ILS "Y" surface _ 1

28.10.2004

Submission:

I was reading the response to JS Park about his "Y surface penetration" and the part about the two missed approach climb gradients caught my attention. In Doc 9368-AN/911 (Instrument Flight Procedures Construction Manual) there is a note on page 14-3 (Precision - Turning Missed Approach) that says, "Simply increasing the climb gradient is not sufficient. The procedure must specify an OCA/H appropriate to the nominal 2.5 per missed approach climb. Special minima can be published in addition to, but not instead of, the nominal OCA/H based on 2.5%" I guess I have two questions:-

1) Is the IFP Construction Manual still valid. I understand at one point ICAO was trying to update it, and

2) How does that note relate to the editors response to JS

Bill Frenz - The MITRE Corporation - Center for Advanced Aviation System Development, USA

Answer or Commentary:

(I.W.

The IFP construction manual is way out of date and an update has been in the pipe line for years. However your quote is also in Pans-Ops (doc. 8168) Part III Chapter 7 paragraph 7.1.6. I was thinking of an approach chart I saw with different OCA/H values for missed approach climb gradients of 2.5 3 4 and 5 %. In theory if one can have a 2.5% and one other missed approach climb gradient, it seems logical that you can have other climb gradients / OCAs as well. However I personally don't think it is optimal.)