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The development of Automatic Landing

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The development of Automatic Landing

Old 8th Sep 2011, 19:58
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The Trident and the VC10 were the first airliners to be fitted with Autoland
The VC10 autoland really didn't begin to compare with the Trident system.

The Trident had a triplex autopilot system perfectly suited to a failsafe autoland operation.

The VC10 had dual autopilot which was never going to deliver autoland reliably on a fleet where handling practice was in far too short supply for line pilots to practice using the system, on routes that only very rarely required its use.

I'm tempted to state the dual autoland on the earlier 747s was even more suspect than the VC10 system, as November Oscar demonstrated at Heathrow.

But that might start an argument.........
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Old 8th Sep 2011, 20:39
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Originally Posted by Albert Driver
I'm tempted to state the dual autoland on the earlier 747s was even more suspect than the VC10 system,
I certainly remember a real smasher of a non-greaser on an early 747 (Wardair at Prestwick, coming up from Manchester) which the crew apologised for and said an autoland they were doing had just not flared it properly. When we continued the flight to Toronto, they said before touchdown there that they were going to do this one themselves !
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Old 8th Sep 2011, 23:02
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But at least the 747 achieved Cat 3 certification, which the VC10 did not.

Only the Super VC10s were autoland equipped, not the Standard VC10.

BOAC management tried to pressurise crews into using the VC10 autoland in order to prove the system for eventual Cat2/3 approval, but met with resistance. As Albert Driver says, the line crews rated the need for handling practice higher but also I believe they mistrusted the autoland because of its unreliability.

As I recall a failed autoland or coupled ILS was one of the factors in the BOAC VC10 low fuel diversion to the military field at Bedford. Massachusetts, not Bedfordshire.
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Old 9th Sep 2011, 14:00
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Originally Posted by Tagron
As I recall a failed autoland or coupled ILS was one of the factors in the BOAC VC10 low fuel diversion to the military field at Bedford. Massachusetts, not Bedfordshire.
Do you have any more info on that incident? I haven't heard of it yet and am interested for my website.

From this same site, here's a bit from an ex-Avionics Engineer about the demise of the VC10 Autoland (his full story is here: http://www.vc10.net/Memories/radio_development.html):
A Cat 3 autoland system was designed by BAC for the VC10. This was a duplicate fully monitored system of Byzantine complexity. Remember this was before the digital age, it was all magnetic amplifiers and analogue computing. Effectively this meant that each function was done four times, and all had to work for the system to meet Cat 3 standards which of course they rarely did. The Radio systems bore most of the blame at the monthly project meetings and as I was the sole wireless man at the meetings surrounded by twenty instrument and autopilot experts from BOAC and BAC I didn’t stand much of a chance. It was decided that the Radio Altimeters needed improving, not surprising really as they were made by STC to a design that must have been obsolete 20 years previously. The quote from STC for a modification package was horrendously expensive so I got lumbered to do it. I replaced all the coax cable with a special low loss version with a silver plated foil screen that was almost impossible to work with. We must have scrapped more cable than we used. We matched all the mixer diodes by individual selection and redesigned the monitor system completely. After about a year’s hard work the Radio Altimeters were working perfectly but the autoland system still did not perform. BAC then came up with a proposal for a package of modifications to all the other black boxes at a cost that made STC’s proposal seem small fry. By this time I felt a little more confident as I had proved the point with the Radio Altimeters and as I had some spare time I sat down at my desk and calculated the probability that all of the boxes would remain working for the four weeks required on average to certify an aircraft to Cat3 standard after a defect. As I recall this worked out that on average a maximum of one aircraft in the fleet would be certified for half the time. I could not believe this result, so I rechecked the maths, re-read the books but could not get a better result. We had already spent millions on the system and were planning on spending several more. I could not believe that my sums were correct, but I wrote it up anyway and went thus armed to the next project meeting where the big mod package was planned to be agreed.
I dropped the bombshell at the start of the meeting by asking the BAC experts what their planned system reliability was. I got a few blank stares, they seemed to have experts there on everything except reliability, but it was agreed that they would show my workings to their specialists at Weybridge and find the errors. Much to my surprise, the mod program decision was deferred. The next meeting they announced that my numbers were wrong, I had omitted to take into account the system wiring reliability so the situation was actually slightly worse than I predicted. VC10 Autoland was promptly scrapped and work started on another mod program to save weight by removing all the surplus equipment. I never got any thanks for saving the corporation all those millions, possibly because I asked the Project Manager who had signed the contract; which had no guaranty that it would work or compensation if it didn’t. 'Me' he replied and walked away.
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Old 9th Sep 2011, 15:50
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I remember the Smiths autopilot controller in the Victor Mk2 had a LOC engage switch which could also be rotated to the L Cable setting. We knew that it was for an early autoland system, but no-one on the fleet had ever used it. Not that the leader cables were in existance then.



