In seaplane flying, what is the most difficult operation? Glassy water ops! Introducing FlareAssist™: An Ultrasonic Altimeter enabling pilots of Experimental Amphibious and Float equipped aircraft to properly judge the height of the aircraft over glassy water. FlareAssist™ consists of an external mounted transducer which uses rapid pulses of ultra-high frequency sound waves, then annunciates the computer-filtered results through the pilot’s headset. Portable and light weight at 3 lbs.
RKittine wrote:The reason I posted that was not in support of it, but for two reasons, one I was surprised that it took so long to get someone to try to make money on something like that and more importantly, to get some additional dialog going, which it apparently did.
skimmerone wrote:I forgot to mention that the ICON LSA folks were at the Lakeathon also and talked about the ICON and it's improvements. Did you know that the instrument panel does NOT have a VSI installed? Any comments?
Tim McCormack wrote:Bob, that last statement is true if you're sure the barometric pressure hasn't changed since you last set it. It doesn't take much change to make a 2 foot difference.
Gee, Grampa Curious, can you tell us a story?
"Well, back when the earth was flat and twin otters were made of wood, there were no GPS signals, because there were no sattelites in Space...." said Kindly Old Just Curious.
Well, how did you navigate?
"Well, while kids like Cat Driver were ripping around down south of 80 in their fancy-schmancy Super-3's, with their ADFs, with beat frequency occillators, we were using astro compasses, and maps and howgoezit charts and a watch", said KOJC.
What's a map Grampa, and how many meg of ram did astro compasses have?
"Well, maps of course are history now, but we used them to get an assumed position and compare it with the nav calculations on the back of the howgoezit chart to have an idea about the longitude and latitude we were at", said KOJC. "We used that junk to arrive at the settings we needed to enter stuff on our astro compass, which wasn't even electrically powered!" said KOJC.
But Grampa, whaddya use the astro compass for?
"Well we had to fly in Grid... you see, this far north, the true north pole is really far away from the mag pole:"
http://maps.google.com/?ie=UTF8&z=4&ll= ... 5&t=h&om=0
"So we could fly in true some time, but, well, let's say you were gonna fly from the Resolute Bay to the North pole... What would your track be?" queried KOJC.
Well, north of course.
"Well what about when you were leaving the pole and flying back to Resolute, what would be your course then?"queried KOJC.
South of course!
"Okay how about from the Pole to New York or Los Angeles or ..."queried KOJC.
That's easy! It's...oh.
"So Francis Chichester, working with Keith Greenaway, developed Grid Navigation. At the North and South extreme latitudes, the lines of logitude converge, so in using true, an adjustment to tracks called convergence had to be applied. Some pilots. not as good at math as others. got really lost with convergence, and couldn't rely on the compass 'cause it was pointing at the wrong Pole."said KOJC.
"...So they created Grid. With Grid, it is assumed that instead of at the top of the world, north is really the whole Prime Meridian. That is, ninety degrees from where it really is on earth. This kind of squashed the earth so that the lines of longitude and latitude were stretched to fit blocks set at 90 degrees to each other."said KOJC.
"To figure out a Grid track, all a pilot had to do was to measure the true track on a map, and subtract the West Longitude from that. That yielded the Grid track. As you progressed along the track, and the longitude changed, you would adjust the aircraft gyro up or down to account for that change. If you were going straight to the North pole, the track from Resolute to Pole would have been True Track (360)minus the longitude of Resolute Bay 114 "said KOJC.
http://maps.google.com/?ie=UTF8&z=4&ll= ... 5&t=h&om=0
http://images.google.com/imgres?imgurl= ... en%26lr%3D
"The return would have been true track (180)- 114= 066"
"To set the aircraft gyro, we used an astro compass"
"We would set the assumed longitude, and the longitude and an old book called an Air Almanac to get the local hour angle of the sun or star. Or we would use a formula [(15 X GMT)- W longitude] to get the Sun's true bearing. Then we would plug in lon and lat, and STB, and turn the astro around till it was facing the sun, then take the compass out of the mount, and read the aircraft's true course. Then we would subtract west lngitude form that, and set the resulting value on the aircraft gyro. Every 30 minutes we would have to do that."said KOJC, rue-fully.
"Of course, some people would forget to wind their watches, but that's another story."said KOJC, with a sly grin.
Wow, that must have been a long time ago, Grampa!
"Well yes, it was, but with fantastically accurate GPSes, nobody ever needs to know that stuff, until the power quits, or the US Govt goes ot selective availability"
Tell us about winding up watches Grampa...
"Well, Grampa's gotta go for his nap now, but maybe you could get Uncle Cat Driver to tell you about Astro Navigation, and Johnson's Point. G'night kids"mumbled KOJC, as he got off his rocker.
AND Grampa Curious toddled off, gin bottle under his arm, for a nap in the noon-day sun.
Arctic Canada From the Air.
Contributor(s): Dunbar, Moira With Keith R. Greenaway.
Publisher: Ottawa: Canada Defence Research Board (hardcover) 1956.
Notation: 1st printing. 541pp. Very good. Illustrations, folding maps, bibliography, index. (Arctic/Polar, Aerial Photography, Aviation)
Arctic Air Navigation
Author: Greenaway, Ketih R.
Publisher: Ottawa: Arctic Research Defence Research Board, 1951,
Hard bound, first edition, frontis. map, illustrated throughout. Two fold-outs in rear pocket contain 1) Sunrise-Sunset-Twilight Nomogram and 2) Graph showing declination of sun and correction to apparent time (as referred to on Pp 114-119). 138pp includes index.
And Kindly old Just Curious's gin-soaked rapidly fading memory.
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