Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 186
Situational Awareness; Distraction
Conflict Airborne Conflict; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Took Evasive Action
Weather; Procedure
We received clearance to takeoff on Runway 28L. Another aircraft was cleared for takeoff on 28R immediately after we were cleared. I would say the aircraft on 28R commenced takeoff roll 10 seconds after us. Winds were 340/20. Our departure was the OFFSHORE 9 which is an RNAV Departure. At approximately 1000 ft; we received a TCAS RA 'Maintain Vertical Speed' from the aircraft that departed right behind us. We complied with the RA and it soon went away as the other aircraft turned away to the right. We informed Departure Control of the RA. We were tracking LNAV guidance throughout the incident. I believe it is possible for this to occur with these crosswinds if the aircraft departing 28R are cleared immediately preceding a departure from 28L. If the aircraft on 28R is on a departure which requires runway heading until 400 ft; it is possible for the winds to push the aircraft into the TCAS bubble of the aircraft to the left. We were on an LNAV ground track (not drifting). If the aircraft on the 28R was on the AFIVA 1 (runway heading to 520 ft); it will immediately drift after takeoff towards the aircraft on the left.
Departures from Runways 28L and 28R at SFO have the potential for conflict and the resulting RA when a strong crosswind is blowing. One departure is an RNAV track and the other is a runway heading. The aircraft departing in heading mode does not correct for drift and may be blown close to the track of an aircraft on an RNAV departure which is corrected for wind drift.