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Author Topic: NR16020 end of the line - what happened?  (Read 40372 times)

JNev

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NR16020 end of the line - what happened?
« on: December 18, 2011, 08:49:17 AM »

Not that the last minutes or hours of NR16020 and her crew haven't been thoroughly examined as they are the subject of at least one major and rational theory of the 'end game': a landing on the reef at Niku.

Because the failure of radio DF at the end of the flight seems to figure so prominently in what happened, consdier an extract from Noonan's own comments about DF reliance and reliability in trans-oceanic flight of the 1930's from Gary LaPook's website "Freddienoonan" - see pdf file there entitled "Noonan's 1936 newspaper article" and subheading "Radio Element" therein for some interesting historic background.

Also see "Fred Noonan's Pan Am Memo" in which he gives a detailed accounting of the application of radio for direction finding means.  See especially his closing paragraph which sums nicely his view of the radio at the time (1935).  Of note, while radio was an important development with much promise, it clearly had limitations.  What FN does provide in sum, however, is that the radio D.F. methodology was quite valuable at 'the end of the line': final homing once a destination had been roughly achieved. 

- I suggest that this memo provides insight into FN's expectations of how radio would be applied on the Earhart world flight, especially in locating Howland island at the 'end of the line'.

It is apparent that the success of D.F. as a tool in the manner FN spoke of would depend on several factors:
- Appropriate equipment (and frequencies)
- Capable operator(s)
- A reliable signal

NR16020 suffered in all of these regards.  FN was then seemingly called upon to apply all of his many skills to find an alternate solution that NR16020 might finally emerge at Howland island.  Among these seem to have been some combination of celestial navigation, an application of dead-reckoning and dependence on reasonable spatial awareness of his environment - the open Pacific and her scattered islands in various directions from where he thought he was located. 

From these tools and this picture in FN's mind as derived from charts and experience would be the hope that NR16020 could still find Howland, or failing that, some other landfall (no doubt FN was keenly aware that he was riding in a landplane over an expanse of water...). 

Herein also lies much of pro and con - from what the logical approach would be, to what FN would have been capable of and what his background suggests he might have done.

If the celestial skills of FN are to be believed, then FN had at his disposal a means of deriving a reasonable placement somewhere in the Pacific.  No question there would have been limits, but to be able to determine something productive seems likely.

That said, back to radio D.F and FN's own thoughts about that resource - obviously celstial nav did have an annoying set of limitations which made the prospect of final homing to a fine point by D.F. signal highly desirable.

So NR16020 was in a 'fix' - without a 'nav fix'.  What FN would do AE would surely follow, as would NR16020.

---

I am aware of critical review of the "LOP".  In particular, Gary LaPook counts the "sunrise LOP" as "myth" in his article "The myth of the "sunrise" LOP" on his site.  I find his article thoughtful. 

I don't agree that the idea can be dismissed as myth - FN had too many tools and too much experience to have not been able to have used some form of this aspect of celestial navigation quite effecively.  Somehow a "line 157 337" was eventually derived.  It would be very odd for that line to just happen to be perpendicular to the sunrise azumith of 67 degrees that day.  Timing of the shot seems to be a major point of argument for Gary.  Exactly when the base siting was taken seems to matter almost not at all as I've labored through this discussion.  What matters most is that some form of this navigation exercise resulted in the placement of a line on the globe according to what we can understand from AE's last transmissions to Itasca that morning. 

FN had an accurate time-of-day at-hand, so far as we can tell - Chater recounts the time-synch effort prior to departure from Lae in good detail.  FN was not careless, except in his trust of AE for management of radio duties and coordination.  He ensured that his tools were sharpened and available. 

I encourage those who have not done so to read these articles for themselves, and other information on TIGHAR, at Gary's site, and others for themselves.
- Jeff Neville

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« Last Edit: October 12, 2015, 03:33:05 PM by Jeffrey Neville »
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Gary LaPook

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Re: NR16020 end of the line - what happened?
« Reply #1 on: December 18, 2011, 01:57:44 PM »

Not that the last minutes or hours of NR16020 and her crew haven't been thoroughly explored already, they are the subject of at least one major and rational theory of the 'end game': a landing on the reef at Niku.


LTM -
Carried over from prior thread:

Re: The Last Takeoff Footage.
« Reply #181 on: Today at 02:50:46 PM »

    * ReplyQuote
    * ModifyModify
    * RemoveRemove

Quote from: Heath Smith on Today at 10:27:47 AM

    Gary,

    I was looking over your links and found this one:

    https://docs.google.com/viewer?a=v&pid=sites&srcid=ZGVmYXVsdGRvbWFpbnxmcmVkaWVub29uYW58Z3g6M2I5OTVhMWZmMmI4ZDFiZA&pli=1

    ---

    Landfalls - The safest way to get to destination

    Landfalls are of two types: course line landfalls and speed line landfalls.

    Course Line Landfall

    The easiest landfall to fly and things being equal, the most accurate. is the course line landfall.

    1. Observe a celestial body that gives a course line, line of position. Plot it on your Mercator chart

    2. Advance the line of position through destination parallel to the one you just plotted.

    3. Fly directly to the line of position through destination and turn toward destination.

    4. Stay on this line of position until another line of position shows you to be off course.

    5. Then repeat the process. But stay on a line of position through destinatiun.  There is no ETA in a landfall other than your best known ground speed.

    Speed Line Landfall

    Because a course line is at times the more difficult type of line of position to observe, and because sometimes only speed lines are available, you will also fly a speed line landíall.

    In this type of landfall fly definitely to one side of destination. When you reach the speed line through destination, turn and fly into destination.

