Large Transport; Low Wing; 2 Turbojet Eng
Flight Crew Last 90 Days 100; Flight Crew Total 15000; Flight Crew Type 5000
Training / Qualification; Situational Awareness; Fatigue; Distraction; Confusion
Deviation - Altitude Crossing Restriction Not Met; Deviation - Altitude Undershoot; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Flight Crew Became Reoriented; Flight Crew Returned To Clearance; Flight Crew Took Evasive Action
Environment - Non Weather Related; Human Factors; Procedure
After a thorough approach brief that included great detail about terrain in the area; we were given a visual approach to [Runway] 26L at ONT. Once cleared for the visual we set 2;800 FT in the alt. window (MCP). We started our base turn abeam FONTA to avoid the higher terrain that sits further to the east of the field. On base turn approximately 5 miles from FONTA (FAF) we noticed we were indicating high on all three glideslope (G/S) indicators. I used Vertical Speed (VS) and started descending out of 2;800 FT and at approximately 2;600 FT we got a 'caution terrain' warning from the ridge (2;200 FT) that sits just southeast of FONTA so I began to level off. We then got a EGPWS 'Terrain' 'Terrain' followed by a 'whoop; whoop pull up'. I began the CFIT maneuver; and as soon as we began climbing the warning went away. We climbed back up 2;800 FT; the published altitude at FONTA; and decided since we were VFR and could see the ridge and the airport environment clearly; to continue the visual approach to [Runway] 26L. Even though we had just gotten a good IDENT on the localizer it is clear now that we were getting an erroneous G/S signal making us think we were high on the visual. In retrospect; we should have stayed at 2;800 FT until getting to FONTA and not trusted the G/S indications we were getting. Even with a very thorough approach briefing; with emphasis on the terrain threats around ONT; we still were lured into making an error caused by the erroneous G/S indications. We certainly should have waited until FONTA to begin descending out of 2;800 FT and then picked up the PAPI. The G/S indications appeared perfectly normal once we joined final. Fatigue was certainly a factor as well. We were both called out on reserve to deadhead west and then operate right away to ONT. After changes and delays we ended up diverting but because of no Customs we were rerouted an hour or so into the flight. We arrived at our divert airport to the minute of our max duty day. We finally cleared Customs over an hour and a half after landing; due to the airport's gateway personnel not being familiar with Customs procedures. We finally checked in at the alternate hotel over two hour after block in. The hotel sits right under the final approach path at airport so we both got next to no sleep during our 11 plus hours at the hotel. In retrospect I wish we had not accepted a visual approach to ONT even though it was CAVU; I don't go in to ONT very often; so I wish we had just gotten vectors for an ILS. It would have been much safer to do so; going into a somewhat unfamiliar airport that is surrounded by terrain.
Lessons Learned. We talked thoroughly about the terrain threats before accepting the visible approach. Even though the terrain was in sight during the entire approach; we allowed an erroneous glideslope indication to lure us into a descent; bringing us too close to the terrain. By accepting a visual approach we may feel like we're helping out Approach Control; expediting our arrival; or just taking charge of our own aircraft; but visual approaches at night can quickly multiply the potential for errors. We thought we had trapped our terrain errors on this approach; but we allowed an additional unforeseen input to lull us into an unforeseen error. In the future I will not be accepting visual approaches at night without a strong reason.
A fatigued flight crew on a night visual to ONT Runway 26L followed a false glideslope and descended below 2;800 FT prior to FONTA but executed the Escape Maneuver at about 2;600 FT after the EGPWS alerted; CAUTION TERRAIN; then TERRAIN; TERRAIN and finally WHOOP; WHOOP PULL UP.