Pre INS Long Range Nav Procedures?
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Pre INS Long Range Nav Procedures?
Could someone give me a rundown on the long range navigation procedures pre INS?
Say a DC-7/Connie/early 707 crossing the Atlantic what techniques from start to finish would be used?
Presumably VOR/NDB at origin and destination but enroute would it just be DR and a sextant on a clear night? What other techniques would the navigator use to establish the position of the aircraft out of range of radio beacons and the best heading to fly?
Say a DC-7/Connie/early 707 crossing the Atlantic what techniques from start to finish would be used?
Presumably VOR/NDB at origin and destination but enroute would it just be DR and a sextant on a clear night? What other techniques would the navigator use to establish the position of the aircraft out of range of radio beacons and the best heading to fly?
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I can only describe the BOAC VC10 operation.
The pilots would set up the track and distance on the doppler display on the forward centre panel. At the top of the display was a left/right indicator. The pilots would attempt to keep this reading zero, using the heading select knob.
The navigator would obtain fixes every twenty minutes, and update this indicator as necessary. The first thing that he would do was to check the compasses, using an astro sight on either a star or the sun. He would obtain a VOR/DME, or VOR/VOR fix before going out of range. The remainder of the crossing he would use a mixture of Loran and Astro fixes, each one having three fix lines. Loran was the favoured system during the day and Astro at night, as Loran often had interference at night. Sometimes he would have to resort to counting the dots from a Consol station, or calling up one of the Ocean Weather Ships for a bearing and distance but most of the time either Loran or Astro would suffice.
After each fix he would update the doppler left/right indicator. He would obtain a final VOR/DME fix when in range and then hand over the navigation to the pilots.
When I joined BOAC, all F/O's had to complete a Flight Navigators course, and obtain the red licence.
Hope this helps.
Edit; Just realised that I've only covered the North Atlantic operation. Of course there were many other Nav sectors. One of the most difficult was over the Pacific, from Honolulu to Fiji during daylight. Often only sun fixes and the doppler would go into 'memory' mode due to the calm water. We also had to navigate over Africa, mainly using astro.
The pilots would set up the track and distance on the doppler display on the forward centre panel. At the top of the display was a left/right indicator. The pilots would attempt to keep this reading zero, using the heading select knob.
The navigator would obtain fixes every twenty minutes, and update this indicator as necessary. The first thing that he would do was to check the compasses, using an astro sight on either a star or the sun. He would obtain a VOR/DME, or VOR/VOR fix before going out of range. The remainder of the crossing he would use a mixture of Loran and Astro fixes, each one having three fix lines. Loran was the favoured system during the day and Astro at night, as Loran often had interference at night. Sometimes he would have to resort to counting the dots from a Consol station, or calling up one of the Ocean Weather Ships for a bearing and distance but most of the time either Loran or Astro would suffice.
After each fix he would update the doppler left/right indicator. He would obtain a final VOR/DME fix when in range and then hand over the navigation to the pilots.
When I joined BOAC, all F/O's had to complete a Flight Navigators course, and obtain the red licence.
Hope this helps.
Edit; Just realised that I've only covered the North Atlantic operation. Of course there were many other Nav sectors. One of the most difficult was over the Pacific, from Honolulu to Fiji during daylight. Often only sun fixes and the doppler would go into 'memory' mode due to the calm water. We also had to navigate over Africa, mainly using astro.
Last edited by Airclues; 11th Aug 2013 at 21:52.
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Yes that's great info. This is purely out of curiosity from a more modern pilot who knows little of the old ways.
I assume the aircraft would still fly great circles though? Would the nav have to calculate a heading change as the lines of longitude were crossed to keep on track?
I assume the aircraft would still fly great circles though? Would the nav have to calculate a heading change as the lines of longitude were crossed to keep on track?
You might find "Red Ball in the Sky" by Charles Blair an interesting read. He was quite a navigator and ten hours over the top from Bardufoss (Norway) to Fairbanks (Alaska) in a P-51 Mustang (solo of course) was quite an achievement.
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I assume the aircraft would still fly great circles though?
These figures were entered into the doppler display and the pilots then flew the aircraft so as to keep the L/R indicator at zero. There was a toggle switch so that the navigator could update the indicator.
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Reminds me of a conversation I had with a friend who was a BOAC Captain. "How do you navigate over the North Pole?" I asked. "Dunno" he said, "I let the boy do it". Happy days.
