Suggest a LF range for fun

[dilbert]

Suggest a Low Frequency radio range at NGP, Com tunable, for us old-timers-don't recall the frequency, but we could tune it at the low end on our car radio.
WOG59

[Johan G]

Is this related to FGCom and the aircraft radios?

[dilbert]

yes. It was still in use up until the 50's, especially in remote areas, so naval patrol pilots had to know how to use it. There were 4
quadrants alternatively broadcasting an "a" or an "n" in Morse code, with a steady tone where they joined; so you maintained course by ear and keeping a steady tone. You knew if you were proceeding toward or away from the station by whether the volume was increasing or decreasing. Challenging in an electrical storm with a lot of static in the ear phones. In those days the only computer was in your head. NGP was the Low Frequency Range call sign for NAS Corpus Christi.

[Johan G]

There were 4 quadrants alternatively broadcasting an "a" or an "n" in Morse code...

Ah, now I am with you. I did not get that it was the radio navigation aid, and thought it was just an extra frequency band on the radio.

I am not sure it can be implemented so that you can tune the regular radio for that (using FGCom). But I am quite sure that something could be set up within FlightGear, most probably without even touching the source code.

Hypothetically a list of LFRs, the direction of their beams and any marker beackons could be added to an XML file that would be read into the property tree. Those properties would then be read by an instrument working as a radio receiver. The "radio receiver" could consist of a Nasal module, three sound files, a property sub-tree and an animated 3D model representing the instrument in the cockpit. I do wonder though if there is provisions for adding that identification signal already or if that has to be done within the instrument.

I think that by doing it this way I can hopefully be made into a generic instrument, that could be added to other aircraft without adding all too much to each of them.


Side note: I was not aware these where used for approaches as well.


For details about those navigation aids (for others ) see:

• On the Beam on Charles Wood's Flight Simulator Navigation web site
• Low-frequency radio range (perm) on Wikipedia
• Richard Harris (not Harrison ) (2013, 2014), "Flying the Beam" LF/MF Four-Course Radio Ranges (includes a small scale map of US beacons)

[dilbert]

Thanks for the response. At 80 my memory me is a little foggy, but I think we tuned it on one of the regular Com radios, as the range frequencies were sandwiched between regular LF Com voice and regular AM (that's why you could get NGP at one end of the car radio dial and also why you got a lot of static in a storm). What you would need in flight gear, not to interfere with normal communications, would be a toggle switch to go from UHF to LF on Com 2. That way you would tune and hear the LF range. (you would tune APC on Com2 and flip the switch to track or talk). There was never any instrument, so none would be required. All the LF ranges were the same except for directional orientation of the 4 radial pattern, with one leg going to the runway. Whatever leg you tracked in on, you got a null at station and turned to the runway leg for final. A LF range would be easily portable to other airports by piggy backing on the go-to-airport feature. If the LF range switch was toggled, a Virtual Range-by hearing- would be spotted 8 miles from the longest runway using the uniform pattern at the inverse bearing of one leg of the runway. Approaching a range you began to hear faint didas, dadits, or the tone. When they seemed loud enough you turned 45 degrees, clock timing how long it took to get to the next radial; after which you turned inbound on the new radial. That told you may minutes you were (miles based on your speed) from the station, and you reported " x miles inbound" to approach control. The beauty of LF ranges was that you could make an approach in any aircraft equipped with an aviation LF Com radio. The same would apply in FlightGear.

[Johan G]

See also the topic Navigation with 4 course radio range.

[daveculp]

My guess is this is unlikely to end up in FlightGear, but I think it would be easy enough to script using existing VOR's as the basis. The A and N audio could run continuously, and the script could adjust volume for each sound according to your radial and distance from the VOR.

[Johan G]

The A and N audio could run continuously, and the script could adjust volume for each sound according to your radial and distance from the VOR.

Ah.