n4gix

Navigation prior to GPS, VOR and NDB!

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The first real "technology" was the low-frequency radio range system. Here is a brief description of how the LF radio range worked:

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The low-frequency radio range (LFR), also known as the four-course radio range, LF/MF four-course radio range, A-N radio range, Adcock radio range, or commonly "the range", was the main navigation system used by aircraft for instrument flying in the 1930s and 1940s, until the advent of the VHF omnidirectional range (VOR), beginning in the late 1940s. It was used for en route navigation as well as instrument approaches and holds.[1][2][3]


Based on a network of radio towers which transmitted directional radio signals, the LFR defined specific airways in the sky. Pilots navigated the LFR by listening to a stream of automated "A" and "N" Morse codes. For example, they would turn the aircraft to the right when hearing an "N" stream ("dah-dit, dah-dit, ..."), to the left when hearing an "A" stream ("di-dah, di-dah, ..."), and fly straight ahead while hearing a steady tone.

Can you imagine having fly for hours listening to that continuous stream of CW characters? When actually "on-course" the two characters sort of blended into a continuous tone, but hearing that was considered a "Bad Thing". The reason being that they were required to fly parallel to, but not directly on the beam! They were to stay to the right of the beam to avoid any aircraft flying the reciprocal course...

For full details of this primitive system, read the Wikipedia article:
https://en.wikipedia.org/wiki/Low-frequency_radio_range

I found this short video that features a flight around a small LF Radio Range in an actual aircraft complete with graphic illustration as well as audio illustration:

 

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Rotary wing:.....I never did the radio range but had the old coffee grinder adf and when that wasn't installed...maps. I started flying rotary wing in the 1970s and used to go all around the arctic and other remote locations with nothing but maps that 2 times out of 3 were  produced decades before and accuracy wasn't 100%. This was also interesting when north of the treeline when snow was present and ground was for the most part flat. Surprisingly most times we got from A to B fine. Compass + timepiece and a heading were part of the deal too. Fixed wing guys then, before gps, used to fly on top, on a heading and let down off their watch, break out and find a camp on a lake and land on ice strips (DC3 & twin otter stuff). Some of these guys had their area of ops memorized. They'd break out and usually know just where they were. They were truly amazing people.

 

When I switched to fixed wing in the 1990's the gps constellation didn't have enough satellites to be sure of 24/7 coverage...there were holes in the coverage depending where the satellite coverage was needed for the US military. I remember one time inbound to Shamattawa in 1996 losing the gps about 30 miles from Shamattawa Manitoba, flying the heading till the low powered adf was picked up at about 10 miles, shooting an fixed card NDB approach to minimums in the dark....On the way back got the gps signal about the same place it was lost. Also, in those days civilian reception was degraded compared to the military signals but it was still great. Sometimes the trip in the arctic could be 5-600+ miles and if a VOR was present you'd just drive out on the desired radial till you lost reception(without a gps), fly a compass heading till you picked up the next one. The quality of the DG/HSI made a big difference. The E110 could have an C172 style DG (mad things interesting - precessed rapidly) where a king air 200 I flew on medivacs had a Sperry unit that was said to precess less than a degree/hour so life with it was good. You worked with the tools you had and got good with them. In the medivac king air 200* we actually had an astro compass and at the time I was reasonably good with it....really cool piece of equipment. *Medivac territory on that contract was the Canadian Arctic with the occasional trip to Greenland. In the 1990s I new one guy, arctic captain on a gravel equipped 737-200 who bought his own Garmin 55 and used to stick the antenna on the window....said it was much more accurate than the Global system the aircraft was equipped with.

 

Wish I'd had a chance to experience the radio Range and learn it from someone to whom it was second nature. There used to be an add-on for an earlier version of flight sim many years ago for this.. Pardon the rambling. Fun memories.

Dave

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Thanks for posting the video, I've read about Radio Range but have never seen/heard a demonstration.

27 minutes ago, dbw1 said:

There used to be an add-on for an earlier version of flight sim many years ago for this..

I haven't tried it, but the Milviz T-50 Bobcat has a simulation of Radio Range navigation

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41 minutes ago, dbw1 said:

Wish I'd had a chance to experience the radio Range and learn it from someone to whom it was second nature. There used to be an add-on for an earlier version of flight sim many years ago for this.. Pardon the rambling. Fun memories.

Dave

Dave, that earlier add-on is still available, but unfortunately it will only work in FS2004.

One of the developers has updated the code to work in FSX and P3D but it's only available in the T-50 package mentioned above.

The LFRR is a ton of fun, recreating the "Good Old Days" of primitive hi-tech navigation... :cool:

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NA ranges are very neat and its great that somebody actually built one today. However,....why on earth did he wear that cheesy Sports pilot shop uniform and hat?!?!?!!

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I learned how to navigate by taking star shots in a Navy C-47.  Used paper celestial tables, a map, a ruler and a compass (the kind with a pointed end and a pencil).  We were lucky if we got within 25 miles of our destination after a three hour flight. Thank goodness the pilots had VOR's in the cockpit or I'd still be flying around totally lost 😁

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I remember the old Narco coffee grinders Dave.

