Thank God we didn't persevere with Decca. It really was designed as a ship's navigation system and designed to work at the speed of a ship. It could be pretty erratic at times. Does anyone else remember having to fit all the keys in exactly the correct order into the turret. I seem to remember that each key had a 3-letter designation (like "JJK" for example) and woe betide you if you got them in the wrong order.
I did a year seconded to BEA on the Viscount 802/806 in 1964 and I can't remember if they were Decca equipped either. On balance, I think they were.
I can remember doing some trials at Larkhill on Salisbury Plain to see if we could use Decca for "blind dropping" (of troops and/or equipment). We selected Decca chains that gave us a good track lane through the drop zone and another chain that gave another lane at 90 degrees or so in order that we could compute a release point making due allowance for wind effect (CARP - Calculated Air Release Point).
After a bit of practice we were getting an accuracy of 200 yards but there were just too many imponderables to make the system reliable.
Just imagine what we could have done with GPS and a Garmin 430 instead of a single Doppler and a Decca?
For that matter, just imagine what Bomber Command could have achieved even with a TomTom!