Spit IIA Speed in game test

[bongodriver]

So Crumpp, let's see your license, it's easier for you FAA guys, it's just a credit card sized thing, I have to take the pages out of my book and scan separately.

[bongodriver]

Here's a quck scan of the CAA published official VFR chart for Southern UK in 1:50000, this one is for the Olympics and shows the Temp airspace, this chart is not valid until the 14th of July, please note the airfield elevation at Biggin hill is shown as 599 feet, if the elevation changes daily then why is it published in the charts which are produced annualy? this chart is a companion to the regular VFR chart which also shows biggin at 599 feet and will continue to do so for the whole 'year' of it's validity, and next years edition will in all probability say the same.

[CaptainDoggles]

Boy. I thought I'd seen some moronic arguments in my time, but this really takes the cake.

[camber]

Originally Posted by CaptainDoggles

Boy. I thought I'd seen some moronic arguments in my time, but this really takes the cake.

I have to disagree Doggles...wildly O/T but a very interesting argument. A lot to be learned from these arguments IMO. And it is not about whether Biggin Hill is at +/- 1ft.

Interesting in that you can see the practical problems associated with having different aircraft flying around relying on pressure sensors (aneroid barometers) that are measuring pressure but displaying altitude or height values.

If everyone sets their altimeters for QNH (current SL pressure), the departure altitude displayed will be close to the surveyed airfield chart height but QNH will need to be continuously updated via radio with the passage of time and distance. Airfields and terrain will be collided with at their correct height, and aircraft in the same airspace will display similar altimeter values, but only if all aircraft are being continuously updated with appropriate QNH via radio.

If everyone sets their altimeters for QFE, height data is only appropriate for the departure airfield for a short period of time.

If everyone sets for QNE (standard pressure), all aircraft altimeters are reading the same flight level (within instrument error), a plus for managing traffic interactions. No updating is needed. However terrain and airfields may appear at different altitudes than physically surveyed data.

Crumpp, it sure seemed, even re-reading, that you were stating that physical airfield elevation was changing in some manner according to pressure and temperature (either physically or to some procedural convention). If you didn't mean that, what did you mean exactly?

[CaptainDoggles]

Sorry camber, I don't think you can convince me that a bunch of guys waving their e peens around and demanding people post their pilot licences is constructive or meritous.

Terrain doesn't move, barring geological activity. The runway at whatever airport doesn't physically move any significant amount.

Barometer readings do change, and change frequently with meteorological conditions.

A child can understand this.

[Igo kyu]

Originally Posted by CaptainDoggles

Sorry camber, I don't think you can convince me that a bunch of guys waving their e peens around and demanding people post their pilot licences is constructive or meritous.

I agree, though I feel the word is "meritorious".

Terrain doesn't move, barring geological activity. The runway at whatever airport doesn't physically move any significant amount.

Relative to sea level, yes and no. There are tides, and they probably move the land as well as the sea.

Beside which the Earth is in orbit around the sun, and moves at many miles per second in that respect.

Barometer readings do change, and change frequently with meteorological conditions.

Yes.

A child can understand this.

All of it? I'm not sure anyone fully understands the tides yet.

[CaptainDoggles]

Originally Posted by Igo kyu

I agree, though I feel the word is "meritorious".

yep i was typing too fast, i guess.

Relative to sea level, yes and no. There are tides, and they probably move the land as well as the sea.

if sea level movrs, then sea level moves. The continents do not bob up and down on the sea. Lunar gravity does not move the earth's crust by a significant amount.

Beside which the Earth is in orbit around the sun, and moves at many miles per second in that respect.

Totally irrelevant.