HELP! Calling All Gear Experts

[Mickey Stateler]

This is a repost... also a Delphi, forgive... I am getting worried and need maximum coverage
Wow... I thought I had seen it all...

We have completely disassembled the entire landing gear system and all the parts. Yes this is probably a bit more than is called for in the AD, in typical Mike Sierra Aviation fashion, everything gets cleaned, new hardware and a fresh coat of paint… inclusive of wheel wells, struts, wheels…. Everything.

While referencing the parts manual that came with N5MA, we noticed a rather odd note in the parts manual. yes... the parts manual

“7/86 - replaced right gear strut housing assy marked 20752-5 with serviceable unit marked 20752-3 – modified by drilling out bushing (figure 26-5) to 9/16. The 20752-3 was from single Comanche and slightly smaller diameter bolt is used”

WHAT?

Sure enough, after visual inspection, 25+ years flying around on the wrong strut.Wow you might say… why was this not discovered before… in prebuy for example? Or the last 1000 Hr Ad?

Unfortunately the log book entry that coincides with this “maintenance” and date makes no mention of the change in part number, only that the right strut was replaced with a “serviceable unit”. The entry in the official log is in a different handwriting, so I assume that work may have been done by a previous owner and signed off by a buddy A&P.

The 1000 AD has been “signed off” twice since the AD came out in 77… Once was in 93, six years after the PA24 strut was installed. I can only assume that it was pencil whipped and not actually completed, as I am quite sure the main bushing on the part wound not have passed inspection. If you look at that bushing now, it is not even round due to the actions of “drilling it out” in 1986. Unbelievable. I think about the number of max gross landings I made since ownership… there have been a few, and the thoughts of that strut giving out under the weight are sickening.

Now I assumed that the housing on the left strut, which is visibly heavier, was incorrect because it has another undocumented part number (27016). Matt Kurke tells me that these were on the latest of the late PA39s and available as a kit for the fleet. I did find a log book entry in 1979 that shows the Left strut was replaced with this kit (PN22833). Of course none of the parts manuals reflect this kit or strut part number and I am hunting for documentation which testifies to the parts legality. Please let me know if any reading this have such a document.
Ideally what I need is a strut from the now unavailable kit that was the heavy struts made in the 70’s. Or… change out to Aussie struts, and I have no idea what that would cost.

Does anyone have one of these (right) Heavy Struts laying around?

What are my other options?

Thank for reading and helping

--mick

N5MA - Fort Worth

[N3322G]

Mick,

Thanks for posting this problem.

As a 39 owner, I can tell you that even the heavier struts have weaknesses. Came out to the hangar one day and found fluid on the floor after 36 years of no gear issues. Turns out the left trunnion had a hairline crack. Found out this is not uncommon and could be fixed by welding by a certified shop in Utah. They did a great job - however, a few years later, the crack returned and the Utah shop fixed it at zero cost. We do land on a fairly rough runway at 52F but I had expected another 36 years of wear before another issue. I share this because IMHO the design of the original parts can be improved and that is what the Aussie trunnion does.

Now I know you and Mason have formidable mechanical skills and various license credentials. I don't; so for me, I would buy the Aussie trunnion just to be rid of the problem and if the Twin's cracks again, that will be our solution. The last time it cracked, the Aussie trunnion was not STC'd here.

Hopefully, other folks will chime in with their opinions. Hope this is helpful.

[Jerry Mazza]

I have a cracked LH main strut. The strut deflated yesterday as I took the plane to the shop for an IFR certification. Is the Aussie strut available now and where are they available? Do you have any idea of the cost? Thanks, Jerry Mazza

[N3322G]

Jerry,

I'm hoping Jim Covington will answer. IIRC he may have a set on his 39. Also fairly certain that this year's Flagship, Miss Scarlet, also has a set - both would have been done by Heritage Aero In Rockford, IL.

I do recall that they were pricey at the time they first became available as an STC but the trade-off in downtime would have been worth it to me. Each owner's situation will be different.

Cliff Wilewski at Heritage Aero graciously donates many hours to ICS as a Tech Director. If you are considering having Heritage Aero do the work, I'd give him a call. http://www.heritageaero.com/

[MULEFLY]

I do not have the Aussie Struts on our PA39 -- 8982Y has the end of run "beefier struts" ... but Bill Schnauffer (custodian of Miss Scarlet) had them put on that wonderful PA30. Pat is correct... Cliff Wilewski of Heritage Aero can give you the details... He and his gang installed them. Cliff's phone... 815-395-0500

All the best!
Jim

[N3322G]

Thanks for correcting me Jim on your plane - always especially nice to be able to help another 39 owner.

[Jim Menconi]

I was taking off in my PA30 and after take off, the gear wouldn't go up. I was also wondering why the plane seemed to be pulling to the left on the runway. Upon landing I checked the gear and found the left trunnion was leaking and couldn't hold any pressure which prevented it from entering the gear bay (the safety system works). I asked the maintenance shop on the field what I should do after a failed attempt to re-inflate it, they unfortunately said either buy a new one or see if there is a used one at a parts yard. I asked around and found a shop in Texas that recommended that I contact the shop mentioned above, in Utah, as they can totally repair this to make it better than new. I contacted them and ultimately took both trunnions (suspecting that the other one will eventually go as well) off and sent them to Utah. He has since completed the repair and they look great. They actually cut out the section with the cracked web and welded a much larger piece in it's place and machined the trunnion to new specs. The shop in Utah charged $990 for one and $980 for the other. I now have much better trunnions than the OEM and they even came back painted. I have pic of the repaired trunnion if anyone wants to see them. Just email me and I will send it on: skyjim47@gmail.com. I don't know if my attempt at attaching the pic actually worked so again, email me if you want to see it. The info for the Utah shop is below:

Bruce W. Tofft
S & B Industries Inc.
333 West 6160 South
Murray, Utah 84107 USA
FAA CRS QE5R142N
801-261-4076
801-261-4149 fax

Bruce is a great guy and does what he promises.

Jim

[N3322G]

Same shop I used - both times.

BTW, nice to hear there was no panic when the problem happened and good decision making ensued with a successful landing.