This report is taken from our US NASA ASRS [1]sister organisation’s CALLBACK publication Issue 533 (June 2024) and refers to some sobering consequences of a B767 crew’s VNAV interactions. The Relief Pilot’s report is a little blunt in pointing out what wasn’t done correctly, and neither report really explores why this incident occurred with 3 pilots on the flight deck. Perhaps the pre-approach briefing was not comprehensive, the responsibilities between PF, PM and Relief Pilot were not clear, or CRM had broken down in respect to following procedures. Press-on-itis and task fixation (everyone focusing on the approach and not monitoring vertical speed in this case) are well-known HF concerns that can be overcome by taking time to sit back and think about the bigger picture rather than dive into a course of action without having properly considered and briefed the potential threats and errors that might be waiting to pounce.
From the Captain’s report:
We began the approach, but updated weather indicated the airport was below minimums, so we coordinated to hold. While in holding, [Company] advised that another flight landed successfully, and with updated weather, we had the visibility required to begin the approach. ATC amended our holding altitude from 5,000 feet to 7,000 feet, but we forgot to put our new cruise altitude in the Flight Management Computer (FMC) like we did before attempting the first approach. We received vectors to intercept the final approach course and commenced the approach but did not recognize our lack of vertical guidance due to not entering a new cruise altitude. The aircraft appeared to be flying the approach in LNAV/VNAV passing the final approach point, but began a descent rate approaching 1,500 fpm that wasn’t recognized. The Relief Pilot and Pilot Flying (PF) began looking for approach lights as we approached minimums. They had the approach lights in sight, and so we continued the approach, still descending faster than planned. All of us were looking for the runway environment. At about the same time the PF and Relief Pilot saw 4 reds on the PAPI, we received an EGPWS terrain warning. I incorrectly called for a go-around instead of a CFIT (Controlled Flight into Terrain) recovery, and during the manoeuvre, the pitch attitude became excessive and we received a low airspeed caution as it decreased to around 105 knots. We completed the manoeuvre, sorted through the distraction of low fuel cautions due to our 10,000 pounds of fuel sloshing during the go-around, and diverted to a nearby airport.
From the Relief Pilot’s report:
Following holding, the crew flew an RNAV [approach]. The crew made common errors on the approach and ultimately descended inappropriately below the minimum descent altitude using faulty visual cues.… The subsequent go-around resulted in a “Caution Terrain” and then “Whoop-Whoop, PULL-UP.” … The descent had inadvertently been continued during the go-around, which caused the GPWS caution/warning. Then, the crew misapplied established procedures on the…go-around, which resulted in excessively slow airspeed. I had to intervene during both the RNAV approach and subsequent go-around to ensure safety. The crew should have realized there was not a proper vertical path and either modified [the] descent rate or discontinued the approach. Also, the crew should have had the situational awareness to know that they were still several miles from the approximate visual descent point and use that information when deciding to proceed below the MDA. During the go-around, the FO became task saturated with non-critical items (FMS, ATC communication, etc.) and failed to monitor the flight path adequately and perform PM duties correctly. This greatly affected the safety of flight during the go-around.
[1] As for CHIRP, ASRS collects voluntarily submitted aviation safety incident/situation reports from pilots, controllers, and others but on a much larger scale (ASRS currently receives 8-10,000 reports a month) and so, unlike CHIRP, they have limited scope to engage with the organisations concerned with individual reports to gain their perspective. As a result, most raw ASRS material is unverified, and some can be a bit emotive or lack perspective, but their alerts and CALLBACK newsletters provide a curated view on topical issues that offer useful areas for thought. For those seeking more data, the ASRS reports database is a public repository that provides the FAA, NASA and other organizations world-wide with research material in support of the promotion of safe flight.