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B707 Without INS - How Did They Navigate?  
User currently offlinemozart From Luxembourg, joined Aug 2003, 2187 posts, RR: 13
Posted (3 years 6 months 2 weeks 1 day 4 hours ago) and read 8645 times:

I understand that a number of 707s did not have INS (and let alone GPS) installed. Given that these planes were usedon long hail routes over the Oceans and other Areas without radio navigation equipment I am wondering how they navigated.

(and please don't tell me "like the Connie" as I don't know either how they did it)

Thanks

22 replies: All unread, jump to last
 
User currently offlineStarlionblue From Greenland, joined Feb 2004, 17068 posts, RR: 66
Reply 1, posted (3 years 6 months 2 weeks 1 day 3 hours ago) and read 8642 times:

My guess would be a combination of:
- Celestial navigation with a sextant using star references or the sun. Just like a ship back in the day in other words. Heck, this was used as a backup on the Apollo moon missions.
- Dead reckoning with a compass and a stopwatch. Think the movie "The Hunt for Red October" when they go through the trench, but with less posturing and torpedoing.
- Triangulation using NDBs (or whatever came before NDBs if they had a predecessor) if they were close to shore.
- Mk 1 Eyeball, i.e. looking out the window at landmarks.

Hey, that's just like the Connie.  

[Edited 2011-04-10 03:56:22]

[Edited 2011-04-10 03:57:00]

[Edited 2011-04-10 03:57:14]


"There are no stupid questions, but there are a lot of inquisitive idiots."
User currently offlineZANL188 From United States of America, joined exactly 8 years ago today! , 3546 posts, RR: 0
Reply 2, posted (3 years 6 months 2 weeks 23 hours ago) and read 8513 times:
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To Starlionblues list I would add:

- VOR/DME
- LORAN
- Ground scanning radar.

Though I'm not sure ground scanning radar was ever used in a 707, I know it was used in Boeings military products. Radar was used to search for known terrain features such as rivers, harbors, etc



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User currently offlinejetlagged From United Kingdom, joined Jan 2005, 2565 posts, RR: 25
Reply 3, posted (3 years 6 months 2 weeks 21 hours ago) and read 8450 times:

Quoting ZANL188 (Reply 2):
Though I'm not sure ground scanning radar was ever used in a 707, I know it was used in Boeings military products. Radar was used to search for known terrain features such as rivers, harbors, etc

I don't think ground mapping radar was used for civil navigation, but Doppler radar certainly was. This uses ground returns to calculate ground speed, aircraft track and wind velocity, which is good data for dead reckoning.



The glass isn't half empty, or half full, it's twice as big as it needs to be.
User currently offlineKELPkid From United States of America, joined Nov 2005, 6407 posts, RR: 3
Reply 4, posted (3 years 6 months 2 weeks 21 hours ago) and read 8435 times:

Omega/VLF was used for oceanic navigation (all Omega stations are now decomissioned)


Celebrating the birth of KELPkidJR on August 5, 2009 :-)
User currently offlineKELPkid From United States of America, joined Nov 2005, 6407 posts, RR: 3
Reply 5, posted (3 years 6 months 2 weeks 18 hours ago) and read 8368 times:

Quoting Starlionblue (Reply 1):
- Mk 1 Eyeball, i.e. looking out the window at landmarks.

That is much harder at 30,000 feet. In a conventional airliner cockpit, it is probably only possible with prominent landmarks such as mountains. However, that is also why many early ex-Soviet types had a glass nose (so the navigator could sit in there and navigate by visual reference to landmarks). The Soviet Union was definitely behind the west in implementing ground-based navaids for civil aviation, which is why domestic flights had to often use pilotage (via a navigator in the nose) as a means of navigation.

I have noticed in GA realms that pilotage via reference to landmarks is much harder at 12,500 feet than it is down low. Even if you are down low, it is much much harder across the midwestern USA (flat terrain as far as one can see, and it all looks pretty much the same: patches of farms, dotted by occasional towns). If you're gonna navigate that way, you might have to resort to "IFR" (I Follow Rivers, I Follow Roads, I Follow Railroad Tracks...)  Interstate Highways are the best way to go if you're "IFR"  



Celebrating the birth of KELPkidJR on August 5, 2009 :-)
User currently onlinePihero From France, joined Jan 2005, 4590 posts, RR: 77
Reply 6, posted (3 years 6 months 2 weeks 17 hours ago) and read 8329 times:
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Quoting Starlionblue (Reply 1):
My guess would be a combination

Yes, that's the word ; we'd combine all the infos we could gather and try and extract a position.

