Narrative:

Helicopter checked in the over the freeway interchange to transition VFR at 1;500 ft MSL westbound. I misheard his words VFR as a SVFR request since the field was reporting IFR. I also missed the ATIS code. I gave him a clearance through class delta SVFR. My local approach 1 (LA1) said he's VFR. I advised the helicopter about the traffic inbound from the north; a challenger; and instructed the helicopter to hold over the freeway interchange (approx 1.2 miles from the ILS/freeway intersection). I advised the challenger about traffic; 11 O'clock; [and] 2 miles holding over the interchange; no factor (the pilot mumbled something [and] said he's in IMC). As the challenger passed the freeway intersection I told helicopter the challenger passed the freeway transition; approved westbound and caution wake turbulence; ZZZ airport wind calm. The helicopter was westbound at 1;500 ft MSL and the challenger southbound on about 2 mile final at 1;800 ft MSL. The challenger advised he was responding to an RA and climbing but has the field insight. I instructed the challenger to continue runway heading and say intentions as my LA1 was coordinating with overlying TRACON. The challenger said he has the field in sight and continue the approach to land. I cleared the challenger to land again. At the time the challenger said he responded to an RA he was at 1;800 ft MSL the helicopter was at his 8-7 o'clock position 1-2 miles; 1;500 ft MSL and had the challenger in site.I advise that the controller in charge and FD/clearance delivery should not be combined on weather conditions like this. Local controller 1 (LC1) and LA1 both missed the ATIS code. I also recommend that the tower as a team talks about SVFR and different scenarios on days that weather keeps changing. Controllers should have a better understanding how RA's work. The traffic was behind so I didn't think it was still a factor.

Related reports:

Google
 

Original NASA ASRS Text

Title: Challenger aircraft had a TCAS RA in IMC; after Tower Controller allowed a VFR helicopter into the Class D airspace.

Narrative: Helicopter checked in the over the freeway interchange to transition VFR at 1;500 FT MSL westbound. I misheard his words VFR as a SVFR request since the field was reporting IFR. I also missed the ATIS code. I gave him a clearance through Class Delta SVFR. My Local Approach 1 (LA1) said he's VFR. I advised the helicopter about the traffic inbound from the north; a Challenger; and instructed the helicopter to hold over the freeway interchange (approx 1.2 miles from the ILS/freeway intersection). I advised the Challenger about traffic; 11 O'clock; [and] 2 miles holding over the interchange; no factor (the pilot mumbled something [and] said he's in IMC). As the Challenger passed the freeway intersection I told helicopter the Challenger passed the freeway transition; approved westbound and caution wake turbulence; ZZZ airport wind calm. The helicopter was westbound at 1;500 FT MSL and the Challenger southbound on about 2 mile final at 1;800 FT MSL. The Challenger advised he was responding to an RA and climbing but has the field insight. I instructed the Challenger to continue runway heading and say intentions as my LA1 was coordinating with overlying TRACON. The Challenger said he has the field in sight and continue the approach to land. I cleared the Challenger to land again. At the time the Challenger said he responded to an RA he was at 1;800 FT MSL the helicopter was at his 8-7 o'clock position 1-2 miles; 1;500 FT MSL and had the Challenger in site.I advise that the CIC and FD/CD should not be combined on weather conditions like this. Local Controller 1 (LC1) and LA1 both missed the ATIS code. I also recommend that the Tower as a team talks about SVFR and different scenarios on days that weather keeps changing. Controllers should have a better understanding how RA's work. The traffic was behind so I didn't think it was still a factor.

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.