Getting to the bottom of Data Link: Ground Radar and Lightnings

[ScottBouch]

Hi all,

I know this topic has come up in the past (other thread), and there are some recollections and opinions out there, but I have struggled to find much in the way of concrete reference material to answer my questions, so I thought I would start here. I have also sent a couple of questions to https://www.raffca.org.uk/ in the hope that someone there may be able to help too.

A.R.I. 18168 aircraft installation consisted of:

• PTR-177 V/UHF radio T/R unit (in lieu of the PTR-175)
• Signal Data Converter
• Selector Address unit
• Head Sound Reproducer

I so far have written up what I have find out about Data Link and Lightnings here: https://scottbouch.com/mcfs/lightnin...-data-link.htm which is mainly aircraft-oriented, not having much information from ground radar stations. I'm looking to fill in the blanks by asking specific questions, as the other thread is mainly broad stroke comments.

My questions are:

A) If Data Link was just trialled:

1. What dates/years was the trial conducted?
2. Which units/squadrons conducted the trial?
3. Why did it fail to enter service fully?
4. What did aircrew think/feel about the pre-recorded voice commands? I have a distant memory of an ex-RAF pilot telling me the "robot voice" telling them what to do was disliked, just can't recall who told me.
5. If the Data Link system was capable of flying the aircraft via the Flight Control System/Autopilot, how did the aircrew feel about this, being at someone else's mercy?
6. Is it true that the space left where the Signal Data Converter would have been installed was used for kit bags? And/or discreet "duty-free" imports?

B) Technical questions:

1. Did the RAF Lightning Data Link use the "Link4" standard? (reference)
2. The "Head Sound Reproducer" unit was the tape player that passed voice commands to the aircrew headsets; was this a male or female voice?
3. Is there a list of these recorded voice commands anywhere?
4. Has anyone got a Head Sound Reproducer knocking around anywhere with tape still inside? (If so, could I get it working?)
5. As command/target data was able to be presented by the IFIS (Integrated Flight Information System) flight instruments, was the Flight Director bead of the attitude indicator able to be controlled by Data Link?
6. If 5 is a 'yes', then was the Flight Control System / Auto Pilot also able to fly the aircraft based on Data Link commands? ie: pilot hands-off.
7. Does anyone have any AP's detailing ARI 18168? Or other related information?
8. Are there any ex-Lightning pilots who still have any flight log books who may have worked on the trials? May be able to find some dates out..

Other aircraft:
I once spoke to a ground radar engineer who told me the RAF F4 Phantom also was compatible with Data Link, however, I don't know if this was in service, or just trials. I can't find any evidence of it in my Buccaneer S2 Vol1 AP's.

I probably will have many more questions as time goes on, but if anyone can answer any of these, or indeed throw any other thoughts into the melting pot, I'd really appreciate it. Ideally I'm looking for specifics rather than generalisations (and indeed documented evidence is king of all), but I will gladly listen to anything that anyone can recall! You may know an answer to a question I've not asked, so please do throw it in!

If I have made any mistakes / bloopers in the web page I've written, please do let me know! I'm trying to keep it factual and show my research.

Many thanks, Scott.

[ORAC]

Have you contacted this chap?

https://incoseuk.org/Documents/Publi...k_Hitchins.pdf

“I was part of the infamous Linesman Mediator project for UK Air Defence: my rôle was operational remote control via data link of many simultaneous Lightning interceptions. “

https://uk.linkedin.com/in/profhitchins

[ScottBouch]

Ooh, that was interesting, thank you... It has brought me to the Linesman Mediator system.... lots of reading and learning to do on this topic too!

I will try and get in touch with him, thanks for the pointer.

There is one interesting line on Wikipedia: https://en.wikipedia.org/wiki/Linesman/Mediator stating: "The interception side was only ever used in the training role of the School of Fighter Control." Difficult to avoid speculating, but some conclusions could be guessed at here regarding the role of Lightnings equipped for Data Link.

Cheers, Scott

[MAINJAFAD]

Originally Posted by ScottBouch

Ooh, that was interesting, thank you... It has brought me to the Linesman Mediator system.... lots of reading and learning to do on this topic too!

I will try and get in touch with him, thanks for the pointer.

There is one interesting line on Wikipedia: https://en.wikipedia.org/wiki/Linesman/Mediator stating: "The interception side was only ever used in the training role of the School of Fighter Control." Difficult to avoid speculating, but some conclusions could be guessed at here regarding the role of Lightnings equipped for Data Link.

Cheers, Scott

Wasn't the Data link suppose to work with GL-161 Tinsmith for overseas operations? The SAM control side of GL-161 data link system was installed in the Bloodhound Mk II system in 1966/67 using the DDL Mk 5 equipment which could be connected to GL-161 via a radio relay system. 41 Squadron trialled it with 1ACC in the UK in 1967 and on exercises in Cyprus in 1968. The two FEAF SAM squadrons were supposed to have got GL-161 data link capability, but the order for their DDL Mk 5 equipment was canned in 1966 as part of East of Suez. When the mods were done to the Launch Control Post, a DDL Mk 5 kit was sent out from the UK to proof the FEAF systems. 3 of them were then given to Singapore with the 3 RAF Bloodhound Sections left at Seletar by 65 Squadron. If the system was developed and trialled before 1967, the basic overview of such work will be covered in the RRE / RRSE half yearly reports held in the National Archives with cover 1961 through to 1967 and a gold mine for information on both Ground and Aircraft electronics systems development in the UK between those years.

https://discovery.nationalarchives.g...yearly+reports

There are also Yearly reports for 1969 and 1970 (1968's copy was missing on transfer).

Most of RRSE's AP archives were given to the Radar Museum at Neatishead in the early 2000's.

[ORAC]

Two points.

First, remember the SLEWC system at Neatishead stood for Dtandby Linesman Early Warning Control. It was a bodge job to fill the gap after Tripwire was replaced by Flexible Response and the idea of controlling everything from West Drayton was binned.

Second, the SFC comment is a red herring. The SFC had, just like Neatishead, a bureaucratic requirement to do a certain number of practice intercepts (PIs) using the simulator, regardless of how many live you had done, of which 50% had to be automated.

IIRC correctly you had to do 40 PIs a month, 20 sim. There were months I did a couple of hundred live Pis (WB/BW F-4s in up to 8 ships, but that’s another story), but still was ordered down on console to do my sim stats.

You’d sit at the consol3 hitting the buttons to watch the computerised instructions pop up and talk to the sim driver… about anything as it was a complete waste of time just to fill a piece of paper filed and shredded a couple of years later.

[ORAC]

41 Squadron trialled it with 1ACC in the UK in 1967 and on exercises in Cyprus in 1968.

You remind me of a story.

The Datalink equipment was installed at The CRC at Caoe Gata at Akrotiri, linked to the bloodhound units on Bloodhound Ridge at Episkopi.

The controller had a switch on the side of the PPI display to activate the link and slave the azimuth and elevation of the FUs to the screen cursor which was placed over a target. the switch was supposed to be left off except during trials.

The Cursor also had an inter-console marker mode (ICM) where the marker could be shared from console to console to allow the Chief Controller to allocate a target to a controller, or a controller to hand over control to another etc.

The operators also got bored during night shifts and used to use the ICM to play Battleships between consoles, using the GEOREF squares as targets.

Cue the night when someone forgot to disable the link and a hysterical Bloodhound unit watched as their missiles slammed from side to side in response to cursors jumping a60-120 miles at a time….