In the northern western hemisphere, the LORAN was the main tool, but was rather awckward to use. The precision was very good with a good navigator.

- Then Celestial navigation, using a pericopic sextant. Personally the most hated instrument as the 707 was prone to a slow dutch roll passengers got used to, but which caused havoc on the stomachs of young naviguessers. And the bloody FEs weren't helping either as , although the sextant had its own timer ( one had to keep the star-target in the bubble for three minutes...) the SOPs demanded that the timing be crosschecked by the engineer. Of course after a nauseating star shot, the Sob would say " oh, sorry sunshine, my stopwatch didn't start..." so one had to do the starshot all over again!
I hated these guys with a vengeance !

- Mainly for northerly navigation, we used the Polar Compass, which was fun because it was mostly an arcane technique : using a free gyro with an accurately known drift rate, we'd compute an estimated flight time, therefore a total drift and set the opposite of that to determine a *gyro heading to follow for navigation. Some crews were pure magicians of the free gyro.

- The radar. This needs to be talked about because there are a lot of inaccuracies about it.
First of all, the sets we used to have were analogic...the digital technology came much later. The frequencies were different : C band versus X band nowadays, therefore longer wavelengths, which in turn were a lot better at ground mapping than modern sets. The accuracy of those displays were quite extraordinary. So for a landfall, they were a precious tool.
Another of their uses was , with a carefully tweaked gain and tilt, the visualisation of the drift angle as a faint blurred sector on the PPI.
The drawback, of course was weak returns, masking returns, possible blind alleys...etc...

- The use of long range radio-beacons (or for that purpose commercial radio stations ) with the ADF was a great asset . We'd rarely use them for positioning purposes, (because of the low accuracy), but for homing reasons.

- As you can see, pure dead reckoning was seldom used, we'd utilize everything wa had at our disposal to confirm our estimated position.

- The Omegta / VLF didn't comle until mid-seventies, but it was rather unreliable in terms of continuous coverage in storms, for instance. But when it worked, it was our first glimpse into the magic of what was to come : the INS and the GPS.



Contrail designer
User currently offlinejetlagged From United Kingdom, joined Jan 2005, 2565 posts, RR: 25
Reply 7, posted (3 years 6 months 2 weeks 17 hours ago) and read 8322 times:

Quoting KELPkid (Reply 4):
Omega/VLF was used for oceanic navigation (all Omega stations are now decomissioned)

I think INS was available before Omega.



The glass isn't half empty, or half full, it's twice as big as it needs to be.
User currently offlineViscount724 From Switzerland, joined Oct 2006, 25626 posts, RR: 22
Reply 8, posted (3 years 6 months 2 weeks 16 hours ago) and read 8270 times:

Quoting Pihero (Reply 6):
- Then Celestial navigation, using a pericopic sextant. Personally the most hated instrument as the 707 was prone to a slow dutch roll passengers got used to, but which caused havoc on the stomachs of young naviguessers. And the bloody FEs weren't helping either as , although the sextant had its own timer ( one had to keep the star-target in the bubble for three minutes...) the SOPs demanded that the timing be crosschecked by the engineer. Of course after a nauseating star shot, the Sob would say " oh, sorry sunshine, my stopwatch didn't start..." so one had to do the starshot all over again!
I hated these guys with a vengeance !

Periscopic sextant in use on a VC-10.

http://1.bp.blogspot.com/_yCkBuwip_Q0/TKNEL7oRw_I/AAAAAAAAABE/JOGWKl2pZ2Y/s1600/vc10_periscope.jpg


User currently onlinetravelavnut From Netherlands, joined May 2010, 1627 posts, RR: 7
Reply 9, posted (3 years 6 months 2 weeks 7 hours ago) and read 8119 times:

Great thread! Thanks Pihero for all those interesting tidbits!

Quoting Pihero (Reply 6):
naviguessers



lol

Quoting Pihero (Reply 6):
The accuracy of those displays were quite extraordinary. So for a landfall, they were a precious tool.



Any chance of a picture/image of one of those displays? As a certified IT nerd I'm fascinated by analog technology.