But there were no avionics in the Luscombe 8E on floats I took my first flying lessons and soloed in.  No started either.  You had to stand on the floats to prop the engine.  That was exciting.

The evening before a cross country flight from Commodore Center in Sausalito to Clear Lake or San Luis Reservoir near Hollister I had the sectional spread out over the dining room table drawing course lines and circling geographic check points and using the old E6B to figure winds.  It was called pilotage or navigation by looking around.

I am currently taking the Great Courses course titled The Science of Flight.  In this morning's lessons they discussed Cat IIIB systems where the pilot only has to control the aircraft to and from the gate while on the ground.  They call that flying.  Too much reliance on those systems results in what happened to the Asiana B777 in San Francisco a couple years ago.  Complacency can become deadly.  It's important for today's airborne systems operators to use the stick and rudder from time to time to maintain proficiency.

Noel

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17 hours ago, vp49p3 said:

I learned how to navigate by taking star shots in a Navy C-47.  Used paper celestial tables, a map, a ruler and a compass (the kind with a pointed end and a pencil).  We were lucky if we got within 25 miles of our destination after a three hour flight. Thank goodness the pilots had VOR's in the cockpit or I'd still be flying around totally lost 😁

I hear you and you were probably much better than I was with it. When doing a medivac flight from say Iqaluit to Resolute (approx 1000 miles) depending on winds it was 3-4 hours so we'd pull it out and practice with it. We had current tables. The 200 I flew in those days had a basic gps used only for enroute and technically it was not the primary enroute method of navigation (wink, wink), ndb's for arctic communities were strong so you could usually get one of two anywhere enroute (famous last words), but it was nice knowing if the word not allowed ever hit the fan with electrical issues and totally loss of electronic nav equipment the astro compass could be used to assist getting us to a general area if needed....never was though. The old 200 with the -41 engines was pretty reliable. That 200 carried 3600 pounds of fuel and up high the burn was under 500#/hr so you could go places and have options.

I just recently picked up an old astro compass at a gun show for $100 that now sits in a prominent place in my home. Very cool.

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Prior to retirement my final aviation years were spent as a simulator instructor and TCE for a large training center organization.I worked in an entry level jet program targeting entrepreneurial types transitioning to their own personal jet that would be operated single pilot.Needless to say the skill level of many of these individuals was poor in many cases and substantial extra time had to be spent in basic hand flown instrument procedure training.Today's training environment focuses on the technology and use of sophisticated avionics and automation but has minimal emphasis on basic flight and instrument skills without the use of those systems. It is that 1% possibility of automation failure where the pilot must revert to basic navigation procedure and flight skills. I was amazed how many applicants could not perform basic instrument procedures without the use of GPS guidance or relied on a moving map for primary situation awareness.The technology today certainly eases the workload as compared to a former era but I will never regret the training and experience acquired from using now outdated systems because you had the skills to fall back on if the flat screens go blank.

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The first rule in any inflight emergency is FLY THE AIRPLANE!  Than means feet on the rudder and hands on the stick (or yoke).  Establish stable flight and then deal with the emergency.  If you can't do that you're in trouble.  Skills atrophy and must be maintained.

I would think a semi-annual checkride with airline pilots would be making a 360 degree turn without losing altitude, finding the VOR (do they still them?), recovering from a stall, and a hands on landing at the bare minimum.

I recall a dozen years ago or more when I was still flying we had to get a biannual check ride with a certified flight instructor signed off on our log books.

Noel

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CW46...... I agree that those who learned to fly with all the automation  can have their hands full when there’s a problem. The last almost 7 years of my career I was mainly federal government pilot spending 90% of the time in the office and 10% in the cockpit. I flew then an analogue king air 90 with first a knl90b and then a Garmin 400 till about 2 years prior to retirement it was fitted with agarmin1000. I was totally at home in the old cockpit but when I got to fly the 1000 thought I’d died and found the promised land. I was 60 when I got my hands on the garmin1000. Old dogs can learn new tricks LOL.  I can totally understand how someone who hasn’t flown an old school cockpit can be in deep kimshee  when the whiz-bang stuff calls it a day. Example....Some are so used to having the avionics do the thinking for them they have a hard time looking at an RMI and seeing the picture from it. A lot are button pushers who did not have sufficient time in their career (not their fault) to develop hands and feet skills plus knowledge to help think out side the box when they have a bad day. (SFO and the south Atlantic?...) That said most military guys though they can have a lot less actual flight time than civilians are usually very sharp and adaptable....disclaimer.... I’m not ex military. I’d have a family member ride with them any day. The next ten years as us older farts retire are going to be interesting.

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On 12/1/2017 at 2:23 PM, fshobby said:

Thanks for posting the video, I've read about Radio Range but have never seen/heard a demonstration.

I haven't tried it, but the Milviz T-50 Bobcat has a simulation of Radio Range navigation

Yes, and that was the reason I got the plane. It is quite intriguing to use that system, but unfortunately it does not work yet in P3D v4. 

In case you are interested, here is a complete list of radio range stations from the 1930s

http://smithplanet.com/fs2004/tools/rr/

Peter

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Thanks for the list of radio ranges. Hopefully it’ll work in V4 down the road or maybe MilViz will sell the RR addon separately.

dave

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