Atc responsible for terrain issues
ah ... NO !!
ATC is NOT responsible for making sure that YOU don't hit a hard bit .. they are responsible for assigning clearances which will, IF YOU COMPLY, keep you nice. However, if YOU DON'T (can't - whatever) comply, YOU are on YOUR Pat Malone ..... and this instantly is relevant if one motor fails to proceed (as RR would have it)
radar is u/s
End result is the same as for radar except that ATC can't see where you are so the tolerances and protocols are far more conservative. The same philosophy applies ... if you comply with the clearance you should be fine .. but don't try to hang YOUR terrain clearance problems on ATC's best endeavours ..
does your performance keep you clear of terrain if you climb straight ahead until above MSA before commencing your turn?
depends on the sums ... if you, or your operator, hasn't put in the hard yards over a hot computer or slide rule ... all bets are either off .. or, at the very least, you are playing Russian Roulette.
Again, if the SID, or whatever other non-failure guidance you have, is complied with by YOU, then you have a reasonable chance of a successful conclusion. However, go substantially below the REQUIRED gradients, or track incorrectly, and you might have done better going to the club and putting your change into the poker machine ...
at what point do performance figures no longer clear you of obstacles. Is it MFRA or MSA?
presuming that the OEI sums have been done correctly and appropriately then you will be on your own at the end of the calculated splays. The sums OUGHT to be done right through to wherever the en-route requirements come into play, generally MSA/LSA as applicable. I am well aware that individual operators vary in their approach and standards.
One I know used not even to bother with the terrain calcuations .. all the runway data was for nil obstacles, ie just the TOD/TOR/ASD data ... some will run only based on what terrain data is published and leave the remaining sweaty bit for the pilot .. who may well be in blissful ignorance. Often, all that saves the day is the fact that we have very few failures early in the takeoff ...
Assume in both cases no obstacles intrude into the swept path for departures since there are no Emer/Compulsory turns.
This assumption constitutes something somewhere between bravado and foolhardiness ... unless you or your ops engineers are both diligent and particular in your sums ...