EMERGENCY AD, T-6 ATTACH ANGLES

[snj-5]

My bad on the air combat thing with respect to WA (didn't mean
to imply they do that). I was once told that any aerobatic
maneuver approved in the -1 for the T-6 should be able to
be accomplished without putting more than about 4 Gs max on
the airframe. When I get mine flying, that's the personal
"limit" I'm going to use (along with a "hard floor" of 4000 agl
for any aerobatics). May sound a bit conservative, but why
beat the heck out of the airframe if you don't have to?

Simulated air combat is a horse of a different color....
(you pull and shoot until the other guy's airplane starts
smoking!). Isn't there at least one U.S. T-6 operator doing SAC
in T-6s (I want to say Top Gun or something like that is
the name of the outfit...???).

In any event, I agree that if the mode of operation tends
to "hammer" the airframe, it might behoove the operator(s)
(whether required by regulations or not) to keep a closer
eye on the airframe(s) being used in this manner.

The thought, once again, occurs to me that the military lowered
the G limit on these things towards the end of their service life.

Bela P. Havasreti

Bela,

I do agree with you to a point on this. But, the true "Air Combat" providers are not T-6 operators. During my time at WA (2001-2003), maybe less than 1% of our flights were of the BFM catagory.

I do agree that operators doing prolonged aerobatics (90% of my flights in the T-6 were aerobatic), that a recurring inspection be done. I think the 200 hour interval is a bit too much, but not a lot I can do on that one.

The 200 hour interval the SAAF was a no brainer, as the cost was picked up by the SA gov't. 200 hours for civilian use is a little overkill. I think 500 hours or a set period of time (like every 12 months or so) would be a good compromise until more data is obtained. This would cover the guys who fly a lot and who fly a little (like the 40 hour a year operator).

[John Sausedo]

[quote="snj-5"]My bad on the air combat thing with respect to WA (didn't mean
to imply they do that). I was once told that any aerobatic
maneuver approved in the -1 for the T-6 should be able to
be accomplished without putting more than about 4 Gs max on
the airframe. When I get mine flying, that's the personal
"limit" I'm going to use (along with a "hard floor" of 4000 agl
for any aerobatics). May sound a bit conservative, but why
beat the heck out of the airframe if you don't have to?

Simulated air combat is a horse of a different color....
(you pull and shoot until the other guy's airplane starts
smoking!). Isn't there at least one U.S. T-6 operator doing SAC
in T-6s (I want to say Top Gun or something like that is
the name of the outfit...???).

In any event, I agree that if the mode of operation tends
to "hammer" the airframe, it might behoove the operator(s)
(whether required by regulations or not) to keep a closer
eye on the airframe(s) being used in this manner.

The thought, once again, occurs to me that the military lowered
the G limit on these things towards the end of their service life.

Bela P. Havasreti [qoute]

When I did my flying, we routinely could perform all maneuvers within about 3.5 G's. The few times that was exceeded was when we were training and the student messed up something. That didn't happen very often. Company policy was no snap rolls or hammerheads (stall turns).

I agree that the T-6 (or any warbird) should not be beaten up with hardcore aerobatics. I have seen routines at airshows and cringe when I see gyroscopic maneuvers like a snap roll. My opinion is, if you want to do that stuff you should go fly a Pitts or an Extra (or something similiar).

As to 4000 foot limit...awesome. It was weird, but when I flew the Pitts, I could take aerobatics down to the deck with no problem. Whenever I got below 3500 feet in a T-6, I felt like I was really low to the ground.

Anyway, back to the thread. Sorry about hijacking it.

[Glenn Wegman]

John Sausedo wrote:

"I do agree that operators doing prolonged aerobatics (90% of my flights in the T-6 were aerobatic), that a recurring inspection be done. I think the 200 hour interval is a bit too much, but not a lot I can do on that one.

