Thanks for the reference @Michael_J !
Michael_J wrote:
I guess the best reference is DOC 4444 section 12.3.4.12
I agree!
Michael_J wrote:
I guess the best reference is DOC 4444 section 12.3.4.12
Airborne_Again wrote:
Do you have a reference?
I guess the best reference is DOC 4444 section 12.3.4.12
I got “track” specifically requested, and clarified explicitly, recently, first time in 20 years, but can’t recall where. May have been EBAW.
“Fly rwy heading” means flying the heading, NO wind correction, as NCyankee says, quite right.
It does mean that, in a crosswind, a faster aircraft will fly closer to the runway track than a slower one, but in the general case of jets this is fine.
Pirho wrote:
“Fly runway heading” means exactly that, make the runway heading a radar heading, no compensation for wind.
Do you have a reference?
Yes from reading 5−6−3, it’s clear that US ATC have mandate to vector on takeoff under MVA and also they assume and own obstacles when vectoring under MVA (caveat is that they do as such to try maintaining 1000ft MOC on +/-3nm nearby obstacles, which is sort of point/route MSA in EASA land)
One sometimes get vectors bellow MVA in radar apporaches (I tried ones at Wittering and Gatwick), my understanding these are part of a radar published let down procedure and the headings will allow one to effectively maintain runway track during final & missed rather than maintain runway heading?
The vectors on parallel runway headings for departure seems more related to traffic & wake separation than obstacle separation? I will be curious to hear if that is possible in some speed, obstacle & crosswind configurations?
In the US, fly runway heading means precisely that, not runway track. This is always important, but especially at airports with parallel runways. One flies the heading without any correction for wind.
Honestly, I’m not sure about the logistics of it. It’s been a while since I have heard ‘fly runway heading’, maybe it is not used much/at all any more for reasons you mention (in the UK at least). I have just had a look in CAP413 and 493 and can’t see any mention of “runway heading”.
Acendotally, regarding radar identification, the airfield I fly from used to get us to “squawk ident” once we switched to radar controller after departure, and at that point we became “identified”. A number of years ago this changed and now the tower controller can provide the identification by visual means, pairing up the aircraft that he can see taking off with a radar feed to the visual control room in the tower. Thus we are effectively radar identified as soon as wheels leave the ground.
“Fly runway heading” means exactly that, make the runway heading a radar heading, no compensation for wind.
So effectively ATC in UK are allowed vector bellow MRVA on runway heading even before having a radar ident? do they own obstacles responsibility during the lowest part of the takeoff or it’s the pilot?
I imagine in airliners with +140kts climb the crosswind drift after takeoff is not an issue, in GA however, “fly runway heading” does not feel right on TnG after ILS with 35G45 full crosswind in DA40 
the takeoff path on initial climb area ICA from instrument runways is only protected +/-15deg along axis after runway departure end DER? maybe for takeoff in slow aircraft while in clouds one should stick to 0.2Vs crosswind from certification (or POH demo XW limit) or takeoff in types with Vy = 150kias 
I am inclined to think “fly runway heading” is only valid after “radar identified” not before
