Drift in the DarkPart 7 of 8
How did it turn-out?
https://photos.app.goo.gl/h9ChWzKSMzvxCrTv8 The DR estimate for Howland was 19:10 GMT, corrected to 19:30 GMT, after they got the sunline and the wind-velocity. (I get this time from the ‘200 out’ call at 17:45). As they approached the Howland sun-line they could not see the island or the smoke from the ship and they did not know if they were North or South. With an accurate sun-line there was no point in circling and drifting downwind or doing a square search. It was ESSENTIAL to remain on the Howland sun-line, correcting for drift, for the best chance of finding the island or to be picked up after ditching.
With three hours of fuel remaining, which way should they turn, North or South? A suitable strategy would be to either: go 1 hour North and 2 hours South or go 1 hour South and two hours North. When Noonan (probably) worked out the wind after the sun-line, he found it was more from the South East, not from the North East and with drift to the left, he may have had an idea that they might be North of track. He probably chose to go South first. With the summer sun over the tropic of Cancer at 23 degrees North, when they turned South, they were looking down-sun and avoiding the glare. With a 10 KT headwind component and 13 degrees of right drift the full impact of the actual South Easterly became apparent. He may have modified the plan and continued South for 1hr 15min anticipating 1hr 45min going North. Either way, they never saw Howland and were at least 10 NM out at the closest. At 20:13 GMT Earhart reported ‘on the 157/337 line.’ I think that between 20:30 and 20:45 they turned North. They were only 10 to 20 NM North of Howland. So Close!
What do we know?
We know they were on the 157/337 sun-line, either North or South of Howland because that is where they said they were. We know the forecast wind must have been wrong otherwise they would have been on track during the approach. We know that the wind must have been a South Easterly because of the pressure information. We know that a NORMAL, but un-forecast, SE trade-wind would put them Left of track. We know they failed to see Howland. We know Itasca did not hear any ‘ditching’ call. We know Itasca set off on track 337 at 10:40am L Howland (22:10 GMT) in daylight and saw nothing on the sun-line within 100 NM of Howland. There was nothing there.
What do I suppose?
Earhart and Noonan were in a dingy 270 miles further North.
If they had been 6 degrees North of track and had gone North first then South, they would have ditched about 20 NM North of Howland at 22:35 (In fact they probably would have made it on their last dregs of fuel). Itasca passed 20 North of Howland after 2 hours steaming and found nothing. Itasca would have heard a final, ‘Ditching’ call at strength five. But they never did.
If they had gone South first then North, at about 22:35. after flying North for 2 hours with a tailwind, they were 290 miles N of Howland, out of radio range at 1000ft. Unseen and unheard. They may have had 40 minutes fuel remaining somewhere among the 12 fuel tanks.
Final Position 178o 25’W 5o 20’ N