I recall an "I learned about flying from that" story in Air Clues from the 80s submitted by a Canberra pilot who was diverting from a midlands airfield after the weather got bad. On the way to the alternate, he was passed to Bedford Approach on the way to his diversion destination. He heard a callsign in the radar circuit staing that he was going to do an ILS to roll (touch and go). Obviously, the weather at Bedford was better than our hero though, so he changed his destination and asked for vectors to the ILS. The other aircrat rolled in front of him, so he was suprised that he didn't see the lights at 200'. He was fed in again and had to go round a second time despite the other aircraft doing another roller. Now he was desparate. He had to land off the next approach or jump out. So he flew past minimums and got the lights in the flare. He taxied in with difficulty, shut down on fumes just as the other aircraft taxied past. It was a Varsity with the words "Blind Landing Experimental Unit" written on the side!
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Old 9th Sep 2011, 16:59
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REasson:

I flew the Argosy for 10 years from 1962 until the end of 1971. We certainly had a leader cable aerial fitted just underneath the radome for the CCWR (the nipple on the tit).

None of us ever knew why the hell it was there.

To my knowledge, Benson was never equipped with a leader cable. If it was, then it ended up in Passey's scrapyard very quickly.

On the other hand, I seem to remember that when I went on the Belfast at the beginning of 1972 at Brize Norton, a lot of money had been wasted on sinking useless leader cables into the farmers fields on finals to runway 26.
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Old 9th Sep 2011, 17:36
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L1011 and Caravelle

The Caravelle used the Lear Seigler system, according to the 1967 reference above. I don't know about the L1011. Unlike the Trident and VC10 systems, the Caravelle system was single-lane, with the pilot as backup, which might explain (because of the reduced complexity) why it achieved certification earlier. The descent guidance on the Caravelle system differed in an interesting way from the British system, again as explained in the 1967 article.
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Old 9th Sep 2011, 20:56
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Jhieminga

VC10 low fuel diversion to Bedford, Mass.

There was an account of this incident in the BOAC flight safety publication, c.1970. If anyone by chance has any copies of old BOAC material in their attic, or if the BA historical collection has a copy, you would be able to read the original report. Unlikely of course so I will describe it from memory, with the usual caveat about the accuracy of recall over a period of forty years. If there is anyone reading this with a more accurate recall or was closer to the event, then please feel free to correct me.

The scheduled destination of the flight was New York, but bad weather at JFK meant there were lengthy landing delays. After a period of holding the decision was made to divert to Boston. The BOS weather was also deteriorating but this was not reflected in the ATIS broadcast, so the crew were unaware of the developing situation.. The first attempt was a non-precision approach (VOR/DME I would guess) and resulted in a go around.

They then attempted an automatic ILS using the autoland system. Whether it was intended to complete a full autoland I do not know, but in any event there was a system failure which resulted in a second go around.

Then a manual ILS was flown but the weather had deteriorated to the point where nothing was seen, resulting in another go around.

The fuel situation had now become critical and at this point ATC offered the military airfield at Bedford. This was only 12nms (approx) from BOS and was VMC, so the flight was able to land without difficulty. Usable fuel remaining, about 15 minutes.

