@Greg47
I do assume that the flight went towards Howland but did not get there. The MS Excel plot also assumes a steady speed from the Ontario point of 155 mph TAS with a wind of -32mph but that speed is not set in concrete for the ETA at HOW at that speed would be 2054GMT. With that constant speed the Electra is 207 miles from Howland at 1912GMT and has 303 USG remaining. All the MS Excel plot workings are done with data from LR 487 regarding Speed for the AUW, which in turn gives the H.P. required and total H.P. figures and I use an SFC of 0,45. We have discussed the TAS of 180mph required with that wind being an extreme power setting and wasteful on fuel and over the MAX Continuous setting..
As I have mentioned previously, the first half of the flight up to the 1030GMT point, when the “Ship in sight ahead” call was made can be reasonably plotted to give the climb out, the cruise periods, the further climbs and the descents that were made “on time” and “on location” and coincidental with the two speeds mentioned (…“making 140” which I do get as G/S and …”making 150” which I get as TAS), the heights mentioned and the radio call times. I have done that and I then assume that the 1030GMT call that saw a ship, was the Ontario and that the Electra was overhead the ship at 1036GMT, six minutes and 12 miles later.
It is what happened after that time that is the factor governing where their location was at 1912 GMT/2014GMT. It is night, they are dependent on Astro Navigation from this point on. We know that at 1415GMT there was cloud and overcast. “Overcast” was again repeated at 1515GMT. ”Partly cloudy” was said at 1615GMT.
What is a reasonable thing for Noonan to want to assist his navigation in the event he has to DED-Reckon as he cannot get Astro .....and the answer to that is a steady speed or a constant on the half-hour or at the most hourly update on the IAS but without Astro he will not know if the wind has changed in speed or direction. He would be working blind..
Has any reader an opinion on that ?