fun last night

[tonycondon]

Yesterday was one of those amazing days. you know the ones? where you spend about 13 hours at the airport?

I flew with my boss to brush him up for his MEI checkride today, then I pulled the glider into the maintenance hangar to work on it for the evening.

Installed a total energy probe. It is a tube that sticks out the top of the glider and has a small hole drilled in the back. The faster I go the more suction is placed on the tube. It is plumbed into the static port on my variometer (think VSI). It should cancel out "stick thermals" where I convert airspeed into altitude by zooming up. Previously my vario would show a climb if I was doing that. With the new system, the vario should just show me the movement of the airmass, which is really what I want to know.

I also installed a PTT switch on the stick. This has been the source of some confusion for me for a while. The headset adapter I have for my handheld has a seperate adapter for a PTT to plug into. It is a weird sized plug. I found out that just putting a standard PTT switch into the mic plug worked so I decided to go with that. I got a doorbell at Lowes and wired it in to the circuit and ran the wire through the stick, presto!

Also built a cradle to hold my handheld, but havent gotten it installed yet.

Finished all this fun stuff up around 1 AM. then back to the airport this morning to put glider back in trailer and squeeze the trailer into Matts T Hangar. Im pretty sure we hold the record for most aircraft in one T hangar. two gliders in trailers, on glider dissasembled, and the flybaby, assembled. Its pretty tight quarters.

 

[ScottM]

I also installed a PTT switch on the stick. This has been the source of some confusion for me for a while.

well that is cool now you won't have to take your hands off of the throttles to key the mic

About the variometer thing though. I don't quit understand what it is your doing or what this describes. If 'you' are pulling up on the stick to convert airspeed to altitude how is that not a climb?

 

[jesse]

About the variometer thing though. I don't quit understand what it is your doing or what this describes. If 'you' are pulling up on the stick to convert airspeed to altitude how is that not a climb?

As a glider pilot you really need to know the vertical speed of the airmass not the vertical speed of the glider. The problem with the standard VSI is the glider pilot will pull up on the stick and this will be reflected on the VSI. It makes it hard to really know how fast the thermal is pushing up unless you are in straight level flight which is not really an easy thing to do.

The total energy probe produces suction as the airspeed is changed. It's also hooked up to the variometer which should deliver an indication taking into account the rate of your speed change combined with your altitude change.

 

[tonycondon]

Jesse, you ready for CFI-Glider?

 

[SCCutler]

Tony, sounds like a great day/night of airplane geeking, and I have to say: that glider looks really sweet... I could hear her whispering to me...

===

And Tony, I believe Jesse is ready for just about anything.

 

[cwyckham]

that glider looks really sweet... I could hear her whispering to me...

Oooh! Was she talking dirty?

 

[SCCutler]

Oooh! Was she talking dirty?

She's an airplane, ain't she?

 

[tonycondon]

Like I said spike, a nice 1-26 would do you (and tommy!) well. about the same performance as mine. a lot cheaper than a commanche 400.

 

[flyingcheesehead]

The total energy probe produces suction as the airspeed is changed. It's also hooked up to the variometer which should deliver an indication taking into account the rate of your speed change combined with your altitude change.

Lemme get this straight.

So, if you pull up on the stick, you climb but you also slow down. With the TEP, the slowdown would result in less suction (higher pressure) but with the climb, the ambient pressure lowers, and the two even each other out?

Are the differences between these pressures always varying equally?

 

[tonycondon]

when everything is set up right, yes. We'll see how good mine compensates, but at least it will do something.

So in the example you say, if I were flying along in air that is not rising or sinking, the variometer would read zero the entire time.
This is all theoretical, the fact is even a very good total energy system cannot compensate for a strong pull up, but it can cancel out the weak stuff so when your hand slips and you feel a little bump in the seat and you look at the vario, it still show that you are not in a thermal.