Ok to make it easier, I am repeating the part about the comments from the Airworthiness Concern
Request for Information (Proposed Alternate Inspection/Repair Procedures, Cost Impact, Etc.) Note: Any comments or replies to the FAA need to be as specific as possible. Please provide specific examples to illustrate your comments/concerns): The ACS is intended as a means for Federal Aviation Administration (FAA) Aviation Safety Engineers to coordinate airworthiness (A/W) concerns with aircraft through Associations and Type Clubs. Please forward any comments you have to Roger Caldwell via e-mail using E-mail: [email protected] The FAA encourages comments on this topic, including, but not limited to the following areas: - Technical comments on improper maintenance and unauthorized alterations performed on the wing spar as noted above for FAA safety recommendation 09.087. - Are the correct models identified in this ACS (Airworthiness Concern Sheet)? (The Sheet lists all models : Make, Model, Series, Serial No.: Ercoupe415C, 415CD, 415D, 415D, 415G, Forney F1 and F1A, Alon A-2 and A-2A and Mooney M10 aircraft) - Are there alternate methods to address this situation? - Have you ever discovered improper or unauthorized maintenance actions or damage as described in this ACS, to e present on any area of the wing spar? - Have you ever discovered other related damage or corrosion on the wing spar, not described in this ACS? If so, what actions did you take to correct the situation? I guess, I'll write my summary to Mr. Caldwell in hope he understands the fact that holes alone are not the issue, rather overstressing the airframe and undetected cracks. Maybe we can get away with recurrent dye inspections for cracks. Hartmut To: [email protected] From: [email protected] Date: Tue, 22 Sep 2009 18:17:47 +0000 Subject: [ercoupe-tech] Re: Approved holes? What is lost in all the debate about structural integrity of the wing spar cap with holes is that this is no longer an engineering issue. It's a regulatory issue now. It doesn't matter if "unauthorized" holes will or won't cause a failure. The FAA and/or the NTSB has decided it's a problem and they are going to dictate a solution. The only choice we have now is whether of not to give them information to arrive at an acceptable solution or let them make a decision in a vacuum. We can armchair engineer the holes all we want, but the fact is this is not going away by denying there's a problem. Dave --- In [email protected], Bob Swinney <bobst...@...> wrote: > > For what it is worth, I am a Mechanical engineer and have worked with > structural engineers all of my life. Whenever I needed to route pipe, conduit > or whatever, the structural engineers would allow holes in the structural > members(I beams or whatever). I have seen some beams that looked like swiss > cheese. If the holes are not over a certain size and if they are placed > properly the integrety of the beam is not compromised. IT just has to > engineered! >  > As far as the breaking point being at a hole, that is normal. If a structure > is loaded past its limit it will break. If there is a hole or a deep scratch > near that point it will take the path of least resistance and go to the hole > or scratch. That does not mean the hole was the cause of the break... >  > An aeronautical engineer needs to analize the situation to determine the > effect of the holes... >  > Bob > > --- On Tue, 9/22/09, Hartmut Beil <hb...@...> wrote: > > > From: Hartmut Beil <hb...@...> > Subject: RE: [ercoupe-tech] Re: Approved holes? > To: ebengui...@..., "Techlist Ercoupe" <[email protected]> > Date: Tuesday, September 22, 2009, 10:36 AM > > >  > > > > Ed >  > Yes I pointed out before that the Alons have holes drilled for the bucket > seat installation. > That's why holes per se seem not be the problem. > But it would be up to UNIVAIR to pull out the engineering data to proof that > to the FAA and at the same time give an evaluation when holes are ok and > when not. >  > I don't see that happening. > What I see happening is that all 415 Spars with not approved holes will be > damned to be replaced. >  > Is anyone having a 337 that shows holes drilled into the spar cap for seat > installation? >  > The only 337 I have on file does that not. http://www.ercoupe. info/?n=Main. > CessnaSeats >  > Hartmut > >  > > > To: ercoupe-tech@ yahoogroups. com > From: ebengui...@aol. com > Date: Tue, 22 Sep 2009 08:42:11 -0400 > Subject: [ercoupe-tech] Re: Approved holes? > >  > > > Morning All > Regarding holes in spar cap: > Alons basically have the same wing spar as the Coupe. > Without going into nomenclature details, > Alons have approximately 16 holes on the spar cap to accept seat brackets. > Does anyone know of any problems > with Alons falling apart because of these approved holes? > Ed > > > > > check out the rest of the Windows Liveâ„¢. More than mailâ€"Windows Liveâ„¢ > goes way beyond your inbox. More than messages > _________________________________________________________________ More than messages–check out the rest of the Windows Live™. http://www.microsoft.com/windows/windowslive/
