B737-800
Situational Awareness; Confusion
ATC Issue All Types; Deviation / Discrepancy - Procedural Other / Unknown
General None Reported / Taken
Human Factors; Procedure; Chart Or Publication
Flying the DATUL2A STAR into Mexico City. After DATUL ATC clears us direct to SMO maintain 250 knots. Descend to 17;000 FT. Approximately 20 miles from SMO; ATC then clears us to 11;000 FT maintain 250 knots 9 NM from SMO fly 220 heading intercept the SMO 160 radial maintain 220 knots. (Restriction on the ILS 05R is 160 knots). Within 1 mile of intercept ATC clears us to 9;000 FT; 700 FT below route minimum. Well below chart MVA. THEN 'turn left 070 climb and maintain 12;000 FT; we have a no comm aircraft in the area.' Gear went up we started the turn (still close to the SMO 160 radial); ATC immediately reclears us for the ILS 5R approach. (This is the first clearance for 5R ILS. Everything up to this point was just vectors for the 160). Heading approximately 150; altitude 9;300 FT. We climbed back up to meet the 9;700 foot transition altitude; requirement met all stabilized approach requirements and landed uneventfully. We were in visual conditions the entire time with the runway in sight with very good terrain S.A. We briefed the DATUL2A and terrain considerations very thoroughly. Our willingness to help ATC was not an issue until rapid fire clearances then it was crazy busy. My suggestion would be to say 'unable' and break off early take the vector above the MVA's.
[Narrative 2 contains no additional information.]
B737-800 flight crew describes an arrival and approach to Runway 5R at MMMX that does not go as depicted or briefed.