Info on the Comet Smiths Flight director system

[40&80]

I completed a Comet ground school and Comet simulator course with Dan Air in the autumn of 1973 but never did the flight training as the course was cancelled on Christmas eve...somethying to do with the Arabs putting up the price of fuel.
I along with another HS748 F/o never received any instruction on the Smiths flight director system as it was all part of an RAF plot to give our seats to ex RAF Comet pilots waiting at the labour exchange...we were being programmed to simply fail the course which the union had insisted we went on.
I understand RAF and BEA and BOAC pilots got several days of dedicated instruction on this thing as it could get people confused.
I wonder if anyone could post me a link or provide the material I need to read to at last get a handle on this piece of equipment and understand how it was all supposed to work before I die!
For my sins I refused the Dan Air recall for the restarted course in Feb1974 having decided to join GF in Bahrain who were less concerned about fuel...but having flown the DC3 I was sad to miss out on flying the Comet but I really enjoyed the GF/ BA training on the L1011 and the LVP training in 1976. Fate is the hunter.

[tubby linton]

Was it the same as the infamous system on the guardsvan?I heard a lot of horrendous tales about that in the 1980s!

[411A]

....but I really enjoyed the GF/ BA training on the L1011 ....

Well then, you experienced the very finest (at the time) as Lockheed was at the absolute forefront of automatic flight control systems intregration, bar none.
It is unlikely to have never been equaled..for an analogue system.
Very very good...the Gold standard, at the time.

Lets see.
A twenty four year old L1011, all coupled up for an automatic approach/land maneuver, both autopilots engaged (four channels, monitored)...and it rolls on so smoooooothly, typical Lockheed.
The very finest.

Oh yes...made in America...with proper Rollers, of course.:ok:

[EGHH]

Not necessarily much help but if you do a google search for "Smiths Flight System" (including the quotes) there are a handful of interesting leads, including a couple of sites of people that used to fly the Comet and even a PPrune thread from 2001 where a fellow by the name of Flanker mentions using the system.

Smiths Flight System (http://www.dh-aircraft.co.uk/systems/sfs.html) has a small amount of into too.

[411A]

Nice going, a thread asking for info about the Comet F/D system skillfully hijacked and converted into an ad for the Tristar in under four posts.
It may have been wonderful to fly (because you keep reminiding us...

You're welcome.
Yes, it was wonderful to fly, and oddly enough....still is.
The only first generation of wide-body jet transport to have never crashed due to an aircraft/engine systems malfunction.

Now, lets us not forget, Comet was first, with jet passenger aircraft.
Credit where credit is due...without a doubt.:ok:

[Georgeablelovehowindia]

From the little bit I saw of the Smiths FD system, when I had a little play with it on the Vanguard sim at BEA: YOU WERE LUCKY! Good grief, if Smiths had been set the task of designing the milking machine, they'd have nailed the udders to the floor and jacked the cow up and down. Still, it seemed to make sense to those perverse people who revel in making things complicated.

You were jolly lucky to miss the 'Ex RAF Club' on the Comet at Dan too, but you've guessed that already.

[Dan Winterland]

It was virtually the same as the Smiths Military Flight System. A horrid contraption which was fitted to the Mk2 V Bombers. It was a capacity sapper and although it was clever when you intercepted an ILS, that was about it. It was particularly useless in the Victor where your pitch could easily exceed the maximum 17 degrees the main display could show.

If you do find out how it was supposed to work, please share the secret as I never had a clue!

[enicalyth]

As some of you guys are in the UK try Doris. Department of Research and Information Services at the RAF Museum Hendon.

[email protected]
tel 020 8358 4873

They are very helpful, if a little slow to answer on obscure queries. But this one ought to be fairly easy from the leads already given.

My daughter operates in and out of London a lot and enjoys digging up the past. She loves Hendon and if no-one is looking pats a nose here and there for me.

Give them a ring or I can ask herself to look up some facts and see how much meat they have on the bone.

[avionic type]

As a ground mech on Vanguards once we got the auto/pilot to stop "hunting " in the pitch mode by fitting a "Deadspace unit " in the pitch channel I believe we could use the Auto/pilot to bring the Aircrarft down the Glideslope to within 200ft of touch down using the Smiths Flight System on the I.L.S and at the end of it's career did not give too much trouble to us Avionioc types .But with the passing of time a rosey glow. might have dimmed the memory , it was about 28 years ago

[avionic type]

One of the problems with the S.E.P.2 was because it was all Magnetic Amplifiers and they tended to "drift "we were always trying to reset the potentiometers to rectify this problem this made the a/c wander in which Mode it was in . I think have my course notes but they were all "techie"[if the mice havent eaten them it was such a long time ago and i could find them] I know an old Vanguard Captain I'll ask him what problems he had.

