You can't bolt on a wing extension and winglet that can generate over 1000 lbs of lift where a wing tip was that generated almost nothing.

There has to be pretty substantial structural changes. Hopefully those are all additions and not mods to original structure, but it is still invasive judging by how much it costs to install (not buy) the winglets, and how far down the wing the installation appears to go from the pictures.

Mike C.

You can't bolt on a wing extension and winglet that can generate over 1000 lbs of lift where a wing tip was that generated almost nothing.

There has to be pretty substantial structural changes. Hopefully those are all additions and not mods to original structure, but it is still invasive judging by how much it costs to install (not buy) the winglets, and how far down the wing the installation appears to go from the pictures.

Mike C.

How many hours to put the original tip back on and leave all the wiring and other stuff in place? That is, just fix the tip? A shop that did winglet installs would likely know (and they probably rean't as busy as they expected to be right now...)

I would ask the FAA to approve this as an AMOC. Your plane has Tamarack stuff still in it, but in a seemingly harmless way, and you should be able to get the plane flying while the winglet debacle grinds to a conclusion.

If it is really is bolt off, bolt on, ought to not be too much time, right?

Find the lead FAA guy listed in the AD (Melvin Johnson?) and call him up and ask if they would approve such an AMOC and how you would go about it.

My instinct tells me this isn't going to be a quick fix, so I would get going on a plan B right now that gets the planes flying while the mess gets sorted out.

Mike C.

Here is a couple of shots from my install which give an indication of the spar attachment method.

It does not look too invasive but at the end of the day it’s a spar...

Andrew

Are those added straps bolted to the old wing or riveted? The Celcos suggest it is riveted.

If so, that's not a bolt on/off. The added straps are riveted in, so they either have to be cut to put on the old wing tip (which makes reinstall of winglet troublesome), or their rivets have to be drilled out and removed.

The worst part of this whole mess is the uncertainty of when/if there will be a resolution. I'd be very surprised if this is something that will be taken care of in the next few weeks. If Boeing can't get MCAS resolved in months, why would anyone think bankrupt Tamarack could resolve this in weeks?

I suppose their could be an AMOC to depower the Tamarack surfaces and then adhere to the crippling Vmo in that mode. You could at least move the airplane, but its utility is severely limited.

I can't recall any other time when two aircraft types, Boeing 737 MAX and Tamarack CJs, are both grounded due to emergency AD due to flaws in an automatic control system.

Mike C.

Mike, I think what gives us some hope is that firstly they solved the problem a year ago and have the data that proves that ie. no failures since. The recent failure in Europe was shown not to have complied with that SB.

The primary regulator is EASA and they have been working with them for 6 weeks now.

So it is a little different from MCAS in that it is proving the already developed solution works.

It is very unfortunate that the FAA mentioned the Indiana crash. I am told the NTSB is very annoyed about that as well and the comment is likely to be removed shortly. According to a contact in EASA, the NTSB has stated to it that there is no evidence at all of Tamarack winglet involvement in that accident.

Do you know if the Tamarack system has data logging? That is, some sort of internal non volatile memory that records parameters as it operates?

I would have put that in the design since they are basically designing for rare events and collecting forensics would be helpful to identify flaws and fix them, and also to possible exonerate the system, too.

The main problem with the "no evidence" argument is that if the Tamarack system did cause the crash, there wouldn't be any obvious evidence to say that regardless, assuming we have no forensics in the Tamarack system itself.

I've become increasingly disappointed with the quality of NTSB findings. Their conclusions sometimes seem to be motivated by what they want the answer to be rather than what the evidence says.

Mike C.

They are riveted on, so it would require drilling them out. I don’t think that’s a big deal in itself. It’s done all the time for various repairs, however this is a spar.

It’s only 6-8” long section and the load at that point is not that great. I guess worst case you double up the angle on the top/Botton of the spar web.

Regardless its a major f$@# around and I really do not want to go there.

Andrew

Jason that is exactly what I have been told. From what I understand with the harmonisation agreement between the FAA and EASA, there has to be an agreement on the AMOC between FAA/EASA/NTSB/AAIB. Imagine trying to get them all to align.....

It’s a shame Brian has now left the company as I found him really good to deal with and has taken multiple calls from me over the last few weeks and kept me up to date.

It’s all not looking good but I have my fingers and toes crossed and doing a silent chant each night

You seem to have good intel on the European side so keep us posted!

Andrew

You and me both.

I don’t see that with them. They are an incredible bunch of people with extremely limited resources. I know the Chairman and have been through their labs and training facility. They are a first class outfit, maybe I am biased but this is not their issue.

Andrew

What's the story on that?

Don’t know yet, Jacob who has stepped up to President is calling me today apparently. Should know some more details then.

Andrew

And now the company has filed for bankruptcy protection. Wonder what this means for the owners of modified aircraft?

https://www.inforuptcy.com/filings/waebke_205883-2-19-bk-01492-tamarack-aerospace-group-inc

Nobody knows for sure, but the odds the winglets have to be removed to get the planes back in the air surely has gone way up.

It also occurs to me that it didn't take very long from AD to bankruptcy suggesting they were teetering close to the edge and might have ended up in the same place even without the AD.

I'd be pretty sure the last Tamarack winglet has been installed. I can't imagine someone electing to buy one in the future.

Given AD, bankruptcy, and likely no future sales, there's really no imperative for Tamarack to clean up this whole mess.

Next shoe to drop, conversion of bankruptcy from ch 11 (reorg) to ch 7 (liquidation). That would be the end of Tamarack officially.

Tamarack owners should figure out a way to get together as an organization, nominate some leadership, and engage with both the remnants of the company and FAA/EASA. Maybe the parts and IP assets can be bought and form a company to support the installed fleet. I consider this unlikely, but it is possible.

Even if the winglets get approved to return to service, if there's no company to provide parts and service support, that's going to be a problem eventually for the equipped planes.

Hard to imagine an outcome where Tamarack is again installing winglets and owners are being well supported.

Programs like Pro-parts isn't going to save the day here, either.

Mike C.