For data, I posted this about 18 months ago...
Right, just to finish off the "there's no wind in Afghanistan" debate, I've been to the Met Off and got the following data from their MIDAS database on average wind speeds:
Location: KANDAHAR
Lat/Long: 3133N 06551E
Elevation: 1010 Metres
300MB/30000ft
Month Wind(Kts) Temperature(C)
Jan 270/60 -41.3
Feb 270/63 -39.8
Mar 270/51 -39.7
Apr 270/41 -37.9
May 270/41 -34.5
Jun 270/28 -26.3
Jul 270/14 -23.5
Aug 270/16 -24.5
Sep 270/24 -28.1
Oct 270/44 -34.5
Nov 270/51 -39.3
Dec 270/52 -39.9
Now these are "average winds", so I'm expecting about +/- 30kts on a daily basis as the normal for these wind ranges over the 28-31 day months. Also, as I stated before, "the 'Seistan' or 'the winds of 120 days' that can blow up to 100mph for up to 4 months between May and Sep in Eastern Iran and South West Afghanistan, all at ground level", will account for the months of May to Sep when the wind isn't blowing at height.
Luckily for the Americans they have much money to waste on this, which is another mad-cap and already proven unwise venture such as this. We, however, in the UK do not. I understand that Mr Gerald Howarth MP may have been already been briefed on the HAV/LEMV and been given the Company "Sales Pitch" (which gets the wind prediction quite wrong or ignores them!). If that is true, then please Minister, leave this scheme well alone as there is a long and distinguished line of others that have been taken in by the airship notion over the past 40 years.
Says it all about wind for me - it'll be lucky to fly for 6 months a year and even then the endurance will be about 2-3 days rather than 21 days. Why, well read below. Plus for the "give it a try" brigade, err, we already have...and it didn't perform as expected...
I can add some information...
The U.S. Navy had been interested in LTA technology since the early 1980s. This led to the Patrol Airship Concept Evaluation (PACE) ca. 1983, and some tests of a Skyship 500. In 1985, NAVAIR commissioned design studies for an AEW airship to work with surface action groups. Boeing, Goodyear, and a Westinghouse/Airship Industries team made proposals. These studies were for vehicles running ~3,000,000 cubic feet.
In 1986, the program was redirected toward an Operational Development Model - basically a proof-of-concept vehicle with an E-2 radar suite. Boeing dropped out, Goodyear bid a ZPG-3W with turboprop engines, WAI bid the Sentinel 5000. WAI won. A mockup of the gondola was built at the Weeksville, NC, hangar.
The USN pulled out in 1988, IIRC. Part of the A-12 eating all of Naval Aviation. But DARPA was interested in the airframe as a carrier for low-frequncy radars and pressed on with the program as funding permitted. Development went slowly, and the fire in the Weeksville hangar in 1994 (IIRC) pretty well killed the program off.
The performance numbers are off...the endurance was 60 hours, not 60 days. But it was planned to refuel at sea, making a 30-day patrol practical.
The politics of the program were very interesting. Within the Navy, the problem was that the YEZ-2 did not have a pointy nose or fire belching out the back. Not to mention that it was a direct challenge to the E-2, and a possible challenge to the P-3...and in the platform-centered communities of that era, this was politically very dangerous.
On top of that, WAI made some politically tone-deaf moves. Most of the subcontractors were in the UK...useful for the Airship Industries design team, bad for Congressional support. The Goodyear design might have been more successful, despite being technically outclassed, on that point alone.
Have a look at the posts here about it 2 years ago - I see no evidence to change my mind.
http://www.pprune.org/military-aircr...istan-isr.html
I'm with BEagle on this one
The B Word