Long after the event I was in conversation with a cabin crew member who had been on that flight, who claimed that the captain had considered ditching close to the coast. I suspect this was not a formal briefing to the cabin crew, more likely an unguarded remark after the event. It was not mentioned in the safety review report so I am inclined to doubt its significance. But it does serve to highlight how marginal the operation had become as a result of a combination of unforeseen circumstances
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Old 10th Sep 2011, 08:35
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REasson - please check your PMs
Thanks
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Old 21st Jan 2012, 00:06
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Hello Reasson,

I am a bit of a Johnny come lately to this thread, but came across it when searching for posts concerning the Canberra prototype, VN799. I have been researching the life and ultimate fate of this machine, and compiling it all in a short web site:

Remembering VN799: A Tribute to the English Electric Canberra Prototype A.1

As you will see, I gathered the accident report from the crash which indeed confirms the fuel leak being the (initial) cause of the accident. However, the final conclusion was pilot error, in that it was felt the pilot should have noticed the leak in the No.2 tank earlier, the gauge not being found faulty, and switched to the No.3 tank instead after exhausting No.1. He did indeed switch to No.3 after the flame out, but then, altitude was too low to successfully relight the engines, leading to the crash.

What I am curious about is the state of their injuries. You wrote that the crew were not seriously hurt, but I would like to confirm the source of this. The 'CAS' column of the card shows 'I(s)' to which I am hoping PPRuners can clarify what this means. 'Injuries slight' or 'severe'? Depending on where you read about the crash, you will hear they died, or were just injured. Despite further digging I have not turned up anything more concrete.

Good thread on BLEU though, very interesting indeed.

ATB,

Steve
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Old 21st Jan 2012, 15:01
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An apocryphal story which might be based on a true incident:

In the early days of Trident autoland ops there was a requirement for all three flight deck crew members to carry a certificate in their licences authorising autoland ops to various limits (ILS Cat 1, 2, 3A, 3B).

So, this particular day, a T-bird is heading for LHR, where the weather is consistently below Cat 1 RVR. The crew discover that not only is the autopilot placarded for Cat 3 ops but all three of the pilots have Cat 3 certificates. Joy! They brief themselves for autoland and carefully rehearse procedures and call-outs.

On handover to London they are told 'maintain 350, join the hold at Lydd, delay not determined.' Assuming the stacks are full of aircraft waiting for the RVR to achieve Cat 1, the Trident crew play their trump card:

'We're Cat 3 qualified, we're requesting clearance to make an approach for an autoland.'

'Roger Bealine, but the RVR is now 700 metres and you're number 27 in the landing sequence.'
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Old 21st Jan 2012, 16:46
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BLEU info

Interesting info on this in Military Forum
http://www.pprune.org/6967034-post2246.html
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Old 21st Jan 2012, 17:09
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Lockheed brought a PSA Tristar to the Gulf to demonstrate it in the hope that GF would buy it. It had a video camera in the flight deck roof, looking forward between the pilots through the screen. You could see the top of the coaming. This then played on all the IFE screens.

The demo pilots' party trick was to capture the approach and then put their hands on the coaming until the aircraft was on the ground and needed to be turned off the runway.
At Doha, a new hangar had caused a kink in the localiser, which all the line pilots who went there knew about, as did most others in the business. So we watched with interest to see how the system would cope.

As we passed the kink, the aircraft started to yaw wildly, with a rolling motion, and this began to amplify quickly.

The 4 hands disappeared from the coaming so fast that they were a blur, and the aircraft quickly came under control and landed.

Shortly after the aircraft came into GF service, I hitched a jump seat ride from Abu Dhabi to London for some urgent reason. John Ross was flying it. As the undercarriage came up, he said "Watch this" and engaged the auto pilot (I suspect that's not the right term, but you know what I mean). Then he said "we won't touch the controls again until we turn off the runway at London. The computer will fly the route we've given it, and will land the aircraft when we get there". And it did. At that time (1974/5?) it was pure magic, at least it was to me.
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Old 23rd Jan 2012, 17:37
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BLEU



Ref; Blind Landing Experimental Unit (BLEU) of the Royal Aircraft Establishment.

I have just been browsing through my fathers RAF record of service

and I notice that on return from France in July 1940 he was posted

to BAT & DU (Blind Approach Training and Development Unit).

Does anyone know if this was a forerunner of the BLEU?