[Basil]

This is the civil version as fitted to the Viscount

http://img.photobucket.com/albums/v233/Capn_Basil/SFS0002.jpg

http://img.photobucket.com/albums/v233/Capn_Basil/SFS0003.jpg

As Dan Winterland says, the presentation made it easy to fly an ILS but, because the compass scale was set and fixed to the QDM, track, or course as desired, it was not much good for lateral orientation. I used the RMI for that.

[40&80]

Hum it is a bit ugly isent it?
I suppose I would have tried hard and eventually learned to love it.
I read it incorporated a small screw that could come loose unseen by the pilot and freeze the pitch up indications and this caused one Comet to crash.
Seeing that picture and reading up on the history of the Comet just makes me realize how rapid has been the progress in aircraft design and development and how brave and skilled the jet pioneer pilots were.

[amber 1]

because the compass scale was set and fixed to the QDM, track, or course as desired, it was not much good for lateral orientation.
This was the common complaint from pilots who had previously used other systems such as Collins. They found it hard to come to terms with the heading not necessarily being at the top. I think those who had not used a flight director system before found it a bit easier to get to grips with.

[411A]

Hmmm, reminds me of some of the older Bendix flight director systems fitted to a very few older B707's...obtuse at best.:hmm::}

[colsie]

That seems a highly confusing and difficult bird to learn.

Modern day pilots I think you get of easy. :E

[Loose rivets]

I came from years on Collins FD 108 onto the Smiths. Had heard years of moans, but quite liked it. :confused: Dunno why.

My pal was looking at the 108 in me shiny jet, when he was on Brits. I kept a dead pan face as I told him that if we did a back CRS we had to take the istruments out of their mounts, and swap them over. A crew walked on at that moment, and the joke was forgotten. Years later, said mate was trainig on 707s, and yep, he started to quote me in the classroom. It was about the time everyone in the room was staring at him that he realized he'd been had. I'd tought him electrickery since he was 6 years old, so I guess it's not so surprising he fell for it.


I completed a Comet ground school and Comet simulator course with Dan Air in the autumn of 1973 but never did the flight training as the course was cancelled on Christmas eve...somethying to do with the Arabs putting up the price of fuel.


I think I can remember Ken Balsden SP? standing in front of our class and saying how worried he was about that price increase. From 10 to 12 old pennies / gal wasn't it?

[Stan Woolley]

I flew the Vanguard at Air Bridge.(Not for very long and never liked calling it anything else btw)

Some things I remember about the Smiths
1/ A lot of people struggled to get through the course because of it.
2/ You had to be really pedantic setting it up for an approach and there were little chants associated with it....'Pitch Up Sense across..?'
3/ Situational awareness was a bit tricky using it.(on my line check I took off from EMA for Cologne and initially after take off lost my direction for a...short....while (just couldn't find south)until after hunting desperately round the cockpit for something familiar I managed to ease the tension and remove the trainers bemused stare!
4/ On an ILS it could show fully centred while the aeroplane was actually curving on to the ILS.

Is that about right or is my memory as cr*p as is usually is? :ok:

[Romeo India Xray]

A few years ago (maybe 6 or 7), I was trying to source an autopilot systems handbook for the Trident (dont ask - oh OK, I was taking a group of air cadets to fly a simulator we could actually afford for them). I wanted the handbook as I had previously flown the sim and remained continually 20nm behind it when the AP was on.

Unfortunately I dont have the contact I spoke to, but I did manage to get in touch with someone at Smiths (now a GE company) after a hell of a lot of phone calls. The result (after a bit of amusement that I was trying to trace this doc) was a full copy of the AP manual turning up in the post.

If the same people are still at Smiths then it is sure worth giving Smiths a call.

[amber 1]

there were little chants associated with it....'Pitch Up Sense across..?'
Yes, that brings back distant memories. The set up for take off was "Off and across, Up and across" and for an ILS it was "Across across, Down and....up??" I think:confused:. Not sure about the "Up". Was that to do with the sense knob? Anyone remember?

