A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David Pike
Date: 2019 Nov 4, 23:45 -0800
Bob Crawley you wrote: Thanks David, most interesting. You made me look again at my AP1234 which is 1941 but Alice through the looking glass. No name written in it but some notes at the back with the name, which might not be a name, D.R.Trainer.
At the risk of you being a fellow navigator pulling my leg, I’ll explain. The DR or Dead/Ded (take your choice) Reckoning Trainer was the RAF’s first brave attempt at a navigation simulator. Never mind digital, never mind analogue, the RAF Navigator Branch used human power, even Mr Link would have been impressed. A Basic Navigation Course comprised twelve students. The DR Trainer comprised two rows of six cubicles set back to back, so that each cubicle was connected to the one immediately behind it. The front cubicle was for the navigator, and the one behind it was for the operator. On a Monday afternoon say, half the course would be navigators, and the other half would be operators. On the Tuesday afternoon, you’d simply swap over, so that in two days the whole course had flown the exercise. As I recall, by 1967, the navigator had an Air Position Indicator (API), a G4B compass, an intercom link to the chap in the opposite cubicle, and maybe a few basic instruments like an airspeed indicator and a radio compass. I seem to remember the operator had a Ground Position Indicator (GPI Mk1) which shone a little arrow onto a chart showing the aircraft’s true position. The operator fed in winds to the system from the exercise sheet and changed the aircraft headings and speeds upon the instructions from the navigator though what were probably M type transmissions to his API.
When requested, the operator could also work out bearings from various beacons to the aircrafts true position and pass them to the navigator. Everything was painted mat black, so to us students at least, it appeared very operational. During early exercises it wasn’t unknown for the aircrafts true position to move right off the chart and start climbing up the wall. Our logs and charts were then marked by our instructors. You could have points taken off for ‘minor’ and ‘major’ errors. However, after four ‘majors’, I think it was, you started to amass ‘double deductions’. This was a cunning system to ensure no one kept just scraping through and passed out as a below standard navigator. It meant that if you failed an exercise, you failed so badly that there was no question about it, and remedial action could be taken immediately, usually by reflying the exercise the next afternoon.
By the time I returned to the Nav School as the Nav Guidance Specialist in 1980, they’d changed to a all singing digital simulator, and when I went back as a civilian in 1998, they had a really super digital simulator which remained in service at least until they stopped training navigators in the early 2000s. DaveP