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Touring Motor Gliders Association (TMGA)

Preparing for Winter wave flying


Eric Greenwell

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I think the Phoenix is a good wave glider, as Russ Owens has shown us over the years. I'd like to make better use of our occasional winter wave by improving a few things on my Phoenix. Cold air and pilot relief are my first priorities.

The steady stream of cold air coming into the cockpit from the flap and spoiler slots between the seats is quite annoying. A small towel can be placed over it, but that's annoying also. I think the air is coming from the wing root, and likely gets to the wing root from openings in the wing, such as the joint between wing and wing tip, and perhaps from the wing/flap gap on the underside of the wing. Sealing the fuselage root might stop all/most of the air from entering the cockpit, but it's a lot of trouble to pull the wings out and seal the pushrod openings (or even trying to do it from the inside baggage area), so instead I blocked what I hope is the major entry point:

59c2b5b43441f_Phoenixwingsealing1.thumb.JPG.9fd6c4e3bfac54d3b6beb2f55d9ba5ef.JPG

I temporarily taped over the rear opening in the outer end of each of the inner panels, as an inspection of the forward hole and the center (tip spar) hole found they appeared to be fully sealed. During the next flight in wave at 28 degF OAT, the cold air coming in seemed very reduced, so on to the next problem.

Pilot relief: I've always been warm enough to wear baggy, comfortable  pants, making it easy enough to use a plastic bottle as a urinal, but even with the engine idling in the winter, I think I'll need to wear some bulky winter clothing. I considered a "tube and bulb" method, with the tube sliding into a short tube mounted in the floor and exiting the bottom of the Phoenix, but that entails some work installing it (there might pushrods or other items in the way, too). I'm now considering something like this "urinary incontinence kit" 

https://www.amazon.com/Complete-Incontinence-Catheters-Self-Seal-Draining/dp/B0121B56TU

The bag could be placed ahead of the seat, under my knees. Since everything is inside the cockpit, it ought to stay warm enough to function in cold conditions.

What do the rest you use? Any suggestions?

 

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Sounds like you are on the right track Eric.  Sealing the aft outboard hole in the wing is a good idea.  Be sure not to seal any hole which does not have somewhere else for the air to go as altitude changes so as not to damage the wing from the differential air pressure.

Unfortunately, sealing around the flap controls and the seat belt holes with towels is about the only answer there.  You can do things to reduce the amount of air coming into those places, but you can't stop it.  Air can get into the control console via the wings, the tail, and the drain holes in the bottom of the fuselage.

I have run into problems with cold air leakage into the cockpit in every glider I have flown.  After a year of work, I have finally solved almost all of the problem in my JS1.  But no matter how well sealed the cockpit is, it remains cold up there!  To compound this problem, it is usually warm or even hot on take-off/tow, so wearing a mountain climbing down suit is problematic at the lower altitudes.  Nothing like being cold and wet up high.

The hardest things to keep warm are my feet.  Even when the plane is in the sun and my body is comfortable, my feet tend to be the coldest part of me, never getting the advantage of the sun shining on them.

My final solution is to  wear wool socks and big puffy down booties on my feet, and carry a down jacket and a down blanket in the plane.  The jacket and blanket can be stuffed into any small place in the plane for use later up high.  I slip the jacket on backwards on my arms and chest while strapped in wearing a parachute when it starts getting cold.  I stuff the blanket down over my legs, over the controls, and up on my body as required.  This keeps my hands warm too.

A friend took me up for a wave flight in Minden in his Arcus.  We were close to 18K for 6 hours.  There was a lot of excess air in the cockpit.  I had on my booties (which my friend had made fun of when we got in the plane) and put on my jacket backwards at altitude.  I used the blanket to stuff into the gear handle slot which is where most of the air was coming from, and stuffed the rest of the blanket wherever it needed to be, which changed during the flight.  My friend was freezing, and I was toasty.

I have installed one relief system in a Phoenix.  It is easy to do.  Remove the seat pan and drill a hole next to the control stick.  Run a tube down the stick and glue it into the hole.  Zip tie the tube to the control stick.  Run your external catheter and tube into the relief tube.

I don't like the corrosive urine getting on the plane, especially the metal parts of the tailwheel and bracket.  So I pee into a gallon size baggie, zip it closed, twist the excess bag a couple of times, and pitch it out the window.  More trouble than a pee tube, but that is what works for me.  In the Phoenix with a passenger, the blanket works well as a privacy curtain.  I can't go with someone watching.  Now you know more than you wanted to! 

