B747 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 21; Flight Crew Total 3573; Flight Crew Type 2478
Situational Awareness
Deviation - Speed All Types; Inflight Event / Encounter Weather / Turbulence
Flight Crew Took Evasive Action
Aircraft; Human Factors; Weather
Takeoff clearance was climb and maintain 15;000. The takeoff was accomplished using max power; Flaps 10. At 800 feet AGL; the nose was lowered and the flaps were retracted to Flaps 5 on schedule. Due to the crossing restriction; I informed the crew that we would continue to climb using Flaps 5 until we made the crossing restriction of 2500 feet and then retract the remaining flaps. Passing 2500 feet; the nose was again lowered and the aircraft accelerated and Flaps 1 were selected. Current conditions were gusty winds and turbulence with airspeed +/- 10 to 15 knots during flap retraction. Once the aircraft achieved the flaps UP speed; the flaps were called for Flaps UP. It was during the transitioning of flaps from position 1 to UP; that the stick shaker occurred momentarily. The airspeed was over the Flaps Up tick speed and the red max flap speed squares were both above the airspeed as well as below the current airspeed. The back pressure on the stick was released and the stick shaker as well as the red squares on the airspeed indicator disappeared. I have never seen these red squares come from below the airspeed; only above the current airspeed. I think this was attributed to a wind shear that occurred at our altitude during flap retraction. We were then instructed by ATC to turn right to a heading approximately 40 degrees from our current course. A right turn to the heading was initiated using approx. 20 degrees bank angle and I noticed that the airspeed was approx. 10-15 knots below the flaps up speed. The indications on the airspeed indicator was a yellow band below the flaps up speed which is normal for a slow speed. The first officer began a slight forward stick pressure as well as another pilot calling out AIRSPEED. The nose was lowered and the aircraft accelerated out normally. After passing 18;000; we all discussed what everyone saw and we are not sure of what the actual causal factors that caused this incident. We believe that there was some kind of wind shear that was contributory to this event.
Upon Climb out on the departure encountered 'Stick Shaker' on first turn. Recovered aircraft and continued climb out.
B747 Flight Crew experienced a stick shaker while climbing in a turn with the flaps retracting from 1 to up. Light turbulence and wind shear may have been a factor in the incident.