Date: 201503
Local time of day: 0001-0600
Location: MMMX.Airport, FO
Flight conditions: VMC
Aircraft: B737 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Takeoff / Launch
ATC / advisory: Tower MMMX
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Human factors: Confusion
Second reporter function: Pilot Not Flying; First Officer
Anomaly: ATC Issue All Types; Conflict Ground Conflict; Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Incursion Runway
Detector: Person Air Traffic Control; Person Flight Crew
Result: Air Traffic Control Issued New Clearance; Flight Crew Took Evasive Action
Contributing factors: Human Factors; Procedure
Primary problem: Human Factors

Narrative: While #1 for Takeoff at the Taxiway Bravo Holding Point for Runway 05L; the Tower controller cleared us to Line Up and Wait Runway 5 Left. We read back the clearance and verified the Proper Runway per SOP. I released the brakes and started to taxi forward while clearing the Final Approach area for other traffic when the First Officer and I noted that a landing aircraft (MMMX normally uses 05R for landings and 05L for departures) appeared to be lined up for RW 05L; I applied the brakes and stopped the aircraft about 20 feet beyond the Hold Short Line so we could confirm with Tower as to which aircraft had clearance to the Runway. At that time Tower realized their error and immediately asked us to Hold Short of Runway 05L while the Tower cleared the landing aircraft to Land on Runway 05L.  Apparently this aircraft (small commuter turboprop) had initially been cleared for Runway 05R approach; but then received a subsequent clearance to sidestep to Runway 05L; but WITHOUT A LANDING CLEARANCE.  After the landing aircraft was cleared to land on Runway 05L; we were subsequently cleared to 'Line Up and Wait Runway 05L' and were finally cleared for takeoff 2 min later without further questions/comments by the Tower Controller.  There was ample room between the Taxiway B/Runway 05L Hold Short Line and the Actual Runway 05L landing area so there was no compromise of safe operating distance to the landing area; however our aircraft was approx. 20 feet beyond the Hold Short Line so I think it is prudent to file a report if the MMMX Tower Controllers decide to file a Runway Incursion Report even if the error was initiated by the Tower Controller.


Second narrative: We were cleared to line up and wait on runway 05L in MMMX. Looking for traffic on final as we were crossing the hold-short line; we observed traffic on short final. The Captain stopped the airplane because it wasn't clear that the aircraft was going to land on 5R. After we had stopped the tower controller told us to hold our position. We advised the tower that we had already stopped. The traffic landed on 05L.


Synopsis: B737 flight crew reports being cleared to line up and wait on Runway 5L at MMMX. After crossing the hold line; a small commuter turboprop is noted on short final and the Captain stops the aircraft well short of the actual runway; at the same time the Tower issues hold instructions and the turboprop lands.