A corporate jet on approach to bfi responded to an RA command to descend to provide separation from ...

Narrative:

We were flying towards bfi. We were at 2;000 about 4 miles southwest of lackr expecting a visual approach to runway 31. ATC had called corporate jet traffic that we were following several times and we were looking for him. They had us slowed to 190 KIAS. We saw another aircraft at our altitude on the TCAS right in our flight path. [The captain] turned off the autopilot in anticipation of an RA; which we did get. We never saw the traffic; but descended per the RA; only to get a terrain alert. As we were VMC; this wasn't a problem. While we were complying with the RA; the controller issued a traffic alert. We responded that we were descending per an RA. She cleared us for the visual approach and sent us to tower. The traffic passed; we returned to our altitude and landed uneventfully.

Original NASA ASRS Text

Title: A corporate jet on approach to BFI responded to an RA command to descend to provide separation from another corporate jet; and got a terrain warning as a result.

Narrative: We were flying towards BFI. We were at 2;000 about 4 miles southwest of LACKR expecting a visual approach to Runway 31. ATC had called corporate jet traffic that we were following several times and we were looking for him. They had us slowed to 190 KIAS. We saw another aircraft at our altitude on the TCAS right in our flight path. [The Captain] turned off the autopilot in anticipation of an RA; which we did get. We never saw the traffic; but descended per the RA; only to get a terrain alert. As we were VMC; this wasn't a problem. While we were complying with the RA; the Controller issued a traffic alert. We responded that we were descending per an RA. She cleared us for the visual approach and sent us to Tower. The traffic passed; we returned to our altitude and landed uneventfully.

Data retrieved from NASA's ASRS site as of April 2012 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.

Attributes
ACN	893621
Time
Date	201006
Local Time Of Day	1201-1800
Place
Locale Reference	BFI.Airport
State Reference	WA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Small Transport Low Wing 2 Turbojet Eng
Flight Phase	Initial Approach
Person 1
Function	First Officer Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Conflict Airborne Conflict Deviation - Altitude Excursion From Assigned Altitude

A corporate jet on approach to bfi responded to an RA command to descend to provide separation from another corporate jet; and got a terrain warning as a result.