Is this relevant, or not? VS selected for climb - and Airspeed/thrust didn't quite keep up.
http://www.airdisaster.com/reports/ntsb/AAR80-10.pdf
AIRCRAFT INCIDENT REPORT. AEROMEXICO OVER LUXEMBOURG, EUROPE.
NOVEMBER 11,1979. DC-10-30, XA-DUH
3. CONCLUSIONS.
1. The aircraft was maintaining a constant Vertical Speed during the period of time immediately preceding the incident.
2. Thrust from all three engines was at an auto-throttle limiting value for several minutes during which pitch attitude increased and airspeed decreased.
3. The relationship between aircraft attitude changes and flight control commands and the minimum airspeeds recorded indicate that the aircraft was in an aerodynamic stall.
4. The autopilot system was commanding aircraft pitch attitude and, preceding the stall, the auto-throttle system was controlling thrust during the climb.
5. The autopilot system was in a Vertical Speed mode rather than an Airspeed or Mach command mode during the climb contrary to prescribed normal operating procedures and recommendations, AEROMEXICO's procedures and contrary to the manufacturer's recommendations.
6. The autopilot commanded an increasing angle of attack while attempting to maintain a pre-selected Vertical Speed which exceeded the limit thrust performance capability of the aircraft at higher altitudes.