Incident
On an unspecified date, Air Canada Jazz flight JZA8105, operated with a Bombardier CRJ705 (registration C-FBJZ, serial number 15037), departed Houston, Texas, for Calgary, Alberta, with 64 passengers and 4 crew members. While cruising at flight level (FL) 400, the crew was advised by Edmonton Centre that traffic was being metered into Calgary, with a crossing time 18 minutes later than planned. Concerned about fuel reserves due to prior routing deviations, the captain reduced power to slow from cruise speed 0.77 Mach to the long-range cruise speed of 0.70 Mach. The autopilot remained engaged in altitude track mode.
While the captain focused on the flight management system to assist the first officer with fuel calculations, airspeed decayed. Approximately 90 seconds later, the first officer noted speed dropping below 0.70 Mach and warned the captain. The captain advanced the thrust levers, but at FL 400, available power was only slightly above that required for cruise. The aircraft continued to decelerate with increasing nose-up pitch. When speed reached 0.61 Mach (180 KIAS), the stick shaker activated and the autopilot disengaged. Both pilots pushed the control yoke forward, initiating a descent and speed increase. A second stick shaker activation occurred 11 seconds after the first, accompanied by buffeting and 10-degree roll oscillations. The crew further reduced pitch, recovering speed to 0.82 Mach (250 KIAS). The aircraft stabilized briefly at FL 386 before descending to FL 380 due to conflicting traffic. The flight landed without further incident; no damage or injuries were reported.
Crew Background
Both pilots had previously flown the CRJ200 model and completed a conversion course for the CRJ705. The captain had initial CRJ200 training in September 2004 and CRJ705 conversion in March 2005; the first officer received CRJ200 type endorsement in October 2004 and CRJ705 conversion in May 2005. The crew arrived in Houston at 0200 MDT on the occurrence day, with the captain sleeping fitfully for 3.5 hours before rising at 0830. The return flight departed at 1725 MDT.
Fatigue Assessment
The captain was not well rested. Fatigue can impair alertness, reduce attention, cause preoccupation with single tasks, and lead to overlooked sequential tasks. The captain's fixation on the FMS after power reduction, at the expense of monitoring airspeed, was consistent with fatigue-related performance decrement.
Contributing Factors
The conversion training for the CRJ705 did not cover flight characteristics at high-altitude cruise, specifically the relationship between cruise speed and minimum drag speed (Vmd). Unlike the CRJ200, long-range cruise speed in the CRJ705 could be below Vmd at altitudes near the service ceiling. The crew was unaware that slowing to 0.70 Mach was below Vmd (0.75 Mach) under the flight conditions, and that insufficient power margin existed to accelerate in level flight. The captain's initial recovery response—increasing power—was ineffective; a descent was required. Company speed recovery training was limited to 10 000 feet asl and did not address high-altitude techniques.
Safety Actions
Following the incident, Bombardier Aerospace issued a message to CRJ705/900 operators emphasizing that climb speeds may be below Vmd under certain conditions, and recommended operations not be conducted below Vmd. Vmd tables were added to the Quick Reference Handbook. Air Canada Jazz introduced a nine-module high-altitude training program for CRJ705 pilots, limited operations to FL 350 until training was completed, and developed a Vmd reference chart. Amendments to the Aircraft Operations Manual warned of the importance of adhering to climb schedules and that the CRJ705 may not accelerate or maintain altitude if speed deteriorates below Vmd. Transport Canada published Advisory Circular No. 0247 on stall recovery training.