the climbing rate gauge should have HUGE variations caused by atmosphere

As a pilot I can say I haven't really noticed any wobbly oscillations of a VSI ... ever. Atmospheric pressure variances do not occur with the great horizontal or vertical rapidity that would be required to make it do so. Remember, it's just a bourdon tube with a calibrated leak.

[gabuzomeu]

By the way, the same scientific maffia introduced gyro scop driven artificial horizon, while a glass of water is a good reference for horizontal in daily experience...

[janpitor]

Originally Posted by gabuzomeu

By the way, the same scientific maffia introduced gyro scop driven artificial horizon, while a glass of water is a good reference for horizontal in daily experience...

Try the glass of water in a turn and you will see why this principle is not used

[mazex]

Originally Posted by raaaid

if i were to build a climbing rate gauge i would do it base on vertical angle of heading and air speed

Well -that's how a computer game designer would think maybe

For a starter - even if it was a good idea, how would you calculate a "vertical angle of heading"? How about AOA (angle of attack) for example? And if you could get the real "vertical angle of heading" - it would have to no use as the aircraft "longitudinal angle" would only be related the air that surrounds the aircraft... And what if that air is moving up or down (which is the thing that happens up there IRL accept a dead calm winter day)? What good would then the fact that the aircraft "moves at an angle of 2 degrees at 200 Mph" do you if the air surrounding the aircraft moves down at 8 m/s? What is the real rate of climb (or descent) then?

Do some reading on variometers as there are a lot of parameters to consider accept the 1940 versions that actually only worked on atmospheric pressure rise/drop that gave many problems...

Start here for example:

http://en.wikipedia.org/wiki/Variometer

EDIT: And no - if you climb through non-turbulent air they don't oscillate (accept for engine vibrations )... In turbulent air the problem is mostly that they oscillate to little compared to reality

[raaaid]

Originally Posted by janpitor

Try the glass of water in a turn and you will see why this principle is not used

neither the gyro work on this conditions due to precesion

well i admit i was wrong if it works dont cahnge it though find it surprising, i guess they dont oscilate to the price of precision

[5./JG27.Farber]

Just totally ignore me...

I guess you guys were not there.........................................


mazex - what about that radar / command fighter thing your too busy to work on? any news?

[IvanK]

Why Water couldn't be used a Bob Hoover classic:

[SQB]

Originally Posted by IvanK

Why Water couldn't be used a Bob Hoover classic:

(video here)

Dangit, you beat me to it! This video demonstrates that non-aerodynamic (simple relative mass * gravity systems) do not give correct readings of attitude and roll. Precession, while annoying for sure, is *extremely* minor when compared to this. Gyroscopes can be re-centred using balance magnets, negating the effects of precession anyway.

To answer Raaaids initial question, I ask you "how would you, using as simple a device as possible, figure out what components of any vertical incoming air is wind (which can be much faster than 20km/h (~5ms^-1) at higher altitudes) and what is the climbing rate." Remember that in normal flight (i.e. when you are actually looking at the climbing rate gague) you climb or descend at ~2-5 thousand feet per minute which is ~25.5ms^-1, not too different from your conservative estimation of wind.


Also, using a pressure based system, pressure changes by ~33hPa per thousand feet, whereas the most brutal low fronts will change pressure by 10-15hPa over the course of several hours. Small variations in pressure at ground level have surprisingly large effects, so it's easy to forget that by climbing in an a/c you travel through a huge range of pressures.

[raaaid]

well you make a mechanism that makes this calculation:

airspeed*cos pitch angle=climbing rate

if your going at 500kph and theres a vertical wind of 20 kph your making an error in just that your real speed will be the hipothenusa of the rect triangle: 20-500-x

so then your horizontal airspeed would be maybe 490 with which the error would be minimum

also planes have artificial horizonts to know your picth angle

edit:

doesnt actually a gyro artificial horizont also go crazy in hard manoubers?

[IvanK]

"doesnt actually a gyro artificial horizont also go crazy in hard manoubers?"

Depends on the gyro system. If its a full 360 degree in pitch and roll it works just fine no matter what you do. Few if any in WWII would have had this capability though.