I was a Herc' nav from '67 to '73 and it is so long ago that I struggle to remember.
In the RAF it was essentially as Air Clues says; a fix every 30 minutes using LORAN or 40 mins with Night Astro plus if you were lucky bearings from Weather Ships and maybe an NDB on Greenland. We always gave the pilot a heading to fly even though IIRC the autopilot could be fed from the Along/Across part of the Nav's Doppler kit.
BUT we always remained responsible for the safe navigation of the aircraft from Take Off to landing. An old mate of mine ( and he remained a Herc' nav' until he was 50 in 1995)said to me recently that I was the only nav' he ever flew with that 'idented' every aid that was used including ILS, VOR etc and kept the 'aural button' ( can't remember the proper name ) selected all the way down the approach. I explained that I considered that part of my role as the aircraft navigator even though PARS, ILS etc were essentially pilot-interpreted aids.
I was well-trained, flying with captains on my first tour who expected nothing less - JW411's mate Dave Carter being one, and several ex WW2 men too.
Changing the subject slightly; we now hear a lot about pilot overload in the modern 2 crew set-up, certainly as a CAA controller it was something I was aware of - BUT if only there was a third crew member, a cross between a nav' and a Flt Eng, someone who was not hankering for the left-hand seat, a lot of that workload could be reduced.
In the RAF it was essentially as Air Clues says; a fix every 30 minutes using LORAN or 40 mins with Night Astro plus if you were lucky bearings from Weather Ships and maybe an NDB on Greenland. We always gave the pilot a heading to fly even though IIRC the autopilot could be fed from the Along/Across part of the Nav's Doppler kit.
BUT we always remained responsible for the safe navigation of the aircraft from Take Off to landing. An old mate of mine ( and he remained a Herc' nav' until he was 50 in 1995)said to me recently that I was the only nav' he ever flew with that 'idented' every aid that was used including ILS, VOR etc and kept the 'aural button' ( can't remember the proper name ) selected all the way down the approach. I explained that I considered that part of my role as the aircraft navigator even though PARS, ILS etc were essentially pilot-interpreted aids.
I was well-trained, flying with captains on my first tour who expected nothing less - JW411's mate Dave Carter being one, and several ex WW2 men too.
Changing the subject slightly; we now hear a lot about pilot overload in the modern 2 crew set-up, certainly as a CAA controller it was something I was aware of - BUT if only there was a third crew member, a cross between a nav' and a Flt Eng, someone who was not hankering for the left-hand seat, a lot of that workload could be reduced.
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Doppler
Keep in mind that doppler, or dual doppler did not show up at least in the US airlines until around 1962 or 63. The airlines did away with the flight navigator when they were able to show that the three remaining crewmembers could handle the duties of the professional navigator minus of course the cel nav portion. In this new world, the pilots and FE used the doppler with continious monitoring & updating via Loran C fixes. Both Loran C along with dual doppler had inherent limitations so there were some limitations on areas of the world that these could be used. In some cases that required adding the human navigator back to the crew. Hi latitude ops that utilized grid naviagtion procedures was usually beyond the scope of the three man crew.
Case in point would be both Pan Am and TWA flew 707's between Europe to the west coast of the US using Polar routings. These were somewhat of a misnomer as they were generally not high enough to be polar in the legal sense. None the less, TWA restricted the latitude to inhibit the grid naviagtion while Pan Am continued to use a navigator with grid navigation for the majority of these flights.
Prior to the advent of Doppler navigationg was a combination of Loran A, Cel Nav, drift meters, pressure pattern, and good old DR.
These links below wil give you a better glimpse of how it was done in the good ole days!
Enjoy,
Stars Are My Friends - Eric Holloway - Google Books
http://propspistonsandoldairliners.*...tors-tale.html
http://propspistonsandoldairliners.*...1_archive.html
http://propspistonsandoldairliners.*...k-shannon.html
Case in point would be both Pan Am and TWA flew 707's between Europe to the west coast of the US using Polar routings. These were somewhat of a misnomer as they were generally not high enough to be polar in the legal sense. None the less, TWA restricted the latitude to inhibit the grid naviagtion while Pan Am continued to use a navigator with grid navigation for the majority of these flights.
Prior to the advent of Doppler navigationg was a combination of Loran A, Cel Nav, drift meters, pressure pattern, and good old DR.
