Landing gear repair

[hilltop170]

Jim Wildharbor sent this article out a few days ago:


Landing Gear for Cessna and Husky

Cessna Landing Gear Straightening and Inspection Information


Does your landing gear appear slightly or even very noticeably bent? Are you concerned about its integrity and past history? Our objective is to correct these conditions and Aleve these concerns while avoiding landing gear replacement costs. We do this by correcting deformation and other external damage, then stress-relieving the part, as well as inspecting for pitting and cracks. Heat treating and re-finishing can also be part of the process.

Steel is susceptible to noticeably weakening with flex cycles, even if it's just bouncing around in the wind on the ground, so keep in mind that new landing gear will always have a significant advantage but at a significant cost. (New Titanium 180/185 gear is $12,000 for the pair and Steel gear is $8,000 for the pair assuming acceptable cores in both cases.)

There now is a reliable Option as your gear, assuming its not pretzel shaped, is probably repairable at our facilities. We send it out to our Landing Gear shop, a very experienced metallurgical organization, that repairs flaws induced by built up stresses and deformed beam dimension. The Landing Gear Works Team has the ability to manufacture Steel and Titanium Cessna Type Landing gear. This experience has given them intimate knowledge and ability as well as the equipment to straighten, inspect, and refurbish used gear leg springs for the Cessna 140 through 206.

HOW it works:
Upon receiving the Spring(s), per our Quality Control system, we measure the dimensions of the spring and record those on its own inspection record. We then remove any paint or primer, Inspect per the appropriate Cessna service manual (Cessna spec 204-1) and Cessna tech print.

The main items of concern are deformation and corrosion pits. If repair is required it is done per applicable sections of the Cessna 100 service manual for the particular plane and AC43.13-1B. If "sprung" or questionable then MIL-H-6875 or ASM2759 is used in the repair procedure. This specification covers the requirements for heat-treatment, Stress relieving and restoring shape which is referred to as fixturing or press work. This is always preformed by a journeyman heat treat personal. The inside surface of the spring should be shot peened and this is checked carefully. Peening puts a stress into surface layers of heat treated spring steels, thereby increasing fatigue strength and resistance to stress-corrosion cracking. That surface should not be grit blasted, sanded, or cleaned with acid based chemicals to avoid damaging the peened surface or introducing hydrogen embrittlement. If needed, the gear can be re-shot-peened. Special attention is paid to inspecting and stress-relieving the lower axle bolt attach area and polishing the holes to eliminate surface work hardened areas. Magnetic Particle Inspection is employed then per AC 43-13-1B chapter 5 Visual and ASTM-E1444-94A CLASS B. This method is used to detect cracks, laps, seams, inclusions, and other discontinuities on or near the surface of ferromagnetic materials. The gear is then cleaned again and a Protective finish is applied per the appropriate Cessna service manual.

In short, Cessna 100 series springs can now be inspected and restored to original shape per industry accepted practice. Part 43 does not require 337 on spring gear. The peace of mind is now an option with out replacement. There is little doubt this inspection will be an AD note someday based on the reports we have all heard and seen of broken springs.

Call for more information!
Seaplanes North, LLC
3830 Aircraft Drive
Anchorage, AK 99502
(907)248-6161



I went to Seaplanes North (which used to be Floats Alaska) in Anchorage yesterday and talked to Ed who is their lead on gear repair.

The gear will be shipped to Tom Anderson at Landing Gear Works in WA, expect a 4-5 week turn-around.

Costs and services provided (prices are $/gear leg):

$1250 -gear inspection including stripping to bare metal, standard repairs (removing corrosion/pitting to .030" deep and mild straightening), NDT inspection, re-arching to match legs, primed or oiled if powder coating is to be done later, and Certificate of Conformance (certifying repairs conform to Cessna Service Manual specs and AC43-13 but is not an FAA 8130 form)
$200 -heat treat, required for repairs beyond minor straightening and re-arching (a judgement call by repair shop)
$200 -shot peen, required if gear has to be annealed for repair then heat treated

$300 -shipping per pair of legs

Floats Alaska will be maintaining a small stock of repaired gear sold on an exchange basis:

$2150+$500 core charge for 170 Lady Legs and early 180 gear
$2880+$750 core charge for 185 gear

The core charge will be charged up front for all purchases and if a repairable leg is exchanged, the core charge will be refunded once inspected and accepted as repairable by Landing Gear Works in WA, their call.

[blueldr]

The above sounds reasonable if you're in Alaska, but if you're in the lower 48 and all the work is done in Washington, there seems to be a lot of relatively expensive shipping costs back and forth to Anchorage.

[hilltop170]

Correct, Blueldr. If you are in the Lower 48, just send them to The Landing Gear Works in Washington directly. The same work will get done by the same people. Jim Wildharbor talked with Tom Anderson so he may have some info on what the charges would be if gear are sent directly to Tom. The point was, the guys in Alaska at Seaplanes North are the ones who took the time to put the article together and advertise what services are now available.

[GAHorn]

I understand that neither option will provide you with anything more than an A&P signoff, as neither facility is a Certified Repair Station.

[N2523D]

I'm I the only one who thinks it is completely ridiculous this company is charging $1200 per leg ($2400 a set) just to strip it, and tell you if it has cracks and is bent correctly? The local prop shop will do the same and even fix the prop for 850 and that is a lot more precision then a gear leg.

Does anyone know of a company doing this service for a fair price so we can get them some advertising?

[blueldr]

There very well may be some aviators around that would be willing to offer some advice of doing business with certain
landing gear and engine conversion operators.

[N3243A]

I'm I the only one who thinks it is completely ridiculous this company is charging $1200 per leg ($2400 a set) just to strip it, and tell you if it has cracks and is bent correctly? The local prop shop will do the same and even fix the prop for 850 and that is a lot more precision then a gear leg.

No you're not. Mr. Anderson (formerly of XP Mods fame) has an interesting business background in some respects depending on who you talk to. From the IO-360 170 conversions to high dollar Ti landing gear legs, there are some unhappy customers left in the cold. Do your due diligence when dealing with him.

[ccondit]

Given the concern expressed by the post of Apr 23, 2013, toward Mr Anderson of Landing Works, does anyone in TIC170A have any viable alternatives to going to them for gear repair/restoration?

[jlwild]

Perhaps some one has found an alternative to The Landing Gear Works, but over a two year period I could not. Many people furnished me leads, but none panned out. Perhaps a new shop will open, however, I am extremely happy with the excellent work done by Mr. Anderson's company on my 1955 "lady legs" 170 B landing gear. I also consider the cost reasonable for all the detailed work that was done beyond just stripping paint and checking for cracks. Heat treating, re-arching to Cessna gear spec, etc. is a time consuming technical process. Re-read the article by SeaPlanes North above and read the detailed engineering tech specs The gear must meet (google works well chasing down the specs).

I highly recommend Tom Anderson based on my experience. His shop turned them around in 5 weeks. They have been on my plane now for five months. Plane tracks perfect during taxi and landings.

You can also find used pair of gear legs if you search long enough. However, the price from the dealers I talked to varied from $1000 to $1500 per leg and were sold "AS IS". Then you have to have them inspected, repaired and inspected by a shop of your choice and the $$$$ just keep adding up. Good luck on beating Tom's cost to repair your existing gear legs.

My phone number is in directory if you want more information.

[bigrenna]

delete

[blueldr]

bigrenna,
Have you personally have had any work done by the company or personnel mentioned in this item?