Maximum Load
.
Ultimate Load =
..
..
Load Factor
So the ultimate loads in each direction are: Ultimate Load FORWARD = FX FORWARD / nFORWARD =1.5 F / nFORWARD Ultimate Load AFT = FX AFT / nAFT = 1.5 F / nAFT Ultimate Load RIGHT = FY RIGHT / nRIGHT = 1.86 F / nRIGHT Ultimate Load LEFT = FY LEFT / nLEFT = 1.86 F / nLEFT Ultimate Load UP = FZ / nUP = 5.44 F / nUP
A. LOADING GENERALITIES
e) Summary
This whole method can be summarized in the following table:
Angle Force Breakdown
Tie down Point Pos. Restraint α (°) β (°) FWD + AFT - LH + RH - UP +
AFTLeft UP 30 60 150 90 75% F 43% F 50% F 50% F 86% F
136% F
FORWARD Left UP 30 60 30 90 75% F 43% F 50% F 50% F 86% F
136% F
AFTRight UP 30 60 210 90 75% F 43% F 50% F 50% F 86% F
136% F
FORWARD Right UP 30 60 330 90 75% F 43% F 50% F 50% F 86% F
136% F
Total Maximum Load Allowed 150% F 150% F 186% F 186% F 544% F
Load Factor nFWD nAFT nLEFT nRIGHT nUP
Ultimate Load 150% F / nFWD 150% F / nAFT 186% F / nLEFT 186% F / nRIGHT 544% F / nUP
ULTIMATE LOAD Minimum of the Ultimate loads
This method can be applied for as many as needed tie down points, adding each time a strap in
the direction which limiting the ULTIMATE LOAD.
Then tables like the following one can be issued and published in the loading manuals of
operators.
Load to be restrained Number of single stud fittings Number of straps hooked on 2 single stud fittings
kg FWD AFT UP
less than 800 4 1 1 2
801 to 1420 6 2 1 3
1421 to 1600 6 2 2 3
1601 to 2400 8 3 2 4
2401 to 3200 10 4 3 5
3201 to 4010 12 5 4 6
> 4010 14 6 5 7
LOADING LOADING
A. LOADING GENERALITIES
Note : the recommended 30° between the rope or the strap with the main direction of restraint enables a high restrained force in the needed direction, indeed by increasing this angle, one decreases the weight that can be restrained by the item. Nevertheless some operators might choose even when applying the recommended 30° to perform the computation with an angle of 45° in order to take into account a margin in case one of the ropes in not correctly tied down.
Angle Force Breakdown
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本文链接地址：Getting to Grips with Aircraft Weight and Balance(111)
