PowerFLARM updates and installation notes

On Tuesday, June 5, 2012 8:50:22 AM UTC-5, Steve Leonard wrote:
On Jun 4, 10:42*pm, Frank Whiteley wrote:

I'd recommend 3M Dual-Lock, much stronger than Velcro or other hook and loop fasteners for your delicate electronic gear, especially if movable between your mistresses. *Typically 5X stronger.http://tinyurl.com/7u7t6q5

Frank Whiteley


Just to be contrary, Frank, I do NOT like the Dual-Lock. It takes
considerably more pressure to engage than regualr velcro. And more
pressure over a larger area (the strip they supply with the portable
takes considerable force to engage if you put it on two, flat, firm
surfaces) means you have to push down pretty hard on the top of the
case of that device to get the stuff to engage. More than once, I had
it come loose and slide down the slope of the glareshield of the
Nimbus. Installation for the one flight so far in the BS1 was with
black electrical tape over the top of it. It never even thought of
trying to move. This is not a good, permanent solution for my
portable, but mine won't get held down with Dual-Lock. I am looking
in to brackets and using the small, threaded mounting holes for each
installation.

Steve Leonard

When I flew with a portable last year at Region 10 I built a little shelf that extended from the left canopy rail in front of the instrument panel. Picture of the shelf he https://lh3.googleusercontent.com/-V...YYYCockpit.JPG

I have no idea what the range was with this but it was good enough that I saw Frank a few times during the contest and got a collision alert once or twice in the start cylinder when he was nearby. We were the only ones with PowerFlarm...

I don't have a glareshield in the Cherokee so that is as good as it gets for placement, unless I want to mount it outside in front of the canopy and build a fairing around that...

Eventually I suppose there will be a brick in my future, but for now I'll probably keep borrowing/renting a portable for contests.

On Jun 5, 7:29*am, Bill D wrote:
the fin is a sealed box.

I hope not! Limited access maybe, but certainly not sealed.

Andy

On Tuesday, June 5, 2012 10:10:25 AM UTC-7, Andy wrote:
On Jun 5, 7:29*am, Bill D wrote:
the fin is a sealed box.

I hope not! Limited access maybe, but certainly not sealed.

Andy

While the antennas installation issues get sorted out (hopefully) what about the display installation? I am hoping for a simple attachment of the remote display somewhere near the top of the instrument panel without obscuring instruments nor forward view and without interfering with canopy ejection in my ASW27. Alternatively I can invest an extra $75(?) for the in panel display to replace my winter mechanical vario which I never needed in 15 years (and maybe sell it for couple of hundred bucks to cover some of the powerflarm cost) but I have a feeling I may regret it one day. Thoughts?

Ramy

On 6/5/2012 7:29 AM, Bill D wrote:
External antennas are way too
draggy.

It depends very much on the antenna; e.g., the dirty looking transponder
3" stubby rod with a ball on top has insignificant drag on an 18 meter
glider. Probably for a 15 meter glider, too, but I don't recall the
numbers. Blade style transponder antennas are even sleeker.

Com antennas are much larger than the 900-1090 MHz antennas we are
talking about, and can have significant drag, but it's a mistake to rule
out external antennas for the higher frequencies.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

On Jun 5, 9:47 pm, Eric Greenwell wrote:
It depends very much on the antenna; e.g., the dirty looking transponder
3" stubby rod with a ball on top has insignificant drag on an 18 meter
glider. Probably for a 15 meter glider, too, but I don't recall the
numbers. Blade style transponder antennas are even sleeker.

Com antennas are much larger than the 900-1090 MHz antennas we are
talking about, and can have significant drag, but it's a mistake to rule
out external antennas for the higher frequencies.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

Guess it sort of depends on what you consider to be "insignificant",
Eric. 15 or 18 meter ship, dry, at best L/D only has maybe 20 lbs
TOTAL drag. 1 lbs may not seem like much, but it is 5%. In contest
terms, 50 points. Per day. If there was a really good, really
accurate TE system without using a probe (Schuemann B Box comes to
mind), the really hot pilots would all think just a bit more about
finding a way to put one of those in their plane and do away with the
now seemingly very draggy TE probe. The vertical portion of it is
about the same length as the transponder antenna, but bigger in
diameter.

