It is completely normal for ATC to vector below MSA in all conditions whenever they are still keeping you above the relevant MRVA – in fact I would nearly say it is more common than not for destinations I fly to that we end up on a radar intercept which is below MSA
Do you have a commercial airport in mind where MSA is under MRVA?
Ibra wrote:
Do you have a commercial airport in mind where MSA is under MRVA?
Maybe I worded that poorly – it was the opposite which I was suggesting is common – whereby MRVA is lower than MSA, therefore ATC will commonly provide legal vectors which are below MSA.
See for example Faro, LPFR:
You can see there is an MRVA of 3300’ in an area with an MSA of 3500’, also 2500’ MRVA in the same area. Converesely, to the south the MRVA is indeed higher at 2400’ compared to the MSA of 1400’.
This is also an airport where it is very common for them to vector you (after confirming visual with terrain) to 2000’ “maintaining visual seperation with terrain” in an area with an MSA of 3500’ an an MRVA of 3000’+.
Don’t forget that the MSA is really an emergency altitude. As long as you’re following a procedure or route (even a route you decided on yourself as long as you determined the minimum altitude) the MSA is irrelevant.
See for example Faro, LPFR
Thanks !
In the US, ATC may vector aircraft off of a charted route down to the MVA or MIA.
5−6−1. APPLICATION
Vector aircraft:
a. In controlled airspace for separation, safety, noise abatement, operational advantage, confidence maneuver, or when a pilot requests.
b. In Class G airspace only upon pilot request and as an additional service.
c. At or above the MVA or the minimum IFR altitude except as authorized for radar approaches, radar departures, special VFR, VFR operations, or by paragraph 5−6−3, Vectors Below Minimum Altitude.
d. In airspace for which you have control jurisdiction, unless otherwise coordinated.
e. So as to permit it to resume its own navigation within radar coverage.
f. Operating special VFR only within Class B, Class C, Class D, or Class E surface areas.
g. Operating VFR at those locations where a special program is established, or when a pilot requests, or you suggest and the pilot concurs.
5-6−2. METHODS
a. Vector aircraft by specifying:
1. Direction of turn, if appropriate, and magnetic heading to be flown, or Vectoring
PHRASEOLOGY−
TURN LEFT/RIGHT HEADING (degrees).
FLY HEADING (degrees).
FLY PRESENT HEADING.
DEPART (fix) HEADING (degrees).
2. The number of degrees, in group form, to turn and the direction of turn, or
PHRASEOLOGY−
TURN (number of degrees) DEGREES LEFT/RIGHT.
3. For NO-GYRO procedures, the type of vector, direction of turn, and when to stop turn.
PHRASEOLOGY−
THIS WILL BE A NO-GYRO VECTOR,
TURN LEFT/RIGHT.
STOP TURN.
b. When initiating a vector, advise the pilot of the purpose, and if appropriate, what to expect when radar navigational guidance is terminated.
PHRASEOLOGY−
VECTOR TO (fix or airway).
VECTOR TO INTERCEPT (name of NAVAID) (specified) RADIAL.
VECTOR FOR SPACING.
(if appropriate) EXPECT DIRECT (NAVAID, waypoint, fix)
VECTOR TO FINAL APPROACH COURSE,
or if the pilot does not have knowledge of the type of approach,
VECTOR TO (approach name) FINAL APPROACH COURSE.
NOTE− Determine optimum routing based on factors such as wind, weather, traffic, pilot requests, noise abatement, adjacent sector requirement, and letters of agreement.
c. When vectoring or approving course deviations, assign an altitude to maintain and, if necessary, a speed, when:
1. The vector or approved deviation is off an assigned procedure which contains altitude or speed restrictions, i.e., instrument approach, etc.
2. The previously issued clearance included crossing restrictions.
3. The vector or approved deviation is off an assigned procedure that contains published altitude or speed restrictions, i.e., SID, STAR, and a clearance to Climb Via/Descend Via has been issued.
d. When vectoring or approving an aircraft to deviate off of a procedure, advise the pilot if you intend on clearing the aircraft to resume the procedure.
PHRASEOLOGY−
FLY HEADING (degrees), MAINTAIN (altitude), (if necessary, MAINTAIN (speed)), EXPECT TO RESUME (SID, STAR, etc.).
DEVIATION (restrictions if necessary) APPROVED, MAINTAIN (altitude), (if necessary, MAINTAIN (speed)), EXPECT TO RESUME (SID, STAR, etc.) AT (NAVAID, fix, waypoint).
