Her final heading should have been 78° so she was approaching from the west/southwest headed east/northeast. We know what the Itasca knew because we have all the pre-flight radio messages.
It's all in the book, Finding Amelia - the true story of the Earhart disappearance - available in soft cover for a mere pittance from amazon or in hard-cover with data-DVD, signed by the author, from TIGHAR at http://tighar.org/TIGHAR_Store/tigharstore.html
I don't agree that it is logical that Earhart was short of the LOP that passed through Howland. Her arrival on that line was governed by Noonan's calculations that advanced his 157/337 sunrise LOP by Dead Reckoning until it fell through Howland (and coincidentally near Baker, McKean and Gardner). I know of no reason to think that Noonan's calculation would not be accurate within about 10 miles. When Earhart said at 1912Z, "We must be on you but cannot see you.." all she was saying is that the clock said they had reached the advanced LOP. I think they were probably within 10 miles of the line but about 200 miles southeast of Howland.
Now if they hit the LOP about 200miles southeast of Howland as you state, then what Noonan didn’t have a clue about was the direction and velocity of the wind. To get blown 200 miles off course means that little or no course correction was made for the wind which appears to have been a left quartering headwind.
I think that Noonan probably hit the LOP fairly accurately because when he clocked the sunrise, he knew, according to the almanac, just where the dawn line that he was on was located, or how far west he was from the LOP through Howland. He knew that sunrise at Howland was at 1745Z and if he was about 200 miles out, he saw the sunrise about 1757Z, so he knew how far he was from the Howland LOP.
In the Monte Carlo Simulation, Randy Jacobson states that “ Thus, we actually calculate much of the time during the MC simulations that Earhart was experiencing 26 knot winds from roughly 58 degrees, rather than the 18 knots winds for the 68 degrees as forecast.”
Depending on the course correction or crab angle necessary to track on the heading to Howland, the 1 in 60 rule would indicate that they could have gone about 10-20 miles off course to the south for every 60 miles traveled. To have drifted as much as 200 miles south, they would have to had strong winds out of the NNE, 030-035 degrees, at about 35 knots. This would put the winds about 45 degrees off the nose of the Electra equating to about a 26 knot crosswind. ( w/v=35deg/35knots,relative angle=45degrees=45/60x35=26knots crosswind component)
It was reported that the plane was heard passing over Tabituea which is 615 miles from Howland on a 078 degree heading. Encountering the stronger headwinds at this point and assuming a true airspeed of 135 knots for about the last 620-675 miles of the flight, it is possible for them to have hit the LOP 200 miles southeast of Howland as without a crosswind correction they would have drifted south all the way to the LOP with a groundspeed of 115 knots culminating a track error of about 18 degrees. (track error=distance off track/distance traveled, DO/DT x 60, 200/675x60=18 degrees). A lesser crosswind component would have put them farther north on the LOP even as close as the 80 mile donut hole which seems to me to be more likely.
It is known that Noonan utilized a E6B computer (Dalton Mark VII navigation computer) or an earlier version of one, however, he would need wind data to figure a heading. The wind correction angle would be calculated as wind speed /TASx60=12degrees, so to track on a 078 degree heading with a 26 knot crosswind component, Earhart would have to fly on a compass heading of 066 degrees for the last 615 miles of the flight.
In my flying experience over water/off shore many years ago, I was taught to estimated the wind by looking at the water. Apparently this did not work for Noonan because he could not see the water until sunrise or perhaps at twilight. Somewhere in that last leg of the flight, there should have been some indication of what the wind was doing or had already done to their direction of travel. Perhaps by the time they hit the LOP, Noonan had it figured out that they were well south but not sure enough to fly 200 miles to the northwest looking for Howland and thought it more prudent to look for land to the southeast.
In a web page on this site authored by Randall S. Jacobson, Ph.D., it is stated that:
“In summary, the weather for Earhart’s approach to Howland indicated good visibility, winds aloft probably about 10 knots from the east, well below the 20 knots forecast the previous day by the Fleet Air Base.”
These weather conditions seem to be inconsistent with the premise that strong northeasterly winds blew Earhart 200 miles off course to the south.
If it was not the wind that caused them to drift so far south, then what caused that kind of error in navigation? According to the photos of the cockpit that I have seen, AE appears to have had both a heading indicator or what looks like a J2 compass along with a magnetic compass. I also see an artificial horizon, attitude indicator, turn and bank indicator, air speed indicator, altimeter and rate of climb and descent indicator. The auto pilot should have held the correct heading without difficulty.
The short of it is that Earhart had all of the instruments necessary to maintain straight and level flight and to maintain course. Obviously there was a disastrous failure in navigation and I have been unable to see any indications of this in the past history of Noonan’s performance other than statements made by him as to the difficulties in determining accurate position fixes.. Noonan had previously stated that he felt that the greatest problem he had while navigating was determining the drift angle of their course which could have been his downfall in the flight to Howland.
In a written report, dated April 29, 1935, submitted by Noonan when he was the navigator of a Pan American Clipper, he stated that aerial navigation, like surface navigation is an “inexact science.” He went on to say that “ hence is it impossible on an extended flight to obtain consistently accurate fixes by any single method, or by any combination of methods. But by understanding of the weaknesses of each method, it should be possible to greatly minimize the errors inherent in all of them.” He also asserted that his experience has shown that a “fix” within the distance of ten to fifteen miles of the true position is about the average accuracy which can be expected in aerial navigation.
It appears then that Noonan was probably navigating the best he could with the information that he could get and once on the LOP was unable to obtain an accurate fix and thus he and Earhart flew into eternity.
In the Purdue archive photos are images of
notes that Noonan would pass to Earhart during the flight. These notes appear to be on small slips of paper, are poorly written and usually give her a position report and a heading to fly. On one note she scribbled, “what put us north?”. This seems to indicate that she did not have the foggiest clue as to why she was holding a certain heading. Passing notes on a stick or handing them to her seems so ridiculous that it is hard to imagine. If it weren’t so pathetic it would be funny.
Many of the photos of Noonan show him with a
cigarette hanging in his mouth. Wonder if he smoked while en route? When fully loaded, the 10E was like a gas tanker flying through the sky. Fumes were probably everywhere. It is quite possible that Noonan flipped opened his Zippo and blew the Electra to smithereens, but I suppose the Navy would have found some debris.
At any rate, this is an interesting project, hope you do well. I have been reading the voluminous forums and documents posted on this site for several years now and am nowhere near finished. I have read excerpts and reviews of the book, Finding Amelia, and will acquire a copy soon.
I know how it feels to be lost over water and no man made objects nor land in sight in any direction. When I first began offshore flying, we had no nav aids and had to dead reckon a course to production platforms, sometimes in low ceiling and vis less than 1 mile. If you missed the platform, you had no idea which way to turn. At that point you would fly a little further on the line and then left and right for a short distance and then if still lost, the only option was to reverse course to land.
Flying to land was the ace in the hole and I feel that this is what AE and Noonan did, fly to nearest known land. I have never known an aviator who would fly in a search pattern or circle around until they ran out of gas. Of course I did not know Amelia Earhart either.