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mounty
10-05-2009, 07:48 PM
Hi Guys,

A quick question for all you 737 drivers. What degree of pitch do you use on take-off? I use about 8 till clear of a tail strike. What degree do you use after initial takeoff to avoid tail strike? I go from 8 degrees to approx 14 for the initial climb out to around 5,000' and then switch to LNAV. Any ideas would be welcome. I can't find any particular specs on this part of the takeoff and climb.

Thanks

Rob

autocadplease
10-05-2009, 08:51 PM
From the real manual:

ROTATION AND LIFTOFF
As the airspeed approaches V1, the slight forward control column pressure is
relaxed to neutral, allowing for a smooth rotation to begin at VR.
At VR, rotate smoothly with one continuous motion approximating, but no more
than 2.5 degrees/sec. Using the normal rotation rate, the aircraft flies off the
runway as the pitch attitude increases, and a runway to fuselage clearance of
approximately 20 inches results.
Rotate initially toward a 15-degree attitude. This will result in an airspeed of
approximately V2 + 20 knots. Initially, the Flight Director will command 15
degrees nose up. However, the F/D pitch command will not be used during
rotation. Indicated airspeed and vertical speed are the primary instruments.
After the radio altitude and vertical speed increase, the Pilot Flying will adjust
pitch to coincide with F/D input. This pitch command under normal situations
will be V2 + 20 knots. The Flying Pilot will maintain the F/D input of V2 + 20
until reaching initial flap retraction altitude.
At light gross weights, an initial climbout at V2 + 20 will produce an excessive
deck angle. A slight difference between aircraft symbol and F/D pitch
command will be necessary to not exceed 25 degrees of pitch. This pitch limit
is for passenger comfort. The F/D pitch command will become synchronized
with the aircraft symbol as the flaps are retracted during acceleration to clean
maneuvering speed.

737 Sec. 3 Page 115
Flight Manual Continental Rev. 11/15/02 #41

Because the aircraft is geometrically limited, it cannot be rotated to a body angle
that will prevent it from becoming airborne with takeoff thrust. Premature
rotation will probably result in the aircraft becoming airborne before the normal
liftoff point, and at a slower than normal speed. Since this speed will be
considerably below the best angle of climb speed, the initial climb profile may
be greatly reduced.
The aircraft has a very low angle of attack on the ground in three-point attitude.
Delaying rotation (waiting for the aircraft to “Fly Itself” off the ground) will
increase the liftoff distance considerably.
The airspeed indicator will lag momentarily during rotation due to the vertical
movement of the static ports relative to the direction of flight as the nose is
lifted.
When a positive rate of climb has been verified on the IVSI and altimeter, either
pilot will call, “POSITIVE RATE.” When a positive rate of climb is confirmed,
the Pilot Flying will call “GEAR UP,” stabilize airspeed at V2 + 20 knots, and
transition to the F/D pitch command.
In roll, the F/D commands wings level to 400 feet RA, then selected bank angle
limit to the selected heading when a new roll mode is selected.
Selection of pitch and roll modes other than TOGA are inhibited below 400 feet
RA.
During takeoff or initial climb, if a center tank LOW PRESSURE light(s)
illuminates, the center tank pump(s) may remain on until the climb attitude is
reduced and the light(s) extinguishes or workload allows for the pump(s) to be
positioned to OFF. When established in a level attitude at cruise, if the center
tank contains usable fuel and the center tank switches are off, center tank pump
switches may be positioned to ON again. Verify the LOW PRESSURE light
extinguish and position both switches to OFF when both LOW PRESSURE lights
illuminate.

Sec. 3 Page 116 737
Rev. 11/15/02 #41 Continental Flight Manual

B737 TAIL STRIKE AVOIDANCE
Analysis of tail strike incidents involving Boeing transport aircraft show that
certain common factors often play a role in these mishaps. Several not so
obvious factors can contribute to a tail strike as well.
Takeoff
During takeoff, the amount of tail clearance achieved for a given flap setting is a
function of airspeed at rotation and rate of rotation. Normal pitch attitude at
liftoff is only 3° to 4° less than the attitude at which aft body contact with the
runway will occur. For optimum takeoff and initial climb performance, initiate
a smooth continuous rotation at VR toward 15 degrees of pitch. Rotate smoothly
at an average rate of 2 ½ degrees/second. This rate will result in liftoff of the
aircraft at a body attitude of between 7 and 10°, depending upon the B737
model flown. The flight director pitch command is not used for rotation. The
point of minimum ground clearance occurs slightly after liftoff, as the aircraft
pitch attitude continues to increase towards 15°.

mounty
10-05-2009, 10:39 PM
Hi,

Thanks Grant. I should read the whole manual! I'm pretty conversant with general knowledge and now it's time to refine that knowledge.

Rob