The DBV Approach is almost like the one in Trabzon, Turkey...When I flew a jet (727) full of passengers into there at night and/or low vis conditions...I always kept in mind one thing...If everything starts to go south...TURN RIGHT!!! Over the Black Sea...Maybe not correct, but if you lose situational awarness...at night, in IMC, Over the sea is better than towards the mountains....

As has been beaten to death here on this thread by many of us "greybeards"...if you're not sure where you are at, IMC or at night being at 2,000' is not the time or place to try to figure it out....

- my post was about ACTUAL MSAs, not some 'TAA' figure - out of interest, why 4300'for TAA when MSA is 4100'? What are the criteria for TAAs?

TAA criteria are in Vol. 4 of Order 8260.58

FAA AFS-420 web site hosts all TERPS Orders on this page.

Thanks again, Zeffy - I could not find any reference to the ROC for TAA procedures (mind you, I got dizzy with all the maths................) Overall it seems odd that the hold at INDRA (1 nm inside ZEDAG) is considered safe at 3800' and yet when we switch to TAA procedures it jumps to 4300'. I assume there is a different (increased) ROC since the terrain is no less 'challenging'.

Incidentally, I see that 8260.19E at 2.74 calls for 200' to be added as an AAO which may account for the 200' discrepancy we see between the FAA and Jepp chart 'spot heights' (basically to allow for the 199' mast), and 2750' + 1000' gives us the 3800' hold, I guess.

Just glad I never had to construct procedures..........................

Sorry for the diversion and back to the accident.

Yes, the criteria are not for the faint of heart.:)

In a very small nutshell: ROC values for TAAs are the same as for airways.:ok:

BOAC:

Chart makers don't use AAO for reference obstacles.

But, the designers made additives to the holding pattern's minimum ROC of 1,000, probably for precipitous terrain and, more important at this location, cold station altimeter errors.

- I was talking ROC not reference obstacles, and Jepp seem to have added 175' (to the reference obstacle)

BOAC:

I was speaking of both in the total context of this aspect of the RNAV 19 procedure. I have no idea how Jeppesen came up with the value they show.

NTSB Report

Accident Docket

ATC Factual