Sunday, July 24, 2016

Thinking about other purchases

After effectively saving a bunch of money by not going with Oratex, I'm looking toward the other expenses.

Helmet
Check!  :-)  Works great for skiing too.


Video camera
GoPro, is a requirement for proper documentation. :-)  Check!

Yaw string
I have some red yard hanging around somewhere...  Check!

Airspeed sensor
Long, long ago I received a Hall wind meter sensor as a gift.  Check.  I still need to make a mounting/clamping bracket for it.

Variometer
Can go two distinctly distinct ways: hang-glider specific, or sailplane specific.

There are hang-glider variometers, like the FlyTec units, which are designed for the same operating regime of Goat.  Airspeed sensors should be set up for the low airspeeds and vario calibrations should be tailored for slow aircraft.  However, few have total energy compensation, which I consider a requirement for a vario (lessons learned from using RC variometers).

There are also equivalently priced sailplane variometers, like the LX Nav units, among others.  These almost all come with full total energy compensation, and I can find total energy probes and mounts that should work (ILEC).    But, these units are not tailored for the low airspeed range of Goat.  Some units offer customizable vario averaging, so the response can be tuned for slow flight.  However, if the pressure sensor selected is set up for handling much higher airspeeds, the low speed range will be exponentially worse.  If anyone has experience trying to use a "real" sailplane vario on a hang glider, please let me know how that went!



Radio
Seems like the hang glider guys like the ICOM radios.  The A14 looks good enough.  What I can't find online is if I need some kind of FCC license to use it for aviation.  Maybe you used to?  http://www.buytwowayradios.com/blog/2012/08/the_basics_of_air_band_radios.aspx  Doesn't look like anyone checks on a license when you go to purchase the radio, so maybe not?  I already have an air-scanner radio for a third party to listen.

Parachute
Sandlin recommends a hang glider style parachute in a throw-bag for emergencies.  All my online research says these are only good for altitudes above a few hundred feet, so this purchase will hold off until getting past the initial ground-effect flights.

Tow Setup
There is a lot of setup to do here, more than I realize now.  The glider side is pretty straight-forward, with the quick release and weak link.  The car towing also needs a release and should also have a tension meter of some kind for better safety.  The rope itself seems to generally be polypropylene from 1000 feet to much longer, if it fits the takeoff area.  Found rope for what seems to be less expensive than I expected: http://www.cumulus-soaring.com/rope.htm#Towrope

Trailer
Uhg, now we're getting into the less fun details.  I do already have a 4x8 trailer kit which is currently disassembled in the basement for storage.  A friend once adapted the same trailer to carry an 18ft homebuilt sailboat by buying a really long steel square tube.  As it seems others do, I'll probably start by making a flatbed trailer and then figure out how to cover it.  I don't have a great place to store the trailer except filling the garage or parking it on the street.  We'll see.

Flying lessons ... sort of
I'm building Goat as a trainer, so it seems ironic to get training to use my trainer.  That being said, just Friday I went out flying in a Cessna 172 with a friend and he let me practice being at the controls.  He configured the plane in slow-flight (~70kts) thinking that would better emulate the control feel of Goat.  There was certainly a difference in the need for and authority of the rudder that I felt.  I also did several turns around a point and turns to various headings.  If the opportunity presents itself again, I'd like to do some stalls to understand the buffeting feeling and the change in control authority leading to the stall.  General Aviation teaches spin-avoidance now instead of spin-recovery ... wonder if they also just teach stall-recovery?  Anyway, Aaron's comment was that I flew fine and should have no problems learning on Goat.

Uhg, that's a lot of things.

2 comments:

Anonymous said...

Dan, WRT handheld radios, you don't need an FCC license to use it in the air, but strangely enough, if you use it on the ground, you do. Here's some vague language by the FCC:

http://wireless.fcc.gov/services/index.htm?job=operations&id=aircraft_stations

You can see that it says, "You may only use your hand-held aircraft VHF radio in your aircraft under the terms of your aircraft license." Essentially, the FCC is passing the buck.

WRT using the Goat as a trainer, I'm not sure that's a good idea. I would recommend finding a soaring club and at least getting to the solo stage before attempting to fly the Goat. It takes a little time to develop the stick and rudder skills needed to fly, but more importantly, it takes more time to develop the aeronautical decision making skills needed to be safe in the air. As an example, when low-time students see that they're going to be short of the runway on final, their instinct is to pull back on the stick to try to extend their glide. This can be a fatal reaction.

Looking forward to seeing your bird completed! :-)

Unknown said...

If you can find someone with an ultralight, or an ultralight instructor (are there any of those around anymore?)...The closest you're gonna get to the Goat is going up a few thousand feet and practice with the power off. Goat will have a better glide ratio, but most of the sounds and feel, not to mention airmanship, will be the same...

Good Luck. I'm building my 4th custom design myself. A foot-launched, electric rigid wing replacement for my paramotor...

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