Tamarack has filed for chapter 11 bankruptcy according to a statement I read on CJP.

They portray this as beneficial to supporting their existing customers.

There is a very real possibility that modified aircraft may never fly again with the winglets.

Mike C.

I wonder if owners saved the removed wingtips and can they be reused?

Or does Textron have enough replacement wingtips in stock and what will they cost?

Be an interesting CJP meeting in early September if these planes are not flying by then.

My impression is that the changes are invasive and possibly destructive to existing structure. I gather that from the in process install pictures.

So wingtips are the least of the concerns. You may be talking about new ribs, spars, leading edge, skins, etc. It would not surprise me if the cost to remove them is about as much as it cost to put them in. It may require an engineering exercise to create an "undo" kit to repair the changes made.

Whoever at Textron decided to pull the relationship with Tamarack should get a gold star.

Mike C.

I saved mine!

I’ve heard that they can be removed to bring the plane back to standard via a field approval but once it is done you can’t go back and put them on again.

I’ve been concerned about this for the last 6 weeks, it’s s real pain.

I’ve been real unlucky of late, haven’t had my Tesla for 2 months as the battery failed and still waiting for one to get into Australia.

Andrew

I doubt Textron has many structural wing parts available for out of production aircraft. If parts are needed I can see the planes being AOG for a while. As well as the cost for a small run of parts.

Will these modified planes have a cloud over them that affects the value like DH does?

This fiasco will have repercussions for a long time.

I can’t tell you how close I came to pulling the trigger and installing them on my aircraft. Obviously at this point I’m really glad I didn’t, but I’m very hopeful this situation has a good outcome and that the product goes on to become successful despite this situation.

Lame.

They let if fail for 1/4 second and then depowered it.

"The video clearly shows that this failure condition with centering strips is not severe."

BS.

Now show us what it looks like if you get full asymmetry and you let it go for 3 seconds.

The roll rate was going to be significant if the 1/4 second failure was any indication.

Mike C.

I am looking at a lead time of 90 days for some structural wing parts for my 2+.

I am looking at a lead time of 90 days for some structural wing parts for my 2+.

That raises questions:

1. Sounds like there is part of the system that monitors itself. What happens if that part also fails?

2. Was this self monitoring system installed on the accident aircraft? When did this self monitoring capability first appear?

3. What does the roll rate look like without this self monitoring system in place?

4. What are the failure modes of the self monitoring system?

These automatic control system things often have very subtle and complex failure modes.

Mike C.

Mike,

If they are taken off there are no other wing parts that need replacement. The old wingtips go straight back on. Depending on how the rivets are removed, there may be some small parts need replacing if you then want to refit the winglets.

Removing an STC and putting a plane back in its TC state should not need a field approval.

That big C clamp and supporting beam shown in the picture I posted previously sure doesn't give that impression. The install seems to require stabilizing the structure, which suggests some significant structure is being changed while the new parts are being riveted on.


True if none of the original parts have been modified (cut, drilled, etc). If they have been modified, then you either need to replace the part with factory original (which may be infeasible for somethings like a spar), or develop an approved undo kit.

If the change back is as simple as you make it sound, why don't owners simply ask for an AMOC to bolt the old wing tips back on, leave all the Tamarack circuits in place, and then fly that way until/if they can put the winglets back on?

Mike C.

Mike

Any thoughts on whether the concept has any merit in a clean sheet wing design going forward?

Why do winglet installs always seem to have a large span increase inboard of the winglet? How much of the benefit is from the winglet vs the longer span added by the portion of the wingtip that is still horizontal? I question this on Kingair installs also.

I know the winglet acts like increased span increasing the bending moment but it seems like increasing the span at the same time is a double addition.

It isn’t. The entire point of the install is that they don’t modify those parts.




They may well do that. The problem is that there are some rivet edge limits that mean replacing the winglet is a bit more complicated. I think owners are waiting for an amoc based on the two service bulletins right now which is the preferred course.

Contacts in Easa suggest they are close to lifting their EAD.