Front Prop Clearance and Nose Strut Deflated

CO_Skymaster · #1 10-05-23, 10:50 PM

I am trying to understand how to inflate my nose strut, but I do not have the equipment to do this yet (jacks, nose gear holder, nitrogen bottle, information how to release nose gear only). I found a two way to do the nose gear release so I could service the strut on this site, but I don't feel comfortable enough to use them. I am currently out of Annual and was thinking about taking my aircraft to an off-field facility and have them service the strut during annual. My nose strut is completely deflated, and I wanted to know if there could be an issue with prop strikes or gear stress if I flew it for a temporary flight to have my annual done.

Thanks for any help,

Karl

Learjetter · #2 10-05-23, 11:32 PM

I would not recommend flying with a deflated nose strut.

On my G-model, the nose strut pressure specification is 35psi.

The procedure is pretty simple. I’ll try to post the pages from the g-model service manual. Nitrogen is best but air works too.

Pretty good article:
https://www.cessnaflyer.org/maintena...-ins-outs.html

mshac · #3 10-06-23, 03:50 PM

No need for jacks. In a pinch like this, I'd just put some weight on the tail until you lift the nose, then fill it with shop air to 35 psi (or three inches of chrome showing is the old school way) then have the shop doing the annual check the fluid and refill it with nitrogen. The moisture in the shop air is the issue, it could cause rust. Worst case scenario is a busted o-ring, and if that's the case it may not hold air no matter what you do.

CO_Skymaster · #4 10-07-23, 03:33 PM

I was thinking of just filling the strut with air until I could get it to another shop for annual, then have them perform the service with nitrogen. The problem I have is to fill the strut with air, the valve is on the backside of the nose strut and when the strut is down it's in an alcove (I have a 1966 337A). I can reach around in the cramped space, but I can maneuver to remove the cap (which I think I can feel there) or get an inlet nozzle on it. From what I read in the forum, I have to be able to release the nose gear lock and shift the nose gear forward to get to it. There are 3 ways to do this from reading the forum:

1. Lift the entire aircraft up as you are performing gear retractions which requires a lot of jacks.

2. Lift front nose with jacks or pushing the tail down, pull the landing gear circuit braker, set the gear to up position, turn the master switch ON, then for a moment push in the circuit breaker, then pull. (I worry about the main gear and if I'm setting up a gear collapse situation either during the procedure or while taxing. I also don't have a circuit breaker I can pull manually).

3. Someone mention taking the rear door on the back of the nose gear which I don't think I can do that as just an owner, that sounds like A&P territory.

I plan to go down tomorrow with an endoscope I bought to attach to my phone to confirm I am indeed feeling the service value, but I can try to reach it again, but I don't think there is enough room to work with the value.

If anyone else has a non-gear retract or a way to safely release the nose gear uplock that doesn't sound like it would give me a gear collapse situation, I would appreciate it.

Karl

Frank Benvin · #5 10-07-23, 11:13 PM

My mechanic filled it while I pulled down the tail and rested the tail on a upside 5 gallon bucket with a pillow on top of it. The nose gear was down and locked while he filled it

CO_Skymaster · #6 10-08-23, 01:15 AM

I am headed to the hanger tomorrow. I will check again. Maybe I can get to it if the strut is extended or maybe I was looking in the wrong place. Let you know if it works.

Thanks,

Karl

Kim Geyer · #7 10-08-23, 08:18 PM

I used a single short jack on the jack point behind the nose gear. I have weighted the tail end down with cases of oil in a pinch (@8- 12 qt.) The nose wheel needs to be off the ground to service it. If you try to do it with weight on it, it will take 250+ psi to get it to move.

CO_Skymaster · #8 10-08-23, 10:32 PM

I went down today to see if I could get access to the Schrader valve to put in some air. It looks like there is a metal cap that can be loosened with a hex wrench, but try as I might, with the aircraft not jacked up and the strut deflated, I could not maneuver my arm in there without hitting the side of my body or head on the gear doors. I'm going to have to purchase a nose jack and try again later. Good news is it looks like my A&P is finally starting to move through his backlog of aircraft for annual. Wither he fixes before I get to it or not, I need to learn how to do it, so I will keep trying to work with it.

Thanks everyone for your help,

Karl

Frank Benvin · #9 10-09-23, 01:26 PM

The cap on the valve should be able to be loosened with your fingers

You can see it in the picture attached

Frank

CO_Skymaster · #10 10-10-23, 10:11 AM

Thanks Frank.

That's what mine looks like, good to see I'm on the right track. I was also looking at a nose jack as my first jack purchase. I was looking at Alpha Aviation (those are the red hydraulic jacks I see on Aircraft Spruce), but I can't find the specific model for the nose. Does anyone have a recommendation for a nose jack model or even another company?

Thanks,

Karl

Kim Geyer · #11 10-10-23, 11:46 PM

If you are only servicing with nitrogen or air I have done this without a jack. I would connect the nitrogen bottle and stet the regulator to @ 30 psi then pull down on the booms till the strut was full extended. When the weight was put back on the nose gear, you can see if you need a little more or not if you don’t have enough extension add a few psi and do it again.

CO_Skymaster · #12 10-10-23, 11:58 PM

Thanks Kim,

But I'm the only one working on the aircraft at the moment. I could go grab a friend of two to help me, but I don't want to rely on that. I think I figured out what jack to get, but I need to go find the measured clearance from the ground to the nose jack point to be sure.

Karl

SteveG · #13 10-12-23, 09:08 AM

This sounds like you're considering jacking the nose wheel off the ground using only a front jack. IMHO that's a poor idea. The front jack point is primarily used to stabilize the aircraft while supported by wing jacks. Lifting the nose without tail boom stands risks dumping the aircraft over backwards. Take care.

mshac · #14 10-17-23, 10:58 AM

Quote:

Originally Posted by SteveG

This sounds like you're considering jacking the nose wheel off the ground using only a front jack. IMHO that's a poor idea. The front jack point is primarily used to stabilize the aircraft while supported by wing jacks. Lifting the nose without tail boom stands risks dumping the aircraft over backwards. Take care.

This is why its really a two-man operation to safely lift the nose. If you do it alone, try to find something to support the tail or you could be buying new lower tail cones

I'm just throwing ideas - old tires stacked up, a rolling toolbox/bench covered with cardboard or towels, the open gate of a pick up truck. A tail stand would be ideal, but finding one tall enough for the 337 can be a challenge.

Let us know how it goes, and remember, without pictures, it never happened.

CO_Skymaster · #15 10-22-23, 06:39 PM

Finally, I was able to remove the nose strut valve cap. Victory is mine!!! Que the maniacal laughter

I was going to upload some photos of how I lifted the nose and that gave me enough room to stick my hand behind the gear to remove the valve cover, but the Managed Attachments for files are failing. I don't know if it is a size issue, but how are people loading the picture that only show up as a link?

I have a nitrogen bottle and regulator which should arrive before next weekend. I will try to charge the strut. I'll let you know how it goes.

Thanks to everyone who helped me with this,

Karl