Tom
Cut and paste from the G550 MANUAL/ AFM
The obstacle clearance procedure is to climb with landing gear retracted,
flaps in takeoff position at a speed of V2 to at least 1500 feet above the
takeoff surface. Use of the obstacle clearance data in this section will
ensure that obstacles will be cleared by a minimum of 35 feet for dry
runway takeoffs. For wet runway takeoffs, 20 feet must be added to heights
read from the charts to assure 35 feet minimum clearance.
A Gross Level-off Height correction grid has been added to these charts
to account for the reduction in climb performance that results during the
climb from the airport pressure altitude to the recommended level-off
height. This Gross Level-off Height grid corrects the base climb gradient
capability at a height of 400 feet above the airport to the average climb
gradient available between the base height of 400 feet and the
recommended level-off height. Before the available climb gradient can
be determined, it is first necessary to determine the recommended leveloff
altitude from the Distant Obstacle Clearance chart. As indicated in
the title, these charts present available net climb gradient performance.
Per CFR 25.115 (Takeoff flight path) for two-engine airplanes, the gross
climb gradient is 0.8% greater than the net climb gradient.
In addition to criteria governing accelerate-go distance and the items
discussed above, the following procedures and assumptions also apply:
1. No configuration change, except gear retraction, is assumed to
be made prior to reaching a gross airplane height of 1500 feet
above the takeoff surface.
2. Gear retraction shall be initiated immediately after lift-off and
positive climb is indicated.
3. The airplane shall attain speed of V2 prior to reaching a height
of 35 feet above the takeoff surface and continue at a speed as
close as practical to, but not less than V2, until reaching at least
1500 feet above the takeoff surface.
4. Net takeoff flight path data shall be determined in such a
manner that they represent the airplane’s actual takeoff flight
path diminished by a gradient of climb equal to 0.8%.
5. Bank angle not to exceed 5°.
Last edited by B200Drvr; 20th Nov 2012 at 23:58.