This assumes FL410 but guys flying these planes know that isn't possible heavy, and not hot + heavy. We saw this today so we had to plan a fuel stop.

It wasn't head-to-head as planned, but it was realistic for a 3 pax golf trip or biz trip with these two planes and that city pair. Efficiency difference was over 25%

More data to come, I know you'll want to dive into it.

I can introduce you to guys that had a reliable 3 hour plane, that is now a reliable 4 hour plane. Same fuel. 33%

If they are going to call stock airplanes "flat wing", which kind of seems insulting like "flat earth", then I think we should refer to the winglet equipped airplane as "bent wing" so we can be fair in the application of demeaning terms.

As most have guessed, this was a setup from the very start. The route was chosen to put it precisely in the exact narrow band where the bent wing airplane can make it non stop and the stock airplane can't.

While there is no question on this particular day with that particular route, the bent wing plane wins by a huge margin by avoiding a fuel stop, this is not by any means a consistent win on the route due to variable winds aloft. Tomorrow, for example, both airplanes need a fuel stop with 160 knot winds on some of the route:

Had they announced this route two weeks ago, and had the winds turned out as they will be tomorrow, both planes have to stop and the test fails to expose that major win. And so it would be any random day, both planes make it non stop, both have to stop, and then, on a few days, the bent wing wins.

What you really want to know is how often such a win takes place. This test doesn't provide that information. If the bent wing provides a 1% advantage, or a 33% advantage, you could end up with the result we have today.

What the test says is having a fuel stop costs fuel and time. Duh.

A further point, given the stock airplane knew, in advance, it was not going to make it, then the optimal approach is to find a fuel stop halfway and carry the minimum fuel on each leg (thus well under gross). This will make the stock airplane climb faster, cruise faster, and use less fuel than max weight departures.

The final figures:

Bent wing: 4:36, 1204 nm, 2610 lbs

Stock: 4:48, 1300 nm, 3650 lbs

The flight times and distances were taken from Flightaware (time does not include fuel stop), fuel was what they posted so has no independent verification. Now that we have numbers, we can examine them to expose certain insights.

Average speed when flying:

Bent wing: 262 knots

Stock: 271 knots

Despite having to make TWO climbs, TWO descents, TWO approaches, the stock airplane was an average of 9 knots faster than the bent wing when airborne.

If the stock airplane fuel stop could have been an implausibly fast 10 minutes long, then the average speed *with* the fuel stop for the stock airplane would have equaled the bent wing airplane. This shows just how close the race was in time when you discount the obviously sub optimal routing the stock airplane took. Further, had the stock airplane balanced the legs more evenly and had more efficient routing, it could have actually been just as fast with the fuel stop as the bent wing was without it.

Fuel efficiency:

Bent wing: 2.17 lbs per nm

Stock: 2.81 lbs per nm

The bent wing airplane used 22.8% less fuel per route mile.

The bent wing flew at FL410, the stock flew at typically FL360. Looking at the stock manual, the change in fuel efficiency going from FL360 to FL410 is 15.7%.

Most of the efficiency gain of the bent wing can be attributed simply to flying higher.

Given the stock airplane had shorter legs, it would easily be able to climb to FL410 without winglets due to less weight, so use of a higher altitude to improve efficiency was clearly an option that the stock airplane chose not to use.

Further, the routing of the stock airplane subjected it to more headwind by going further west, and by weaving around so much on the second leg. Take those out, and the route efficiency improves even more.

Much of the rest of the bent wing efficiency advantage has to be explained by the fact the stock airplane did TWO climbs. There is simply not much left that can be assigned to the winglet benefit.

This test was horrible conceived and executed. It actually made the winglet airplane look quite bad, more than it actually deserves. The winglet airplane IS better than this test showed, quite frankly.

The critical errors in this test:

1. A route which required a fuel stop for the stock airplane. This means the fuel stop dominates the entire result.

2. Flying a route with headwinds. The winglet airplane lost lots of performance slowly climbing into a very stiff headwind while the stock airplane zoomed along faster with less headwind at a lower altitude. That really marginalized the benefit in time and average speed.