Aaron.

Last edited by AARON O'DICKYDIDO; 23rd Jan 2012 at 17:37. Reason: Spelling
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Old 23rd Jan 2012, 18:21
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From Ray Sturtivant's "Flying Training and Support Units"/Air Britain.

The answer is no.

BAT and DU formed at Boscombe Down 18th September 1939 flying Ansons.

Disbanded 6th June 1940, reformed at Boscombe Down 13th June 1940.

Redesignated "Wireless Intelligence Development Unit" 30th October 1940 flying Ansons from Wyton, to determine the characteristics of German target location beams.

Redesignated 109 Squadron 10th December 1940.

BLEU formed at Woodbridge 16th July 1945.

Ciarain.
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Old 23rd Jan 2012, 21:44
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Thanks for that.

Aaron.
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Old 27th Mar 2012, 14:51
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Thurleigh Fog Landings

REasson
Having noted your special knowledge in this subject and having just found this forum, I am risking boring you once again with my swan song at RAE Bedford.


The night London Airport was mine

I was coming to the end of my 3 year tour with the Blind Landing Experimental Unit (BLEU) at RAE Bedford, where I had been posted to carry out the automatic landing trials on the Vulcan. These trials had been initiated after it was realised that in the event of a nuclear attack upon the British Isles, there would be a need to disperse the Vulcan (V.Force) to designated airfields around the country. Since this would have to be carried out regardless of the prevailing weather conditions there was clearly a requirement for an ‘All weather landing system ‘. Automatic landing was the obvious choice.
The main test aircraft at BLEU were Varsity’s. These sturdy twin engine aircraft were used in all manner of tests apart from Automatic Landing. They were pleasant to fly and could carry an immense amount of test equipment and ‘Boffins ‘. In addition to the Varsity, Auto Land was installed very successfully in, Vulcan, Comet 4, Canberra and the American Airliner the DC 7. When flying the latter we always had the aircraft’s American captain on board and oddly enough we had to obtain a Private Pilots Licence, validated for that aircraft.
We flew in all weather conditions as a matter of course, and indeed, sought out airfields we knew were closed due to bad weather to assess the available approach lighting facilities. Occasionally Mr Calvert the grand master of Visual Aid Studies flew with us and it was he who declared. The Varsity was the perfect vehicle in which to carry out these tests in relative safety. Many of these airfields were American and I often wondered what their aircrews thought when they heard a solitary aircraft doing circuits and bumps in thick fog when they could hardly see to drive their cars.
The validity of these tests is self evident. There can be few pilots who enjoy the prospect of a long instrument approach, the transition from instruments to visual, through an uncertain cloud base and variable ground conditions such as, rain, snow, mist or fog. The inputs imposed upon a pilot at the latter stages of an instrument approach are enormous. I recall a senior line pilot saying during a lecture on this subject.....”At 100Ft when you have yet to see the runway, following an instrument descent, you reach the threshold of PAIN.” He was so right.
All our automatic landing tests were carried out using a single channel system. That is to say one of each piece of equipment, Autopilot, Radio Altimeter, ILS (Instrument Landing System) receiver.etc.The proposed civilian versions (Trident) would have three of everything as a safety, belt and braces measure. The whole process, apart from some switch pulling, was automatically controlled....Height and heading....ILS and glide path acquisition ...And one of my favourite items ‘Automatic throttle control...‘ Dial your speed’...What more could one ask for. It meant that the pilot could literally sit ‘ Hands off ‘with confidence until the point of touchdown. In the event of any crosswind, the drift angle was automatically kicked off just before this point. Naturally in fog one does not anticipate strong wind.
We had a long standing contingency plan that if London Airport was ever closed because of fog we would go in and carry out circuits and landings to demonstrate the system. On the 4th December 1962 my colleague ‘Pinky Stark’ went there to do just that but unfortunately his aircraft lacked a vital piece of test equipment which was to have given him directional guidance after the automatic pilot had been disengaged on landing. He was thus restricted to do touch and go landings. Had the fog been less dense and he could have seen at least two centre line lights he would of course have carried out full stop landings.

