Wing Pull

[FlyingMonkey]

The next 100 hour inspection AFTER two years, sure reads like it's required on the third year.  If you do a 100hr at one year, a 100hr at second year, the next inspection AFTER two years is on the third year.  Based on English that requirement is every third year.

[Tom Baker]

I think everyone is putting to much emphasis on the 100 hours, and not enough on the inspection. We use the 100 hour/ annual inspection checklist, but do condition inspections. Anytime you do a condition inspection you should consider it a 100 hour inspection. If you put the emphasis on the word inspection it becomes more clear. If you did your last wing inspection on April 1, 2019, and you are doing your condition inspection today it is due. The reason why is because April 1, 2021 was two years, and this is the first inspection using the 100 hour/ annual inspection checklist. If you had done you condition inspection on March 31, 2021 you could technically wait till you next inspection which could be 3 years. It has been my experience that for most owners the second condition inspection after the wing inspection is more than two years after the wing inspection had been performed.

Now for someone who is flying commercially say around 125 hours a year. They do a condition inspection every 100 hours at around 9 month intervals, and they did their last wing inspection on April 1, 2019. The did their second condition inspection since then November 1, 2020. If they continue to fly at the same number of hours per year they will be doing their wing inspection in June or July when they reach roughly 300 hours since the last inspection, but if they stopped flying the airplane the wing inspection wouldn't be due until the next condition in November.

[FlyingMonkey]

Call it conditional or 100hr, that still ends up requiring a wing pull every third inspection.  If you fly less than 100hr a year, that's every third year for the wing pull.

[Tom Baker]

1 hour ago, FlyingMonkey said:

Call it conditional or 100hr, that still ends up requiring a wing pull every third inspection.  If you fly less than 100hr a year, that's every third year for the wing pull.

I agree you can call the inspection what ever you want, but the FAA wants it called a condition inspection. I am pretty sure we can all agree that we use the Flight Design 100 hour/annual inspection checklist for our condition inspections. If it is a day past past two years from the previous wing inspection when you perform your 100 hour/annual/condition inspection it is the first inspection after two years, and the wing inspection needs to be done. If you do the inspection a day before two years it can wait another year. You can't just automatically say I can go three years because I flew less than 600 hours.

It is all about the fact that you are performing and inspection, and whether it has been more or less than two years since the last wing inspection. Not about how many hours it has flown.

[FlyingMonkey]

44 minutes ago, Tom Baker said:

I agree you can call the inspection what ever you want, but the FAA wants it called a condition inspection. I am pretty sure we can all agree that we use the Flight Design 100 hour/annual inspection checklist for our condition inspections. If it is a day past past two years from the previous wing inspection when you perform your 100 hour/annual/condition inspection it is the first inspection after two years, and the wing inspection needs to be done. If you do the inspection a day before two years it can wait another year. You can't just automatically say I can go three years because I flew less than 600 hours.

It is all about the fact that you are performing and inspection, and whether it has been more or less than two years since the last wing inspection. Not about how many hours it has flown.

But we're not talking about an FAA requirement, we're talking about a manufacturer-stated service interval, which they have set as "the next 100hr inspection after two years".  So it really sounds like there are two requirements, the FAA mandated one for a conditional inspection, and the FD one for a wing pull on the next inspection after two years.  So if you fly less than 100hrs a year, and perform a conditional inspection each year, and put a line in that conditional entry that the inspection also complies with the FD 100hr requirements, then you have complied with both requirements, and you are legal to pull wings on the third inspection, at three years.

None of this matters to me, really...I'm ELSA and can do the wing pull whenever I want to as long as I can certify the airplane is in a condition for safe operation (I do it every two years).  But I think the above fully makes sense for the SLSA owners based on the language you quoted.

[Tom Baker]

1 hour ago, FlyingMonkey said:

But we're not talking about an FAA requirement, we're talking about a manufacturer-stated service interval, which they have set as "the next 100hr inspection after two years".  So it really sounds like there are two requirements, the FAA mandated one for a conditional inspection, and the FD one for a wing pull on the next inspection after two years.  So if you fly less than 100hrs a year, and perform a conditional inspection each year, and put a line in that conditional entry that the inspection also complies with the FD 100hr requirements, then you have complied with both requirements, and you are legal to pull wings on the third inspection, at three years.

Your scenario would be true if you did your condition inspections on the exact same day each year because you second inspection is on exactly two years and not after, so yes you could legally wait until the third year.