3. Flying at different altitudes. Basically means the winglet advantage is lost compared to the basic efficiency gain of higher altitude. Any pilot can fly their CJ higher to gain efficiency without an expensive mod.

4. Flying different routes. The stock route was clearly not efficient and that is made much worse in strong winds when you wander around.

The above errors actually make it unfair to the bent wing airplane!

There is a way to concoct a test which seems far more objective but still biases the test in the winglet favor. Here's how:

Pick a start city out west. Say Utah. Pick an eastern destination city within reach of the stock airplane. Say Ohio.

Pick a day with good tailwinds and hopefully hot temps.

Fly the stock airplane as high as you can, reaching FL410.

Fly the winglet airplane as high as you can, FL410.

The fact this is done with a tailwind means the plane that can climb faster goes faster more so than if it is in still air. The winglet airplane will do that somewhat better, particularly if you have hot temps at altitude.

This will still be biased to some degree, but at least it will be less obvious how, and it will produce much closer numbers.

Mike C.

The fuel stop means the stock plane wouldn't be heavy any more, need less fuel for half the distance, so fly it to FL410 instead of FL360. Choose a better fuel stop airport that isn't adding so much distance, including flying west into the headwind so much, and balances the legs to be more equal. You should be able to do a quick turn under 30 minutes, too.

For example KGWW is just about exactly halfway.


Efficiency difference per route mile was 22.8%.

Efficiency gain from FL360 to FL410 is 15.7% per Cessna data, or almost 70% of what you achieved is just altitude choice.

There was a second climb and wandering routing that caused further loss of efficiency for the stock airplane.

Not much left to attribute to the winglet themselves after all those factors are taken into account.

Mike C.

Easy, make the fuel stop further off course.

Mike C.

The ground time in CAE was a joke to. 47 mins. Common

Agree and I was hoping that is what we would see. Maybe this thread might get Jacob and the team to try this out.

Andrew

This test says a lot more about tamarack marketing then it does about any aircraft. Who wants to cut up their $$$ jet and take a potential market hit years down the road on resale. IMO if you need a little more range buy a little more jet.

I just ran the flight plan for two CJs that I fly using their profiles in FF. I’m confident they are accurate representations of these two planes, mine with winglets and the other doesn’t.

Attached are the results for these two specific planes.

Around 9% which is what I have commented on I see for my missions. For my missions this is very beneficial and I don’t have the extra $1.0M to upgrade to a CJ2.

Andrew

This is probably the biggest reason that this recent test was such a poor one. A nine or ten percent improvement, along with the ability to avoid fuel stops on longer legs is really great. By concocting this apples to oranges flight to make us believe the 33% fairy tale, they've turned off a bunch of pilots and created distrust in their organization. It's a shame.

Can you summarize what you’ve done there Andrew? It’s confusing.

That's an absurdly sweeping statement and patently false.

I haven't added any comment as I already own the worlds most efficient high speed aircraft (ahem)..lol

I considered the Citation family (particularly the Citation 1) prior to buying my Piaggio and the Tamarack winglets were def part of those conversations.

I liked them and would've done it if I would have ended up buying the airplane. The reasons?

6% cost in fuel savings over 10 years of anticipated ownership would get close to paying 1/2 of the 180K upgrade at 5 - 6 bucks a gallon (I fly 250 hours a year) AND

They look so cooooool.

But thats about it. 6% is pretty much what you can expect and the occasional not having to stop for fuel.

For some thats worth it for some not. All I can say is for me it was worth it. Did I tell you how cool they look? (Just not as cool as the Avanti lol )

Do the tamarack winglets come with supplement or replacement performance charts and pages for the POH?

Are those shared online somewhere?

