I know nothing of the subject at hand, I'm just asking you to recalculate your 1125%.

Let's just say yea and call it a day!

Let's just say yea and call it a day!

Yes, they did.



There is no possibility, under ANY circumstances, that the winglets allow 45 minutes more endurance, or increase range by 20%. The charts they provide are a lie.

They are praying on wishful thinking and lack of analytical skills. The data they provide is either fudged or has significant hidden biases not disclosed.

If I had 20,000 hours jet time, that would not change any of the above.

Mike C.

Criticizing Cessna's numbers I am using.

However, you are basing your assessment on a flight planning guide (paper numbers - not actual data)

You now seem to be saying the paper numbers are correct. Given that, you should find my conclusions to be valid since they derive directly from Cessna. Those numbers show there is no possible way the winglets increase endurance by 45 minutes at MCT, thus exposing the Tamarack chart as deceptive.

Mike C.

And that would be how to hide unstated biases from view.


In other words, not apples to apples.

Fundamentally, if you produce charts that show 45 minutes more endurance and 20% more range, you are promising that performance even if the chart was created with an intellectually dishonest, but yet data based, method.

The main claim is that winglets reduce fuel flow in the engine even at the same altitude.

From their press release:

JetPingu pilot Hugo Dobler, explains, ‘We selected the Tamarack Active Winglets because of the significant fuel savings and the increase in value for the aircraft. In addition, the extended range will allow us to offer our guests many more destinations beyond our current three‐hour limit. I am really looking forward to my first flight with winglets’.

That does not sound like a person expecting 3-5% improvement. I also think it is telling that he has yet to fly the winglet airplane.

Mike C.

You mean Cessna's assumptions of ISA for their FPG?

That's why ISA exists, to give everybody a nominal reference for performance.

Do you mean to say the entire industry is making naive assumptions?

If anything, the people who believe in this mod are the naive ones, I am the skeptic.


Exactly how big a difference will it be? 45 more minutes and 20% more range is a HUGE promise well outside the plausible range for winglets. That's in "snake oil" territory.

I understand you want to believe this mod works as advertised because you have an underpowered airplane in need of help in the high flight levels. Wishing doesn't make it so, unfortunately.

The winglets WILL help the performance of the airplane. No doubt about that. The only argument is by how much, and if the price is worth it.

PS: Cut out the name calling and ad hominem stuff. Contributes nothing to the discussion.

Mike C.

Interesting tidbit on winglets from wiki.

Learjet exhibited the prototype Learjet 28 at the 1977 National Business Aviation Association convention. The Model 28 prototype employed the first winglets ever used on a jet and a production aircraft, either civilian or military. Learjet developed the winglet design without NASA assistance. Although the Model 28 was intended to be a prototype experimental aircraft, performance was so impressive that it resulted in a production commitment from Learjet. Flight tests, made with and without winglets, showed that the winglets increased range by about 6.5 percent and also improved directional stability. Learjet's application of winglets to production aircraft continued with newer models including the Learjet 55, 31, 60, 45, and Learjet 40.



Direct testing showing in 6.5 % more range with winglets.

Erwin - I don't know of a Learjet that ever had trouble getting up to altitude even on hot days. On the CJ, if you couple the 6.5% advantage with assuring climb to altitude on hot days, the improvement gets better.

However, arguing with Mike in circles accomplishes nothing. Mike's never flown a CJ but is somehow an expert from reading a generic planning guide. Whatever.


Good point. Perhaps you could use this advice.

Even the ones without winglets. They are not underpowered like a CJ for the most part.


The FPG is not generic, it is specific to CJ1.

Mike C.

You are comparing apples with cucumbers.

Learjets have a very different wing then a Citation. The performance change winglets give on a Lear wing design have no relationship to how a winglet may perform on a CJ wing.

I realize the aircraft are very different, what I found interesting was the measured difference being very close to what Mike estimated.

Hopefully the winglets will be as big an improvement as is claimed. I am interested to see the range of conditions where the winglets can actually eliminate the step climb.

Eliminating the step climb is a big deal, I need no convincing of that.

This was today in the Lear 31A. ISA plus 10. Full fuel and 3 passengers and climbed to FL450 in 26 minutes (15500 lb takeoff). No level off required. I've said it before and I'll say it again. I love the citation 500/525 line but there's some things they just won't do.

How threads devolve (evolve?) on BT...

[YouTube]https://www.youtube.com/watch?v=rMz7JBRbmNo[/YouTube]

Mike C.

We mostly agree, and stated the charts are misleading.
But you call it fraud, I call it marketing and slimy (often the same thing).

Tim