BA One Eleven Quindar Tone
 

I came across a gem on Instagram this week when the radio on the BAC111-510EDs was descibed as having a Quindar tone, I thought that beep had been a figment of my imagination! What was it? You could always predict a G-AVM* machine by the beep on ATC. What was it intended for?

It was definitely real. I have some old recordings on cassette (!) where it is very evident. I don't think it was unique to the G-AVM* 1-11s though, and think it featured on some other operators' 1-11s also, though maybe less pronounced.

I seem to remember from my early controlling days that Jet Provosts would have a tone at the end of transmissions to indicate that their gear was down - a similar thing perhaps?

You remember correctly, it was the Ultrasonic Undercarriage Position Indicator (UUPI). A triple tone at the end of the transmission. There was also the flashing white nose light that provided a visual confirmation at night.

YS

You learn something every day. I trained on the JP in 65/66, and knew about the nose light (although I believed it was steady). I had no idea of the UUPI. I guess no point in overloading the studes brains!!

I think the JP's UUPI came just after that time - I was a QFI on them until April 66 and it had not been fitted when I left. The idea was a result of several gear-up landings by studes. Oh dear.

I can confirm that the JPs at 6 FTS didn't have it in 67 but were going to - as I learned during a Hats On interview with the CFI having (thankfully) received the dreaded Red Very on short finals. Thanks also to the rapid spool up time of the Viper, although it didn't seem like it at the time either.

I don’t know when the UUPI was introduced, but it was around when I was instructing in the early ‘70s. I’m pretty sure the nose light flashed as there could have been potential for confusion with a steady white front and back.

Some versions of the Mirage also transmitted a superimposed tone in the circuit but I don’t know what the purpose of it was.

YS

A lot ( but not all) One Eleven 500s had the tone - all of Court Line's did. NO other series did AFAIK.

Most BAC1-11s I worked on had Collins 618M comm TRs. as did many other transport aircraft of that era. I wonder if there was a pin jumper on the connector to enable the tone.
Some a/c had King KTR9000s.

What was the purpose of the tone on the 1-11s?

This article explains the Mirage system to prevent landing with undercarriage still up. Unfortunately the system did not prevent the event!
Very commendably honest test pilot wrote the article.

https://qam.com.au/qam-content/aircr.../wheels-up.htm

Back in the late '60s and early '70s, all BEA Tridents transmitted a 'beep' at the end of a transmission.

Thanks, that's an intereresting and refreshingly candid report! I vaguely remember hearing of a system similar to the one described, it may have been in relation to the Mirage. However the tone transmission I heard was sometime after that incident and similar in characteristics to the UUPI fitted to the Jet Provost; i.e a short triple tone when the transmitter was keyed with the undercarriage down.

I also found this reference in the National Archive that would seem to indicate that the UUPI came into RAF service circa. 1970. There is also an account of it's invention by Guy Jefferson.

YS

I had heard of that but by the time I became a "listener" it no longer featured. Didn't the BEA/BA 1-11-510s have an avionics fit that had some commonality with the Trident but was non-standard when compared to 1-11s generally?

Yes there was an early plan to have the same crews fly both the T bird and the “Super” 1-11 hence the highly modified cockpit away from the standard version.

ISTR the -510s had a Smiths autopilot instead of the Elliott one on other 1-11s, also they had a DECCA Nav system.
Another difference, BEA didn't want the front airstairs so to keep the aircraft in balance there was some ballast installed under the radome.

That's right - my main function during an automatic approach and landing was to carefully set up the kit before engaging a large switch on the center pedestal. It was labelled "Prime Land" and if all was well it locked magnetically. As the system was single channel I then had to monitor and call out any deviations which would result in a go-around - the most exciting bit being the autopilot disengage light coming on after DH when I would yell "LAND MANUAL" usually followed by a huge thump on the runway!!

At least one Dan Air 1-11 had the beep. I don't remember if it was a -500 or a short body type.

Chevvron , that was the worst aspect of the T1/2 course ...learning to do those ''beeps'' ...... Never did get it right , indeed must have been off sick when that was covered . Certainly was not in the ARB tech test ..

Every day a learning day .

rgds condor .