Live From Amsterdam!
User currently offlineGlom From United Kingdom, joined Apr 2005, 2820 posts, RR: 10
Reply 10, posted (3 years 6 months 2 weeks 5 hours ago) and read 8080 times:

Quoting Starlionblue (Reply 1):
Heck, this was used as a backup on the Apollo moon missions.

You undersell its importance. Star sighting was a primary means of realigning the platform.


User currently onlinePihero From France, joined Jan 2005, 4590 posts, RR: 77
Reply 11, posted (3 years 6 months 2 weeks 5 hours ago) and read 8071 times:
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Quoting jetlagged (Reply 7):

I think INS was available before Omega.

  
Sets for air navigation started well after 1971, when the entry into service of the sixth station made the Omega truly global.
I don't know how early it was for military use, bu I saw the first civilian applications on a Falcon 20 in 1973 and on the TAAG 732s in 1975.
Omega was killed by the GPS and all stations - bar one, for sub communications - destroyed before 2000. There is somewhere on the web a video of the destruction of the La Reunion antenna by explosives... rather impressive as the mast was - IIRC- some 450m tall.

Quoting Viscount724 (Reply 8):
Any chance of a picture/image of one of those displays?

I'm quite sure I have some. give me some time.

Quoting KELPkid (Reply 5):
The Soviet Union was definitely behind the west in implementing ground-based navaids for civil aviation, which is why domestic flights had to often use pilotage (via a navigator in the nose) as a means of navigation.

I wouldn't say that. The Soviets had the equivalent of most western equipments - the equivalent of VORTAC, ILS...- but for security reasons and some rather strict ideas on secrecy, nothing was published : a VOR would have revealed an airway orientation, two would have given distance information... which could have provided dastardly western viper scientists vital information for their targetting solutions...etc...so the airways were seeded with extra-powerful NDBs which allowed some accurate homing solutions, therefore aligning with the centerline was quite easy, even with thunderstorms around (and flying outside 10 km of the axis would get you an up-to-date fighter as an escort... not recommended !). The trusted airlines of some "friendly" countries were provided with boxes that allowed western nav receivers to use the Russian equivalent. There was one such box for something ressembling the ILS.
As for independent airborne solutions, one has to know that the Soviets were way behind the West in computer technology and they explored some outlandish solutions : we know that their strategic bombers used an automated star nav ( called IIRC TSN), with a str-following sextant in the seventies.
The glass nose was for a possible bombing sight and I suspect that it was more a bluffing plot than anything else.

[Edited 2011-04-11 02:25:31]


Contrail designer
User currently offlinePolymerPlane From United States of America, joined May 2006, 991 posts, RR: 3
Reply 12, posted (3 years 6 months 2 weeks 5 hours ago) and read 8062 times:

Quoting Pihero (Reply 6):
Yes, that's the word ; we'd combine all the infos we could gather and try and extract a position.

Was there any airways in the old days? or you just fly "direct" to your destination? How do you navigate through traffic?



One day there will be 100% polymer plane
User currently onlinePihero From France, joined Jan 2005, 4590 posts, RR: 77
Reply 13, posted (3 years 6 months 2 weeks 4 hours ago) and read 8051 times:
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Quoting PolymerPlane (Reply 12):

Was there any airways in the old days?

I'm old-ish but not that old !   
When I started flying as a cadet at the air academy, there were airways, and had been for quite some time.
In the pioneer era, everything was VFR and most of our VFRs procedures come from that period.
The IFR era started with the adoption of flight levels according to your route orientation and rather strict flight plans, to be adhered to .

Quoting mozart (Thread starter):
nd please don't tell me "like the Connie" as I don't know either how they did it

Funny you say that, because with the avent of high-altitude flying, the use of one of the most artistic navigation methods was lost : Pressure navigation, which allowed two things, using an MF radio-altimeter : 1/- wind computation through some arcane "geostrophic wind" theory and 2/- determine the actual pressure of one's estimate, thus generating a "PLOP", aka pressure line of position, another means of refining one's dead-reckoning.
If one looked at a circular computer, there are a few indications for that navigation : the LATitude and the ALTitude



Contrail designer
User currently offlinefaro From Egypt, joined Aug 2007, 1556 posts, RR: 0
Reply 14, posted (3 years 6 months 2 weeks 3 hours ago) and read 8022 times:

After a 6-hour transatlantic crossing, what degree of accuracy did one get with Omega/Loran C/VLF? Otherwise said, how many nm off nominal flight plan track would one typically be as you come in to intercept the first land-based navigation beacons?

