O-2 & L-19 Wing Inspections?

[bdk]

From AvWeb...

Wing Inspections Eyed For High Wing Cessnas

The president of the Cessna Skymasters Owners and Pilots Association says thousands of Cessna high-wing aircraft could be affected by a potentially expensive new wing inspection procedure proposed by the company. Herb Harney told AVweb the Supplemental Inspection Documents (SIDs) now being prepared by Cessna will require the removal of the wings of Cessna 336 and 337 push/pull twins, to check wing attach and strut attach bolt fittings for cracks and corrosion. In the U.S., the inspections will be voluntary but those in Part 135 service will be guided by the standard operating procedures of the operator. Harney said that in other countries, however, recommendations by the manufacturer must be met and Skymasters are scattered all over the world. The process is complicated and could cost as much as $60,000 per airplane, more than many Skymasters are currently worth. But the Skymaster shares the same basic wing hardware with all the other Cessna high wings and, under Cessna's current thinking, any aircraft more than 20 years old would be subject to the SIDs, Harney said. AVweb contacted Cessna for comment but the company was unable to respond by our deadline. Harney said U.S. operators may not necessarily escape the inspections.

Harney said Cessna is currently planning on rewriting the aircraft service manuals to include the inspection recommendations. He said maintenance companies, with their normal abundance of caution, may require the inspections before signing off on the aircraft because of the service manual amendments. If that became a common practice, more than 140,000 aircraft could be affected. Harney stressed that the SIDs are still being developed and could be changed but he also said that Cessna is planning implementation of the first SIDs by July of 2010, starting with Cessna 336 models.

[skymstr02]

This particular SID concerns the Cessna 336 and 337 line, all variants. It does not include the 305 model (L-19/O-1's) at this time.

It is optional if the owner wishes to comply with at this time, if the aircraft is operated in accordance with FAR part 91.

[bdk]

These are limited to the fuselage then? Are the parts in question aluminum or steel? Does the wing get inspected as well as part of this inspection? Dye penetrant or eddy current inspection method?

[skymstr02]

the fittings are aluminum with bronze bushings pressed in. When I restored my plane, I replaced all of the wing attach bolts with new units from Cessna. There was no corrosion but I didn't NDI the fittings as there was no requirement to do so.

I do not know the NDI method, but eddy current is better than dye pen.

[John Dupre]

As stated these inspections are not mandatory in the US. They will probably be in other countries that rely on the manufacturer's mandatory requirements. The Skymaster group is trying to build up concern that these inspections will eventually apply to all Cessna high wing strut types in order to help dilute the impact on their type.

There is a school of thought that Cessna is trying to drive older types out of service in order to reduce liability exposure. A similar series of supplemental inspections was developed for the 400 series low wing twins. One result of these was that numerous problems were found, from manufacturing mistakes to fatigue problems due to high cycle and hour rates. The older Cessnas were developed under the old CAR 3 rules that did not specify a life limit to the airframe (typically hours and cycles on the wing spar or center section). Cessna claims that they need to develop some requirements to guarrantee airworthiness of these older types.