The Cessna 120-140 Association Forum

Can TSO'd Grove wheels and brakes be installed on a 120/140 with a 337?

Gary,

Have you to talked to Grove? When looking at their web site I see that there are approvals for Piper, but I didn't see any for Cessna. Not saying you couldn't get a 337 field approval, but an STC would be simple. I'm sure others will chime in.

Gary,
I recently installed the Grove axles on my 120. Grove will provide you with a copy of a 337 Field Approval for an installation on a 140 in Nebraska (I believe) a dozen or so years back. The local FSDO up there (Lincoln, I think) established the authorization with approval from the FAA ACO in Wichita. This approval can be used as "FAA approved data" to attach to your proposed 337 that can take to your local FSDO. You should not install the axles until you get a field approval concurrence from your FSDO after they look at your proposed 337. That's the way it worked with my local FSDO in Scottsdale, AZ. They were very helpful.

Not to pick a fight, but, previously approved 337's are "acceptable" data, not "approved" data, unless the approval date is prior to 1-Jan-1956. If a later field approval were approved data, no further approval would be necessary. If you have approved data, e.g. AC43.13 or a 337 with a field approval prior to 1956, you can do the work, cite the approved data on your 337, and mail it directly to OKC, just as with an STC.

In fact, IIRC, old form 337's had a block you could check if you wanted the approval to apply to more than one aircraft.

John,
Point taken - thanks for that clarification, good to know.

I installed Grove axels with a field approval. Another route, if you have a machinist to re-drill the holes, is to install C-170 ski axels which are approved under a Cessna service bulletin with just a log entry. I tracked the parts down at Texas air salvage.