Pre INS Long Range Nav Procedures?

[Contacttower]

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?

[Meikleour]

Doppler Computers for drift and groundspeed - backed up by use of LORAN and/or sextant sun/star shots via the port in the cockpit roof of the B707.

[Airclues]

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.

[Contacttower]

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?

[JW411]

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.

[Airclues]

I assume the aircraft would still fly great circles though?

We flew on the North Atlantic Tracks, exactly as today. Therefore the routings were different every day. The tracks and distances between each waypoint (every ten degrees of longditude) were calculated in advance and shown on the flight plan. If, for any reason, there was a track change then the navigator would calculate the new tracks and distances.
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.

[JW411]

I am going to try and persuade one of my old SODCAT friends to join in. (SODCAT equals Society of Directional Consultants and Allied Trades).

[HEATHROW DIRECTOR]

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.

[Brian 48nav]

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.

[Spooky 2]

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://books.google.com/books?id=Wch5I3XpeG4C&pg=PA158&lpg=PA158&dq=DC7C+navigator&source=bl&ots=0_KOmXzekN&sig=0fIR42p0L8gvDnsIHYm47lMec0o&hl=en&ei=IE9YTddah63wBr_ywewG&sa=X&oi=book_result&ct=result&resnum=7&ved=0CEMQ6AEwBg#v=onepage&q=DC7C%20navigator&f=false)

http://propspistonsandoldairliners.********.com/2011/04/boeing-707-navigators-tale.html

http://propspistonsandoldairliners.********.com/2011_03_01_archive.html

http://propspistonsandoldairliners.********.com/2010/02/navigating-pan-am-dc-6-new-york-shannon.html

[John Hill]

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.

[Spooky 2]

Never heard that story. Would have run out of fuel way before getting that far along.:}

[John Hill]

Errr, the Pacific extends way past Hawaii!:E

As I recall the story they were out of Nandi bound for Canton.

[WHBM]

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.
Apart from this witticism, polar flight was one of the last challenges. Away from any ground navaids, the problem with Astral navigation at high latitudes was the lengthy periods at some times of the year where the sun is just below the horizon but the sky is still bright enough that stars cannot be seen. A patented addition to the sextant allowed this to be overcome, the first deployment was the first high polar flight, the SAS DC7C flying Copenhagen-Anchorage-Tokyo (which allowed such a route to start), and of course a professional navigator to handle it all.

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.

[ICM]

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.

[John Hill]

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.

[topgas]

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.

The Accident Report makes interesting reading.
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.

[Centaurus]

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.

[Dan Winterland]

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!

[John Hill]

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.

[Contacttower]

I have to say this thread has received a lot more responses than I had hoped for, I am very grateful. :ok:

[ICM]

Just a postscript to my earlier reply. Unfortunately I don't have all the details to hand some 40 years on but, when the NAT Track system was introduced, most (all?) civilian operators were then using Omega and/or multiple INS. There was a minimum equipment requirement as I recall and the MOD Air Staff had to get a specific exemption for RAF transport aircraft to fly these routes with a Nav, Doppler-based computers and Loran C. I did my last such VC10 flight from Dulles to Brize Norton on 3 April 1978, and I believe that the RAF's VC10s began to have Omega installed later that year.

[SOPS]

Ok, I have a question. Why did the Doppler stop working over calm water, as stated in an earlier post?

[Wodrick]

Doppler stopped when following the St Lawrence Seaway too, I think it was something to do with the calmer waters not reflecting enough signal back and acting like a mirror and reflecting the signal forward.

As a radio engineer I was once sent with a 707 MAN -YYZ with all the Doppler bits the company owned to keep it running in flight. We changed the external bits prior to departure and off we jolly well went.
I got the Doppler going just past the Irish coast and, with a minimal VOR fix off we went, Doppler, Loran A and the Nav. I was most impressed as the Nav did minimum correction and hit Gander on the nose. That's how I know about the seaway !

A quick spin in YYZ and back to LGW. The new nav was up and down like a yo-yo constantly making corrections. We were supposed to be coming in around BFS and then down to LGW. when the drivers eventually got a fix from an NDB we were missing by miles and heading to go round the top of Scotland. All ended well though. Grand times.
G-AYSL for those interested.

[ICM]

SOPS: Probably more than you need to know here - see under "Overwater Errors":

Avionics Navigation Systems - Myron Kayton, Walter R. Fried - Google Books (http://books.google.co.uk/books?id=1KLTUWLz8jcC&pg=PA481&lpg=PA481&dq=Doppler+over+water&source=bl&ots=6inMZjjgZ0&sig=5gPXEEl9acgQh-Qwq_IAn44tAGA&hl=en&sa=X&ei=6h8KUtXvH6KR0AW3kIHwBg&ved=0CEUQ6AEwAg#v=onepage&q=Doppler%20over%20water&f=false)

One night starting on a long flight direct from Travis AFB to Wake Island, the Doppler would not lock on properly at all .... until we had a rapid decompression on levelling at FL 350. Once things were sorted out with the aircraft heading back home we found it had locked on perfectly, so probably more a snag that needed a thump rather than an overwater thing!

