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novicef
8th Oct 2007, 13:10
I am looking for rules of thumb that can assist me. Example a conversion to V/S for a gradient required when a speed is known. Rates of descent for a LLZ approach when the Glide Path is other than 3 degrees. There was a thread covering this sort of thing a while ago, but I cannot find it using the search facility.

Thanks.

Tmbstory
8th Oct 2007, 14:12
A rule of thumb is 300 ft a nautical mile from the runway.(eg.900 ft. should be 3nm.)

On the Jeppesen approach plate it will show the rate of descent for various ground speeds in feet per minute.

For different glide slope angles, do an exercise & make your own table.

SFI145
8th Oct 2007, 15:47
Gradient (%) x G/S (Kts) = V/S (ft/min)

E.g ILS (5%) x 140 kts = 700 ft/min

BOAC
8th Oct 2007, 16:05
novicef - look at the bottom of the screen:ugh:

cxa340so
9th Oct 2007, 15:57
google search "rules of thumb for pilots" and there it was......

http://www.flightinfo.com/rulesofthumb.htm

javelin
9th Oct 2007, 20:40
A fully loaded A330 will always go to 370 - trust me, I'm a docker :E

Slasher
10th Oct 2007, 05:36
ROC fpm / GS kts = climb gradiant.
Examples
1000fpm / 150kts = 6.6% (mental 2:3 = 66:100 = 6.6%)
400fpm / 85kts = 4.7% (mental 1:2 = 50:100 = 5% minus a bit)

RAT 5
10th Oct 2007, 21:40
3 degree glide path:

V/S = Gnd Spd divide by 0.2 + 50. e.g. 170/0.2 = 850 + 50 = 900. If the G.Spd is 175 round up or down to 170 or 180.

If slope is slightly steeper add 50 or 100fpm and see what happens. Reverse is true for shallower slope.

Nor sure what would happen on 6 degree slopes into special runways.

For those that say look at the Jeppe plate; I say on a dark night the text is too small to read. On modern EFIS a/c you have actual G.Spd readout, not an estimate from tower wind, so why not use it.