I have the BLR winglets on my C90B and I was surprised when contacting BLR about potentially missing POH pages that none are required

Weird to have the marketing material claim shorter takeoff, faster climb, and better cruise economy, but then have no new POH pages

So this is why I ask

Its been really interesting to read the analysis of Mike C. which I think is spot on. Andrew Vann seems also to be very fair and unbiased and has real world experience. He claims a 9% efficiency gain which seems a bit high but probably realistic and comes mostly from the ability to climb directly to FL410. We saw that on yesterday's flight and has a M2 owner/pilot I can confirm that there are very significant gains flying at FL410 vs. the mid 30s. I go to FL410 even on 300 to 400nm legs as it only costs me a couple of minutes but saves 100-200#s of fuel.

I'd also like to point out that the Tamarac representative on an earlier post said it turns the airplane into a 4 hour plane vs. 3 hour plane. THE only explanation for this is the fact that the winglet plane can climb directly to FL410 whereas the stock plane will burn more fuel in the step climb to FL410. Does that result in an hour difference - I am skeptical. It is important to note that pulling the power back from HSC isn't fair. In other words, you can't keep the stock airplane in HSC the entire time and say it is a 3 hour plane vs. the winglet plane plane is a 4 hr. plane with a non-HSC setting. Nor can you keep the stock airplane at FL360 the entire time vs. FL410 for the winglet plane. Not a fair comparison.

The M2 is a 3.5 hour plane if you climb directly to FL410 and keep it at HSC. You'll cover 1,300NM doing 390-400KTAS and land with 800 #s. If you want to go further, say Cessna's 1,500NM, you have to pull it back and it will do it. Note that at HSC at FL410 the plane is burning about 670-700 PPH. At mid-cruise weight, 600 PPH gets you about 360 KTAS and 500 PPH gets you about 330 KTAS.

The "blinglets" on the M2 don't do anything (that's according to Cessna). They are just ramp appeal. All of the performance gain over the original CJ is attributed to the increase in engine thrust. That gets the M2 directly to FL410 at MTOW in 24 mins. The CJ needs to step climb and once it reaches FL410 I believe it burns around 600 PPH and cruises around 360 KTAS. If an M2 driver flies his plane like a stock CJ once he reaches FL410, and burns 600 PPH, you'll increase the range to about 1,400NM which is a significant improvement over the stock CJ. Another words, the increase thrust in the M2 allows it to climb directly to FL410 which gives it a significant range increase.

Don't believe me? Look at Cessna's numbers on their aircraft range tool on their website. HSC for the CJ with one passenger and one 200 # pilot is listed at 1,312 NM for HSC NBAA IFR (100NM) reserves vs. 1,385 NM for the M2. Note - The M2 flight planning guide lists the NBAA IFR (100NM) reserves as 627 #s (which is a bit light in my book). I assume it would be the same for the CJ. BUT keep in mind, the M2 goes significantly faster at HSC at FL410 and therefore, since it is the same airframe, has a lower specific range at HSC vs. the CJ. You can't go faster for free! Using the Flight Planning Guide for the M2, if you climb directly to FL410, then cruise at 600 PPH for the entire time, and use a standard descent I get 1,428NM range with NBAA IFR (100NM) reserves (627 #s). That is a 116NM increase in range over the stock CJ that can only be attributed to the ability to climb directly to FL410. That's an 8.8% gain in range over the stock CJ.

The stock CJ has always been underpowered and therefore the winglets do make a big difference because they allow it to climb directly to FL410. I am not disputing that nor do I think Mike C. is. We just both agree that it doesn't result in a 33% gain in efficiency. I can believe the 9% Andrew claims and most of that is attributed to the ability to climb directly to FL410. Taking a look at yesterday's flight - notice the really slow climb speeds for the winglet climb. They knew they needed to get to FL410 with as much gas as possible if they had any chance of making it non-stop. Based on their slow cruise speeds I bet they were in LRC the entire time as well.

Net/net - Most of the gain is attributed to the ability to climb directly to FL410. As I point out above in my rough estimate it equals about an 8.8% gain in range. The rest, perhaps .2% or a bit more if my numbers are off which they surely are, is attributed to a very small gain in efficiency in cruise like Mike C. points out. So the gain in efficiency and/or performance is real but it is probably around 9% which is what Andrew reports from real world experience, not 33% which is what Tamarac claims. I believe Tamarac is doing themselves a major disservice making that claim....