A flight crew cleared for the boi runway 28R visual was advised about downwind traffic and deviated ...

Attributes
ACN	1406619
Time
Date	201611
Local Time Of Day	1801-2400
Place
Locale Reference	BOI.TRACON
State Reference	ID
Environment
Flight Conditions	Marginal
Light	Night
Aircraft 1
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Route In Use	STAR BEWTE TWO
Flight Plan	IFR
Person 1
Function	First Officer Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Conflict Airborne Conflict Deviation - Procedural Published Material / Policy Deviation - Track / Heading All Types Inflight Event / Encounter CFTT / CFIT

Narrative:

Arriving into boi from the north; we planned a visual approach that would be backed up by the RNAV X 28R. Upon check-in with ATC; we were told to expect clearance for the RNAV X. As we approached the IAF; however; ATC said that we would be following another carrier aircraft that was approximately four miles ahead of us on downwind. We advised that aircraft was in sight and we were cleared for a visual approach behind other carrier.seeing that spacing would be an issue if we were to remain on the RNAV track; I slowed the aircraft and went into heading mode to extend the downwind. Just as we started to turn base; we received a terrain caution. I disengaged the autopilot and autothrottles and initiated a climb. The alert ended; and we maneuvered to the south to remain clear.because we were hemmed in by terrain to the east and north and by the other carrier aircraft to our south; we probably should not have accepted the approach clearance. In retrospect; the better option may have been to request vectors for a straight in approach.

Original NASA ASRS Text

Title: A flight crew cleared for the BOI Runway 28R visual was advised about downwind traffic and deviated north to gain space. The EGPWS 'CAUTION TERRAIN' alerted and the crew initiated an escape maneuver followed by an uneventful approach.

Narrative: Arriving into BOI from the north; we planned a visual approach that would be backed up by the RNAV X 28R. Upon check-in with ATC; we were told to expect clearance for the RNAV X. As we approached the IAF; however; ATC said that we would be following another carrier aircraft that was approximately four miles ahead of us on downwind. We advised that aircraft was in sight and we were cleared for a visual approach behind other carrier.Seeing that spacing would be an issue if we were to remain on the RNAV track; I slowed the aircraft and went into heading mode to extend the downwind. Just as we started to turn base; we received a Terrain Caution. I disengaged the autopilot and autothrottles and initiated a climb. The alert ended; and we maneuvered to the south to remain clear.Because we were hemmed in by terrain to the east and north and by the other carrier aircraft to our south; we probably should not have accepted the approach clearance. In retrospect; the better option may have been to request vectors for a straight in approach.

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.

A flight crew cleared for the boi runway 28R visual was advised about downwind traffic and deviated north to gain space. The egpws 'caution terrain' alerted and the crew initiated an escape maneuver followed by an uneventful approach.