B747-400
Flight Crew Last 90 Days 200; Flight Crew Total 19500; Flight Crew Type 200
Situational Awareness; Training / Qualification
ATC Issue All Types; Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Became Reoriented
Procedure; Aircraft; Human Factors
Leaving Beijing is always challenging. This trip was no different; especially due to events that delayed our departure for several hours making us all very tired even before pushback. From pushback until takeoff; we were assigned 3 different SIDs by ATC. We also had a bleed air MEL which required pilot action and several NOTAMs regarding taxiway closures (requiring our attention) which all contributed to our extremely high workload while taxiing for departure. The First Officer was the pilot flying and thoroughly briefed each and every SID we were assigned by ATC including the last one; the LADIX 8C. (However; he did not see the SID had a minimum climb gradient so he didn't brief it.) I was able to follow along during his briefing while I was taxiing; and; while we were stopped short of the runway awaiting departure; I was able to look it over again in more detail. I immediately noticed this particular departure required a minimum climb gradient of 7.6%. When I first saw it; my first thought was; 'Wow! That sure is steep!' I thought about it for a minute but didn't articulate my concern to the rest of the crew. I did this because I remember being told over and over again during training events that; 'Engineering analyzes all these SIDs and ensures our aircraft can meet the performance requirements' Even though I wasn't entirely comfortable; I rationalized it away. If only I had taken a look at the climb rate requirements at the bottom of the chart for the climb gradient; I would have easily determined that we couldn't meet the gradient requirement. But; because of how tired I was from the delay (at the time; I had been awake for over 17 hours); I didn't. There were 3 at or above altitudes in the SID. The first wasn't a problem because ATC had leveled us prior to the crossing thus negating the restriction. The next one; I realized just a mile or so from it; that we weren't going to make it but I didn't have time to advice ATC. I was able to inform ATC of our inability to meet the third 'At or Above' well prior to that fix. Once established in cruise; we obviously researched this issue. Nowhere in the FOM; briefing pages; or Flight Manual were we able to find any information or charts to help us determine whether or not we could make this (or any) published minimum climb gradient. (Some stations like EDDF have cautions in the briefing pages about minimum climb gradients.) All four of us also had the same reaction: we all believe we have been told at one time or another; 'Engineering looks at all SIDs and unless there are published warnings; our aircraft can meet these.' Well; I'm here to tell you that that IS ABSOLUTELY FALSE. There is no chance a fully loaded B747-400 can anywhere near meet the climb gradient requirement of a few published SIDs out of ZBAA. I should have refused the ATC clearance due to our inability to meet the climb requirements and requested a different SID. After our research; we determined the LADIX 41D has nearly identical routing but does NOT have the climb restrictions. I will not make the same mistake again!
Prior to departure from ZBAA; we were assigned Runway 19 with an appropriate departure. Prior to pushback (I think); the assigned runway was changed to 18L with the departure changed to the TONIL 8B (not sure because I no longer have access to the airport charts and these are not on the company issued iPad). None of the crew including myself noticed the climb gradient requirement and did not note the possibility of making the altitude restrictions on the departure at the current aircraft gross weight. After takeoff; it became apparent that we would not be able to make the departure altitude restrictions; both from monitoring the aircraft performance as well as from the FMC messages (UNABLE NEXT ALT). We advised ATC and were issued new altitude clearances that we were able to comply with. Fatigue was a contributing issue to this event as the crew was fatigued from having the departure time changed several times at the last minute resulting in a departure approximately 5 hours later than normal from ZBAA. The crew was initially notified about a 3 hour delay AT PICKUP TIME at the hotel; then notified about another one hour delay at the rescheduled pickup time. This caused me to be significantly more fatigued than normal at departure time and may have been why I did not notice the climb gradient and climb restrictions when reassigned a new departure.
B747 flight crew departing ZBAA reports accepting a SID with a climb gradient that exceeds the aircraft capabilities. ATC assigns lower crossing restrictions when advised unable published restrictions.