Friday, March 23, 2012

2012 Annual Inspection (v)

There are no new items to talk about today in connection with N631S's annual inspection, but some aspects of compliance with the Seat Rail Airworthiness Directive (AD) warrant further discussion.

As mentioned in yesterday's post, Mike the IA measured the rails and the roller assemblies as required by AD 2011-10-09, and all was in order except for one roller assembly that will be replaced. But the AD, in addition to specifying the actions required for compliance, adds:

"Repetitively thereafter do the actions at intervals not to exceed every 100 hours TIS or every 12 months, whichever occurs first..."
This differs from the old AD which basically required recurrent action annually. Since N631S and I have been flying about 150 hours each year this would mean an extra time for the seats to come out and the inspections to be accomplished. That's a non-trivial amount of work (and cost)!

Fortunately, the FAA recognized that a 100 hour recurrence interval is burdensome for owners of "personal" aircraft to a degree that isn't commensurate with the resulting reduction in the risks that the AD was intended to ameliorate. So, the Small Aircraft Directorate at the Wichita Aircraft Certification Office provided relief in the letter reproduced at left (click to enlarge), authorizing an Alternate Method of Compliance (AMOC) with the AD.

The AMOC letter states:

"Aircraft owners/operators who do not operate for the purpose of carrying any person for hire or to give flight instruction are no longer required to perform the seat track inspection in AD 2011-10-09, paragraph (g) at 100 hour intervals, and may instead perform these inspections at 220 hour intervals or during annual inspections whichever occurs first."
So...hooray! N631S is back to annual inspection of the seat rails and rollers, at a time when the seats are out of the airplane anyway. But (there's always a 'But'), there is one more complication. The AMOC letter also says:
"Before using the AMOC, you must notify your Principal Inspector in the Flight Standard District Office (FSDO)."
In most cases, that's pretty straightforward. But the address on record for N631S is in Virginia while compliance with the AD is being accomplished in Connecticut. Which FSDO should we call – Dulles or Bradley? So, I called the FSDO at Dulles, got the duty Airworthiness Inspector on the line and asked him. He thought about it and said that we should notify the FSDO at Bradley, because the notification is connected to the accomplishment of the AD and that work was being done within the Bradley FSDO's territory.

On Monday I'll report all of this to Mike the IA so he can log it all correctly, and then we're good on the seat rail AD for another year.



Gary said...

Details details.....

I always enjoy annual time, despite having to write the check. I do the owner assisted and it really has helped me come to know and understand my plane.

I am enjoying the write-ups and product specfics info on the Cessna. Good luck on finishing up and may 31S be back in the air soon.

Frank Van Haste said...

Hi, Gary...

I wish I had the time to go the owner-assisted route. I did it once a few years ago and found it to be rewarding as you say.

I think we're getting close to done with the "looking for trouble" phase. Couple of days of fixing, and hope to be back on the flight-line by mid-week.

Thanks for stopping by.