NOTE− After a climb via or descend via clearance has been issued, a vector/deviation off of a SID/STAR cancels all published altitude and speed restrictions on the procedure. The aircraft’s Flight Management System (FMS) may be unable to process crossing altitude restrictions once the aircraft leaves the SID/STAR lateral path. Without an assigned altitude, the aircraft’s FMS may revert to leveling off at the altitude set by the pilot, which may be the SID/STAR published top or bottom altitude.
e. Provide radar navigational guidance until the aircraft is:
1. Established within the airspace to be protected for the nonradar route to be flown, or
2. On a heading that will, within a reasonable distance, intercept the nonradar route to be flown, and
3. Informed of its position unless the aircraft is RNAV, FMS, or DME equipped and being vectored toward a VORTAC/TACAN or waypoint and within the service volume of the NAVAID.
PHRASEOLOGY−
(Position with respect to course/fix along route), RESUME OWN NAVIGATION,
or
FLY HEADING (degrees). WHEN ABLE, PROCEED DIRECT (name of fix),
or RESUME (SID/STAR/transition/procedure).
f. Aircraft instructed to resume a procedure which contains published crossing restrictions (SID/STAR) must be issued/reissued all applicable restrictions or be instructed to Climb Via/Descend Via.
PHRASEOLOGY−
CLEARED DIRECT (NAVAID, fix, waypoint) CROSS (NAVAID, fix, waypoint) AT/AT OR ABOVE/AT OR BELOW (altitude), then CLIMB VIA/DESCEND VIA (SID/STAR)
EXAMPLE−
“Cleared direct Luxor, then descend via the Ksino One arrival.” “Cleared direct HITME, cross HITME at or above one one thousand, then climb via the Boach Five departure.”
g. Aircraft may not be vectored off an Obstacle Departure Procedure (ODP), or issued an altitude lower than published altitude on an ODP, until at or above the MVA/MIA, at which time the ODP is canceled.
NOTE− Once an aircraft has been vectored off an Obstacle Departure Procedure, the procedure is canceled and ATC cannot clear the aircraft to resume the ODP.
h. Aircraft vectored off an RNAV route must be recleared to the next waypoint or as requested by the pilot.
i. When flight data processing is available, update the route of flight in the computer unless an operational advantage is gained and coordination is accomplished.
j. Inform the pilot when a vector will take the aircraft across a previously assigned nonradar route.
PHRASEOLOGY−
EXPECT VECTOR ACROSS (NAVAID radial) (airway/route/course) FOR (purpose).
For vectors below the MVA, the following exceptions apply:
5−6−3. VECTORS BELOW MINIMUM ALTITUDE
a. TERMINAL. As described in facility directives, when vectoring a departing IFR aircraft, or one executing a missed approach, when ISR is not displayed in the full data block and before it reaches the minimum altitude for IFR operations if separation from prominent obstacles shown on the radar scope is applied in accordance with one of the following:
1. The flight path is 3 miles or more from the obstacle and the aircraft is climbing to an altitude at least 1,000 feet above the obstacle, vector the aircraft to maintain at least 3 miles separation from the obstacle until the aircraft reports leaving an altitude above the obstacle, or;
2. The flight path is less than 3 miles from the obstacle and the aircraft is climbing to an altitude at least 1,000 feet above the obstacle, vector the aircraft to increase lateral separation from the obstacle until the 3 mile minimum is achieved or until the aircraft reports leaving an altitude above the obstacle, or;
3. Radar facilities may vector aircraft below the MVA/MIA, provided:
(a) No prominent obstacles are within 10 NM of the departure end of runway (DER).
(b) Aircraft must be allowed an uninterrupted climb to meet the MVA/MIA within 10 NM of the DER.
NOTE− ATC assumes responsibility for terrain and obstacle avoidance when IFR aircraft are below the minimum IFR altitude (MVA, MIA, MEA) and are taken off departure/ missed approach procedures, or if issued go−around instructions, except after conducting a visual approach. ATC does not assume this responsibility when utilizing a Diverse Vector Area (DVA) or when operating on SIDs with or without a published range of headings in the departure route description.
b. After reaching the first MVA/MIA sector, all subsequent MVA/MIA sectors encountered must be met.
c. At those locations where diverse vector areas (DVA) have been established, radar facilities may vector aircraft below the MVA/MIA within the DVA described in facility directives.
d. At those locations using radar SIDs, radar facilities may vector aircraft below the MVA/MIA, in accordance with facility directives.
e. At locations that vector aircraft conducting a go−around or missed approach, use authorized headings and display those prominent obstacles stipulated in facility directives until reaching the MVA/MIA.
Thanks for the details, I recall reading section 5-6-3 with vectors on takeoff
In UK, ATC say “flying runway heading” I think they mean “fly runway track” 
Ibra wrote:
In UK, ATC say “flying runway heading” I think they mean “fly runway track”
Not only in the UK. AFAIU, that is unfortunately what it means generally.
Runway heading and runway track are two different instructions.
“Fly runway heading” means exactly that, make the runway heading a radar heading, no compensation for wind.
“Climb straight ahead” or “Track extended runway centre-line” (the second of which I have never heard), means compensate for wind and maintain a track.
“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
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.
