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matt_gold

pre-VOR navigation....how the heck.....

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So, flying around in the Stearman in heavy winds, feeling very much like I am kite-flying myself, a bit dismayed after failing a clandestine mission and presumably going to jail for illegal trafficking as I'm sure my character deserves for accepting such a dodgy cargo (and probably will again) I got to thinking....

 

How did the pilots navigate before VOR stations? How on earth would they have crossed the oceans and known where they were going without receiving VOR signals and cross-referencing maps?

Actually, how do they do it now?!?! VOR is line of site, the world is round, and the oceans are....well they are oceans, and not littered with VOR buoys....or are they?

 

I know, I know, basic stuff. As usual, much gratitude for the free flow of information from the pros.

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Before VOR`s there were NDB`s (since WW1).

But in early times the flew only VFR using, landmarks, railroads and roads.

For long distances over ocean they used the same then boatmen: compass, sun and stars.

 

Today there are many systems onboard an aircraft.

IRS, GPS, VOR, DME, NDB and Databases in their FMC with predefined waypoints.

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Dead reckoning navigation was a big part of it. If you know where you start from, know how fast you are going, and what direction you are going, a map and a clock can give you a fairly good idea of where you probably are, especially if there's anything on the surface to compare to what you see on the map. In a way, dead reckoning is still used by aircraft that carry inertial navigation systems; they've just automated the process.

 

For long over-water flights, celestial observations with a sextant wasn't really totally killed off until GPS became dominant. The sextant kits finally got pulled out of large US Navy aircraft just a few years ago. Nobody really remembered how to use them, anyway.

 

The old VLF Omega system gave you a pretty good idea where you were, too. With only 9 stations covering the entire world, you could fix your position pretty much anywhere. The abandoned Kaneohe Omega station up near the entrance into the H-3 tunnels was another thing I had hoped to see in Flight, but it's not there either.

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Celestial mainly, such as in ... that the Angels be with me....

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Two fundamental skills you learn in Private Pilot training are Pilotage and Dead Reckoning.

 

Pilotage is as Heimi described... referencing to landmarks, rivers, roads, railroads, lakes... anything prominent and easily distinguishable from the air.

 

Dead Reckoning is the ol' "give me a map and a compass and I'm there" (and as the Ray said... knowing groundspeed to estimate checkpoints):

  • you plot a bearing (course) on a Sectional Chart, which gives you a "True Heading"
  • Apply the local Magnetic Variation (taken from the dashed magenta lines on the Sectional). Maui e.g. has almost a 10°E Magnetic Variation, so you subtract 10° from your (true north) course (east is least, west is best... i.e. subtract east, add west)
  • Apply the aircraft's Magnetic Deviation taken from the compass card. Could range from 0° to 2°or 3°.
  • Compensate for crosswind. (E6B)

One "race" I was involved in at Sim Outhouse... we could only use NDB (mainly). Fine and dandy, but when navigating over the South Pacific from Australia to Chile... there are literally hundreds of miles (over the ocean) with no Nav beacons. Dead Reckoning works excellent. Was a blast to see the ADF needle "come alive" (indicating an island / runway) after hours over the water.

 

One skill I was never taught (it's on the bucket list) is Celestial Navigation. I think the U.S. Navy taught their pilots this until sometime in the '90s. This is the way Charles Lindbergh would have navigated across the Atlantic... using a sextant for a position fix and using dead reckoning to determine course.

 

The sextant kits finally got pulled out of large US Navy aircraft just a few years ago.

 

Wow Ray... would be the bees knees to pick up one of those kits...

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Wow Ray... would be the bees knees to pick up one of those kits...

 

I'm sure they either went for scrap, or the cases are stacked to the ceiling in some warehouse "just in case we ever need them again."

 

I don't think you'd want one, either. They aren't standard sextants like you normally see... there was a periscope-style receptacle in the top of the fuselage that you mounted the sextant into when using it. I'm not sure they would even be useable without being mounted. I never even took one out of the case, myself.

 

I can find the North Star and (on a good night) the Southern Cross (depending on what side of the planet I'm on), and that's about it.

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Reminds me of a dialog from the movie Hanover Street that went something like:

 

Crew1: Isn't it funny how sometimes it looks like the propellers are running backwards?

Crew2: Backwards?? How can you be sure they're not running backwards?

Crew1: Well, if we take off facing Germany, and we end up in Ireland, then they were running backwards.

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The sextant here: http://library.avsim...=root&Go=Search

 

is also installed on the VC10 model.

The greatest story of dead reckoning is Ernest Shackleton crossing 800 miles of the Southern Ocean in seas so rough they were only able to take 4 sightings of the sun!!

 

vololiberista

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The sextant here: http://library.avsim...=root&Go=Search

 

is also installed on the VC10 model.

The greatest story of dead reckoning is Ernest Shackleton crossing 800 miles of the Southern Ocean in seas so rough they were only able to take 4 sightings of the sun!!

 

vololiberista

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Actually, how do they do it now?!?! VOR is line of site, the world is round, and the oceans are....well they are oceans, and not littered with VOR buoys....or are they?

