Boeing Co 767, VH-ZXC

The crew of an aircraft waiting for clearance to taxi across an
active runway observed a departing Boeing 767-300 scrape its
hydraulic tail bumper during rotation. This information was then
relayed to the pilot in command of the departing aircraft who
elected to continue the flight in accordance with the non-normal
checklist. Maintenance personnel inspected the aircraft when it
arrived in Sydney and determined the strike was minor. A repaint of
the skid was all that was required for the aircraft to continue in
service.

A second officer undergoing promotional training to first
officer was the handling pilot during the incident. This was the
fourth sector of line training and the takeoff was conducted during
a moderately gusty 15 kt wind. The crosswind component was
estimated to be in the order of 8-13 kts. Takeoff and initial climb
performance depend on rotating at the correct airspeed and proper
rate, to the rotation target attitude. Early, rapid or
over-rotation may cause aft fuselage contact with the runway. Aft
fuselage contact will occur at a pitch attitude of 9.8 degrees on
the 767-300 with the wheels on the runway and landing gear oleos
extended. For optimum takeoff and initial climb performance, a
smooth continuous rotation is initiated at the calculated rotation
speed (VR) to the rotation target attitude. Rotation should be
smooth and at an average pitch rate of 2 to 3 degrees per second. A
10 degree body attitude will be achieved in approximately 3 to 5
seconds with all engines operating, and liftoff will occur at a
pitch attitude of 8 to 9 degrees. When the rotation rate is greater
than 3 degrees per second, the minimum tail clearance decreases,
and may result in contact with the ground. The minimum tail skid
clearance on a normal takeoff is approximately 61 cm and occurs
after liftoff. This is a consequence of the aircraft geometry and
the dynamic forces that are acting after rotation has been
initiated.

Analysis of Quick Access Recorder (QAR) data for this incident
indicated that rotation commenced at an airspeed approximately 5
kts above the calculated VR. The recorded data also showed the
pitch attitude of the aircraft during liftoff did not exceed the
attitude that would result in aft fuselage contact. However, the
aircraft was subject to a rapid rotation during much of the liftoff
period. A maximum pitch rate of 4.6 degrees per second occurred one
quarter of a second after main landing gear liftoff, coinciding
with minimum tail clearance.