DSCN4028.MOV

20170513_163201.jpg

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I'm hoping the wing end seal will stop most of the air that comes from the spoiler/flap slot and the seat belt holes, but I won't know until I fly for sure until I fly in colder weather. I assume the air coming in the drain holes is too small to be a problem, and I'm sure (but haven't done any testing) the tail openings are in a suction area, so air isn't getting in there; however, the suction might pull some air into the cockpit (maybe it will suck out the air from the drain holes?).

My feet have also been the coldest part of me. In my ASH 26 E, I wear three pairs of ski socks and large shoes to compensate for the sock thickness. That's been satisfactory down to 0 degF OAT.

Our wave flying is almost always in the winter, so starting out wearing a cheap snowmobile suit should work as well in the Phoenix as it does in the 26 E. I have used the backwards jacket before in other gliders and it worked well, so I'll keep that in mind.

The blanket is a new idea to me. Don't think I could fit it into the 26 E, but shouldn't be a problem in the Phoenix, even with a passenger. I'll try to find a suitable one.

Question: have you had frost problems on the Phoenix canopy, and if so, how did you cope with it?

 

 

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We have seen only the rear third of the canopy frost over.  Minimum OAT we have seen is about 15 F.  Russ has added some clear panels to his Phoenix for wave flying, a photo is enclosed.  You can see in the photo that the rest of the canopy is clear, so don't know if he has experienced extensive frosting or if this was insurance just in case.

849kmPho.jpg

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For pilot relief, I find it easiest to wear a viynl condom cath with a 6-10 inch length of surgical tubing attached. I usually fly wearing pants with zip on/off pant legs. By unzipping one of the legs an inch or so, the tube can be left in the exited position for easy access. Carry an empty plastic beverage bottle of suitable size  with a tight fitting cap. When you gotta go just slip the tube into the bottle and relax. Clearly label the bottle.  Practice this at home before trying it in flight.  I had the local tailor at the dry cleaner put a button hole, sans button, at a suitable spot for the drain tube. It works well too. Carry an old credit card, or the like, to scrape off interior frost in a pinch. It won't scratch the canopy. 

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Dave,  thanks for the info. I was thinking along those lines, so I'm glad to have the validation. Because I have urgency and frequency issues (remnants of my prostate cancer treatment), I decided to permanently connect the line to the bottle (a one liter oil container in my case), which I place under my left knee on the floor. A small duffel bag of stuff I might need in flight sits on the floor just ahead of it, keeping it in place. I tried it yesterday, and it worked well. After I test the simplifications I made, I'll post some pictures.

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On my last flight, I discovered a way to keep the air from entering the cockpit through the flap/spoiler handle slots, and the seat belt holes: put the flaps in -4! I tried it at 60 knots and 90 knots - same result. I think the flap in 0 degree setting increases the air pressure at the wing/flaperon junction, forcing air into the wing via the flaperon control rod holes. Note that this was with my wing sealing of the main wing and wing tip junction (see description at the start of this thread). Some thoughts...

  • Use flap -4 setting when flying in cold air, and save yourself the trouble of sealing anything
  • Now knowing that a lot, maybe all, the cold cockpit air comes from the wing, seal the flaperon push rod or the wing roots (fuselage wing roots or the actual wing roots), in addition to the wing/wing tip junction. This sealing harder to do, but likely reduces the cockpit cold air intrusion the most.

I have another idea that I will try on the next flight: remove a few inches of the wing root tape from the top/aft part of both wing roots. The hope is the lower pressure top of the wing will suck the cold air from the wing root area, and prevent it from entering the cockpit. I suspect that air escaping the rear wing root area might degrade the glide, but I have no idea how much.

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  • 2 weeks later...
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The attached picture shows how I revised the sealing of the inner wing at the tip parting line, making the strobe/navigation light connector easily accessible. The wing tip lighting cord is quite long, so I wrap it once around the spar while the wing tip is hanging after placing the spar in the wing spar opening. On the last flight, I was comfortable down to 20 deg F OAT, dressed in blue jeans, sweatshirt, and a light vest. Late in the day, under cloud shadows, I did start to feel a little cool. The idling engine supplies a totally inadequate amount of heat to the cabin, so I'll be dressing warmer when the temps drop below 20 deg F.

Wing seal with strobe wire.JPG

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