Date: 201602
Local time of day: 1801-2400
Location: PSP.Airport, CA
Flight conditions: VMC
Light: Night
Aircraft: Large Transport; Low Wing; 2 Turbojet Eng
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class E SCT
ATC / advisory: TRACON SCT
Aircraft component: GPWS
Component problem: Design
Reporter organization: Air Carrier
Reporter function: Pilot Flying; First Officer
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Confusion; Human-Machine Interface; Situational Awareness
Second reporter function: Captain; Pilot Not Flying
Anomaly: Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Detector: Automation Aircraft Terrain Warning; Person Flight Crew
When detected: In-flight
Result: Flight Crew Returned To Clearance; Flight Crew Took Evasive Action; Flight Crew Became Reoriented; Flight Crew FLC complied w / Automation / Advisory
Contributing factors: Human Factors; Procedure; Aircraft; Environment - Non Weather Related
Primary problem: Human Factors

Narrative: We were cleared and flew the SBONO1 arrival followed by the night Visual Approach RWY 31L; to cross SBONO at 7000 feet. After crossing SBONO at 7000; 210 knots; flaps 1; I began the descent to cross the next to altitude of 6000 feet. At about 6400 feet; the 'Terrain; Terrain' audible warning sounded once. I looked at my ND and observed that the aircraft was about 0.3 NM right of course; and an amber terrain area about the size of a dime was displayed just to the right and slightly behind the aircraft. It should be noted that the inbound course on the arrival to SBONO is 252 degrees and the outbound track from SBONO is 192 degrees. During my approach brief at cruise; I had discussed the terrain and the terrain escape maneuver and the mandated maneuver compliance during night time operations. When the warning sounded; I announced that I was executing the escape maneuver. We climbed to 7000 feet; with the warning sounding only once. The Captain advised ATC; and when we were assured of terrain clearance; we then continued the approach to landing.

Callback: The reporter stated that his Captain experienced an EGPWS Terrain warning flying into PSP on a night visual the week before. The reporter stated additionally; that a week after this event on the same approach the EGPWS activated again even though the crew felt in a safe state on night visual. However; they did again announce to ATC and executed the escape maneuver. The reporter now believes his Company's EGPWS database may have an error causing the Terrain Warning too early. He felt an issue could develop if a full escape maneuver were executed but an error made with the surrounding high terrain. The reporter talked with another pilot about his experience and was told PSP vectored that pilot's flight onto a night visual.

Second narrative: [Report narrative contained no additional information.]


Synopsis: Air carrier crew flying the PSP Runway 31L night visual approach executed a terrain escape maneuver while descending toward 6;000 after an EGPWS terrain warning. The flight crew suspects an EGPWS database error because several similar EGPWS warnings have occurred in apparently safe descent states.