Narrative:

During descent and arrival to apc airport while talking to oakland center we were approximately 14 miles from the airport. We advised oakland that we had the airport in sight. We were south and slightly west of the airport at this point. We had briefed the visual approach to runway 18R. We were expecting a right downwind to runway 18R as that was the most expeditious way for us to reach the airport. This was also expected due to the rising terrain that we could see east of the napa airport. We were cleared by oakland for the visual approach and we began our decent from 4000 feet to 1500 feet. We were handed over to napa tower. We were instructed by the tower to remain south of the airport and to expect a left downwind to runway 18R. We complied with those instructions. As we were turning downwind; still cleared for the visual approach we were told to extend our downwind. We immediately noticed the rising terrain in front of us. We were advised by the tower of a low altitude alert and to check our altimeter. We chose to climb to 2000 feet to top the 1st ridge of hills in front of us. We also received a GPWS terrain caution warning during the climb to this new altitude. As we leveled off at 2000 feet we could see a second ridge that was higher in altitude in front of us. We were advised to report a departing aircraft in sight. However; the departure end of the runway was well behind us. We were advised to extend our downwind and the tower would call our base turn. At this time we were given a second low altitude alert by the tower. We chose to climb to 3000 feet. We were advised to turn base. We began descending for the airport at this point and we were advised of a third low altitude alert. We began a stable approach to the runway centered on the VASI. We landed without incident. It seems unclear to the tower the amount of space required by a jet to fly a left downwind approach to this runway at this airport. I am not sure how the approach could be flown in a stable manner without triggering a low altitude alert by the tower. The pattern altitude required to fly this approach seems extremely high and counter to completing a stabilized approach without excessive decent rates. I am also not sure why a right hand pattern can't be used as its track would be mostly over water.

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Original NASA ASRS Text

Title: A jet crew on a left downwind visual approach to APC Runway 18R was given an extended downwind and because of raising terrain received several ATC low altitude alerts; as well as an EGPWS CAUTION TERRAIN.

Narrative: During descent and arrival to APC airport while talking to Oakland center we were approximately 14 miles from the airport. We advised Oakland that we had the airport in sight. We were south and slightly west of the airport at this point. We had briefed the visual approach to runway 18R. We were expecting a right downwind to runway 18R as that was the most expeditious way for us to reach the airport. This was also expected due to the rising terrain that we could see east of the Napa airport. We were cleared by Oakland for the visual approach and we began our decent from 4000 feet to 1500 feet. We were handed over to Napa tower. We were instructed by the tower to remain south of the airport and to expect a left downwind to runway 18R. We complied with those instructions. As we were turning downwind; still cleared for the visual approach we were told to extend our downwind. We immediately noticed the rising terrain in front of us. We were advised by the tower of a low altitude alert and to check our altimeter. We chose to climb to 2000 feet to top the 1st ridge of hills in front of us. We also received a GPWS terrain caution warning during the climb to this new altitude. As we leveled off at 2000 feet we could see a second ridge that was higher in altitude in front of us. We were advised to report a departing aircraft in sight. However; the departure end of the runway was well behind us. We were advised to extend our downwind and the tower would call our base turn. At this time we were given a second low altitude alert by the tower. We chose to climb to 3000 feet. We were advised to turn base. We began descending for the airport at this point and we were advised of a third low altitude alert. We began a stable approach to the runway centered on the VASI. We landed without incident. It seems unclear to the tower the amount of space required by a jet to fly a left downwind approach to this runway at this airport. I am not sure how the approach could be flown in a stable manner without triggering a low altitude alert by the tower. The pattern altitude required to fly this approach seems extremely high and counter to completing a stabilized approach without excessive decent rates. I am also not sure why a right hand pattern can't be used as its track would be mostly over water.

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.