Air carrier flight crew reported current procedure for a visual approach to Runway 8 at ITO resulted in EGPWS alert and CFTT event while turning toward plotted final.
Synopsis
Air carrier flight crew reported current procedure for a visual approach to Runway 8 at ITO resulted in EGPWS alert and CFTT event while turning toward plotted final.
Narrative
PHTO landing Rwy 08; however; there is no visual approach published. There are recommended points and altitudes in our Airport Briefing Guide. Due to low scattered clouds crew requested ILS Rwy 26; but was refused by Hilo Approach due to outbound traffic on Rwy 26. Due to clouds down to 2;000 ft; crew was unable to fly the recommended route visually; which starts at ARBOR at 4;500ft. Crew was first vectored east of the course down to 2;100ft; but still not clear of clouds. Approach then vectored crew to 1;500; but vectors did not align crew on the recommended visual flight path - 166 course from ARBOR direct to RWY08 three-mile extension. When crew called 'field in sight' at 1;500; I flew an intercept heading (estimated 190 degrees ??) back towards the recommended LNAV course with intent to intercept both LNAV course and VNAV flight path. About 1 mile from RWY 08 three-mile extension point; Aircraft was configured flaps 20; Gear Down; 1;500 ft (Radar Alt ~ 1;320ft ??); autopilot and autothrottles engaged. Just prior to establishing LNAV course; the GPWS system announced 'Caution Terrain'. I disconnected both the autopilot and auto throttles; turned heading left away from rising terrain with intent of continuing this left turn to final (which is the direction of lower terrain and the ocean). During this time GPWS announced Terrain-Pull UP. In my professional judgement; given the rising terrain and low scattered clouds I elected to continue the left turn and continue the visual approach. I firmly believed this was far safer than going max power; 20 nose high and flying back into the weather towards higher terrain vs lower terrain to the left. I called for flaps 30; finished the Before Landing Checklist; and landed the plane uneventfully. Cause: I believe the cause of the event is the current structure of our recommend visual procedures into PHTO. The course from ARBOR to RWY08 3-mile extension cuts across the shoreline and flys 'too inland' towards rising terrain. This is even more problematic when crews are vectored east of the course due to weather; and then make a bid back towards this LNAV course in an attempt to get on the recommended ground track. It is my understanding that at least one other crew has previously experienced a GPWS advisory when making a similar bid to get back on the ground track from the east. After our flight; I contacted two friends. They shared their published visual approaches; which while different; both clearly utilize points that remain over the water and hug the coast line. Both of these carriers have greater experience flying into PHTO. Suggestions: There are two changes we could make to RWY08 ops into PHTO. First; we could recommend crews shoot the already published LOC 26 approach; Circle-to-Land RWY08. Second; we could change our current visual arrival to better mimic those used by other carriers. Their ground tracks hug the coast line; resulting in a slightly tighter final; but avoid flying further inland toward the upsloping terrain; which caused our GPWS event. Regardless; I think we should immediately lower our recommended altitude at ARBOR from 4500 to 3000. Looking at the VOR DME approach into PHTO; its clear ARBOR has already been TERPS'd to this lower altitude. This lower altitude would allow an even more gradual descent toward the 3-mile extension point.
Second reporter narrative
Flying our visual approach procedure from our airport briefing guide to rwy 8. Requested rwy 26 because of lower clouds but denied. Was cleared down to 1500 when runway was acquired and cleared the visual. With the autopilot on used heading select to position the aircraft on our line from ARBOR to 3nm extension. Was still below the PTH but approaching it from below. Configured with gear; flaps 20 and speed approx 150kts. Approaching the final turn and with our arrival check procedure accomplished and in a slight decent CAUTION TERRAIN was announced. PF clicked off the autopilot and was making a correction to slow our rate of decent when TERRAIN PULL-UP was announced. Because of the terrain in sight; clouds approximately 1000ft above us and on a perfect 3 to 1 to the runway an escape maneuver was not accomplished. We configured flaps 30 and flew a non eventful approach and landing to the runway. Cause: We are using a company approved approach guidance for reference. When flying the procedure as published there are no issues. If flying the procedure when cleared and at a lower altitude I believe the rising terrain just north of the approach corridor comes into play for triggering the EPGWS. We are looking outside as we approach the turn to final and even though we are on or close to the path the terrain can trigger these warnings. Suggestions: I think these procedure needs to be vetted more. I believe another point could be created between ARBOR and 3nm with an at or above altitude to keep from getting drug in but in a position to be stable at 1000ft. Another carrier has a published RNAV visual approach procedure that is selectable from the FMS and I think provides better terrain clearance. There is also an option for an approach to 26 circle to land 8.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.