broad reach ….. when the centre gear of a fully loaded 747 suddenly encounters a steep gradient which I'm estimating at 4-5m high and very solid. The gear assembly fully compresses and then punches up into the aircraft up just aft of centre, breaking its back. The rear section snaps down and on impact with the object, separates from the front but is carried forward by momentum. All this happens in less than a second. ………
TyroPicard 2. They appear to be at a slight angle to each other.
This web-page shows the relative positions of the four bogies (on a -400). Click on the picture of the book to get a bigger picture.
http://www.amazon.com/gp/product/cus...Fencoding=UTF8
http://www.amazon.com/gp/product/cus...Fencoding=UTF8
The corresponding photo on the cover of the -200 book does not give such a good view.
It seems almost impossible that the aircraft could have been at such a nose-up attitude high that the front bogies left no sign of impact on a berm 4 m high. But how else can you explain what the photo of the berm shows?
Question: Assuming it was at such a nose-up angle, and nearly at flying speed (and therefore on the ground), what would you expect to see in the way of tracks
before the berm?
On the flat ground
before the berm I suggest you would see very little because there was little load on the ground - the plane was almost flying. As the leading wheels of the trailing bogies start up the slope of the berm I would expect a large load on the
rear wheels and for the tracks to start a bogie length
before the slope of the berm starts.
I suggest that is exactly what the photo shows.
The slight divergence of the wheel tracks as they go up the berm might be associated with the progressive collapse of the undercarriage as suggested by broad reach.
Cheers,
