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Author Topic: Ouch!  (Read 409 times)

donv

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Re: Ouch!
« Reply #15 on: June 13, 2019, 04:42:16 pm »
The word came straight from Twin Commander's structural engineer. Is it legal to only do one side? I don't know that, but it was Twin Commander's official recommendation to do both.

Bruce Byerly

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Re: Ouch!
« Reply #16 on: June 13, 2019, 05:19:47 pm »
The word came straight from Twin Commander's structural engineer. Is it legal to only do one side? I don't know that, but it was Twin Commander's official recommendation to do both.

May be that since you have to have the same boots on each side, and they had to replace the dissimilar boot, that they figure they are halfway there.  Probably comes down to “recommendation” vs. “requirement.”

donv

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Re: Ouch!
« Reply #17 on: June 13, 2019, 06:06:17 pm »
The boots on both sides were already going to be replaced. They were both pretty beat up.

That said, it may come down to that, although they didn't phrase it that way. They did say they've had to do it several times previously on 690s, including one they owned... so I'd guess they've double-checked.

donv

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Re: Ouch!
« Reply #18 on: June 13, 2019, 06:30:19 pm »
They forwarded me the email. It says "you will have to replace the other side as well since it would still be a -147 skin and these must be kept the same gage to keep the stiffness of the horizontal balanced.  Twin does not make the -147 longer since it was deleted and replaced with the -249."

Bruce Byerly

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Re: Ouch!
« Reply #19 on: June 13, 2019, 07:07:48 pm »
Got it. They ought to have tech support Dept on the same page . . .

Probably too busy trying to undo the mess the forestry service has done with their alert on the tail. Seems that some operators have forgotten to do some basic maintenance.

donv

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Re: Ouch!
« Reply #20 on: June 13, 2019, 07:18:36 pm »
What is the deal with the forestry service and the tail?

Also, FYI, they sent me the serial number effectiveness on the thicker tail leading edge skin. It looks like 96069 and subsequent on the 1000s and 15039 on the 900s had the thicker skin from the factory.

Bruce Byerly

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Re: Ouch!
« Reply #21 on: June 13, 2019, 10:55:25 pm »
Fuselage station 386 I believe. Vertical attach point. There were clearly visible long cracks found on the bulkhead and attach frame of a particular 690 that showed evidence of working over time. Seems like it should have been caught earlier but, in any case, demonstrates why the area is inspected and is important. The latest model planes had design changes in the area.  Approximately 26 planes have been repaired over the years.  I’m sure you will be hearing more about this as awareness and safety are everyone’s priority.

Adam Frisch

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Re: Ouch!
« Reply #22 on: June 14, 2019, 06:50:49 pm »
Does it only apply to 690's, Bruce?
Slumming it in the turboprop world - so you don't have to.

Bruce Byerly

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Re: Ouch!
« Reply #23 on: June 14, 2019, 11:18:27 pm »
Does it only apply to 690's, Bruce?

Adam, from my perspective, there’s nothing in particular to apply other than good practices. The focus is on 690’s as they are most common and are flying the majority of the forestry work, tens of thousands of hours per year. Low level in the summer.  It’s hard work.

But, I know it’s always been prudent to look closely at the tail of any Commander and should be part of regular inspections.  I ferrried one that had half of the rivets holding the lower vertical spar together sheared. Turned out that it had been damaged in a tornado at some point as I recall. 

It’s a little like that leak that you dealt with. The plane was talking to you and it just took someone to actually look at it to see the issue. I’m fairly certain that there’s nothing new about any of it.  They are proven and capable (just look at the one that flew with half the tail knocked off!) but need to be kept up with just like any plane.

donv

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Re: Ouch!
« Reply #24 on: June 15, 2019, 01:36:25 am »
Well, mine only gets better. When they opened up the stab, one side was fine but the other side had two ribs with mis-drilled holes (from the factory) and one rib with a crack in it. All repairable, and in fact at least one of the ribs is in stock at Twin Commander, but still...

Bruce Byerly

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Re: Ouch!
« Reply #25 on: June 15, 2019, 01:53:16 am »
Well, mine only gets better. When they opened up the stab, one side was fine but the other side had two ribs with mis-drilled holes (from the factory) and one rib with a crack in it. All repairable, and in fact at least one of the ribs is in stock at Twin Commander, but still...

Are they mis-drilled if they made it this long?  Seems like they might get grandfathered in . . .  :P

It’s never fun to spend money on things that don’t make it shinier, faster, or easier to fly but hopefully it’ll be good for the next 30 years.

donv

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Re: Ouch!
« Reply #26 on: June 15, 2019, 11:25:41 am »
That's what I thought too! I also said, well, didn't some inspector at the factory sign off on this, hence it's good?

But the answer was, maybe, but as far as they're concerned, it's not good.

All in all, I'd prefer that they repair it, but it irks me that the factory did that.

Steve binnette

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Re: Ouch!
« Reply #27 on: June 15, 2019, 11:54:25 am »
That is so weird Don.   Do you have any photos?

donv

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Re: Ouch!
« Reply #28 on: June 15, 2019, 12:00:29 pm »
Sure...


SKYFLYER

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Re: Ouch!
« Reply #29 on: June 15, 2019, 03:58:11 pm »
Sort of makes one wonder how long it has been flying around like that...