These links below wil give you a better glimpse of how it was done in the good ole days!
Enjoy,
Stars Are My Friends - Eric Holloway - Google Books
http://propspistonsandoldairliners.*...tors-tale.html
http://propspistonsandoldairliners.*...1_archive.html
http://propspistonsandoldairliners.*...k-shannon.html
Last edited by Spooky 2; 12th Aug 2013 at 09:43. Reason: Links
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I have never been able to find confirmation of a tale I hear long ago about a Pan Am Stratocruiser(?) crossing the Pacific where the crew nodded off and woke so far off course they had to land on the grass at Faleolo, Samoa.
Mr WHBM Senior was a nav on a couple of types in WW2, always critical of those ops he heard of where drops were wide of the mark, said there was no excuse if the nav knew how to do it properly. Unfortunately, many were only in it after an abbreviated training.
The loss of Hermes G-ALDN in the Sahara in 1952, which was mis-navigated and flew the wrong heading for several hours, was brought about by no navigator being available at Tripoli on crew slip, and a standby FO being assigned who didn't understand the instruments fully.
Last edited by WHBM; 11th Aug 2013 at 23:05.
Well, having been stirred from my den by JW411, I feel obliged to join in, and I'd say that most of the important points have been covered already. Much, of course, would depend on the kit to hand - and I'd say that, in terms of the times (mid 60s - mid 70s), I did pretty well. The RAF's Belfast and VC10 had Doppler-fed GPI 7, giving both twin-track and Lat & Long readouts, together with Decca ADL 21 Loran C for fixing where there was cover. The USAF's C-141A had an early digital computer, ASN 24, again Doppler-fed, with an earlier Loran C equipment whose designation now escapes me. All three had Astro via peri-sextants, of course. They all had VOR/ADF/TACAN and radars capable of fixing, but not much use in that regard after coasting out.
So, yes, there would be, say, a VOR overhead outbound. RAF Transport procedures at that time required a top-of-climb Astro heading check to ensure there was no gross compass error in play and, after that, you settled down to a fixing cycle. On the Atlantic, with NAT Tracks to adhere to, I usually did a track trawl with a 15/20 minute cycle, somewhat in excess of the minimum requirement, making such computer changes as were necessary. NAT tracks approximated to Great Circle tracks, altering every 10 degrees of Longitude, so that was all quite straightforward.
Away from the North Atlantic, in the Indian Ocean, South China Sea, the Pacific south of Hawaii, things would be quite different. Little or no Loran, so Astro – OK by night, less so by day unless you were in the right part of the month for Sun/Moon fixing. Otherwise, it could be single Sun lines and, depending on the Sun’s azimuth, these might help with checking track or groundspeed or possibly neither to any useful effect. I have on a very few occasions used the “find the island” technique – ie deliberately aiming off to left or right to have a better idea of where the destination was likely to lie as ETA approached, and getting things straight once a terminal NDB or other aid was in range.
In many ways the oddest route I flew was on NorthPac 1, an 11-hour great circle routing from the Tokyo area down into central California, and I don’t recall ever starting in daytime. Radar fixing in the early hours off the Kamchatka Peninsula, monitored by Soviet AD radars, some Tacan around Alaska, and then south-east towards home with no useful Loran into a rising sun, giving good groundspeed checks when what was needed were good heading checks (the 141 did not have a good compass system) as the US West Coast ADIZ penetration loomed ahead.
I’d do it all again tomorrow, I guess.
So, yes, there would be, say, a VOR overhead outbound. RAF Transport procedures at that time required a top-of-climb Astro heading check to ensure there was no gross compass error in play and, after that, you settled down to a fixing cycle. On the Atlantic, with NAT Tracks to adhere to, I usually did a track trawl with a 15/20 minute cycle, somewhat in excess of the minimum requirement, making such computer changes as were necessary. NAT tracks approximated to Great Circle tracks, altering every 10 degrees of Longitude, so that was all quite straightforward.
Away from the North Atlantic, in the Indian Ocean, South China Sea, the Pacific south of Hawaii, things would be quite different. Little or no Loran, so Astro – OK by night, less so by day unless you were in the right part of the month for Sun/Moon fixing. Otherwise, it could be single Sun lines and, depending on the Sun’s azimuth, these might help with checking track or groundspeed or possibly neither to any useful effect. I have on a very few occasions used the “find the island” technique – ie deliberately aiming off to left or right to have a better idea of where the destination was likely to lie as ETA approached, and getting things straight once a terminal NDB or other aid was in range.
