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Author Topic: Direction to Howland Is?  (Read 27177 times)

Cameron Scott

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Re: Direction to Howland Is?
« Reply #15 on: March 24, 2010, 07:38:35 PM »

Yesterday was a long day at the Armoury and I didn't have time to reply.

I just finished reading the Hooven report. He puts a lot of time on the possible landing at McKean Island. I didn't really know how to say this until I read the article and talked with a friend of mine who is a bush pilot up here in Canada.

If she was on a line of 157/337, she would have seen McKean Island first and possibly landed there. I have read your report on McKean island where you found nothing and there is no evidence for a landing on McKean. From the pictures it looks like she could have landed there. So if she didn't land there, it can be for the only two reasons I can think of. Either she didn't like the island to land on or she couldn't see the island. I think it is more likely that she couldn't see the island from the prevous posts by Ric on the matter. So that leaves two reasons why she couldn't see the island. Either the conditions of sight were bad or she turned before the line with Howland. The line 157/337 would lead her towards Niku even if she entered onto it early. If she entered on to it later, then she would have been more likely to land on McKean or miss them all together.

My friend says that as a pilot flying into remote areas in the sub arctic, they follow certain principles that would have been the same to AE. They fly on thier course until the clock is up and then they start looking if they haven't found thier landing strip. I do not know if the Electra had a clock or if they were just taking bearings off of the sun. As my friend says, if you are lost and short on fuel, you put down as soon as possible. So if this was the case for AE's line of thought, she would have probably tried to put down on McKean which she probably would have seen first.

Now I don't know a lot about navigating by air but I do it on the ground a lot. In the last post by Ric, it is layed out pretty clearly why Noonan probably would not have made a mistake and ended up turning before the 157/337 line with Howland. I have seen many people who are tired and stressed become impatient. They end up improperly pacing thier legs and end up turning on a false way point before they actually reach it.

I guess that what I am trying to ask is doesn't this make it a stronger case for Niku if they turned before the 157/337 line with Howland?

Cam
« Last Edit: March 24, 2010, 08:08:49 PM by Cameron Scott »
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Martin X. Moleski, SJ

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Re: Direction to Howland Is?
« Reply #16 on: March 24, 2010, 10:34:37 PM »

... I do not know if the Electra had a clock or if they were just taking bearings off of the sun.

Fred had a chronometer.  They spent a couple of extra days in Lae to get a good time check before taking off for Howland.

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... I guess that what I am trying to ask is doesn't this make it a stronger case for Niku if they turned before the 157/337 line with Howland?

In the absence of evidence from the cockpit, how can anyone decide rationally whether they turned on or before the line?

If the evidence points to Niku (as it seems to me to do), then the question of why they missed or skipped McKean is moot (arguable but irrelevant).  
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« Last Edit: March 25, 2010, 04:55:48 PM by moleski »
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Todd Attebery

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Re: Direction to Howland Is?
« Reply #17 on: March 25, 2010, 03:45:35 PM »

200 nm southeast ?  Really ? that far off ?  I guess I need to go back and sharpen the pencil, but that seems like a lot me !     I've been trying to learn about navigation in this era, and had assumed that they would have at least used some form of offset navigation.   http://tighar.org/Projects/Earhart/forum/FAQs/offset.htm   Even if they planned to use the radio, a small offset (maybe 20 miles) would at least increase the odds that they need to turn right when they got the advanced LOP. 

I assume that Noonan would be able to get both a Lat and a Long fix at sunrise, is that true ?    If that was about 200 nm out or roughly 2 hrs (assuming 105 kts), then that would be roughly a 45 degree heading error to be 200 nm off. 
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Martin X. Moleski, SJ

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Re: Direction to Howland Is?
« Reply #18 on: March 25, 2010, 05:02:52 PM »

200 nm southeast ?  Really ? that far off ?  I guess I need to go back and sharpen the pencil, but that seems like a lot me !     I've been trying to learn about navigation in this era, and had assumed that they would have at least used some form of offset navigation. 

The only (weak) evidence against your assumption is that the last transmission said they were flying "north and south" on the line of position.  If they had used an offset, it seems to me that AE would have said, "We are flying north on the line" or "We are flying south on the line."

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I assume that Noonan would be able to get both a Lat and a Long fix at sunrise, is that true?

