Values of preliminary critical forces of longerons
and other thin-walled closed-profile rods can be calculated using the analytical expression suggested by S.
200-inch-thick outer skin, a series of longitudinal stringers, or "longerons," that have been riveted to the outer skin, rows of radial tear strips (which stop the outer skin from ripping in the event it is punctured), and an array of L- and T-shaped shear clips that have been riveted to the longerons.
Here, at the first station, workers temporarily stake J-shaped longerons between the panels.
The frames run perpendicularly to the longerons, and nest up between them.
The details of support boundary conditions at the longeron ends were difficult to specify; based on the geometry of the end supports, partial rotation coefficients were calculated and input as boundary conditions.
This hysteresis was attributed to the splitting of one longeron near the right support plate.
The AD currently requires repetitive inspections to detect cracking of the longeron
splice fittings at stringer 11 on the left and right sides at body station 2598, and the replacement of any cracked fittings with a new one.
The FAA has also proposed an AD that is applicable to certain Boeing Model 747-400 series aircraft that would require repetitive inspections to detect fatigue cracking of the longeron
splice fittings at stringer 11 on the left and right sides at body station 2598, and various follow-on actions.
An amendment superseding an existing AD has been issued by the FAA that is applicable to certain Boeing Model 747-100, -200, -300, 747SR and 747SP series aircraft that requires a one-time inspection to detect cracking of the longeron
splice fittings at stringer 11 on the left and right sides at body separation 2598, as well as replacement of any cracked fitting with a new one.
This new Australian twin spindle Long Spars & Longeron
(LSL) machine tool is only the second one of it s kind in the world; the first machine was installed at our F35 machining facility in Samlesbury, Lancashire in 2012 having been designed jointly by the manufacturer Starrag and our own engineers.