 

Oceanic navigation is now made using inertial systems or GPS, under specific procedures, because there are no VORs nor radar coverage (that's why finding the Air France A330 in the Atlantic Ocean was so difficult). Until a few years ago sextans or similar instruments were used to check and correct the route. Moreover on this very long routes you can't follow a "straight line" using a constant heading because on a sphere the shortest path is a different kind of "line" and heading may chnage along the route.

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Don't forget the LORAN (LOng RAnge Navigation) system that was very much depended on for pre-GPS long range navigation by both ocean going vessels and aircraft!

 

http://en.wikipedia.org/wiki/LORAN

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The greatest story of dead reckoning is Ernest Shackleton crossing 800 miles of the Southern Ocean in seas so rough they were only able to take 4 sightings of the sun!!

 

 

Polar explorers back then were tough S.O.B.s! I've read Shackleton's book South several times, and I'm amazed at what they endured. There was an excellent TV movie a few years back starring Kenneth Branaugh as Shackleton.

 

William Bligh's 3,600 nautical mile journey on an open boat was a pretty amazing feat of navigation and survival too.

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Holy smokes thanks folks...I am going to have to go home and absorb all this new info.

 

Oh, and I really want a vintage sextant for next christmas

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As indicated, there have been a small number of sextants for FS over the years, interesting to try once, but seriously a moving map with GPS is so much easier! :LMAO:

 

By the way, "dead" reckoning is not dead at all, but rather "ded." as in deduced reckoning. It also helps a lot to know prevailing winds when using this method.

 

Best regards.

Luis

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Actually, how do they do it now?!?! VOR is line of site, the world is round, and the oceans are....well they are oceans, and not littered with VOR buoys....or are they?

 

In the olden days, airliners & bombers carried along a navigator. The navigator poured all over the charts with rulers, pencils, and possibly headphones for an old style radio wave, and then told the pilot which direction to fly. Today's GPS can tell the pilot which direction to go...........and get them to the proper location within three feet. It can also give a correct altitude within 10-30 feet. Since GPS uses two dozen satellites in orbit, it doesn't have problems with line of sight. The GPS will pick up eight to twelve satellites, and use the best signals. It only needs three or four. The newest up to date airliners use GPS as the number one navigation system. It updates the inertial nav system, instead of the older VOR/DME method, which would do the updates while the plane taxied at the airport.

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The "LONE EAGLE" Charles Lindberg could have show and explain it..No radios!!...DEAD RECKONING...reckon Correctly,or yer dead....Yes ,A compass,a chart ,and a time piece!...As you know a Compass has many peculiarity's like Deviation,variation,dip errors,Northerly turning error,Acceleration error....Factor in the wind DIRECTION,WIND SPEED,..weather,Controlling the plane....its a Task! with out room for error!..THE e6b or simply the "whiz wheel", FLIGHT COMPUTER HELPS A LOT......The same for early explorers in sailing ships!....Stars ,if you can see them are an other way to find yer way!...Over the vast seas ..looking at the direction of the swells...can help...Of course yer eyes are the most important..Out of the Cockpit!..Over land ,towns had some Rooftops with their name....Road charts helped greatly,The IRON RAILS most helpful..Rivers,Roads,as all topography.is!....Binoculars and Good Sunglasses are a must!!

 

...http://www.centennialofflight.gov/essay/Government_Role/navigation/POL13.htm..

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By the way, "dead" reckoning is not dead at all, but rather "ded." as in deduced reckoning.

 

This is one argument folks use who support the idea that dead reckoning is actually "ded reckoning".

 

This is certainly one of those things debated in aviation. My purpose here is not to argue which is "correct"... just to introduce an article where the writer seems to have done some legitimate research into the origin of the term.

 

One thing you might be interested in knowing, as pointed out in the article, you will not find the FAA (or Coast Guard) using the term "ded" or "ded.". It's termed as "dead reckoning". :Nerd:

 

Btw... just as Fr. Bill's tagline says, “People don’t need an important issue to fight about. They’ll take anything available and inflate it to the size they need.” ... so I thought I would do that here. :Just Kidding:

 

Here's that article mentioned above: Is "dead reckoning" short for "deduced reckoning"? http://www.straightd...duced-reckoning Enjoy!

 

btw Luis... :drinks:

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I go with "dead" simply because "deduced reckoning" is redundant. It's like thoughtful thinking. Just%20Kidding.gif

 

Plus, as noted, that's the way official entities I am familiar with such as the FAA, US Navy, etc. spell it.

 

Personally, I believe "dead" refers to precision, such as "dead on target" or "dead accurate", not life & death.

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I go with "dead" simply because "deduced reckoning" is redundant. It's like thoughtful thinking.

 

 

A. I ordered Markinson to have Santiago transferred off the base immediately.

 

Q. Why?

 

A. I felt that his life might be in danger once word of the letter got out.

 

Q. Grave danger?

 

A. Is there another kind?

 

(Exchange between Lt. Daniel Kaffee and Col. Nathan Jessup in "A Few Good Men".)

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