How about this. Maybe you are one of those who likes their inspection signed off on the first to gain an extra month of flying time. You had a condition inspection signed off March 1, 2019, and flew 30 hours. nest year you only flew 25 and had it signed off on April 1, 2020. Now you have it in the shop for the inspection waiting until Saturday to sign it off on May 1, 2021. Is your wing inspection due this inspection? Isn't this the first inspection after two years? It is after all two months after two years.

 

 

 

 

[FlyingMonkey]

3 hours ago, Tom Baker said:

Your scenario would be true if you did your condition inspections on the exact same day each year because you second inspection is on exactly two years and not after, so yes you could legally wait until the third year.

How about this. Maybe you are one of those who likes their inspection signed off on the first to gain an extra month of flying time. You had a condition inspection signed off March 1, 2019, and flew 30 hours. nest year you only flew 25 and had it signed off on April 1, 2020. Now you have it in the shop for the inspection waiting until Saturday to sign it off on May 1, 2021. Is your wing inspection due this inspection? Isn't this the first inspection after two years? It is after all two months after two years.

 

 

 

 

That makes sense.  You could do it in such a way to gain a month of time between inspections, or you can do it a few days early each year to gain a year before wing pulls.  Dealer's choice! 

[Tom Baker]

Whether you gain a month or not, if the inspection is done a day after two years after the last wing inspection you are supposed to do the wing inspection.

[Roger Lee]

I talked to higher ups in more than one organization. (Side note:  There has never been a wing spar issue found on a CT.) The wording is vague enough that nitpicking over the 2 years or the first 100 hrs. after made no difference to any of them on either side of the fence you want to fall on. The groups also said that 100 hr. inspection on the fuselage wasn't necessary, but it was on the engine.

Bottom line for me since I spent 30 years in courtrooms and depositions is:

 If I'm going to sign a legal document that puts me in the legal lawsuit crosshairs I'll do them both at the same time and reset both times (100 hr and annual) and FULLY cover myself when these groups go to fighting on whether they have to be done or not. It's far better to be safe than sorry because on the sorry side there are no do overs. You may argue in court you're 100% right, but you can still lose.

So now you have to decide for yourself which way you want to go and if the risk outweigh the rewards.

Want to be average or a cut above?

 

[Tom Baker]

9 hours ago, Roger Lee said:

 If I'm going to sign a legal document that puts me in the legal lawsuit crosshairs I'll do them both at the same time and reset both times (100 hr and annual) and FULLY cover myself when these groups go to fighting on whether they have to be done or not. It's far better to be safe than sorry because on the sorry side there are no do overs. You may argue in court you're 100% right, but you can still lose.

Roger, I don't think anyone is in disagreement about signing off the inspections. What you seem to be missing from the MM is that it doesn't say 100 hours after two years, it says the first 100 hour inspection after two years. You could basically drop the 100 hour figure out of the statement and say the first inspection after 2 years. If you sign that inspection off a day after two years and don't do the wing inspection thinking it is okay to go three years you are contradicting the statement you made above about doing things right.

Also the inspection is more than just inspecting the spars and wings. It is also about inspecting the fuselage. While I haven't seen many issues I have seen a few. There were some CTSW's that needed shims on the wing pins because the wing tips would move for and aft. I have also found a rear bushing on a CTLS that was worn to the point that the wing was moving up and down at the pin. That required a MRA and a fairly major repair. 

[Roger Lee]

When I talked to the other organizations they didn't care about something like 2 days. Just so long as it was in the same month. Just like an annual. It may have been done last year April 5, but isn't over time until the end of the last day of the month.

[Jim Meade]

Roger,

What are the names of the organizations?  What are the names of the people?

 

[Tom Baker]

11 hours ago, Roger Lee said:

When I talked to the other organizations they didn't care about something like 2 days. Just so long as it was in the same month. Just like an annual. It may have been done last year April 5, but isn't over time until the end of the last day of the month.

So what if the previous inspection was done on the last day of the month two years ago, and you are doing it on the first two years later? I agree that the timing is probably not that critical. The manual does give some leeway, because it says the first inspection after two years. That next inspection could be a day after two years or a year after. All I know is that I can defend my choice of doing the inspection on two year intervals without worry, even if sitting in the witness chair. Trying to defend stretching it out to three years might be a little harder to defend depending on when the inspections were actually done. 

[Madhatter]

Ok I have to put in my 2 cents. This issue with calendar time for wing inspection drives me crazy. The manufacturer should be determining the wing inspection by hours flown or cycles on the wing, ( the  British Bulldog records load cycles in military use). Sitting in a hangar is not going to cause an issue for the wings. Some may say you could have corrosion.  The wings are carbon fiber and if you get corrosion on the fittings then take the plane out of the  ocean surf. Anyway now I'm happy to have my rant.