Got rid of my TE probe

[John Johnson]

In another forum on a different topic, Eric Greenwell mentioned removing his TE probe after switching to electronic vario compensation.  Huh?  Hmmmm...

I started using eTE a while back to avoid prop wash interference when the motor is running and decided I prefer the vario's response even with the motor is stowed.  But I never thought about actually removing the probe.  

Well, I moved my plumbing around to exclusively use the nose pitot and fuselage statics and capped off the TE receptacle.  (I don't use a pneumatic vario any longer, replaced it with a standalone SxHawk, so both my varios are eTE compensated.)   Just a simple change really but I love it!  Last year, I gouged my sunglasses and almost put my eye out on the damn probe.  So convenient and tidy now and no more messing with the probe while putting the covers on and off.   

Probably obvious to everyone else but thought I'd share anyway.  

JJ

[Dirk]

For what it is worth, I've been flying with my vario in 'compensation mode' and it compares really well with the old school winter TE vario.  I like having the two options for comparison purposes and backup.  But if push came to shove and I needed more panel real estate - I could see ditching the old TE instrument.

[David S]

Long ago I read that eTE requires pitot and static ports that are located close together because even small delays between the signals wreaks havoc with the TE calculations.  From your success story it would appear that the issue is not so dire.

Thanks,

   ...david

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[John Johnson]

David,

  Apparently that's not an issue for my SxHawk and V9 varios.  Their manuals show using nose pitot and fuselage static hookups in the eTE mode:

thx, JJ

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[Eric Greenwell]

Before I switched to eTE and removed the fin mounted probe, I flew with two Cambridge 302 varios: one connected to the nose pitot and fuselage statics; the other connected to the TE tail probe. After several flights, it was clear the indications were so similar while cruising and thermalling, there was no reason to prefer one over the other. When the motor was running, the TE connected vario was much less useful than the eTE vario, so it and the TE probe were removed.

Eric

[krasw]

If you like electronic compensation using fuselage static ports, you will love it with proper static pressure probe. I use the Löfgren probe with my TE adapter. It really shows how noisy the static pressure readings are from fuselage ports.

[Eric Greenwell]

My TE and eTE comparisons were in an ASH26E, and the fuselage and probe statics responses were similar - no "noise" with either. What glider were you using to do your comparisons?

Eric

[John Johnson]

I want to correct some misinformation I posted earlier.  Despite the diagram in the SxHawk showing nose pitot and fuselage statics connection in eTE mode, I came across this contrary statement while reading further this morning:

I apologize for spreading misinformation.  However, after two 7hr flights using the nose/fuselage hookups, I haven't noticed any issues or difference in my 2 varios behavior from the previous eTE setup using the TE probe connections.  

BTW, I'm not sold on Hawk.  So far, it's been more of an interesting gadget without substantial correlation in helping me find / work lift more readily.  Watching the red TE needle catch up to the blue Hawk needle (or vice versa) or encountering lift going towards (or away from) the yellow energy arrow leave me thinking I'm no better off than before - just more distracted.    I do wonder if in certain 'gentler' conditions I'd find it more useful.  When in low to mid altitudes and you need to find lift, Arizona's desert thermals are often a collection of multi-core garbage with 1/2 turn strong lift / 1/2 turn sink.  Maybe in more classical single core thermal scenarios, Hawk is a more useful indicator.  Anyway, my investment is limited to the SxHawk and I'm glad I didn't spring for upgrading out of my old gen 3 LX9070.

JJ

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[Dave Nadler]

On Sunday, May 10, 2026 at 2:45:50 PM UTC-4 John Johnson wrote:

I want to correct some misinformation I posted earlier.  Despite the diagram in the SxHawk showing nose pitot and fuselage statics connection in eTE mode, I came across this contrary statement while reading further this morning:

I apologize for spreading misinformation.  However, after two 7hr flights using the nose/fuselage hookups, I haven't noticed any issues or difference in my 2 varios behavior from the previous eTE setup using the TE probe connections.  

 

There are many different kinds of static ports and different gliders and manufacturers, and plenty of gliders have 3 different static sources. And some are more accurate than others ;-) Without specifying the glider type and static location, and if using an external probe the exact probe type, these discussions are not helpful and certainly not generally applicable. If I do a talk on varios at the upcoming SSA convention I'll include some static port silly business ;-)

[krasw]

On Monday, May 11, 2026 at 4:52:43 PM UTC+3 Dave Nadler wrote:

There are many different kinds of static ports and different gliders and manufacturers, and plenty of gliders have 3 different static sources. And some are more accurate than others ;-) Without specifying the glider type and static location, and if using an external probe the exact probe type, these discussions are not helpful and certainly not generally applicable.

We do not have inch long TE-probes stuck on fuselage because fuselage skin boundary layer has turbulent airflow sensitive to pitch and yaw. This is why we generally try to install any pressure sensing probes as far from structure of the glider as practical. Exact same thing applies for pitot, static and TE. With noisy static and pitot you can get away with it using instruments that averages noise out. Altimeter and ASI (to some degree) are fine, sensitive variometer less so. This is the reason TE compensation is still used widely, imho. You connect your high-end variometer to fuselage static and are not happy, conclusion invariably is that electric compensation does not work.

[Jeff Stetson]

In response to JJ's comment on HAWK ... I find it very useful in my relative brick of a motorglider (Ximango) in our relatively weak Michigan conditions, but requires some interpretation. Where it works best is in filtering out foolers, that is, when the vario shows an up, but HAWK shows nothing, it's in fact nothing. However, it can be quite optimistic taken by itself. I look for a WAY UP from HAWK followed by a tickle up from the vario before turning. It's a little faster than vario. But following a weaker response from HAWK alone tends to result in circles with no net gain. Also, particularly in really choppy conditions, HAWK can lose its mind. A particular symptom is the live wind indication gets way off, like in my last flight, showing a 30 kt crosswind when the reality was more like 10. Go straight for a bit, and reset it in flight. After thinking for a few seconds, it recovers nicely. I've not yet found live wind very useful in finding thermal lift, in part because the yellow arrow is more like a triangle than an arrow. OTOH, I find it extremely useful on descending to land in anticipating wind gradients that might be encountered.