|Quoting Chksix (Reply 1):|
dropping it mounted in a rig from 30 ft
|Quoting 3DPlanes (Reply 3):|
Solving for t, gives 1.37 seconds to go 30 ft. With v at impact equal to 2630 feet per minute.
|Quoting TristarSteve (Reply 7):|
Many years ago, the Royal Air Force decided to try out the autoland on their newly acquired Tristar.. They had not been trained on autoland, but found out later that the tech log entry stating that autoland was not available was not just a training issue, but backed up by several pulled and collared circuit breakers. The collision with the ground threw the mighty L1011 back into the air, and also broke the wing main spar and punctured the fuel tanks in many places. Five tonnes of fuel was lost during the following circuit and manual landing.
|Quoting CitationJet (Reply 9):|
Landing gear on commercial aircraft certified to Part 25 criteria. The landing gear limit (once in a lifetime) load is 10 feet per second at the maximum landing weight and 6 feet per second at the maximum takeoff weight per FAR 25.473. In addition the gear is tested to a reserve energy requirement (ultimate load case) of 12 feet per second. At 12 feet per second at max landing weight, the tires can blow, and the structure can permanently deform, but the landing gear cannot break.
|Quoting Cedarjet (Reply 8):|
So they just let it fall onto the runway from circuit height, thinking it was being flown by the computer?! Oh man. Government work. What can you say?!
|Quoting PhilSquares (Reply 5):|
On the 744, 600 FPM is the value that will satisfy the on board monitoring system.
Knowing that cracks me up now that I realize the error in my FlightSim practice.
|Quoting BAe146QT (Reply 14):
I may be remembering this incorrectly, but I'm sure I read that for the 737 at least, it's possible to get the descent rate too low.
Something to do with the wheels not spinning up and therefore flat-spotting the tyres.
Unfortunately the 737-700 was particularly prone to a dramatic shudder from the main landing gear if you tried to land smoothly. Fortunately Boeing started fitting shimmy dampers to this series from L/N 406 (Nov 1999) and a retrofit was made available.
On the 744 the descent rate will be around 900 fpm on the glideslope.
|Quoting FredT (Reply 15):|
Edit: An excessively smooth touchdown can delay the activation of the weight on wheels switch. This can, depending on the aircraft and the function of its systems, cause secondary effects.
I had a good look at the wings, and the pilot had the ailerons flapping up and down while we floated for quite a while.