The International Cessna^® 170 Association

Well... I went and did it.

I decided against buying a 170 as my first plane. I just couldn't justify the added expense starting from scratch and getting into flying. I read several posts on this and other sites about starting small and enjoying flying, not letting it become a financial burden.

That being said, I just agreed to buy a lil Champ. It has an O-235, 26" tires, VG's, etc, so it should be a great lil plane for learning to fly around Alaska.

Now I need to find a mechanic to do a pre-buy inspection on it. The current owner is a mechanic himself, who just put a bunch of money into the plane at the last annual very recently. If anyone has any suggestions for a good Champ guy in Anchorage, I'm all ears !

Thanks again to everyone for all their help in my search for a plane ! I'll definitely be sticking around here, as the knowledge on this board is invaluable ! And someday I'll have the 170 that I wanted....

Hasta ~

Bob K.
Anchorage, AK

Don't do a prebuy... do a full blown annual. Check the wooden spars, and remember some of the worst examples of airplanes out there are owned by mechanics! Good luck,
David

BobK wrote:Well... I went and did it.

I decided against buying a 170 as my first plane. I just couldn't justify the added expense starting from scratch and getting into flying. I read several posts on this and other sites about starting small and enjoying flying, not letting it become a financial burden.

I think that is a very wise decision, and I second everything that David said..... Having learned to fly in a Champ I can tell you they are fun little airplanes.

Personally I would run from a wood spared Champ. The AD is written in such a way that it is almost impossible for it to pass. If I remember right when that AD first came out the manufacturer stated that in order to properly inspect a set of wings per that AD would take something like 22 hours of labor. Now you will find mechanics out there that will do a quick visual inspection and sign it off but if you inspect it directly per the AD it is tough to find a good one. I know of one guy that replaced his spar with a new wood one after it failed the AD. One year later at the first annual the new spar failed the AD. If you buy it plan financially on replacing the spars in the near future. Having said that I would say it is a rare spar that is structurally unsafe when it fails the AD. Most are structurally sound but the AD just has a very broad criteria for grounding items. Its a bummer because I really like champs too. They are a good flying plane especially with the big motor in it. Good luck,
Shawn

American Champion Aircraft Corp.

Rochester, WI 53167

Service Letter

406 Revision A

May 6, 1998



Title: Wood Spar Inspection

Applicable Models:

All Model 7's, 8's and 11's with wood spar wings

Description:

There have been reports of cracks developing in wood spars, both front and rear. There are many possible causes to the cracking including: high flight time, wing damage history, high acrobatic time, over-stress history, or having been exposed to changes in humidity over several years. Compression cracks have been found emanating from the upper and lower surfaces of the front and rear wing spars at both ends of the reinforcement plate for the lift strut attachment. Longitudinal cracks have been reported in all areas of both front and rear spars, including through the wing root. See figure 1 for example locations of spar cracks.

Approval:

Revision A to this service letter is approved by the FAA, Manager, Chicago Aircraft Certification Office, ACE-115C, by letter dated May 6, 1998, as an alternative method of compliance with AD 98-05-04, paragraphs (a)(1), (a)(2), (a)(4) and (f), only.

Compliance:

American Champion Aircraft recommends that the inspection presented herein be accomplished before acrobatic flight, within the next 30 days, or 10 hours of flight and at each 100 hour / annual inspection, thereafter. Also, immediate inspection is mandatory if the aircraft is involved in an over stress condition, tip ground strike, or nose over.

The inspection procedures described herein are not intended to be a substitute for a properly performed 100 hour / annual inspection. Refer to Advisory Circular (AC) 43.13-1A:

Acceptable Methods, Techniques, and Practices; Aircraft Inspection and Repair.

Inspection: (Sides/Ends)

Remove all wing inspection covers and wing root gap cover. Using traditional methods, (such as flashlight and mirror) inspect full span along the front and rear wing spars for longitudinal cracks through bolt, nail, and spacer holes. Inspect the butt end of both spars for cracks. Additional inspection holes should be added as necessary to do a thorough inspection and check all areas of concern. Service Letter 417, Revision C, may be used as a guide for installing additional inspection holes.

Inspect for loose or missing rib nails per Service Letter C-139. If loose or missing nails are found, inspect spar by the rib for damage resulting from the rib rubbing against the spar. If the friction between the rib and spar has broken the wood grain completely across the spar and more than 1/16" deep, this is cause for rejection. Also inspect for nail hole elongation. Rejection must also occur if the nail holes have elongated such that wood grains are broken more than 1/16".

Inspection: (Bottom/Top)

The only area where it is possible to positively identify a compression crack is on the top and bottom surfaces of the spar. Both front and rear spars need to be inspected. The key areas to be concerned with are shown in figure 1. Additional inspection holes may be necessary to do a thorough inspection. Service Letter 417, Revision C, may be used as a guide for installing additional inspection holes.


