2.
The persons who schedule the recovery must make the decisions about the tethers (number and locations). These decisions must be made at the location of the incident. There are many conditions that have an effect on these decisions:
A. The type of airplane incident.
B. The recovery method and procedures to be used.
C. The equipment which will be used.
D. The ground conditions in the area.
E. Wind conditions
3.
The persons who schedule the recovery must know the data in this document. They must also know or have:
A. Practical background of recovery experience.
B. Specific recovery data for this airplane.
C. Operation and limitationsof recovery jacks, lifting bags, cranes or related recovery equipment.
3-00-1
GENERAL STABILIZING DATA
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3-10 INTRODUCTION 3-10-1 Wind Loads
1.
You can have very large loads from the wind on the airplane. These loads change with the wind direction and the wind velocity. When the airplane is on jacks, the wind forces must not cause large loads than the usual maintenance loads. Do not use jacks in wind speeds higher than 40 MPH, 35 knots or 64 km/hour.
2.
Do not use pneumatic bags in wind speeds higher than 23 MPH, 20 knots or 37 km/hour.
3.
Do not use movable cranes and slings in wind speeds higher than 30 MPH, 26 knots or 48 km/hour.
4.
Removal of the vertical fin can decrease the wind forces on the airplane when it is being lifted and when
it is on the jacks. This also decreases the wind forces when the airplane is being towed.
NOTE: THE WIND LIMITS ARE FOR JACKS THAT ARE FULLY EXTENDED.
3-10-1
WIND LOADS
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3-10-2 When You use Jacks and Tethers
1.
When you lift the airplane with jacks, there can be large horizontal forces at the jack points. If a jack is not fully vertical on all sides, these forces can occur. They usually occur while the airplane turns to a level attitude because of the movement (arc travel) of the jack points. Unless special recovery jacks per Items 2 or 3 are used, tether lines are required.
2.
There is a jack (the strut-type that has no mechanical lock ring for the vertical direction) that turns a large angle (through 8 degrees of arc). This jack turns while it aligns with the jack point and the airplane changes its position (to a level attitude). The horizontal force is the result of the multiplication of these factors:
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本文链接地址：757 Airplane Recovery Document 飞机恢复文件(57)