[Airclues]

ICM

I believe that the twice daily NAT Track system was introduced in 1965, but perhaps one of our ATC friends could confirm this. When I was attempting to navigate a VC10 along these tracks in the late 60's and early 70's they were spaced 120nm apart (thankfully). The stricter nav equipment regulations came in when they moved to 60nm spacing. The BA VC10s were then fitted with INS to comply with these regulations.
My last flight as a navigator was on 3rd April 1975 (EGPK-KJFK)(G-ASGC) and we didn't have INS fitted at that time.

[John Hill]

You may be interested to read my new thread "A Wandering Clipper".

[swordfish41]

This is slightly off topic, and about much earlier times but a very good description of navigating over water from island to island is contained in a book by Francis Chichester, "The Lonely Sea and the Sky".
He was most famous for sailing single handed around the world, but in the 1920's he flew a Gipsy Moth from London to New Zealand, and made many solo flights across for example the Tasman sea. Two chapters describe the process, Landfall on a Pinpoint and the following one Wrecked. The book contains a reproduction of the chart Chichester plotted in the Gipsy Moth as he flew across the Tasman sea. Anyone interested in aviation should try to get hold of a copy of this book. Its fascinating, and gripping stuff.

[Warmtoast]

I was no NAV, but stationed at RAF China Bay (Ceylon) in 1957 I made a couple of trips in 205/209's Sunderlands from Seletar to China Bay via Penang.

As pointed out to me at the time by the NAV, once we'd passed the northern tip of Sumatra he turned west and tuned in to the China Bay NDB and followed the needle all the way across the Indian Ocean to China Bay.

The China Bay NDB was a powerful piece of kit, 15kW ISTR and highly praised by the navigators of the various RAF aircraft that transited the Indian Ocean/Bay of Bengal.

FWIW here's what the China Bay NDB looked like from the air in 1957. Two 220ft high radio masts with the aerial elements strung between them.

http://i145.photobucket.com/albums/r231/thawes/RAF%20China%20Bay/ChinaBay-NDB2_zpsadaa5d1c.jpg

http://i145.photobucket.com/albums/r231/thawes/RAF%20China%20Bay/ChinaBay-NDB_zps93d65ef4.jpg

...and here's a Sunderland arriving safe and sound at China Bay.

http://i145.photobucket.com/albums/r231/thawes/RAF%20China%20Bay/ChinaBay1957-SunderlandAlightingAre.jpg

[WHBM]

Long ago I read that from halfway across the Atlantic you could get to within 100 miles of London by homing in on the BBC Long Wave 198 khz signal, which comes from Droitwich.

True ?

[JW411]

Well, despite having 3 Litton 72R INSs in my DC-10 with Laker, I always had the ADFs tuned to 600 kcs westbound across the Atlantic and 200 kcs eastbound.

The first one was a radio station somewhere in Labrador and the other was Daventry (198 kcs).

Either one would at least help you to avoid missing Canada or UK.

Finesse could come later!

[John Hill]

I was a passenger on an Air NZ DC8 1975 (or so) Rarotonga to Fiji. I was on my way to a posting at Hannan International, Niue which was one of the waypoints.

They did a slight turn to left, then right so the passengers could see the island and I was quite interested too as it was my first glimpse of a small green island marked by little more than the areas of blazing white coral runway surrounding the black runway.

As far as I could tell they were homing on the Niue NDB and when overhead flicked a couple of switches for their new course to Nandi. I do not know if they were then homing on Nandi or flying on a stern bearing from Niue.

[JimNtexas]

I was a USAF student navigator in 1975. I recall the instructors telling us that the last civilian airline navigator in the U.S. had just retired from Flying Tiger.

We did learn day and night celestial, use of drift meters, grid navigation, doppler, radar navigation, plotting Loran fixes using time delay lines, pressure navigation, and CONSOLAN.

And a bunch of other stuff I can't recall.

I went into fighters, but when I got deployed in a trash hauler I always asked the nav if I could take a cel shot, and usually they'd let me.

Celestial nav is kinda cool.

[John Hill]

I studied for a nautical 'Master, Ocean Going' for small ships in the mid 70's. This was after I had crossed the Pacific on a small sloop using the tables for celestial sight reduction but for that course we had to use the haversine method. Haversine "half the inverse of the sine" if I recall correctly. As far as I remember it was a brilliant processs (maybe invented by Bowditch?) which enabled a sight to be completely calculated by processes of addition only. However I never got to go deep water sailing again and never used the skill.

[Spooky 2]

One last reference for those still interested.

B707 Without INS - How Did They Navigate? — Tech Ops Forum | Airliners.net (http://www.airliners.net/aviation-forums/tech_ops/read.main/296754/)