Narrative:

During departure off of 26L; at 1;400 feet on the georgia 5 departure; aircraft issued an RA calling for 'descend; descend'; requiring a descent in VMC conditions. As pilot flying; I leveled off the aircraft while talking to the captain; but due to the low altitude I slowly moved the aircraft into a descent (approximately 50fpm). The mfd showed the target at plus 0.0 and at 0.0 feet above; on top of the aircraft icon. Transponders were both set on the second unit. Pilot monitoring notified tower we had an RA; and the nearest target was 4 miles down range 2;500 feet above us. Tower stated no other observed traffic. During the descent; around 1;100 feet; the RA was still calling descend; and the egpws called out 'don't sink'. I leveled off around 1;000 feet; strongly believing we had an issue with the transponder and after discussing it with the captain. The captain switched us to the number 1 transponder and the issue resolved. The transponder was written up upon arrival [at our destination].if we had been in IMC conditions; this could have led to a really nasty situation with no time to react. The RA asked for a 500 fpm descent; and at 1;400 feet there was little time to resolve the issue. The egpws call further made it confusing by calling don't sink when the RA was calling out 'descend; descend'. Needless to say; we didn't comply with the initial expected climbout on the SID.we believe that the transponder interrogated itself; which led to a false RA. We had just reached acceleration height; so work load was fairly high. We expected that the RA was valid; however; when looking for traffic; checking the mfd and talking to tower we determined that there was erroneous data being provided to us.

Related reports:

Google
 

Original NASA ASRS Text

Title: A Q400 First Officer reported receiving a TCAS RA and 'Descend' command shortly after takeoff with no other aircraft in the vicinity. When the crew responded to the 'Descend' command; the EGPWS alarmed with 'Don't Sink'.

Narrative: During departure off of 26L; at 1;400 feet on the Georgia 5 departure; aircraft issued an RA calling for 'Descend; Descend'; requiring a descent in VMC conditions. As Pilot Flying; I leveled off the aircraft while talking to the captain; but due to the low altitude I slowly moved the aircraft into a descent (approximately 50fpm). The MFD showed the target at plus 0.0 and at 0.0 feet above; on top of the aircraft icon. Transponders were both set on the second unit. Pilot Monitoring notified tower we had an RA; and the nearest target was 4 miles down range 2;500 feet above us. Tower stated no other observed traffic. During the descent; around 1;100 feet; the RA was still calling descend; and the EGPWS called out 'DON'T SINK'. I leveled off around 1;000 feet; strongly believing we had an issue with the transponder and after discussing it with the Captain. The captain switched us to the number 1 transponder and the issue resolved. The transponder was written up upon arrival [at our destination].If we had been in IMC conditions; this could have led to a really nasty situation with no time to react. The RA asked for a 500 fpm descent; and at 1;400 feet there was little time to resolve the issue. The EGPWS call further made it confusing by calling don't sink when the RA was calling out 'Descend; Descend'. Needless to say; we didn't comply with the initial expected climbout on the SID.We believe that the transponder interrogated itself; which led to a false RA. We had just reached acceleration height; so work load was fairly high. We expected that the RA was valid; however; when looking for traffic; checking the MFD and talking to tower we determined that there was erroneous data being provided to us.

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.