Narrative:

We took off from runway 1 in dca. We were on the REBLL4 departure. Wet runway; no flex. Mtow was 77.6 and our T/O weight was around 76.6. Winds 190/7. Temperature 8C and pressure of 29.96. Visibility was 5 NM br and broken 006. I was pm (pilot monitoring) and had WX radar on and PF (pilot flying) had terrain on. We were at about 350 when we first received a 'caution terrain' caution message. As that happened PF was requesting navigation mode. Then we received a 'pull up; terrain' indication. We followed terrain avoidance procedure and applied max thrust. We had very little margin between pli and low speed awareness. Meanwhile tower switched us over to departure. We stayed on the SID as we tried to avoid P56. We continued the climb and we were out of the condition within seconds. Everything happened in a few seconds.terrain mode was always showing green and positive clearance from obstacles. We switched controllers again and didn't have a chance to notify ATC about the event. We continued the climb and the rest of the flight without any major issues. We were on the vertical and lateral path for the SID. At least that's what we could see in our display. We can't really tell if it was a system malfunction or if it was a legitimate event because we were IMC. So we applied the recovery procedures. If it was a system malfunction I would say it could have been a momentary dual radio altimeter failure that triggered an unwanted alert. But if it was a real event I would imagine that the wind pushed us further to the north of the path than what we thought we were in which case it might be appropriate to maybe slightly modify the departure or simply do not take off with no tail wind at all. But what the other instruments were showing us differ from the egpws alert.

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Original NASA ASRS Text

Title: EMB-175 flight crew reported receiving an EGPWS terrain alert departing DCA that may have been a false alert.

Narrative: We took off from Runway 1 in DCA. We were on the REBLL4 departure. Wet runway; no flex. MTOW was 77.6 and our T/O weight was around 76.6. Winds 190/7. Temperature 8C and pressure of 29.96. Visibility was 5 NM BR and BKN 006. I was PM (Pilot Monitoring) and had WX radar on and PF (Pilot Flying) had Terrain on. We were at about 350 when we first received a 'Caution Terrain' caution message. As that happened PF was requesting NAV mode. Then we received a 'Pull Up; Terrain' indication. We followed Terrain avoidance procedure and applied Max Thrust. We had very little margin between Pli and low speed awareness. Meanwhile Tower switched us over to departure. We stayed on the SID as we tried to avoid P56. We continued the climb and we were out of the condition within seconds. Everything happened in a few seconds.Terrain mode was always showing green and positive clearance from obstacles. We switched controllers again and didn't have a chance to notify ATC about the event. We continued the climb and the rest of the flight without any major issues. We were on the vertical and lateral path for the SID. At least that's what we could see in our display. We can't really tell if it was a system malfunction or if it was a legitimate event because we were IMC. So we applied the recovery procedures. If it was a system malfunction I would say it could have been a momentary dual radio altimeter failure that triggered an unwanted alert. But if it was a real event I would imagine that the wind pushed us further to the North of the path than what we thought we were in which case it might be appropriate to maybe slightly modify the departure or simply do not take off with no tail wind at all. But what the other instruments were showing us differ from the EGPWS alert.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.