Flight Crew Air Transport Pilot (ATP)
ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance
Chart Or Publication; Human Factors; Procedure; Weather
After takeoff on 26L at ATL on a RMBLN 7 RNAV SID the Tower called and asked 'you are in a right turn; correct?' I said that we were on the RMBLN 7. The Tower Controller said to turn right to 300 degrees; which we immediately did. Just prior to the turn I noticed that the north wind had blown us slightly south of the magenta line. The wind was out of the north at 55 KTS. We maintained the 300 heading as we switched to Departure. Departure asked if we saw the traffic at 10 o'clock. We did; and told him so. It was an RJ; turning away from us. The Controller said to maintain visual contact. He then asked if we had difficulty on the RMBLN7. I assumed that this was his way of asking me why we were on a heading. I replied that the north wind had caused a southerly drift; and hence the 300 heading. He then cleared us direct to RMBLN.We should always engage the autopilot on RNAV SIDs. If the Tower was concerned about a conflict; I would have appreciated an immediate instruction to correct; rather than start the conversation with a question (which wasted a few seconds before the correction was issued).
After takeoff in NAV TRK mode; the flight director and CDI were all showing on course on the initial 275 heading. Tower asked if we were in a right turn. The turn to the 288 course to SNUFY was depicted on the map as still ahead of us and we had not yet reached that point on the departure. Tower turned us to a heading of 300 and switched us to Departure. Departure asked if we had trouble flying to SNUFY. According to all the indications in the cockpit we were on course on the departure and not even to the point to make the right turn to SNUFY. As far as we were concerned; we never deviated from the RNAV SID track.
The Tower was alarmed and issued a heading to an MD-80 departing 26L at ATL on the RMBLN RNAV SID when they drifted south immediately after takeoff while flying the charted 275 heading with the winds out of the North at 55 KTS.