Autostabiliser question

[belfastvern]

Hi there, i am a helicopter engineer currently doing a degree in aircraft maintenance and the the essay i`m doing at present is on autopilots and asks me to explain how it has developed from the autostabiliser system through to the modern AFCS. I`ve got plenty of info on afcs but am struggling with finding history. I got a monster reading list from the uni and was looking for a bit of assistance to narrow it down before buying books that are useless. any help would be greatly appreciated.:D

[sycamore]

BFV,if you go to the `flightglobal` website,archives,and look up 1956-1794/4 pdf file ,that might give you some background.Further searching for` heli autopilots` will also get you some more.If you want simplicity,remember Igor started by flying around his garden,in bowler hat and overcoat,next day he wanted to go further,and a bit faster,so he put a canopy on it,but got tired,and decided he needed some help,from a few mates called Sperry,Honeywell,Lear,Elliot ,who made `autopilot/auto stabs` things for aeroplanes; he could now go further,and in bad weather;he didn`t want to pay for another pilot to help all the time,and sometimes the system failed,dramatically,in cloud,so he had to work hard;so,he put 2 systems in his helo,now a bigger helo,to carry his military friends;he had also sold a few helos over here,and another mate called Louis Newmark knew a bit about electronics and `wiggly amps`,and he really improved it a lot.Igor could now fly day /night/IMC and his mil. friends flew his helos out/from their boats,and try catching big fish-submarines, by dipping their `ear-trumpets` into the water,and listening,but it was difficult; so LN designed an automatic`transition down/up`,and hover over the water,whilst the ear-trumpets were deployed, AFCS that could fly the helo in all weathers
and sea states,and all the overpaid pilots did was sit on their hands.Pretty good .Igor and his mates were very happy,especially the `Glovers` at Yeovil ,who made his helos,except they always had difficulty with windows,which leaked in wet weather..not good for Louis`s electronics,even to this day!!
Nowadays,its possible with improved nav systems(GPS/datalink) to fly coupled approaches to airfields and ships,and in some cases without a pilot.....B

[PlasticCabDriver]

Very good essay sycamore, all salient points covered, but I'm not sure 265 words is long enough for a degree essay (then again nowadays it might be). Could you pad it out a bit more?

[sycamore]

P-C-D,yes I think I could,but don`t have any `red `left,;I was thinking about the last mini-paragraph,in relation to the NS accident,and the systems I flew some 35 yrs ago at AAEE and RAE,in WX3/S-K/Puma /Gaz,for steep/offset approaches using `Madge`,coupling it to the autopilot,and doing transitions to the hover(difficult over land with rad-alts) ,but now with GPS etc it is `easily` possible if only someone would do it;and it is being done actually by QQ`s VAAC Harrier,to moving ships/vehicles.Unfortunately,it requires a bit of brass to get it going...See QinetiQ`s web for VAAC Harrier...Syc

[IFMU]

sycamore,

I believe Sikorsky has always bought pieces parts from vendors, but they have also always had their own dedicated autopilot & stability people to do the core design and test work.

-- IFMU

[sycamore]

IFMU, yes,it was a little `tongue in cheek`;obviously the designer will know the stability derivatives etc of the a/c,and a/c systems to design their own, but there are always specialist `outside` companies who may have better products.Anyway,meant to be a `hint` at further research for the poster.