Faro



The chalice not my son
User currently offlineStarlionblue From Greenland, joined Feb 2004, 17068 posts, RR: 66
Reply 15, posted (3 years 6 months 2 weeks 3 hours ago) and read 8019 times:

Quoting Glom (Reply 10):
Quoting Starlionblue (Reply 1):
Heck, this was used as a backup on the Apollo moon missions.

You undersell its importance. Star sighting was a primary means of realigning the platform.

Thanks for setting me straight. I don't know quite why I wrote it that way. I just re-read Chaikin's "A Man on the Moon" for the third time a couple of month ago too...



"There are no stupid questions, but there are a lot of inquisitive idiots."
User currently onlinePihero From France, joined Jan 2005, 4590 posts, RR: 77
Reply 16, posted (3 years 6 months 2 weeks 3 hours ago) and read 8001 times:
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Quoting faro (Reply 14):
After a 6-hour transatlantic crossing, what degree of accuracy did one get with Omega/Loran C/VLF?

All these nav systems are / were not time dependent as the INS is.Their accuracy was quite constant throughout the flight.
The Loran was by far the most accurate - less than half a nautical mile, then the Omega was about a nautical mile.
I've always used the VLF with the Omega, so I'd think that the accuracy was comparable.
In those days, that kind of accuracy was verging on the ridiculously un-manageable as, for instance 1 Nm was equivalent to 7 seconds of flight, way way beyond the 3 minutes required by ATC.



Contrail designer
User currently offlinemandala499 From Indonesia, joined Aug 2001, 6919 posts, RR: 76
Reply 17, posted (3 years 6 months 1 week 6 days 23 hours ago) and read 7892 times:

Quoting Pihero (Reply 6):
but which caused havoc on the stomachs of young naviguessers.

That's it mon ami!!!! I feel extremely offended!   

Quoting Pihero (Reply 6):
- Then Celestial navigation, using a pericopic sextant. Personally the most hated instrument as the 707 was prone to a slow dutch roll passengers got used to, but which caused havoc on the stomachs of young naviguessers. And the bloody FEs weren't helping either as , although the sextant had its own timer ( one had to keep the star-target in the bubble for three minutes...) the SOPs demanded that the timing be crosschecked by the engineer. Of course after a nauseating star shot, the Sob would say " oh, sorry sunshine, my stopwatch didn't start..." so one had to do the starshot all over again!
I hated these guys with a vengeance !

What's more fun is astro-navigation using a proper sextant and not a periscopic one! Those days navigation was a REAL art!

Polar navigation using the polar stereographic projection charts & Polar grids was definitely an art of it's own!!!!!!

Quoting travelavnut (Reply 9):
Any chance of a picture/image of one of those displays? As a certified IT nerd I'm fascinated by analog technology.

Hmmm.... let me see what I can dig out of my past research...

Some maybe off the topic ones... past tools of the trade!

From the Navigator School...
http://www.globalsim.web.id/publicservice/Stargazer/NavigatorAstrobubble.jpg

Various sextants used in aviation:


Then the periscopic sextants...


Here is the automatic astro-compass... never made it into the civilian market as far as I remember...


But... I guess U're looking for this:


That's an astronavigation suite...   

Quoting Glom (Reply 10):
You undersell its importance. Star sighting was a primary means of realigning the platform.

It was the main backup tool in the early days of space exploration!

This is the auto-astro-sextant for the Gemini IV!

Quoting Pihero (Reply 11):
As for independent airborne solutions, one has to know that the Soviets were way behind the West in computer technology and they explored some outlandish solutions : we know that their strategic bombers used an automated star nav ( called IIRC TSN), with a str-following sextant in the seventies.
The glass nose was for a possible bombing sight and I suspect that it was more a bluffing plot than anything else.

A complex bombsight with drift meter is just the beginning... The Norden Bombsight was one heck of a tool for navigation (and bombing of course)...

The Russians had some outlandish mechanical and electro-analogue kinematic computers which could put the Sperry K system and the Delco Carousel and their derivatives to shame... (but all these came from naval gun computers being miniaturized!)

Whilst the west went digital as quickly as they could... the Soviets still loved their electro-analogue systems!

The visual driftmeters went out in the west with the doppler driftmeter radar.