[avionic type]

What a wonderful system!!!! From about 1976 onwards we were doing fully automatic landings down to Cat 3C but went back to 3B because it was all very well landing nearly Zero Zero but the crews complained they couldn't find their blasted stand, it cost B.E.A. a fortune to get it to that point but it paid for itself by getting into L.H.R.when all others failed in foggy weather. and it led the way for all other planes to get to the same standard [ if the operator would afford it.] its only drawback was the pitch computers were electro /mechanical and would sometimes stick so that channel was automaticlly switched out so it went from triplex to duplex and it became an manuel landing after 200 ft It kept me in work for very many years.:ok::ok::ok:

[40&80]

Around 1975 at LHR an elderly Indian gentleman complete with turban would stand in the back of a mini truck and shine a high power pencil beam of light onto the L1011 radome...we would steer to remain attached to this beam and he would positioned us to either the takeoff point on the runway for a LVP departure or to the terminal finger so we could let our passengers off....the ground radar voice steers we had practiced in the sim coordinated and monitored (blind) with the ground run monitor and taxi chart in the cockpit did not in practice work.
On one occassion my friend in his L1011 was positioned several times first to 27L and then over to 27 R for 90mins in an attempt to get legal Takeoff vis...sitting on stand we thought it hilarious as we heard him creeping back and forth at 1.5 kts in the turns and 3 kts on the straight bits following the beam of light...luckily for us there was only one light and one Indian available and most of our passengers did not make it to the airport before we ran out of duty hours.

[411A]

Said once, said again...credit where credit is due to the Brits for the superb Trident autoland performance.

NB.
L1011...without equal.:ok:

[L337]

Trident G-ARPB carried out the first Cat 3B landing at Heathrow (28L) on 4th Nov 1966

The first TriStar was delivered to Eastern Air Lines on April 26, 1972.

Have to hand it to the British, they did all the early development work toward autoland capability, something most have easily forgotten...or never knew.

[guym-p]

I realise I'm very late to this topic, but I only came across it recently, and joined PPRuNe specially to reply.

I'm the chap who wrote the (woefully inadequate) page on the Smiths Flight System, referred to by EGHH. I've since read an awful lot more about it, and replaced the page with a complete section. If there are any howlers, please let me know! The new section starts here:

The First Autopilots (http://www.dh-aircraft.co.uk/systems/first_autopilots.html)

In answer to 40&80: I have manuals for the Comet 4 that cover the Smiths Flight System. Not full detail; not the complete Smiths Instruments manual, but chapters in the Comet 4 Systems Manual, Operations Manual and Flying Manuals. Do let me know if you're still looking for more information. I might be able to help.

In answer to 411A: by really, really amazing coincidence, John A. Gorham, the British Smiths Instruments engineer who was project manager for installing the Military Flight System in the Vulcan, moved to Lockheed as Assistant Chief Engineer on the L-1011. Among other things, he proposed and managed the autopilot development.

So, 411A's post was not so far off-topic after all!

[stevemdc8]

I have built a full-scale, fully-functioning Vulcan flight simulator. It's very amazing (I just joined PPRUNE, and it won't allow me to post photos until I have 10 posts).

I'm still trying to fine-tune the software code for the Director Horizon instrument, and I really don't understand how it works. Does anyone have any updated info on the Director Horizon, or training materials? Thanks for any info!

[guym-p]

Do you have a copy of the Vulcan B Mk.2 Aircrew Manual (AP 101B-1902-15)?
If not, Peter Gill at FlightManualsOnline is a very reasonably priced source of scans.

Chapter 12 of that manual gives a good outline of the Military Flight System (by Smiths) including the Director Horizon and Beam Compass.
It also references RAF manual 112C-0800-1B Automatic Pilot Mk 10 B/C, which you may be able to find on line. It may be too obscure to have been scanned, though, in which case you could ask RAF Hendon Museum, RAF Cosford Museum or BAE Systems Heritage at Farnborough, and plan a visit to the UK ...

Are you in touch with the Vulcan Simulator project here? I can't post a URL, but they have a Facebook page and have been modifying real instruments to operate as simulator instruments.

Otherwise it depends what you need to know. I have more information on the civilian version, the Smiths Flight System, including civilian Director Horizon and Beam Compass instruments. It has many similarities, but, crucially, the Director Horizon instrument was different.

Guy.​​​​

[BoeingDriver99]

Reading the older posts initially thinking who is this tosser who sounds exactly like that 🦖 411A.... lol.... the man himself.

[stevemdc8]

BoeingDriver99, a "tosser..." now, that's funny. Had to look up the meaning of that, since that's a British term.

Nope... not 411A, or whoever you're "tossing" about.

Genuinely looking for information on the Director Horizon and how it works. Maybe I need to source the Smiths instrument manual somehow.