WARNING

Compression failures are often difficult to detect with the unaided eye. Do not expect an open crack or gap. Compression failures start as barely visible, minute, jagged series of lines running cross grain on the top or bottom of the spar.


Important:

The initial inspection described below does not guarantee adequate access to complete the inspection and, is not recommended for inspectors without wood compression failure experience. Also, thìs method is inadequate for aircraft with wing damage history since last spar inspection.

For initial inspection of the spar top, a high intensity flexible light (for example: 'Bend-A­Light') and small inspection mirror can be used in conjunction with a small wooden wedge. First temporarily push the leading edge skin away from the front spar cap gently with the wooden wedge. After closely illuminating the area of concern with the 'Bend-A-Light', inspect, as closely as possible, with the small inspection mirror. This method is useful at the ends of the doubler plates on top of the front spar. This is considered an initial inspection only. If there are any questionable findings, further inspection through additional inspection holes is required.

For initial inspection of the spar bottom, a high intensity flexible light and two mirrors can be used. After resting one mirror on the fabric under the area of concern and placing the 'Bend-A-Light' adjacent to the area, inspect with the other mirror, usìng the reflection off of the former mirror. Again, this is considered an initial inspection only. If there are any questionable findings, further inspection through additional inspection holes is required.


NOTE

It may be helpful during compression failure inspection to apply upward or downward force at the wing tip.

Alternatively, the top and bottom of the front and rear spar may be inspected through inspection holes on the bottom of the wing using a flexible probe borescope.

Instructions:

If any damage was found in above inspections, it requires that the spar be repaired or replaced. Minor chafing and small indentations are not cause of rejection. Spar repair shall be accomplished in accordance with AC 43.13-1A Acceptable Methods, Techniques and Practices or other Federal Aviation Administration approved data.

Yeah, the wood-spar AD is a bummer with Champs... But there are still lots of them flying, so Im not too concerned about it. I spoke with the current owner/A&P at length about this very issue, and he has already added additional inspection holes/covers on the underside of each wing. He said he spent the time and did the wood wedge/mirrors/bend-a-light inspection with his IA during the last annual, and they found no issues with the spars.

It would be great to find a "perfect" airplane, but the bottom line is that all these things are 50+ years old, and everyone is going to have some sort of issue with it... This one hasnt been subjected to aerobatics, nor do I have any indication of wing damage as of yet, so Im moving forward. I believe I have found a mechanic with Champ experience to do a pre-buy/annual inspection on it before I fully commit to purchasing the plane.

My point of view is that Id rather buy this plane, being a taildragger with several AK mods already on it, and build a couple hundred hours than to buy a C-150 and be stuck on airport. Granted, a C-150 typically wouldnt have any kind of AD issue to worry about, but Id rather learn to fly a taildragger, because thats what I see myself flying in the future. Beyond that, cost prohibits me from venturing into C-170 territory, and C-120/140's aren't very prolific in the for-sale ads here.

Thanks for the responses ! I'll keep ya posted on the results of the inspection...

Hasta ~

Bob K
Anchorage, AK

The Champ is a great starter airplane and good airplane to become tailwheel proficient in. I had one for years, with the 85 continental. I had to comply with the Spar AD - no big deal to inspect. In my case I had to cut access panels in the upper wing fabric to get the inspection done right. The spare AD is the result of pilots attempting aerobatic maneuvers the Champ was just not designed for. I also recall there were some door post rust issues with the older ones. A good group fro information on the Champ - rivals this association - is the National Aeronca Association. http://www.aeroncapilots.com - Hangar it if you can.

When I was first looking for an airplane I was looking for a Champ... instead I wound up with the 170. I believe a Champ in good shape would be a pleasure to own and fly.
David

Hey Bob. Many of us own more than one plane. A Champ is a great start to your fleet.

Wood is the original "composite" material and has the advantage of no "memory" of previous stresses as long as it's elastic-limits are not exceeded and as long as rot is not present. (read: indoor storage in a dry hangar)
Few of these old airplanes have had that kind of storage all their lives.
I advise you to disregard any sellers comments about what kind of condition the airplane was found to be in "last year" as pure sales-pitch. It might be true. It might not. Current conditionis what you are buying...not last year's. (and ditto on the "previously owned by a mechanic" aircraft.... while many mechanics keep their planes in excellent condition...there are many more who find acceptable unairworthy aircraft conditions due to "familiarity breeds contempt." (The plumber's house has the worst plumbing, the electrician's house has open wiring throughout, if you've ever known one you know what I mean. Tradesmen frequently accept work that they'd never expect their customers to accept, because their customers are expected to pay for it!)
The absolute worst-condition airplanes I've ever seen were owned by IA/AP mechanics. (and one of them had perfect paperwork.... Pure B.S., but that paperwork sure looked good.)