Originally Posted by Bucking Bar

The NTSB just came out with it's findings in the G650 flight test accident in Roswell NM on 2 April 2011. While it has been known that aircraft stall remarkably differently in ground effect (near instant spanwise propagation and ~ 2 degrees less AOA), there is no certification test that requires VSO in ground effect (only VLO) and it is probably impossible to actually test, safely. Working backwards from the Gulfstream accident, and at least another half dozen events where good data was captured, has been enough to seriously concern the NTSB and Aircraft Certification folks at the FAA.

Politically, there is a lot of resistance to lowering V Speeds at the moment. It can be noted that the crew of the G650 were very close friends of some of the managers in the FAA's Certification Branch.

The 737-800 has a great wing. The wing isn't the issue on that airplane. In one airline's experience even VREF-5 is enough to get the tail. The brakes bite well on initial application, but as the thing slows down the effectiveness of the spoilers / ground lift dumpers is reduced. It seems to me the airplane likes to hydroplane below 60 knots on wet surfaces. It sets you up for an excursion when you feel the solid decelleration and then once you think you've got it made, it starts sliding. My technique on wet surfaces (and it matches our training) is full reverse and at least brakes 3 or equivalent manual braking. Others may argue that this is too conservative, but I start thinking "short" below 7,000 feet, figuring I'll overfly 1,000 feet before being able to get on the brakes and prefer to be at a reasonable taxi speed prior to the 1,000 foot marker. That's 4,500 to 5,000 feet used.

The 757, 767, and 700 all realistically land 1,000 to 2,000 feet shorter (slower & lots more brake per pound), in my swag ... humble opinion. I don't claim to be a Luftwaffle test pilot on his fourth cup of coffee, either. It's just a all night trans con to a wet runway at SFO sort of opinion.