Nose Gear Strut Crack

[Dave S]

Skot,

I'd agree with the folks indicating re-welding by a competent person if the only issue is a crack with no other underlying problems such as corrosion.

If I understand the photo correctly, this looks to be the bottom of the strut where it is welded to the tube which the nose wheel fork swivels on.....Correct?

I'd check an additional item ......the vertical tube which the nose wheel fork swings on calls for inserting a foam plug during original assembly/build, sealed with hysol up the inside of the threaded end an inch or so to clear the cotter pin.....the reason for this is to seal the vertical tube from moisture and corrosion. Due to the location down in the weeds - this spot is particularily succeptible to corrosion as the inside is not painted or powdercoated. Checking the integrity of this plug is an annual condition inspection point. If the plug is not there, or is damaged, this is a particularily nasty place for moisture to get up and rot the vertical tube from the inside out. The weld is basically naked and unprotected on the inside of the tube without the plug. Tube rust/corrosion from the inside out can make a weak spot where developement of a crack could be a secondary effect of corrosion/rust/thinning of the metal.

If the original plug is intact and no rusting - the plug will likely have to be renewed after welding/treatment as it will probably fry from the welding.

Buying a new one is a certain way to go if it ends up the original can't be safely fixed.


Sincerely,

Dave S
KF 7 Trigear
912ULS Warp Drive

[SilverFox1]

One more opinion. It's great that you posted a photo but I can't be sure from the photo exactly what happened there but it may be that there simply was no weld penetration into the piece that appears to have cracked. What we are looking at may just be the edge of the filler wire bead that failed to get the metal hot enough to melt it and make a good weld. Even if there was some penetration, it may not have been deep enough to make a strong enough weld for the application and this may have allowed the filler bead to break away from the part creating what looks like a crack when it may just be a bad weld. If the metal of the strut did fracture I would replace it, but if it is just a bad weld then rewelding it is the appropriate fix. Like others have suggested I would TIG or GAS weld it with my personal preference being TIG.

[SWeidemann]

Silverfox,

My intent is to take the strut to my regular IA for a look and also my local EAA Technical Counselor. John & Debra's opinion will count too. My guess is it may be a weld issue of not much significance and may have been there for some time. An option is to paint the spot and keep up regular inspections to see if ther is any new cracking activity. However if my IA doesn't like it I will need a fix. I know a new strut will be $$$.

Thanks much, Skot

[PapuaPilot]

Hopefully all of the people you mention will recommend fixing or replacing it. Do you really want to fly your plane with a crack on the landing gear?

If your nose gear fails and collapses what would the cost be then?

[Kurt.A]

Silverfox,

My intent is to take the strut to my regular IA for a look and also my local EAA Technical Counselor. John & Debra's opinion will count too. My guess is it may be a weld issue of not much significance and may have been there for some time. An option is to paint the spot and keep up regular inspections to see if ther is any new cracking activity. However if my IA doesn't like it I will need a fix. I know a new strut will be $$$.

Thanks much, Skot

Paint and fly is not an option in my opinion. It is always cheaper to fix it right the first time.