PDA

View Full Version : IAP's


jau
23rd Jan 2004, 18:34
hi all,
Just a quick question on IAP's. On the UK plates the minima are quoted as altitude and height. (ie for a field elv. of 300ft, minima would written as 500' (200) )
I see on the US plates that there is a bit more info. For example,

503/24 200 (200-1/2)

I take it that the 503 is altitude and the 200 is height, as the field elevation was 313 ft. Whats with the /24 and the (200-1/2)?
jau

M.85
23rd Jan 2004, 19:01
if i remember correctly..the /24 would be the RVR..hence 2400 RVR vis..
the height in bracket is the height of DH above ground level(AGL above runway threshold)
Stand to be corrected of course:8

M.85

200 is DH in AGL and 1/2 stands for Half a mile (Statute mile)in vis as minimums to start the approach..basic Cat1.

gear down props forward
23rd Jan 2004, 20:43
I do not have Jeppesen charts, so they may be slightly different than the charts issued by the FAA National Aeronautical Charting Office.

In the FAA IAP minimums section, M.85 has it right, in addition, the numbers inside the parentheses are for military aircraft only.

Precision approaches:
DA-vis DH (military-minimums)
or if RVR available: DA/RVR DH (military-minimums)

Non-precision approaches: MDA-vis HAT (military-minimums)
(HAT=height above touchdown)

Sorry, I do not have an example of where the military minimums deviate significantly from the civil aircraft minimums. Of the IAPs that I have seen, usually the military minimums have been slightly higher than civil minimums, however, the regulations state that a military aircraft may continue an approach to a civil airport, even when below published minimum altitudes.

I have also seen that on pure military approaches (eg. TACAN IAP to a military airfield), they publish the minimums just like on a civil airport IAP, with "military minimums" still in the parantheses.

example:
Tacan Rwy 18 Hurlburt KHRT, 38' MSL: 440-3/4 405 (500-3/4)

One may perform an IAP when the weather is knowingly below minimums, if operating a non-commercial aircraft under part 91 of the regulations. Abuse of this "privelege" may one day become regulated, so that no more "look and see" approaches can be made. Sometimes, the weather observation station is in its own "cloud," and the part 91 guy is able to make it into the airport when the 121/135 guys have to go to their alternate or hold for better reported weather.

M.85
23rd Jan 2004, 20:56
Props is right.
I used NAA charts too in my old airline as they were FREE unlike the Jepps ones..
Pain in the B** to go back to jepps but manageable..
The military section is correct i wasnt sure anymore therefore i didnt post it.

M.85