Before there were VORs....

[ArkhamAsylum]

A boring day of ODO led to some curiosity-based research into the history of air navigation. I saw these strange beacon-like objects in a museum a while back, and I think this article explains how they were used.

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

Executive summary: the USPS's ancestors led the push to have pilots flying at night (back in the days A4's was just getting interested in flying machines). Since unaided pilotage is difficult, and dead-reckoning requires wind-corrections based on pilotage, Post Office air fields started using rotating beacons to identify the landing strip, as well as a solid light pointing toward the next field in the journey (creating the effect of an airway). These beacons were only visible to about 40 miles, so they started using intermediate beacons (sometimes in the form of fires) every 10 miles along the path. The beacon towers had painted numbers for daytime use, and sequenced flashing for night use. The next logical upgrade was the incorporation of radio transmission, which was the birth of a radio-based airway, which is a different story altogether.

http://en.wikipedia.org/wiki/Airway_(aviation)

This article attests that airways were invented to keep civilian pilots out of military airspace. The first radio navaids transmitted Morse code, and later a steady frequency, to aid pilots in staying on course. This time also saw the birth of airborne 2-way radio transmitters (stemming from the need for PIREPs). At some point after WWII, VOR was developed and popularized, and the rest is history.

I apologize if any of this info is inaccurate, as it is a summary of several hours of time-accelleration. I'm hoping that someone who actually flew around using these legacy navaids can chime in with a few amusing anecdotes.

 

[KBayDog]

"In the early days of flight, there were no navigation aids to help pilots find their way. Pilots flew by looking out of their cockpit window for visual landmarks or by using automobile road maps."

For us rotor trash, "The More Things Change..."

 

[blackbart22]

When I made booze runs from NORIS to El Pusso along Amber One there were still a few red beacons marking the route. Also in advanced training in AD-5s my instruments instructor had me fly up to San Antone and do a radio range orientation and approach. They were about to decommision the last two ranges and he said that he wanted me to be able to say that I'd done it. He did mark me down because I didn't seem to be able to hear the volume of the beam increase as we approached the beacon. What he didn't realize was that the AD-5 that we were in had an ARN-7 ADF instead of an ARN-6. The ARN-7 had an Automatic volume control built in. The change in volume was in his head.

 

[phrogpilot73]

...ADF...

I thought those were for listening to AM radio on long cross countries...

 

[KBayDog]

I thought those were for listening to AM radio on long cross countries...

Yeah, I couldn't help but notice that our 1 Dec 09 NATOPS finally removed the ADF steps in the PCL.

(I noticed this only because I was pissed that we don't have an ADF to listen to AM radio, and I was tired of seeing "CDNU/RADALT/ADF - OFF" in the PCL!)

 

[Jim123]

Way back in the 1920s some of the aviation pioneers campaigned to get cities to paint the town names on rooftops... the pitch was something about modern commerce. Aeronautical commerce improved after pilots didn't have to idle their airplane's engines and get directions by yelling back and forth to someone on the ground.

IIRC, UHF/NDB instrument approaches (homing on the ATIS broadcast- simple and elegant!) used to be a big deal for military field instrument certification too.

Sheesh! Kids these days don't know how good they got it!

 

[usmarinemike]

I thought those were for listening to AM radio on long cross countries...

I thought it was a switch position that didn't do anything.


Seriously though, I wonder why civilian aviation went with the VOR and never adopted TACAN. One box gives bearing and DME. Every civilian plane I've been in has an extra box for DME that you set to the TACAN channel at a VORTAC anyway to get the DME. I'll be the first to say that DME isn't a necessity, but it's a lot nicer than stopwatches and radial cuts to fix a position. And besides (maybe it's just the mil equipment Ive been using for the past year) UHF TACAN seems to be a lot less jumpy than VOR. And yes, I do know how jumpy ADF can be.

 

[Flugelman]

I thought it was a switch position that didn't do anything.


Seriously though, I wonder why civilian aviation went with the VOR and never adopted TACAN. One box gives bearing and DME. Every civilian plane I've been in has an extra box for DME that you set to the TACAN channel at a VORTAC anyway to get the DME. I'll be the first to say that DME isn't a necessity, but it's a lot nicer than stopwatches and radial cuts to fix a position. And besides (maybe it's just the mil equipment Ive been using for the past year) UHF TACAN seems to be a lot less jumpy than VOR. And yes, I do know how jumpy ADF can be.

I'm guessing that the primary reason is cost. The extra equipment to add DME would be significant $$$ in a small GA airplane.

 

[usmarinemike]

I'm guessing that the primary reason is cost. The extra equipment to add DME would be significant $$$ in a small GA airplane.

That's just the thing. Every GA plane I've flown has DME. The nav radio pulls the VHF signal from the VOR for bearing and the DME box pulls the UHF signal from the TACAN that's collocated with the VOR. There are relatively few VOR/DME navaids out there that aren't actually VORTACs.

 

[FlyinRock]

I remember trying to do intersection holds with an old VHT3 coffee grinder back in the 60's. The radio ranges were being phased out then but I was still required to work with them. ADF/NDB was still in use here and I used it a lot outside of CONUS. with the advent of GPS, much of what we have been using for the past 40 years is rapidly becoming obsolete. Even today I have IFR studs asking how I can do approaches with VOR and not use GPS. They get upset when I start turning off NAVAIDS and ask them to find their position.
Have we forgotten how to use our heads and brains?
Semper Fi
Old Jarhead

 

[Fog]

Is the ARN-6 ("Bird Dog") still in some naval a/c?

 

[Kaman]

It is fascinating at how much progress has been made in such a short period of time. From the time of Lindbergh's flight in 1927 to going to the moon was only 42 years. As late as 2007, I was routinely shooting NDB into Augusta, ME if the weather didn't permit us to circle off the LOC. Even today, I fly an airplane that is a slant/A in 121 operations. However, in a few years this too will be a thing of the past as ADS/B, FANS and all the other advances to navigation technology are introduced and perfected. A word of caution though...As spectacular as all these advances are, history has shown that anything designed, built and operated by man can be deadly until the bugs are discovered and worked out.

Regards,

ex-Navy Rotorhead

 

[BlkPny]

In Viet Nam we flew out of a VNAF base. In bad weather they would turn off all Nav aids, "since no one was flying", and turn off the field lights at night. If we were coming home in the weather, we would get below it and fly until we came across the Bassac Mekong river. If we were to the northwest, we would fly downstream until we flew over Football Island. We would count to three, drop gear and flaps, and turn right. The runway would be right in front of us. If coming from the southeast, we flew upstream until we passed the tall crane, trying our best to not hit it, then counted to two and turned left. Since "no one was flying", we could land on the runway in the direction we were headed, no matter what. Our call.

The only real problems arose when the weather was really bad, during the monsoons, T-storms, or the dry season when they burned off the rice paddies and the smoke was like flying in a milk bottle. We would call our bunker, and the duty officer would call the tower on a land line and ask them to turn on the nav aids and lights.

 

[yak52driver]

I thought those were for listening to AM radio on long cross countries...

I used to listen to WLS, the Rock of Chicago, on my solo XC's back when rock was still on AM...

 

[ArkhamAsylum]

I appreciate all the stories coming out of the Olde Days of aviation. This is good stuff for us newbs to think about how good we have it.