On the 5th December 1962. Having flown the Comet in the morning I was told to be ready to take a Varsity to London Airport that night to complete the demonstrations. On this occasion I would have the aircraft equipped with the new ‘Runway Guidance Indicator’. This was in ‘Breadboard state ‘. Not yet built into the instrument panel. It consisted of a tube passing over my right shoulder, projecting a Sperry Zero Reader ILS signal onto a ‘Head Up Display’, on a glass prism, mounted on the instrument panel coaming. This piece of equipment was essential in the exceptional conditions which prevailed. The actual ( RVR ) Runway Visual Range on this night was 45 Feet. To put that into perspective, runway centre line lights are spaced at 100Feet, thus only one centre line light could be seen at any one time. Another interesting observation would be...That an observer standing at the edge of the runway, would be unable to see a fully lit Vulcan, stationary on the centre line! I had never before experienced fog as dense as this. The London Airport runway is 300ft wide and the Vulcan a 110ft wingspan.
We took off from Bedford at dusk and carried out two circuits and full stop landings to test the new ‘Runway Guidance’ equipment. It was working efficiently so we left Bedford and was soon circuiting London Airport. The conditions were most unusual; above 300 feet the sky was clear but in the London basin lay this dense ‘ Pea soup’. There were no signs of lights beneath.... London was at a standstill... No buses, no trains... We were to learn that none of the VIP’s scheduled to join us for the demonstration could get to the airport.
However, we were there and plunging into the ‘soup’ on ‘Auto’s using the standard ILS, for azimuth and glide path indication... Soon after we entered the fog we heard the clatter of ice being thrown off the prop’s onto the fuselage....De-icers on...We were already ‘locked’ on the glide path and quite soon the Inner marker beeped, there was no sign of approach lights although we knew they were on....Touch-down still no lights, but we were on the centre line as I could feel from the centre line light pods touching our nose wheel.....Throttles and Auto-land were switched off and I kept straight manually using our new toy...runway guidance.....very gingerly on the brakes lest they cause a swing and so to a full stop. Now, not being able to see any lights at all, how was I going to turn around and return to the take off point? LAP Airfield Radar came to our aid and was able to navigate us through 180 degrees and direct us back to the take off position for a further circuit.
We were supposed to gather up a number of VIP’s at this point but as I have said the fog was such that they were unable to get to LAP. We did however manage to pick up Captain Poole the BEA training pilot. He was brought out in a van navigated by the splendid Ground Radar...I’m sure they could see a Ferret cross the runway.
We carried out four circuits and landings and returned to Bedford....I have often wondered what the authorities would have said had they known that my Instrument Rating had expired some days before!!!!!

Flt.Lt.C. Grogan AFC
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Old 27th Mar 2012, 16:35
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I remember going to BLEU Bedford in the late 60s or early 70s for a project on a cardboard bomber which used a monocular to simulate calvert and other lighting systems in low vis conditions. I never heard a result of the trials. does any one have any knowledge?
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Old 13th Aug 2012, 18:31
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Canberra VN799

Steve
Apologies for not responding earlier but I haven't looked at this thread for months!
As you say at your website, the crew members of VN799 on its final flight were Flt. Lt. Harry Maule and Mr. Mike Burgan. I worked with both of them during the period 1955 -1958. They were certainly very much alive, although I don't think either of them ever mentioned VN799 to me. One source of information is an internal BLEU memo, FS 77 - BLEU - THE FIRST DECADE written in 1977 by Tom Prescott, who was head of the guidance section at BLEU at the relevant time (1953). Tom said “The aircraft was a complete write-off but the two occupants, the pilot and a member of the civilian staff, escaped with nothing more than a few cuts and bruises” although from another source I believe Harry spent a night at a local hospital. Harry was posted away from the Unit some years later but Mike worked at BLEU for many years after I left. The Operations Record Books for the RAF Unit at RAE Bedford show that he carried out automatic landing trials in the Vulcan amongst other work during the early 1960s. The memo FS 77 incidentally includes a photo of the wreckage of VN799.
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Old 13th Aug 2012, 19:09
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Cheers for this update, Roy, I am responding via PM now.

Steve
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