Only if he could shoot another celestial body (the moon or a planet or a star) just before or just after getting the LOP from the sun observation.  The observation of the time of sunrise, all by itself, just gives information about longitude.  From navigation tables, Fred could derive the angle of the LOP at sunrise (337/157 in that part of the world at that time of year).
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           Marty
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Cameron Scott

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Re: Direction to Howland Is?
« Reply #19 on: March 25, 2010, 06:47:36 PM »

This is all very interesting. I can't wait to see the results of the May expedition.

I now see that it was probably very improbable that they turned on 157/337 early. I guess my line of thinking was that if they were on the right course (78), or even just south of their course, they would have needed to turn early in order to not see the islands. I thought this would he to be the case if they flew north and south. They would have still hit Howland turning early but with FN's skill, I don't think this was the case now.

I think that we are all kind of saying the same thing. When I am navigating across country, I will orient myself so that I know where a road or railway is, just in case I become geographically embarrassed. This is a safety net and I think that this is exactly what FN did. In the Hooven report he says this along with the people on this board. It makes a lot of sense. I was wondering why she would fly for 1, 2, 3 or more hours south. If she was being reassured that she would find land, she would have kept going.

So does anyone have an idea how did she make a mistake from 80-200 NM?

Cam
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Martin X. Moleski, SJ

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Re: Direction to Howland Is?
« Reply #20 on: March 25, 2010, 10:33:16 PM »

So does anyone have an idea how did she make a mistake from 80-200 NM?

Miscalculation of the strength and/or direction of the wind?

Too many clouds to get good "cuts" (two or three intersecting LOPs derived from star sightings) during the night?

Too much confidence in radio direction finding?
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Cameron Scott

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Re: Direction to Howland Is?
« Reply #21 on: March 26, 2010, 03:50:58 PM »

Is there anyway to figure out when or how some of these effects would have started to take place? There was the sighting of the ship along the way so I guess it would have been after that.

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Martin X. Moleski, SJ

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Re: Direction to Howland Is?
« Reply #22 on: March 26, 2010, 04:50:19 PM »

Is there anyway to figure out when or how some of these effects would have started to take place?

I don't think we can answer that question.

Here are the radio logs of the Itasca.

On this page, under "Final Flight," you can see what Randy Jacobson makes of the information in the logs.
LTM,

           Marty
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Ted G Campbell

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Re: Direction to Howland Is?
« Reply #23 on: March 27, 2010, 07:05:44 PM »

I tend to agree with Ric,  AE/FN ended up South of Howland/Baker.  Why?

FN would most probably have targeted an offset to the south of Howland, somewhere between Howland and Baker.  This would give him some assurance that he could find where he wanted to be.

If he gets to the LOP and turns north (if aiming between the islands) he is sure to run into Howland.  If he turns south (under the same situation) he is sure to run into Baker and thus knows he is south of Howland, a 180 and wa-la Howland.  If he gets to the LOP and turns north and no Howland or Baker he knows that his only way out of the mess is to turn south and look for any island.

Think this through.  If his offset was to the north and they find nothing then they do a 180 and fly south, if they can’t find anything (Howland or Baker) within a reasonable time FN knows they are in deep do-do; they must really be a long way north with no options and south is his only salvation.

Ted Campbell
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Martin X. Moleski, SJ

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Re: Direction to Howland Is?
« Reply #24 on: March 31, 2010, 06:51:01 AM »

I tend to agree with Ric,  AE/FN ended up South of Howland/Baker. ...

Randy Jacobson's Monte Carlo simulation also supports that as the most probable outcome.

I'm not in a position to defend the Monte Carlo method.  I can see that it is a way of dealing with aggregates of probabilities that are only very loosely bounded by the information available.  In the article, Randy summarizes all of the navigation information available from the messages received from NR16020 and explains why we cannot correlate the positions given with the time at which the position was transmitted.

The two charts at the bottom of the page summarize the results.  The first chart shows where AE and FN thought that they were (very close to the vicinity of Howland).  The second chart shows a cloud of probabilities about where they actually were (SW of where they thought they were).
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Bill Lloyd

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Re: Direction to Howland Is?
« Reply #25 on: April 29, 2010, 08:45:07 PM »

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.





« Last Edit: April 29, 2010, 08:51:16 PM by Bill Lloyd »
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