Under carridge dynamics
Under carridge dynamics
(OP)
I have become strangley interested in aircraft undercarridge systems. Some questions....
What are the general dynamic behaviour of the mechanisms? I would imagine the landing shock/g-forces' to be significant. Are the loads typically fed through the wings structure?
When a large airliner lands, the rear-most wheels of the central boggies touch down first, and then the front wheels. Why don't the boggies touchdown in a horizontal manner?
What are the general dynamic behaviour of the mechanisms? I would imagine the landing shock/g-forces' to be significant. Are the loads typically fed through the wings structure?
When a large airliner lands, the rear-most wheels of the central boggies touch down first, and then the front wheels. Why don't the boggies touchdown in a horizontal manner?





RE: Under carridge dynamics
as for the boggie, different planes have different arrangements (more than one way to skin a cat). B747s (i think) have the boggie trimmed nose up (so the aft wheels hit first). this causes a pitch moment on the boggie, intended to absorb some of the energy of the airplane impact, i think be extending the time of the impact event. if you look at the gear arrangment, big planes B747, A340, DC10) have secondary main gear mounted on the fuselage; these are positioned at different fuselage stations, again i think to extend the time of impact.
no-one would have a horizontal boggie, 'cause i dont think you want all the wheels impacting at the same time (much like you generally don't want a three point landing) and it would be way to complicated to arrange (given the airplane's pitch on landing).
try reading a general airplane design book, Niu, Torenbeek, Raymer, or a specialist undercarriage book.
RE: Under carridge dynamics