grid mora

traveller

Active member
Joined
Aug 2, 2002
Posts
35
Total Time
6000
What type of altitude clearance does a grid mora provide? Is the the 1000agl and 2000agl in Mountains? Just like most other. Where do you find this information?
 

MTOP_set

Member
Joined
Jan 22, 2002
Posts
33
Total Time
6000+
Jeppesen (Introduction)

traveller,

I won't retype it or tell you what it is, you are on the right track. You can find the info on page 6 of the Chart Glossary in the intro section of your Jepps.
 

172driver

Well-known member
Joined
Apr 4, 2002
Posts
744
Total Time
4000
I have always wanted to know how much obstacle clearance is provided at MDA on a non-precision approach, assuming on course. How about at DH? Have to delve into TERPS to find this out?
 

flywithruss

Rocky Top!
Joined
Nov 26, 2001
Posts
237
Total Time
4150
Obstacle clearance at MDA on a non-precision approach is 300 feet ... and you would have to go to the TERPS, I believe, to find this out. Unless, of course, you did what I did ... I looked at the chart for the localizer approach at the airport where I used to teach ... there was a tower right on the final approach course about 2 miles out up to 1060 MSL ... so, the minimums for the approach were 1360 MSL ... pretty easy math.

I'm sure there's a standard for DH, but I don't know what it is. It is less important because, unlike an MDA, you won't be hanging out there. You get to DH, you either land or miss, whereas on a n-p approach you might be flying at MDA (or a stepdown fix, for that matter) for a mile or two to the MAP.

Fly safe ...

R
 

The FNG

Well-known member
Joined
Jun 18, 2002
Posts
52
Total Time
3,000+
The 300' obstacle clearance only applies to circling minimums. Additionally a circling MDA will not be less than 350' HAA.

Obstruction clearance on final varies according to the type of approach and other criteria such as: length of the final, distance to the altimeter source, and alignment of the final to the landing runway.

Normally an MDA requires a 250' required obstacle clearance (ROC) predicated on a 7:1 descent gradient. (This is one of the reasons why the "dive and drive" method of flying a non-precision approach is giving way to the "constant angle" technique) The MDA DOES NOT necessarily provide a clear zone all the way from the FAF to the MAP. The straight-in landing MDA will not be less than 250 above TDZE.

The ILS GS normally provides obstacle clearance from 660' at the OM to 110' at DA (200 DH); but if required vis is at or above 1 mile an obstruction could penetrate the GS inside the DH.
 
Last edited:
Top