[stevemdc8]

Hi Guy, thank you. Yes, I've got the Mk.2 Aircrew Manual from Peter, and I've read the part about the Director Horizon a ton of times... still don't understand it. It's the kind of thing that one needs to see work in person. And, I've been in good contact with the folks who built the Vulcan sim in the UK -- great people! There seems to be some questions about its functioning, even on their part. I simply saw this thread, and I figured I'd ask around.

I'll check with the RAF museums and see if they have any old training materials on it. Thanks!

BTW, I helped dismantle Comet 4C N999WA (formerly XA-NAS) at KORD in the early 1980s and 1990s as a teenager... I still look at those photos wishing I could go back in time. The City Of Chicago destroyed the airplane, despite our plans to salvage it for the Smithsonian.

[Check Airman]

BoeingDriver99, a "tosser..." now, that's funny. Had to look up the meaning of that, since that's a British term.

Nope... not 411A, or whoever you're "tossing" about.

Genuinely looking for information on the Director Horizon and how it works. Maybe I need to source the Smiths instrument manual somehow.
BoeingDriver99 was talking about 411A, an L1011 pilot, and forum member who has flown west. If you were around when he was, you'd understand. It was a salute to the gentleman.

[stevemdc8]

Very good -- thank you for clarifying. I appreciate it!

[Centaurus]

While on the subject of flight directors. The RAAF bought several new HS 748's in 1966. Two for the No 34 (VIP) Squadron at Canberra. The rest for the School of Air Navigation at RAAF East Sale. Around the same period the RAAF also bought two BAC One-Elevens and three Mystere Falcon 20's. The RAAF were talked into putting (I suspect by an enterprising Collins salesman) the Collins FD 108 into each of these aircraft.

In the case of the HS 748's, a difficulty soon arose integrating the Collins FD 108 system with the British Smiths autopilot system. What was originally planned as a four week 748 conversion course at Woodford, Cheshire (a pretty airfield in those days) finished up as a five month English holiday on full allowances for the two RAAF crews of the VIP Squadron (four pilots, two navigators and various maintenance personnel).

That holiday included a one day course at Weybridge courtesy the Collins flight director people. We were given lots of pretty brochures during the two hours of lectures in the morning. At lunch time it was down to the local pub for a slap-up extended lunch and unlimited grog. End of the Collins Flight Director course.

The HS 748 was not exactly a high speed turboprop. There was no way you needed a flight director system. The instrument panel that came with the prototype HS 748 G-ARAY was well laid out including the standard "Six Pack" of flight instruments. Not like the abortion of a cockpit layout as in the Viscount. I think the Viscount had Sperry zero readers back then. But someone must have conned the RAAF procurement officer into buying the Collins FD 108 for the RAAF HS748's

I say that because I believe the initial procurement chappie was an elderly Wing Commander with previous Dakota transport flying experience. He had been behind a desk for years. Not his fault he wasn't a current pilot and knew SFA about the advantages and disadvantages of flight directors.

We soon learned that blind reliance on flight director guidance could be a trap. Back at the squadron there were pilots who loved the FD 108 gimmicks like automatic 45 degree intercepts of the localiser and the fun of flying the "little aeroplane" into the V-Bars of the FD system. These pilots became addicted to using the FD and became multi-fingered switch flickers. Others soon realised their basic instrument scan in IMC was gradually being degraded because of the compelling presence of the flight director. So they simply switched it off.

The same situation exists today where basic raw data instrument flying skills have gone the way of the dinosaur leaving pilots to rely totally on FD guidance even on a sunny day. A few of us dinosaurs could see this coming way back in 1966.

[stevemdc8]

Centarus, excellent points. The flip side is this: flying a BE1900 for seven legs, 8 block hours, in a 12-hour duty day, in February, in the Great Lakes, with winter Thunderstorms, icing, windshear, and constant turbulence all day long -- with no autopilot, no flight director, and brown-bagging food and water. The result is arriving back at base at 1AM on the last leg, and on short final approach, the First Officer literally falls asleep while hand flying the aircraft on the ILS (I smacked him gently in the arm while yelling, "Wake up!"). This was not an unusual duty day -- this was regional flying in the 1980s and 1990s. Same thing on Metroliners and Jetstreams. Of course, the poverty pay and roach motels were icing on the cake.

So, this is a case where an autopilot and flight director really were needed. Yes, we were s***-hot with instrument-flying skills, but the end objective is to get the plane safely on the ground without bending any metal.

There was the Vulcan crash after the world tour in 1956, and although there were some poor choices made, one wonders whether a flight director would have been useful after that long and challenging flying.