It may seem like fly specs in the pepper, but over time, it adds up.
So, why do we have TE probes? Because they work, and nobody else has
come up with something that works as well. At least, not as far as I
know.

Steve Leonard

Hopefully not hijacking this thread, but electronic compensation such as the one my 302 is using seem to be as good as the TE compensation my winter is using, so looks like I could get rid of the TE probe (except that in many cases it is also the pitot).

Ramy

On 6/5/2012 9:20 PM, Steve Leonard wrote:
On Jun 5, 9:47 pm, Eric wrote:
It depends very much on the antenna; e.g., the dirty looking transponder
3" stubby rod with a ball on top has insignificant drag on an 18 meter
glider. Probably for a 15 meter glider, too, but I don't recall the
numbers. Blade style transponder antennas are even sleeker.

Com antennas are much larger than the 900-1090 MHz antennas we are
talking about, and can have significant drag, but it's a mistake to rule
out external antennas for the higher frequencies.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

Guess it sort of depends on what you consider to be "insignificant",
Eric. 15 or 18 meter ship, dry, at best L/D only has maybe 20 lbs
TOTAL drag. 1 lbs may not seem like much, but it is 5%. In contest
terms, 50 points. Per day. If there was a really good, really
accurate TE system without using a probe (Schuemann B Box comes to
mind), the really hot pilots would all think just a bit more about
finding a way to put one of those in their plane and do away with the
now seemingly very draggy TE probe. The vertical portion of it is
about the same length as the transponder antenna, but bigger in
diameter.

It may seem like fly specs in the pepper, but over time, it adds up.
So, why do we have TE probes? Because they work, and nobody else has
come up with something that works as well. At least, not as far as I
know.

I recall it being ounces, not pounds, but I can't find my notes. Here's
a number from Rami Antennas for their transponder antenna:

"The AV-22 is a rod style transponder antenna utilizing its BNC
connector for mounting to the airframe. The antenna is designed to
operate at speeds up to 350 mph and altitudes up to 50,000 feet. It has
a drag force of 0.41 lbs @ 250 mph."

At 125 mph (108 knots), the drag would be 0.1 lbs; at best l/d of 54
knots, it would 0.025 lbs, or 0.125% of your 20 lb drag, rather than 5%.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

On 6/5/2012 10:15 PM, Ramy wrote:
Hopefully not hijacking this thread, but electronic compensation
such as the one my 302 is using seem to be as good as the TE
compensation my winter is using, so looks like I could get rid of the
TE probe (except that in many cases it is also the pitot).

Works for me! It's particularly valuable for a motorglider like I have,
because the prop wash drives the TE nutty. My glider uses the nose pitot
for the airspeed indicator, not the one on the TE probe, and I think
that is common.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me

On Jun 5, 12:10*pm, Andy wrote:
On Jun 5, 7:29*am, Bill D wrote:

the fin is a sealed box.

I hope not! *Limited access maybe, but certainly not sealed.

Andy

I recently looked really hard at the ASW27 tail, to try to put the
transponder antenna in there. So far, I've concluded it can't be done
without cutting holes. The closest I came was putting small antennas
like flarm and transponder in the tail battery compartment and fishing
the coax down where the TE tube goes, but the tail is sealed off from
the fuselage boom so I couldn't see how to get the coax through
without cutting holes. Of course if you're willing to cut holes, it's
easier.

If anyone figures out how to retrofit antennas in the tail without
major surgery, pass it on!

John Cochrane

I can't help noticing that the portable has two not too obtrusive rubber ducky antennas. Why is the same solution not provided for the brick?

Mark