Glider Wings on a 747?

On Friday, November 23, 2012 12:30:03 PM UTC-7, Peter Higgs wrote:
At 16:45 23 November 2012, kirk.stant wrote:

On Friday, November 23, 2012 10:00:08 AM UTC+1, wrote:

Great responses Papa3 & BobW. For those wanting to quantify glide

ratios,=

the Airbus A330-300 quotes a glide ratio of 18:1 with a double engine

fail=

ure. This includes the added drag from the RAT, an emergency windmill

that

=

extends to provide hydraulic and electrical power in such a situation.

Not

=

bad for a 238,000kg machine Casey



Yeah but what is the sink rate? And at what speed?



Kirk

66





Well lets do some Mathematics....



Estimated best L/D speed 160 knots

Therefore vertical speed = 160 / 18 = 8.89 knots



and that equals 8.89 x 6000 =53,333 ft / hr



which equals 53,333 /60 = 889 ft/min.



QED

I believe U-2 best power out glide is 250knots. Yes quite different, but I know of two that flamed out 300 miles off the UK and returned, albeit not to homeplate.