Tail numbers?

Those two owners don't believe Tamarack's statements that a solution is imminent?

Mike C.

I don't have their permission to post that - they are both CJ3 aircraft. I think imminent means different things to different people. I believe the logic they are using is similar to some I have seen on here (I think some by you) which is that the winglets introduce an unknown quantity now - or down the road - so returning to factory eliminates that issue. There are some other factors that I think are coming into play here as well - so it isn't a simple - "this caused it" decision.

I can only say that if I had a winglet equipped aircraft, I am not sure what I would be doing right now. I'd probably be waiting to see if a solution was imminent - but it would be very stressful.

Now that they have been in use for a while, there should be operational data to show whether they actually worked as advertised. If they do, it may be worth waiting out the current problems.

It is not surprising the winglets may be removed from some CJ3s. The performance improvements have not been as good as in the CJ/CJ1.

What to do may depend on model by model. The CJ/CJ1 owners may see enough benefits to wait and see. For some CJ3s the benefits may have been disappointing and better to go back to stock and move on.

They don't work as well as first advertised. Nothing could.

Their advertising has since removed most numerical claims and they specifically disclaim any specific numerical performance improvement.

"Tamarack does not and cannot guarantee the performance of your aircraft."

https://app.box.com/v/CJ3-CJ3plus

"Combined with a faster time to climb and much quicker acceleration when leveling at cruise altitude, the fuel savings significantly extend the range of the CJ3."

Notice the lack of claims regarding reduced fuel burn in cruise, which they used to claim.

The charts given in the above document raise certain questions, like why the Tamarack equipped airplane has 200 lbs useful load in the charts, but the brochure claims only 81 lbs weight for the mod. What happened to the missing 120 lbs?

Mike C.

That is what I heard from some CJ3 operators. I think the AD may have been the final push.

-Jason

Also for the CJ/CJ1 the Tamarack mod could be 20%-25% of the aircraft value and a big nut to walk away from.

For the CJ3 the Tamarack mod could have cost 5%-8% of aircraft value and may be better not to have it on for resale.

Lots of different factors for owners to consider.

That is what I heard from some CJ3 operators. I think the AD may have been the final push.

-Jason

They don't work as well as first advertised. Nothing could.

Their advertising has since removed most numerical claims and they specifically disclaim any specific numerical performance improvement.

"Tamarack does not and cannot guarantee the performance of your aircraft."

https://app.box.com/v/CJ3-CJ3plus

"Combined with a faster time to climb and much quicker acceleration when leveling at cruise altitude, the fuel savings significantly extend the range of the CJ3."

Notice the lack of claims regarding reduced fuel burn in cruise, which they used to claim.

The charts given in the above document raise certain questions, like why the Tamarack equipped airplane has 200 lbs useful load in the charts, but the brochure claims only 81 lbs weight for the mod. What happened to the missing 120 lbs?

Mike C.

Tamarack doesn't seem to have data that stands up to scientific scrutiny and they clearly have a vested interest.

A new owner of winglets will be predisposed to see improvements and few if any of them do hard science to measure it. After all, if you spent $250K on something, you'd probably not say the winglets are not worth it and lower the market value of your airplane.

So actual hard data is hard to come by.

The benefits of the winglets are real but will vary on which model they work best on. In certain corner cases, they can make a large difference, such as heavy, high, and hot. When operating that close to the edge, the small aerodynamic benefits of winglets are amplified.

The CJ3 brochure from Tamarack that I linked to above has this anecdotal example but it contains a few numbers to work with:

CJ3. Paris, TX to Paris, France. One Stop.

Carrying two pilots, one passenger and loaded to max takeoff weight, the jet departed Paris, Texas flying 2,104 nautical miles to St. John’s, Newfoundland (CYYT). The flight had a 4 knot tailwind and flew at 376 knots true airspeed for 5 hours and 32 minutes. The total fuel burn for the first leg equaled 3960 pounds (107 gallons per hour block fuel burn). The St. John’s, to Paris Le Bourget flight, a distance of 2244 nautical miles, took 5 hours and 45 minutes flying at 373 knots true airspeed with a 17 knot tailwind. The total fuel burn for the transatlantic leg was 4210lb (108 gallons per hour block fuel burn). Combined with a faster time to climb and much quicker acceleration when leveling at cruise altitude, the fuel savings significantly extend the range of the CJ3.

We don't have enough data (temps, winds, FA track, etc) to recreate this flight using the stock Cessna data (which is usually known to be a bit pessimistic in the CJ line), so it is hard to judge how well the winglets did their job. I'll note that Cessna claims 2,040 nm range for the CJ3+ (doesn't say under what conditions) and the numbers above seem in line with that given the tailwinds and likely ISA plus conditions, so doesn't seem like a huge range increase to me.

CJ3+ fuel capacity is 4710 lbs, so they landed in Paris with 500 lbs on board. That seems really tight to me! I can't imagine Cessna's range number of 2,040 nm was with less reserve.

I bet the CJ3 range is improved, but I bet it is under 5%. Was that worth the 80 lbs less useful load, the install cost, the system hassles, the higher hangar rash potential, the rougher ride in turbulence? Does seem marginal. The grounding by AD, of course, kills the value proposition.

Mike C.

Compensated owners? In what way?

Mike C.

Hi Mike,

I know you don’t like Tamarack as a product or company. In all my dealings with them (I’ve had two sets of winglets installed!) they have been an incredible company to deal with and their service and commitment to me as a customer has been outstanding.

Their claims of savings were overstated for my particular airframe as I have advised before. I did not pay the price as noted in a bunch of posts in this forum FYI.

Some of my specific missions were not possible pre-install. These are over water flights with no options for landing. I fly in the citation over 300 hours per year so know the planes and performance well.

There is a known issue with that CJ3, Tamarack recognised this and resolved it with clients. I’m not sure you will get the specifics on the forum, but we will see.

I am very fortunate to be flying an M2 at the moment with my grounding , so it has not affected me at all - maybe I’m an outlier in that respect.

Would I have had them installed given every thing I know now? Probably not, but I am where I am and sure hope it all get resolved. I don’t wish anyone issues in Aviation as it is a small community and complex / expensive enough.

Being a structures guy there really is not a lot involved in getting them removed, but I’m fortunate that I’ve got time to wait before I commence that.

Andrew

My views are not the result of some sort of arbitrary like or dislike of the company, they were objectively derived from considering their advertised claims. They either didn't know or were lying about what the winglets would do, or some combination of both.


Except about being honest about the benefits and delivering an airworthy product.


So they are paying hush money to unhappy customers?

Why did they not recognize the problems BEFORE taking customer's money?

Mike C.

Mike you really are a glass half full sort of guy aren’t you?

The fact is a number of owners posting here were happy with their winglets means something. We are all suffering with the ADs but I for one am still happy with the product. It allows my aircraft to cross the Atlantic from Canada to 10 minutes from my house.

Were their initial marketing claims correct on the CJ3, no. But that doesn’t mean that they are a worthless product. On the CJ1/1+ they seem to make a very significant difference. Is it worth the money, who knows? This is aviation and if we start applying that criteria, we would all give up flying.

Since the performance differences are now known is there any chance Cessna will come up with a wing for the CJ series with the longer span and winglets but as a fixed passive system.

What is the weight difference between the active winglet system and control surfaces vs the structure needed for the wing to have normal winglets installed.

How much of the benefit is the winglet or just the longer span wing?

Could it be almost as good with a tip extension and no winglet?

I would imagine it would be only available as an improvement to a new airplane and not a retrofit kit for older airplanes. But who knows.