Narrative:

Shooting a nav ILS with a pt; announcing our position with center and CTAF; TCAS showed no traffic in area with center telling us no traffic in the area we get a RA of climb; showed no prior warning out to 6 miles; within 1 mile it tells us to climb to 300 ft below; we climbed up an additional 500 ft; the RA turned into a TA. We continued the [approach] with pt; inbound on apt we picked up airport visual. Only then did previous traffic make traffic report. Collision was avoided; but seems really close when IMC! Traffic was VMC; for their practice [approach]; we were IMC due to the terrain in the area not allowing us to descend into VMC.

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Original NASA ASRS Text

Title: The pilot of a BE200 complied with a TCAS RA while conducting an ILS approach to a non-towered airport in IMC.

Narrative: Shooting a Nav ILS with a pt; announcing our position with Center and CTAF; TCAS showed no traffic in area with center telling us no traffic in the area we get a RA of climb; showed no prior warning out to 6 miles; within 1 mile it tells us to climb to 300 FT below; we climbed up an additional 500 FT; the RA turned into a TA. We continued the [approach] with pt; inbound on apt we picked up airport visual. Only then did previous traffic make traffic report. Collision was avoided; but seems really close when IMC! Traffic was VMC; for their practice [approach]; we were IMC due to the terrain in the area not allowing us to descend into VMC.

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.