Classic British Flight Sim

Nice job Peter, I very rarely manage to land on single spot ships in FS as I never seem to have enough peripheral vision to achieve a hover (although I did mange to get the R22 on the back of a superyacht in FSX that was more through throwing it down at the last moment!).

Although cross deck landings aren't unusual and in fact with the Lynx during daytime ops you can pretty much depart facing anyway you want if you're pointing into wind, most small ship operations are done with the ship sailing into wind at a slight angle. The standard NATO SHOL (Ship Helicopter Operating Limit) is a wind from Red 20 at 20 knots, i.e. 20 degrees off the ship's port bow, this ensures there's minimal turbulence off the hangar and you can approach up the ship's wake, or do a low level flyby down the ship's side into a wingover at the stern to end up alongside the flight deck, but one time my driver tried that we ended up in a 100' hover. Although to be fair we were alongside the flight deck!
Obviously most helicopters can operate to more generous limits than the NATO SHOL, with aircraft AUM playing a part in which SHOL to use, but it's handy when operating with a foreign unit. Most (all?) UK types have a set of SHOLs for each ship type they've been cleared to operate from which displays the information in a nice graphical format so that if the wind is inside the circle/small square of acceptable winds it's all good. There's generally a caveat that some areas of the SHOL were made by extrapolation as it wasn't possible to get the right wind during the trial period and that the hatched areas should be 'explored with caution'.
Having said that we should probably do cross deck operations on the Fort Vic Class as the apartment block sized hangar creates all kinds of turbulence in it's wake.

SkippyBing wrote: The standard NATO SHOL (Ship Helicopter Operating Limit) is a wind from Red 20 at 20 knots, i.e. 20 degrees off the ship's port bow,

Thanks for all that info Skippy...I'm presuming that all this is Apparent Wind rather than True Wind...In fact I can't see much use for True Wind on a moving ship, but I guess the guys do need it for Flight Planning.

BTW...I recall that I was navigating a Sycamore in real life out of Thornaby and bound for points South...We got airborne in sea fog and were crawling along at very low level in visual contact with the ground. The vis was so bad that we had to go very slowly because of the proximity of many pylons. One side effect of this slow speed was the fact that we had a bit of a breeze behind us and were in fact going very slowly backwards through the air...This meant that we were using more power than usual as we had no translational lift...When pylons were spotted we had insufficient excess power to climb to go over the wires. The pilot was not going to go under the wires so we had to back off far enough to charge forwards fast enough to grab some translational lift and climb over the wires and then flare smartly on the other side to get the speed right off again for the bad vis. Anyway, to cut a long story short, the rotor gearbox did not like this treatment and the oil in it overheated and we had to put her down in a farmer's field. Ken Woodcock, the pilot kept the engine running but got out and ran over to the farmhouse to tell the farmer that we would be resting here for about 20 minutes to cool the gearbox. The other pilot Wg.Cdr. Primavesi remained on board with me while this was happening. Well after a debate and waiting for the temperature to reduce, we decided to abort and return to Thornaby...The return was much easier as we were flying into wind and had plenty of translational lift. In no time flat we were back on the ground, shut down and went for a tea break...After tea the fog just disappeared and off we went again at more normal height and speed...We never got to our destination and crashed in a field some hours later...But that's another story

Still sounds like you had better serviceability than we get!

I'm presuming that all this is Apparent Wind rather than True Wind...In fact I can't see much use for True Wind on a moving ship, but I guess the guys do need it for Flight Planning.

Peter, all the performance calculations for getting on and off the ship are done with the Apparent/Relative wind, the tricky bit is if you have to work out your single engine performance figures as this gives you a min single engine speed there then follows some debate as to what wind you need from the ship to be able to land on e.g. if the ship is going at 15knots to give 25 over the deck and your min single engine is 15kts can you hover alongside the ship, oh and what's that as a ground speed as the ASI doesn't work below about 40kts!
I've been known to use true wind for flight planning, annoyingly the computer in the aircraft will generally come up with some far more accurate figures once we're airborne though!