Tamarack announced today EASA certification of their active winglet system for the CJ, with FAA certification expected this summer.

http://www.tamarackaero.com/news-release.html
https://www.ainonline.com/aviation-news ... j-winglets

The test bed aircraft is N86LA. Sn 0012. I operated that airplane for 5 yrs before selling it to the current owner who leased it to the Tamarack folks. Good little airplane.

Robert

There is a second airplane (there may be more) owned by a fellow CJP member that agreed to install a set to do some conformance testing (N300BV).

This is what he had to say before the installation:

I have over 10,000 hours, 4500 in citations, including 2600 in my CJ1, plus ten years flying fighters in the Air Force and Air National Guard.

The performance I experienced during my flight in their test aircraft in which I flew with Nick out of Sand Point ( 2131' elevation ) with full fuel and the computer equipment they used for testing, we climbed straight to FL400 in 20 min. I normally fly 2-3 hours legs in my CJ1 at FL370-410 and I have not been able to get to FL400 in less than 45 min. Another thing that I noticed, although I did not time it, the aircraft seemed to accelerate up to cruise speed much quicker. While I agree with your thoughts about testing, Tamarack has been spending their time and money on certification rather than flights for marketing purposes. If this was not as it is represented, Cessna would never had bought into it. I have visited their facilities twice, and I can assure you they are a first class engineering house. Normally when you add winglets to an aircraft, it requires strengthening the wing which adds weight degrading some of the performance the winglets offer. The Tamarack system does not require that , which allows for the increased performance they experience.

His tail number is blocked on Flight Aware so I don't know how much flying he's been doing, but I would imagine after Tamarack gets through the certification process, we'll start getting more information on the performance gains, the most enticing of which, for me, are the GW increase (both for MTOW and ZFW) as well as the hot and high performance.

Some interesting data has been published by Tamarack regarding the performance gains for the CJ following their active winglet certification. First, is the 400 lb weight increase - that's 2 normal pax with bags. Then is the endurance and reduced block fuel flow. I spoke with a CJP member who already installed a set on his CJ under an experimental certificate and his impressions/experience was in line with this.

Interesting.

Hopefully everyone can tell this chart is bogus.

Mike C.

Bogus??? Exactly what is bogus about this?

The data for this plot comes from 4 averaged data points from the table below. Tamaracks winglet data starts at 1.02 hours while the first data point for the CJ starts at about 0.6 hours average flight time. Perhaps, for the lower average block times (at and below 1 hour flight time), more data is needed to draw definite conclusions - 3 averaged data points may not be enough. However, there is a trend that is worth noting.

Now, if you want to argue there is no performance improvement and it is all just marketing BS, I would be interested in understanding your reasoning. Or perhaps your claim is that this data is fabricated?

http://www.tamarackaero.com/flight-log-chart.html

Alex,

Those graphs certainly show impressive performance gains. Have you analyzed the payback time period for the installation investment?

How does the engine know it should magically change its fuel flow because the wing shape is different?

Please, do try and explain this. Every engine maker needs to know.

Mike C.

Now about this chart:

So, given the chart specifies you are using MCT, maximum continuous thrust, then the engine power levers are put in the same place for all flights.

The winglets don't add fuel capacity.

Yet, at the same power setting, the plane flies about 45 minutes longer if you have the winglets, leaving the same amount of reserve at the end.

Those of you who believe the chart is honest and accurate should not admit that in public as that would say more about you than the winglets.

Mike C.

Do you think mike that maybe the premise was the endurance is longer because of increased climb performance to altitude, which in turn reduces time at cruise fuel burn?

If the CJ gets higher earlier, it burns less fuel and stays in the air longer. Seems simple to me, but I didn't go to MIT...

I went to public school. The shame.

Do you think getting to altitude, say, 5 minutes faster would net 50 minutes more cruise time?

The answer is no.

Mike C.

It's definitely not an engineer's graph. But I get where it's coming from. A laugher for any technical professional, but it's making a point.

I think in general these types of data collection tend to be kind to the modification as well. But I believe it is right within about a 10% swing or so.

No doubt this is a good program, well worth the effort. Probably worth the money too.

Making arguments in a rude and abrasive manner or by insulting other people, a common pattern for you, does not make them right or disqualify Tamarack's testing data. Lacking social skills and civility really detracts from any valid argument you might be trying to make. Your insight and input are welcome - your belligerence is not.

Let's see here - the CJ data is not up for discussion - I hope. Those are pretty close and accurate numbers. The Tamarack numbers are based on actual flight data of more than 4 years of testing and which were part of the system's certification data. A fellow CJP has installed a set on an experimental basis and I have kept in contact with him - he is experiencing the same performance gain reflected in this perhaps less than technically accurate manner.

As far as the physics, the drag reduction in addition to the improved climb performance (not 5 minutes - more like 15) is what makes the difference. Tamarack has also been forthcoming in providing testing data to potential customers, and from what I have seen, and if they did not deliberately fabricate the numbers, this chart is fairly accurate if not presented in a technically correct way.

The data table from where these charts came is there for you to discuss. I look forward to reading your comments - not your insults.