Classic British Flight Sim

Hello everyone, I've been searching the net on and off for a week now and then it hit me that if I posted here someone would probably have the answer at hand.

I'm trying to find information on how aerial navigation was done on your side of the pond during the classic era ( late 40's to the beginning of VOR use); in the US we had the radio ranges and civil airways flown by commercial flights. Was something comparable in use for Europe at that time or were other methods being used? I've found references to HFDF but no info on station locations, instruments, etc. Any and all help is greatly appreciated as it would help me develop some realistic flight plans from some timetables that I have from that era.

Tied in with this would be routing. Direct, nav aid to nav aid, or other?

I should also include a big thank you to the aircraft designers that make this site their home, absolutely great stuff, the HS748 is one of my personal favorites.

Thank you for any help on this,

Hi Al

Welcome to the forum

I don't know if this will help

http://www.navfltsm.addr.com/

Regards

Garry

Hi Al

Decca was a leader in navigation equipment during the fifties. It derived of course from your side of the Atlantic.

Hope this helps you also.


http://www.jproc.ca/hyperbolic/decca_hist.html

Regards Nigel.

A bit vague, but there was an article about early radio nav (WW2/late 40s) in last months Aeroplane magazine (the May issue). It involved some sort of rotating beacon and counting the number of beeps you heard with a number of stations allowing you to get a cross cut. Unfortunately I don't have my copy to hand or I'd scan it in.

Thank you Gary and Nigel. Both sites I had already found although the Decca one is closer to what I am looking for. What I am trying to get to is what was used before VOR and DME and the current system of low and high altitude airways, intersections, etc.

If I were a BOAC captain or navigator in 1950 and I was flying from London to Cairo, as an example, how would I have flown and navigated this trip. What navaids were available for use at that time and would I have used any particular system of airways?

Thanks again,

There were numerous aids used. The VDF letdown was used. This consisted of the a/c transmitting regularly for Direction Finding, and was given a QDM ( mag bearing to the station) until it was overhead the airfield. It then started a letdown on a charted and promulgated track which would keep it clear of obstacles. with a procedural turn back to the field at a stipulated time. This was a cloudbreak predure, and was superseded by the NDB letdown when ADF was available , which effectively was the same procedure but using an NDB as the Direction Finding reference, instead of tranmitting for DF. IIRC there was a limited number of Radio Ranges - I'm pretty sure Prestwick had one . For precision approaches GCA was available at selected locations, Heathrow and Ringway as it was then called having the facilities as well as many Military aerodromes, where the a/c was tracked by radar in both azimuth and elevation, and talked down by the GCA controller.(Peter MacLeland will tell you about this as I've no doubt he did many in his RAF career) It was very accurate indeed with a good operator. Later as Secondary Surveillance Radar became more widely available , the Surveillance Radar Approach became used ( it was used quite a lot in my early days in the 60s) where no ILS was available, whereby the a/c was guided in azimuth by radar, but not in elevation, the glide information being imparted by the controller saying every mile or so " you are now 3 miles from touchdown, heading is good, your height ( QFE was used) should be 900 feet" , and these terminated at 1/2 mile

I hope this helps

Chris


Edit : I've just seen your latest post. Long distance navigation sometimes used used Very Long Waveaids such as LORAN but the usual nav was done with DF , and Star /Sun sights using a bubble sextant. These were in use until the advent of INS in the 1970s : Tonks's VC10 will still have an astrodome unless it's been covered up

Al, celestial navigation and dead reconing using drift meters and other ground reference beacons to determine their true track and airspeed were the primary use in "undeveloped" airspace. No flights were flown outside of "postitive" control airspace like the UK or Europe without a navigator, and even then, many times a navigator was still flown as there were still many areas of the domestic airspaces that did not have positive control in the form of radar or airways navigation using radio beacons of some form.

In the 1950s and early 1960s, ADF would have been the primary form of radio navigation in most locations, and in fact, may European airports didn't get any additional navigation aids until VORs were installed in the late 1960s.

Decca was a fairly good navigation system, it only suffered in that it wasn't consistent. The atmosphere caused a lot of variation in it's accuracy, and thus, many operators used it only for general reference while using other forms of navigation as primary unitl good INSs were developed in the mid-1960s to replace Decca.

and talked down by the GCA controller

Not quite the long distance navigation of interest, but GCA was certainly in use at Northolt during the mid-60s. Heathrow radar would bring Northolt bound C-47s, etc to line up with whatever the approach method was in those days (can't remember) but in bad weather, GCA took over.

But at Heathrow in the same era there was Precision Approach Radar (PAR) which talked down the pilot. One to one communication on an assigned frequency. "do not acknowledge further instructions....report runway in sight" was the start of that procedure once communication was established.

The level of accuracy was obviously beter than the ILS:

"on the glide path, on the glide slope"

"turn left 1 degree, heading 278"

"50 foot above the glide slope"

etc

Peter won't remember all that - he flew Tridents

Ian, when I was at Scampton they had a GCA trailer parked next to ATC, I once spent a few hours in there watching the controller talk down several Vulcans. To monitor the screens, one for heading and the other for the Glideslope was interesting to say the least especially when the controller said half a mile to radar touchdown..........your're approaching radar touchdown...........at radar touchdown now.......continue visually, I will stand by if further help needed.

Even in the mid 70s after the advent of VORs in Europe - we still used
celestial nav on long over water flights - freelance navigators were still
very common and IAS had a dozen or so Perismatic sextants - they screwed into a fitting behind the F/Es position on the Brit then the Nav took out his
Celestial Almanac and shot a star sight through the sextant - it was very accurate as well. George Beresford the Chief Nav for Britannia Aiways gave me a load of OOD Almanacs - I think they wound up in 10F ATCs library - and Dave Welch who was a freelance Nav for Britannia and IAS (amongst others taught me to use the sextant. Probably the best person to fill you in on pre 1970s Navaids in Europe would be Pete P - but I havnt seen him post in forever.

Leif