The 200 hour interval the SAAF was a no brainer, as the cost was picked up by the SA gov't. 200 hours for civilian use is a little overkill. I think 500 hours or a set period of time (like every 12 months or so) would be a good compromise until more data is obtained. This would cover the guys who fly a lot and who fly a little (like the 40 hour a year operator)."[/quote]


Hello John,

If I may opine:

That's the point of recurrance by flight time and not calandar time. The idea of calandar time would punish the people who fly the least which is probably the majority of T-6 owners, whom I'm guessing, fly less than 50 hrs a year. That would be like having the Govt. make everyone pay the same amount for income tax reguardless of how much money you make! Stress, fatigue does not accumulate, so to speak, while it sits in the hangar. If it was a yearly inspection it would be a real burdon to the average operator. The way it is presently makes the most sense as the people who fly the most get to do it the most which would be "WA" and "Top Gun" etc., which should consider themselves lucky, as the guys really sucking air over this are the "SkyTypers". They get to do it as often or possibly more often then "WA" and "Top Gun" and they fly straight and level formation and have seven or eight airplanes! Think about that!

I think the present AD is fairly reasonale, the average operator having to do it every four to five years is not really the end of the world. The first inspection is a little annoying and time consuming due to stripping off lots of paint. After they have been cleaned up and re-coated with a light coat of corrosion resistant primer, it should be a lot easier to acccomplish the next time. There may not be very many cracked angles found, but I guarantee you there has been a lot of corroded angles discovered and cleaned up or replaced that would probably never have been detected, not to mention bolts replaced. At lease it is getting people to look at them! When I bought my Harvard in 1987 the first thing I did was strip and inspect the angles and install new bolts and everyone laughed at me and told me it was a waste of time, "nobody has ever broken one of them"!!!

I agree that possibly later it could be extended to 300 - 500 hours, but for the first cycle, and until they figure out what's going on with these angles, 200 is reasonable.

Anyway, just my thoughts.

Glenn

[jcw]

glenn
while i'm glad some people identified some bad angles from coorrosion with this new AD i am afraid this was the wrong way to find that problem. AD 50-38-01 is very specific about every annual inspecting the angles for coorrosion so it looks like if they are just now finding them then they have not been performing a good annual inspection... i just hate redundancy

just my thought on the subject

take care

jcw

[Glenn Wegman]

Jeff,

That's a good point!

In hindsight, the stripping of paint from the angles should probably have been required by that AD which in turn might very well have prevented this new AD.

Glenn

[bdk]

...as the guys really sucking air over this are the "SkyTypers". They get to do it as often or possibly more often then "WA" and "Top Gun" and they fly straight and level formation and have seven or eight airplanes!

I think the Skytypers are out of T-6s and went to C-150s and Grumman Tigers now. Those old SNJ-2s they had were real corrosion buckets though, especially the wet center sections.

[Glenn Wegman]

Hi Brandon,

I believe there a different groups as I too have seen the Grumman Tigers years ago. I am pretty sure Larry Arkin still operates the SNJ's somewhere around Long Island, NY.

Glenn

[jgrifft6]

I can answer the Skytypers question... The NY group still operates the SNJ-2s and the Cali group run by the Stinis's have been using Grumman Tigers. I'm actually leaving in 2 weeks to go fly with them in Japan for an ad campaign for a sports drink in the Tigers. I stumbled onto it while looking for a summer job and got 6 weeks in Japan flying formation... can't beat that. Interestingly, one of their Tigers that's in Japan is my old airplane, N4557L, that was the first plane I landed when I was 11 y/o. I'll make some videos and post them for the group if I can.
Jason
ps - theres a website in japanese with a video and some pics at:
http://www.waterlanders.com/event_sky_top.html

[TheBoy]

Does anybody know anything more about the eddy current option? We are about to comply with the AD on a local T-6G, and would love to avoid stripping paint. Any info would be great.

[Stoney]

Two companies have an AMOC for eddy current, NDT Inspect-air in WI and Tailwind Inspection in OK.

[jcw]

stoney
we applied for and have been approved for an AMOC using eddy current on my 6. took some paperwork but not that difficult.

[TheBoy]

Thanks guys. We'll look into that.

[Pat M]

The skytypers on Long Island fly out of Republic Airport. It seems like I hear them at least once a week flying over the house. They put on a nice formation routine at the Jones Beach Airshow this year.

[Stoney]

Jeff
who's doing it? Or should I not ask?

[Cindy]

Does anybody know anything more about the eddy current option? We are about to comply with the AD on a local T-6G, and would love to avoid stripping paint. Any info would be great.

check out the eaa website....they have a bunch of great info. aopa probably does as well.