In many ways the oddest route I flew was on NorthPac 1, an 11-hour great circle routing from the Tokyo area down into central California, and I don’t recall ever starting in daytime. Radar fixing in the early hours off the Kamchatka Peninsula, monitored by Soviet AD radars, some Tacan around Alaska, and then south-east towards home with no useful Loran into a rising sun, giving good groundspeed checks when what was needed were good heading checks (the 141 did not have a good compass system) as the US West Coast ADIZ penetration loomed ahead.
I’d do it all again tomorrow, I guess.
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Of course there were still pilots flying long over water distances with little more than dead reckoning until the GPS systems came available. People flying things like a Paynee to NZ or Australia from the US.
The loss of Hermes G-ALDN in the Sahara in 1952, which was mis-navigated and flew the wrong heading for several hours, was brought about by no navigator being available at Tripoli on crew slip, and a standby FO being assigned who didn't understand the instruments fully.
http://fer3.com/arc/imgx/G-ALDN-26-May-1952-report.pdf
The navigator had mis-set an instrument because the graduations were in tens of degrees and he thought they were single degrees, and when a star didn't fit the expected plot it was disregarded, resulting in a 60 degree drift.
I flew for Air Nauru 1976 to 1985 operating F28 and 737-200. We also had the 727-200. Most flights were several hours over-water such as Nauru to Fiji, or Nauru to Guam, or Guam to Manila or to Kagoshima. Honolulu to Majuro in the Marshall Islands was nearly six hours in a 737 and nothing much in between. Forecast usually 24 hours old.
Tarawa (Gilbert Islands now Kiribati) to Christmas Is in the 737 and 727 was a long hop as was Nauru to Samoa with only a couple of atolls for pin-points in good weather. No ETOPS in those days. Navigation in the F28 was basic navaids of NDB/VOR/DME and DR when out of range. Diverting off track around extensive areas of CB was done using the One in Sixty Rule by timing.
Same with basic radio aids in the 737 and 727 although later we had Omega which was unreliable over water. It was a blessing when we finally got INS.
Longest trip with only a P8 compass for steering was over nine hours from Perth to Townsville in a Lincoln bomber. Gyro compass was u/s. Bugger all pin-points over the desert in between. The navigator did a good job though as at the time we spotted the east coast of Australia a pin-point showed we were only about 50 miles off track.
Tarawa (Gilbert Islands now Kiribati) to Christmas Is in the 737 and 727 was a long hop as was Nauru to Samoa with only a couple of atolls for pin-points in good weather. No ETOPS in those days. Navigation in the F28 was basic navaids of NDB/VOR/DME and DR when out of range. Diverting off track around extensive areas of CB was done using the One in Sixty Rule by timing.
Same with basic radio aids in the 737 and 727 although later we had Omega which was unreliable over water. It was a blessing when we finally got INS.
Longest trip with only a P8 compass for steering was over nine hours from Perth to Townsville in a Lincoln bomber. Gyro compass was u/s. Bugger all pin-points over the desert in between. The navigator did a good job though as at the time we spotted the east coast of Australia a pin-point showed we were only about 50 miles off track.
Last edited by Centaurus; 12th Aug 2013 at 13:58.
Did a pond crossing in a Victor once, (W to E) where all our Nav kit failed. Solar activity wiped out the OMEGA, the sea was so smooth the Doppler fed GPI wouldn't work, we were out of range of fixes for the H2S/NBC, the available NDBs and TACANs were too far away, and the audio was so poor on the ADF we couldn't even manage a Consol count. So the SODCAT representative got the sextant out and we managed to coast in 30 miles off track. I was impressed, but Shanwick weren't and we got violated!
Incidentally, this was when pond crossings required two long range Nav systems. OMEGA counted as one, the Navigator the other. One fed by electricity, the other by pies!
Incidentally, this was when pond crossings required two long range Nav systems. OMEGA counted as one, the Navigator the other. One fed by electricity, the other by pies!
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I crossed the Pacific once, NZ to US, using nothing more than a plastic sextant, a Seiko watch and 249(?) tables. But that was on a 32' sloop so we had plenty of time to take the sights.