3 degree slope

greenwich · Post by **greenwich** » Sun Mar 20, 2005 10:30 am

...what's that 3 degree slope calculation "rule of thumb" again???

Thx

G

Arthur Q · Post by **Arthur Q** » Sun Mar 20, 2005 10:42 am

I think this is it, but don't quote me...

Take your rate of descent eg. 700fpm double the 7x2=14 add 0 to it
Gives you 700fpm at 140 kts should give you 3 degrees slope.

With that said I could be wrong it's been a while since I had to think.

backon3 · Post by **backon3** » Sun Mar 20, 2005 10:47 am

(Groundspeed divided by two) times ten = fpm (to maintain 3 deg)

CAWI · Post by **CAWI** » Sun Mar 20, 2005 10:58 am

easy way...half of your groundspeed.....add a zero.

Check this out......Very handy

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

greenwich · Post by **greenwich** » Sun Mar 20, 2005 2:08 pm

Thanks crew... (1/2 gnd speed add a zero!)

Also, what was the one that went something like....

"1,000' AGL three miles back, 2,000' AGL six miles back", etc., etc????????

G

C-150Pilot · Post by **C-150Pilot** » Sun Mar 20, 2005 2:12 pm

HAHA I like this one

#10 - Correct time to Lower Gear
Preferably before coming into contact with the runway surface.

greenwich · Post by **greenwich** » Sun Mar 20, 2005 5:34 pm

WTF???

gowest · Post by **gowest** » Sun Mar 20, 2005 5:58 pm

1 nm= 300agl, 2 nm out=600 agl and so on...

Panama Jack · Post by **Panama Jack** » Sun Mar 20, 2005 7:13 pm

TLAR= That looks about right!

Cap'n P8 · Post by **Cap'n P8** » Mon Mar 21, 2005 9:12 am

I have two. First using groundspeed, almost the same as a previous post. Take half the groundspeed, put a zero on the end...and add 30.

Eg. 120 kts g/s = 60 = 600 = 630'/min

Second calculates height at a certain distance. Take the distance back, multiply by 300 (multiply by 3 and add two zeros) and add the surface elevation.

Eg. 5nm x 3 + 00 = 1500 + height ASL of surface = Target altitude for distance back

CAWI · Post by **CAWI** » Mon Mar 21, 2005 10:45 am

Why add 30'. Just curious.

Panama Jack · Post by **Panama Jack** » Mon Mar 21, 2005 12:05 pm

upontop325 wrote:I have two. First using groundspeed, almost the same as a previous post. Take half the groundspeed, put a zero on the end...and add 30.

Eg. 120 kts g/s = 60 = 600 = 630'/min

Wow, I have trouble just keeping my VSI within 100 fpm of target!

Cap'n P8 · Post by **Cap'n P8** » Mon Mar 21, 2005 12:40 pm

Why add thirty? Beats the hell out of me...just what I was told that's all. But hey it's only meant to get you in the ballpark anyways. I actually just learned that one a month ago when I went stateside to do my ATP checkride on my FAA ticket.

helmetfire · Post by **helmetfire** » Mon Mar 21, 2005 11:10 pm

Or simply:

tan of 3 deg x distance from rwy in ft= your target altitude agl'

eg.
tan 3deg* 6080'=318' agl

Make sure you have your calculator handy as you're hand bombing the approach.