clean it off and leave it dry. That's how it was designed to be.
 
Dan Thomas said:
Clean it off and leave it dry. That's how it was designed to be.
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I'll stick with what our approved TO's say.... Wipe them down and leave a thin film of 5606 on the exposed chrome. Ours get done every flight as part of the preflight or postflight based on what they look like. They also get completely wiped down any time the a/c goes on jacks before being down jacked.
 
I use mineral spirits to clean the chrome on my strut.
It seems to leave just the right amount of lube and evaporates quickly.
McFarlane recommends it.
 
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jmarine225 said:
Thanks for all the replies. As silly as it is, I went to my plane and slowly let some air out and pulled down on the prop a bit. Strut was stuck and dropped down to the normal position.
Click to expand...
I'd be willing to bet it was overcharged. If it was just a stuck strut and you let some out and pulled on it. Good chance it would end up being too low when it gets unstuck.

In my experience they are very finicky. I'm concerned it might be too low when you actually fly it because you say you slowly let some out. A quick nick of the schrader is all it has taken for me to go from too much pressure to too little.
 
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jmarine225 said:
Thanks for all the replies. As silly as it is, I went to my plane and slowly let some air out and pulled down on the prop a bit. Strut was stuck and dropped down to the normal position.
Click to expand...
They do stick! So do the mains sometimes. A little pump of the brakes usually gets the nose strut down, and a little tail wagging helps with the mains if one sticks. I’m flying a 182 now and the nose strut sticks all the time but I’m used to it from owing the Cherokee before this.
 
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