2012-10-11 elevator nose plate AD

June 5, 2012

It is too bad we all did not participate (actually, none of us did) in the FAA input aspect of AD 2012-AA64. I recently purchased a 0.44â€ dia flexible borescope which:

- is far superior to a mirror

- only requires a 0.44â€ hole for access

- can take photos (or movies) for historical comparison

- provides magnification

AD 2012-AA64 identifies 59 G109â€™s to which this pertains, which obviously corresponds with our knowledge of our community. The estimated inspection (preparation/modification) compliance costs given was $934. That hardly includes the time and money required to get the aircraft to and from an appropriate facility capable of performing the work. (any estimates from our fellow members?)

Would it be more desirable, or more effective, to approach both Grob and the FAA with questions about alternative inspection methods. For instance, using the borescope would certainly minimize the hole required. Could a hole be provided in the internal vertical member, just to the rear of the Nose Piece?

I live about 10 miles from the FAA office to whom we are directed for further information. I would be happy to see if eyeball contact is possible for further exploration. (The first step would be a covert recon/analysis of the â€œapproachabilityâ€ factor of Mr. Rutherford.) Any interest in mobilizing a group effort?

June 5, 2012

It is too bad we all did not participate (actually, none of us did) in the FAA input aspect of AD 2012-AA64. I recently purchased a 0.44â€ dia flexible borescope which:

- is far superior to a mirror

- only requires a 0.44â€ hole for access

- can take photos (or movies) for historical comparison

- provides magnification

AD 2012-AA64 identifies 59 G109â€™s to which this pertains, which obviously corresponds with our knowledge of our community. The estimated inspection (preparation/modification) compliance costs given was $934. That hardly includes the time and money required to get the aircraft to and from an appropriate facility capable of performing the work. (any estimates from our fellow members?)

Would it be more desirable, or more effective, to approach both Grob and the FAA with questions about alternative inspection methods. For instance, using the borescope would certainly minimize the hole required. Could a hole be provided in the internal vertical member, just to the rear of the Nose Piece?

I live about 10 miles from the FAA office to whom we are directed for further information. I would be happy to see if eyeball contact is possible for further exploration. (The first step would be a covert recon/analysis of the â€œapproachabilityâ€ factor of Mr. Rutherford.) Any interest in mobilizing a group effort?

June 14, 2012

I live in Kansas City and a visit to meet with the designated FAA representative on the most recent AD should be easy to arrange. Since no public responses were submitted to the FAA during the solicitation period, they simply went ahead with Grob’s suggested “fix”.

It is reasonable to assume that Grob’s current apparent financial condition resulted in the proposed method being resolved during a “water cooler discussion” and no significant amount of thought went into it. In the following series of email correspondence, #2 from Grob acknowledges consideration being given to the use of a borescope but incorrectly assumes the cost to be greater than their ludicrous (in this case) solution.

A small diameter hole in the horizontal top rib of the vertical stabilizer would intuitively seem to be structurally acceptable and require minimal labor/time investment. The acquisition of a borescope will be less difficult and expensive than the designated materials.

Support from other Grob G109 owners might make a more convincing argument to take to the FAA contact, not to mention interest from Grob.

Here are the emails exchanged so far, including #4, an email from Tom who arrived at the same borescope conclusion independently. The email trail is sequential.

(1) Email to Grob:

Von: Stu Ostrander [stu.ostrander@gmail.com]

Gesendet: Dienstag, 5. Juni 2012 21:10

An: -EVL-Productsupport

Betreff: Grob Aircraft Service Bulletin No. MSB817-58, and Grob Aircraft Service Bulletin No. MSB 817-060,

Dear Sirs;

The FAA has issued AD 2012-10-11 in response to Grob Aircraft Service Bulletin No. MSB817-58, dated November 24, 2011 and Grob Aircraft Service Bulletin No. MSB 817-060, dated November 24, 2011. In it, they direct any questions of Grob be sent to this email address.

Grob's suggested inspection method does not take into consideration that the number and location of approved or appropriate facilities, capable of completing the modification described, is limited in the United States. And most often, the distances from any owner to such a facility is a major logistical concern.

It seems possible that there is an alternative inspection access that would be less onerous to complete and potentially provide superior results. Inspection Borescopes with photograph (and video recording) capability are readily available. Even the less exotic examples will pass through a 10 or 11 mm diameter hole, and provide both light and magnification on the surface to be inspected.

The advantages are:

- smaller hole

- photographic record

- light

- magnification

If a smaller hole is possible, is it reasonable that the location could also be varied. The vertical internal brace just to the rear of the Nose Piece to be inspected might be a logical location. If a 10 mm hole could be drilled in that member, would there be any need for any other work to be performed in providing access?

The FAA estimate to accomplish the currently recommended 110mm hole is almost $1,000 but does not include the tremendous costs in time and money required to get the aircraft to and from an acceptable repair facility.

There are 59 G109’s affected by this AD. We are spread across the entire United States. Our group of owners would greatly appreciate your assistance in defining a less difficult method to address this issue.

Stu Ostrander

G 109B (ser no 6229)

(2) Grob response:

On Tue, Jun 12, 2012 at 6:21 AM, Reinhold Michael <M.Reinhold@grob-aircraft.com> wrote:

Dear Mr. Ostrander,

thank you very much for your mail. Your comments are much appreciated,

since we have considered the issue from a similar point of view.

Nevertheless, we came to conclusion, that we had to supply a simple

solution to all G 109B operators. Borescopes may be readily available in

the US, but they are not in other parts of the world, hence we favour the

“mechanical” solution, as this requires nothing beyond very basic equipment.

Of course, in case you wish to approach FAA for alternative means of inspection,

you are invited to do so, however, presently we are not in a position to provide

engineering manpower for any such project.

In case of questions, please do not hesitate to mail or call.

Best Regards

(3) 2nd email to Grob:

From: Stu Ostrander <stu.ostrander@gmail.com>

Date: June 12, 2012 4:57:01 AM PDT

To: Reinhold Michael <M.Reinhold@grob-aircraft.com>

Subject: Re: Grob Aircraft Service Bulletin No. MSB817-58, and Grob Aircraft Service Bulletin No. MSB 817-060,

Dear Mr Reinhold,

Thank you for your response to my recent inquiry. Your answer held both promise and disappointment.

Grob’s reasoning that the installation of an inspection cover would be less difficult to accomplish is not understandable. Flexible shaft, high quality, minature camera borescopes are now available for $150. If it is possible to drill a 12mm hole somewhere, the costs will be much less than the $1,000 the FAA has estimated to accomplish the current method.

The FAA estimate far under states the true cost. I would not be considering approaching the FAA for a change if many of the 59 US owners were not overwhelmed by the logistics and cost of the AD as written.

If Grob considered the borescope as an alternative, is it reasonable to suggest that their analysis included the basic technical considerations of where to locate the hole?

I am not looking for a detailed engineering study by Grob, only the least assistance to be able to provide to the FAA an alternative method acceptable to them. If I can show them something from Grob that says it is acceptable to drill a small access hole, it would likely go a long way to receiving their acceptance.

Stu Ostrander

(4) Input from Tom:

I am concerned that the proposed inspection plate AD is not the ideal solution for inspecting the attachment plate. Cutting a 110MM hole in the vertical fin, where the unit is depends on the skin for structural support, would not be my first choice. I suggest the least structurally destructive solutions to visually inspect for corrosion would be to use a bore scope through a 17mm hole. A new bore scope cost $99.

I know you are very active with this group and I would like your thought on trying to steer off this structurally invasive AD, for a less destructive solution. Thanks!

Tom

June 14, 2012