Total energy probe

[duzgis]

Hello everyone,

I would be interested to hear from PIK-20D owners who have replaced the original downward-curved total energy probe with a modern TE probe.Which probe did you install, and how well did it work in practice? In particular, did you notice any problems with stick thermals, sideslip sensitivity, over- or under-compensation, or a slow variometer response?We are currently considering the following three options:

1. CARBONaero Ball Style TE probe – preferably the 1 metre version with a 10 mm fitting.https://www.navboys.com/CARBONAERO-BALL-TE.html
2. ESA Systems RU/ST TO1007, 10/40 mm – 860 mm overall length, installed with the measuring head pointing upwards.https://www.navboys.com/ESA-TO1005-8-40mm.html
3. ESA Systems DN/ST TO1002, 10/40 mm – 745 mm overall length, with the measuring head aligned horizontally.https://www.navboys.com/esa-total-energy-te-probe-dnst-type-st1-840-end-piece-to1000.html

The PIK-20D currently has an LXNAV S100 electronic variometer and a Winter mechanical variometer with a capacity flask. Both instruments use the same TE line, which is divided by a T-piece at the nearest accessible point.With our present ESA DN/ST 10/30 probe, the S100 sometimes produces a false “stick thermal” indication during pitch changes. It also indicates climb when the glider is deliberately sideslipped with either left or right rudder. Before testing another probe, we will check the complete pneumatic system for leaks, restrictions, incorrect connections and damaged tubing.I would especially appreciate hearing from pilots who have real flight experience with any of these probes on a PIK-20, PIK-20D, or another glider with a similar tail arrangement.Which probe gave you the cleanest and most accurate TE compensation? Did one design perform noticeably better during pitch changes or sideslip? Was it also able to operate an electronic and a mechanical variometer from the same TE line without creating response problems?Also, does anyone have the original PIK-20D pneumatic instrument connection diagram, showing the original pitot, static and total-energy plumbing? If so, I would be very grateful if you could share a copy, photograph or link to the drawing.

Photographs of the probe installation, its orientation and details of the pneumatic connections would also be very helpful.

Thank you for sharing your experience.

[john firth]

As I recall, my PIK 20E came with  the same long probe with a SINGLE hole.  It did not give enough compensation

and was subject to yaw error.

Many years ago, I was consultant to Cambridge Aero; the Nicks single hole probe was being produced; we tested this on a ASW 19

and concluded that it under compensated seriously.  Frank Irvine found the same result in a wind tunnel.  His solution

was two holes  a specified distance from the tip which was angled down at about 20 deg and  2ft ahead of the stabiliser

This was tested by me on a Kestrel  and proved to compensate for a pullup from 100 Kts at 45 deg, with error +/-  1 kt.

The pressure field ahead of the tail assembly  will vary from glider to glider; fine tuning may be needed.

This probe,  2 ft long with custom socket,  was produced for CAI and sold widely.  I have one non anodised sample left; you can have it 

( no Socket)  for $30 plus P and P $10.

I am using one on my PIK 20E.

regards

John Firth ,

Ottawa

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[Varley Ibbo]

I made probes for power station chimney work. I lost my pik20d one and made another based on experience and guessing using 10mm copper tube. It works fine with the original Borgelt vario and cost me zilch as I had the tube lying around the workshop. Just cut one junior hacksaw cut to imitate the original tube. Modded the cut until compensation was good and used it ever since.

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[Rob Frith]

I am in the process of “adjusting” my original Nicks probe by reaming out the hole a bit at a time after each flight.    I do not want to be too aggressive as I have no plan in case it starts under compensating.   I fly have flown about 40 flights this year so I expect it to take a few seasons to get good compensation     Or if the John’s probe is still available I would be interested.    

Cheers

Rob Frith

On Sep 2, 2026, at 1:38 PM, Varley Ibbo <varl...@gmail.com> wrote:



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[Jarek Mosiejewski]

Hi,

If you are using LXNAV S100, you could consider running it with electronic compensation and do away with the probe altogether.

Regards

Jarek

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Regards
Jarek

[Alexander Tummes]

Hi

A installed the  CARBONaero TEK Probe... Works fine so far and looks cool... But will try next season to switch to fully electronic compensation with XCVario...

[Scott Hamby]

My understanding is having both the actual TE from a probe, along with it's internal calculations and sensors, is better when using LXNAV S100.

Scott 

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[Tony]

T & flask(s) should be as far away from the two instruments as practical...

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Tony

[Scott Hamby]

My understanding is also no flask for S100.  Tubing from TE probe straight to S100 (as well as static and pitot). I'm in the process of installing one now. If you know otherwise, LMK. 

Scott

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Tony