"The third USS Ontario (AT–13) was a single screw seagoing tug."
Mission and Location
- Not long after Parker’s message reached Itasca, the U.S. Navy’s main radio station in Hawaii, Radio Wailupe near Honolulu, contacted the cutter with a wire for Black from Earhart. Amelia’s telegram from Bandoeng had taken more than sixteen hours to wend its way through the system. Her instructions were very specifc. For the flight from Lae to Howland she wanted Ontario, the navy ship positioned halfway along the route, to be ready to transmit on 400 kilocycles. When she got close, she would call the ship and it should then send the Morse code letter N (dash-dot) repeatedly for five minutes. At the end of each minute the ship should also send its call letters, NIDX, twice. By hearing the letter N and identifying the call letters Amelia could be sure that she was listening to Ontario. She would then, presumably, use her direction finder to home in on the ship and make sure she was on course for Howland. Her instructions for Itasca were somewhat different. Rather than wait for her to call, the cutter was to transmit the Morse code letter A (dot-dash), the ship’s position, and its own call letters, NRUI, every hour on the half hour on a frequency of 7500 kilocycles. “Position ships and our leaving will determine broadcast times specifically. If frequencies mentioned unsuitable night work inform me Lae.”
- However, on March 14, 1937, during preparations for Earhart’s originally planned flight from Howland Island to New Guinea, USS Ontario reported that it was “en route to plane guard station latitude 03 05 South, longitude 165 00 East for Earhart flight.” The ship was assigned the same position, halfway between Lae and Howland, for the July flight.
- Ontario to CINCAF, 0310Z, March 14, 1937; CNO to Naval Station Tutuila, 1700Z, April 28, 1937.
- From Bob Brandenburg, 23 February 2009 Forum
- The message data base shows that on 19 June (Record No. 143) Itasca requested the Governor of Samoa to get information on the frequencies available on Ontario (and also Swan).
- On 20 June (Record No. 147), Samoa told Itasca "ONTARIO TRANSMITTER 500 WATTS FREQUENCY RANGE 195 TO 600 KCS EITHER CW OR MCW NO HIGH FREQUENCY EQUIPMENT ON BOARD". The phrase NO HIGH FREQUENCY EQUIPMENT ABOARD is critical. Earhart couldn't transmit on on a frequency Ontario could copy.
- On 26 June, Earhart requested -- via Black -- that "ONTARIO STAND BY ON 400 KCS TO TRANSMIT LETTER N FIVE MINUTES ON REQUEST WITH STATION CALL LETTER REPEATED TWICE EVERY MINUTE". The key phrase here was "ON REQUEST". Apparently Earhart either didn't receive -- or ignored -- the fact that Ontario had no HF equipment on board. It would be reasonable for Ontario to assume that Earhart knew what she was talking about, and had the means to request the desired transmission.
- On 1 July, Earhart sent to Black "ASK ONTARIO BROADCAST LETTER N FOR FIVE MINUTES TEN MINUTES AFTER HOUR GMT FOUR HUNDRED KCS WITH OWN CALL LETTERS REPEATED TWICE END EVERY MINUTE STOP PLAN LEAVE BY TEN THIS MORNING NEW GUINEA TIME". Apparently, Earhart discovered that her previous plan -- for Ontario to transmit when requested -- was not feasible, so she shifted to this new plan for transmissions on a schedule. However, she appears not to have considered the time delays inherent in communications via relay stations in the mid-Pacific, and assumed that her revised request would get to Ontario in time.
- I don't find any record of Earhart's revised plan reaching Ontario. If it didn't get through, then Ontario would be expecting Earhart to request the signal when she wanted it, and Earhart -- not knowing that the revised plan didn't get through -- would be expecting Ontario to be broadcasting the DF signal on her requested schedule. Result: no DF signal from Ontario.
Interpretation of Earhart's instructions
"Her instructions were very specific. For the flight from Lae to Howland she wanted Ontario, the navy ship positioned halfway along the route, to be ready to transmit on 400 kilocycles. When she got close, she would call the ship and it should then send the Morse code letter N (dash-dot) repeatedly for five minutes. At the end of each minute the ship should also send its call letters, NIDX, twice. By hearing the letter N and identifying the call letters Amelia could be sure that she was listening to Ontario. She would then, presumably, use her direction finder to home in on the ship and make sure she was on course for Howland" (Finding Amelia, p. 62).
Location of the Ontario and Myrtlebank
- We know of only two ships in the general area that Earhart might have seen: the USS Ontario, whose position at that time was 2°59.02′S, 165°23.20′E, very close to the great circle path from Lae to Howland, and the MV Myrtlebank, a merchant vessel scheduled to arrive at Nauru the following morning, having departed New Zealand. The Lexington Search Report provides an approximate position of the Myrtlebank of 1°40′S, 166°45′E. Again, we speculate that Navy personnel inferred the Myrtlebank position based upon the State Department telegram. Based upon correspondence between TIGHAR researchers and the Third Mate of the Myrtlebank, who claimed he heard a plane that night cross his starboard quarter, we have roughly determined the limits of the Myrtlebank position at 1030 GMT: a 20nm by 10nm region oriented at 350° centered at 2°20′S, 167°10′E. At this juncture of the narrative, we are uncertain as to which ship, if any, Earhart saw that night, but will speculate later when we attempt to reconstruct the navigation of her flight. The deck logs of the Ontario report the seas are calm, visibility at least 40 miles, and cloud cover from 20 to 40%.
- NARA, RG. 59, File 800.79611.