Quoting Pihero (Reply 13):
Funny you say that, because with the avent of high-altitude flying, the use of one of the most artistic navigation methods was lost : Pressure navigation, which allowed two things, using an MF radio-altimeter : 1/- wind computation through some arcane "geostrophic wind" theory and 2/- determine the actual pressure of one's estimate, thus generating a "PLOP", aka pressure line of position, another means of refining one's dead-reckoning.
If one looked at a circular computer, there are a few indications for that navigation : the LATitude and the ALTitude

OMFG! This one is one hell of a lost art!!!!!

Quoting faro (Reply 14):
After a 6-hour transatlantic crossing, what degree of accuracy did one get with Omega/Loran C/VLF?

With a good navigator... less than 1NM laterally and less than 10NM longitudinally longitudinally using anything but INS! And for some guys, such accuracy can be achieved on trans-polar routes on a good day!

NOTE: The above images were obtained from the respective web-addresses, some are linked to where it came from/where I found it, some, heck, I can't even remember where I got them from!

Mandala499



When losing situational awareness, pray Cumulus Granitus isn't nearby !
User currently offline26point2 From United States of America, joined Mar 2010, 836 posts, RR: 0
Reply 18, posted (3 years 6 months 1 week 6 days 2 hours ago) and read 7597 times:

Quoting faro (Reply 14):
After a 6-hour transatlantic crossing, what degree of accuracy did one get with Omega/Loran C/VLF?

Used VLF/Omega for years between Calif and Hawaii in the 90's (pre- GPS). About a 5 hour flight. Position was blended (averaged) between sensors and was typically about 5 NM off when OGG DME reception was obtained 200nm from Maui. Not too bad.

BTW-many years ago there was an NDB nav station aboard a stationary ship about midway to Hawaii.


User currently offlineSAAFNAV From South Africa, joined Mar 2010, 281 posts, RR: 1
Reply 19, posted (3 years 6 months 1 week 5 days 21 hours ago) and read 7508 times:

Wow!

As interested as I am in Astro Nav, I am very glad that I don't need it anymore. Sure, it's nifty, but it could really complicate Nav Course!
Old Fashioned Air Plotting is bad enough as it is.

GPS is the way to go!  

Erich



On-board Direction Consultant
User currently onlinePihero From France, joined Jan 2005, 4590 posts, RR: 77
Reply 20, posted (3 years 6 months 1 week 5 days 20 hours ago) and read 7467 times:
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Quoting 26point2 (Reply 18):
Used VLF/Omega for years between Calif and Hawaii in the 90's (pre- GPS). About a 5 hour flight. Position was blended (averaged) between sensors and was typically about 5 NM off when OGG DME reception was obtained 200nm from Maui. Not too bad.

I don't understand your statement : The Omega-VLF was not time-dependent. As it computes position on a hyperbolic grid of interferences, if you have reception, you have a position, unless you lose reception and in this case the system tells you that it's continuing on dead reckoning on the latest position with drift and heading.
I don't know how the receptipon was on that route but my experience was of a very accurate system



Contrail designer
User currently offline26point2 From United States of America, joined Mar 2010, 836 posts, RR: 0
Reply 21, posted (3 years 6 months 1 week 5 days 16 hours ago) and read 7389 times:

Quoting Pihero (Reply 20):
I don't understand your statement

Thanks. I'm not a tech guy, just a pilot, and I don't understand how VLF/Omega worked ....seriously....but I recall a drift of about 1 mile per hour in those days.


User currently onlinePihero From France, joined Jan 2005, 4590 posts, RR: 77
Reply 22, posted (3 years 6 months 1 week 5 days 15 hours ago) and read 7377 times:
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Quoting 26point2 (Reply 21):
I recall a drift of about 1 mile per hour in those days.

Unless you had one IRS in that set-up, I can't see any reason for a drift.
Omega / VLF works on exactly the same principles as the LORAN, i.e pairs of transmitting stations operating on the same frequency. It is demonstrated that the interference comes out in the form of hyperrbola... add a coding of each station, et voilà ! one line of position ; add now another pair, with the same results and one's position would be at the intersection of two hyperbolae...and the accuracy only depended on the availability of received stations.
With TAAG, the accuracy was judged sufficient for us to enter the coordinates of a "ghost beacon" five Nm before a runway threshold, thus giving us the opportunity to devise a simple accurate let-down on that bush airfield.



Contrail designer
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