Thank you Woody for finding that 1936 Manual
(I read the whole thing.)Up to page 20 of the manual and, I can see why AE was a tad reluctant to get too involved with the successful operation of the RDF. ...
Homer Simpson
This Manual had a lot more to do with the design, installation, testing and calibration of Radio Direction Equipment
than Pilot/Navigator's proper use of the equipment.The most beneficial method of teaching Radio Direction Navigation was (and is) the use of a simulator with a plotter and printer:
The original Link Trainer was created in 1929 out of the need for a safe way to teach new pilots how to fly by instruments.
"...The second major component is an external instructor's station, which consists of a large map table, a repeated display of the main flight instruments, and a moving marker known as a "crab." The crab moves across the glass surface of the map table, plotting the pilot's track. The pilot and instructor can communicate with each other via headphones and microphones. ..."
The above would have been the easiest way for Amelia and/or Fred to become a competent Instrument Pilot/Navigator.
BUT...
Homing to a Station is briefly covered in Woody's Manual and could be easily taught without simulation to any Student Pilot (who was interested) in less than one day.
Where it becomes complicated and simulation helps is when you need to Navigate a
Specific Path (or Track) To (or From is even more complex) while compensating for the effect of wind (drift).
They could have easily survived without this knowledge.Homing to a Station is simply pointing your nose at it and as the Manual shows will result in a downwind curved track to the station,
but it gets you there.It was tragic that both Amelia and Fred considered Radio Navigation to be strictly the responsibility of the Radio Operator and they had absolutely no interest in learning anything about the subject.
Just the most basic knowledge
(a one day course) would have saved their flight
and lives.The
only need for Morse Code is to Identify the Transmitting Station
and the two, three or four letters are constantly repeated at a slow enough speed for a non code reader to confirm identification.All they would have needed to do after receiving and Identifying Itaska's 500 Khz* Beacon would have been to rotate that Loop to find the two Null's and determine which one was toward (rather than away) by a simple Heading Change to mark the direction of bearing change.
They would then have oriented the Loop Forward (as was pointed out
in another thread) and keep the nose pointed at the Itaska.
*500 Khz was just one of several Frequencies that Itaska had in the range used for Radio Navigation, but Amelia requested that they transmit continuous A's (dit-dah, dit-dah, etc.) on 7,000 Khz which was well above the Frequency she needed to Home on.
From Half Way down
this Wikipedia site:
In use, the RDF operator would first tune the receiver to the correct frequency, then manually turn the loop, either listening or watching an S meter to determine the direction of the null (the direction at which a given signal is weakest) of a long wave (LW) or medium wave (AM) broadcast beacon or station (listening for the null is easier than listening for a peak signal, and normally produces a more accurate result).
(LW) and (AM) refer to Frequency Ranges needed.
From Amelia's response to Itaska's 7 Mhz A's, she Knew to look for the Null,
but did not know to request it on an LW (or AM) Frequency from Itaska... She would have also needed to do the brief heading change to choose the correct one of the two Null's she would identify.
(As documented in that Wiki, there are ("Huff-Duff") Direction Finders which can determine direction from Higher Frequency Transmitters, but they would never fit in an Aircraft. Itaska had installed one ashore on Howland Island, but had run its Battery Dead by playing with it before Amelia had gotten in range.)