Does anyone out there have any facts/figures for the amount of wing lift you could expect from the Harrier's wing whilst you're in the hover?
The reason I ask:
When flying the GR7 from Illustrious, the boat was usually turned into wind for landing. I've always thought (is it pyschological?) that a stiff 20-30 knots over the wing makes the jet hover at a slightly lower power setting than I'd expect.
Using the very conservative figure that the wing is producing 1000lb lift at 50kts (the number in the books for RVLs), and assuming the lift coefficient stays the same, surely by just factoring for the difference in dynamic pressure, you should get around 200lb at 20kts. Can you make that assumption?
I'm now flying an AV8B II+ with the USMC and they insist on turning the boat around and running downwind for landings. According to the USMC software, you lose about 400lb performance if the apparant wind over the wing is greater than 15kts.
I've asked around what their reasons are. No one seems exactly sure - have heard 'laminar flow breaks down below 50kts', 'stronger wind means the SAAHS is going to be working the reaction controls more' and 'stronger wind blows out the LIDS cushion'.
Have no idea what they're talking about with regard to laminar flow breaking down - certainly don't remember that rule from university.
I can see how in a gusty wind the SAAHS would work harder - but a steady wind (like that produced from a boat steaming along at 30kts) should be fine shouldn't it? And besides it'd have to be working really hard to use up the 400lb their software says it does + whatever lift effect the wing's producing.
As for the LIDS effect - I was always under the impression it only really cut in around 15-20'. While on a windy day you do get a bit of 'suck down' I've never thought of it as being so bad that I'd e.g. come into the hover on a 20kt day at a land base 400lb below my VL figures.
Operationally, it would really help if the boat didn't have to keep turning into wind for launch and downwind for recoveries - especially when someone calls up for recovery low on gas (eg bingo-ing out of Iraq...) and there's a launch cycle in progress. Basically I'm just trying to clear my name for the huge faff I caused the other day by being able to tell them they didn't need to turn the boat around.