    ---

    It seems to me (with zero expertise in this area) that Course Line Landfall requires being able to measure some celestial body (Sun or stars). This would also imply (to me) that in order for Earhart to end up on the 337/157, they must have had a approach heading 90 degrees from the advanced line of position (Howland) and that they would have definitely had some celestial reference to use. Again, to me, this seems like a risky strategy in pre-dawn conditions, perhaps overcast, where you cannot be certain that you will find any reference. This approach only works assuming you have some reference correct?

    The Speed Line Landfall on the other hand requires that you chose a point that is "definitely to one side of destination". This might be used when you may perhaps have only ground speed data that you have recorded since your last verified position correct?

    So given the above advice, are we not just debating over the the degree of being "definitely to one side of destination" if a Speed Line Landfall was used?

    Thanks in advance.


Good, I'm glad that you took the time to read that excerpt from the 1944 Navigator's Information File. You should also read the other references I posted such as Force Manual 51-40 (1951 and 1973) and Weems (1938) and other reference books available here. You can also read my analysis here. From your question I think a little more explanation might be helpful since that excerpt didn't cover some more basic stuff about celestial navigation.

A "course line" LOP is one that runs parallel to your course line (or nearly so) so when you plot it on your chart and compare it with the desired course line you can ascertain if you are on course or off to the left or to the right. Since LOPs plot at right angles to the azimuth to the celestial body, a course line LOP involves observing an object out on the wingtip (or nearly so) and after you do the computations the resulting LOP is parallel to your course line.

A "speed line" LOP is one that plots across your course line at a ninety degree angle (or nearly so) and shows how much progress you have made towards your destination and this allows you to calculate your ground speed and estimate the time you should arrive at your destination. Or. more accurately, the time you will have flown far enough to reach your destination  since a "speed line" gives you  no information as to whether you are on the correct course to actually hit your destination, you may arrive at the correct distance but be far off to the side.

Since being on course is the most important part about finding the destination, and the exact time of arrival is less important, you must find a way to get on a "course line" that runs through the destination. If there is only one celestial object available for observation you must arrange it so that your final approach is on a course that puts the object out on the wingtip and so the resulting LOP is a "course line." This is the entire purpose of turning off to one side to then intercept an LOP that is a "course line" through the destination.

At night there are a myriad of celestial objects to observe so the "celestial landfall" procedure is used during the day when the only object available is the sun. From the time of sunrise until an hour later at Howland on July 2, 1937, the azimuth of the sun was 067° true. An LOP derived from observing the sun anytime within this one hour period results in the LOP running at right angles to that azimuth making the LOP run 157° and 337°. Noonan had no choice in the chosen course to use to approach Howland, it was dictated by the location of the sun, and they had no control over that. By turning off to the side of the direct course to Howland, when they determined that they had intercepted the LOP they then turned ninety degrees thereby putting the sun out on the wingtip and establishing themselves on the "course line" running through Howland. Noonan would then take additional observations of the sun to ensure they were staying on course to Howland.

Risky, sure, but that's all you've got before LORAN and GPS and this technique was the standard method used throughout WW2 for finding islands. But not as risky as a surface navigator might think, since you are usually on top of the clouds, and even if some clouds are above you they usually do not prevent observations for long periods of time.

--------------------------------------------------------------
Prior discussion on this topic can be found on the Last Takeoff Footage thread.
gl
« Last Edit: December 18, 2011, 06:17:29 PM by Gary LaPook »
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JNev

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Re: NR16020 end of the line - what happened?
« Reply #2 on: December 18, 2011, 07:34:39 PM »

...Since being on course is the most important part about finding the destination, and the exact time of arrival is less important, you must find a way to get on a "course line" that runs through the destination. If there is only one celestial object available for observation you must arrange it so that your final approach is on a course that puts the object out on the wingtip and so the resulting LOP is a "course line." This is the entire purpose of turning off to one side to then intercept an LOP that is a "course line" through the destination.

At night there are a myriad of celestial objects to observe so the "celestial landfall" procedure is used during the day when the only object available is the sun. From the time of sunrise until an hour later at Howland on July 2, 1937, the azimuth of the sun was 067° true. An LOP derived from observing the sun anytime within this one hour period results in the LOP running at right angles to that azimuth making the LOP run 157° and 337°. Noonan had no choice in the chosen course to use to approach Howland, it was dictated by the location of the sun, and they had no control over that. By turning off to the side of the direct course to Howland, when they determined that they had intercepted the LOP they then turned ninety degrees thereby putting the sun out on the wingtip and establishing themselves on the "course line" running through Howland. Noonan would then take additional observations of the sun to ensure they were staying on course to Howland.

Risky, sure, but that's all you've got before LORAN and GPS and this technique was the standard method used throughout WW2 for finding islands. But not as risky as a surface navigator might think, since you are usually on top of the clouds, and even if some clouds are above you they usually do not prevent observations for long periods of time...

gl

Very good, Gary - but they did not seem to find Howland.

What do you think happened next?
- Jeff Neville

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Tom Swearengen

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Re: NR16020 end of the line - what happened?
« Reply #3 on: December 19, 2011, 10:02:03 AM »

Wow====I'm amazed at the information presented by Jeff and Gary. For me to understand all of this, someone would have to physically show me how it works! Yeah, I'm not real smart. But--I do believe that Fred knew the islands in the pacific "around" his flight path, either by maps, or first hand knowledge from his days at Pan AM. So, I'm thinking that, they couldnt find Howland, and knowing that Niku and some of the other Phoenix Islands were close to the 155/337 LOP in a southeast direction, he knew that if they flew along that line they would encounter land. Hopefully Howland, with its runway and provisions for servicing the Electra. If not, Niku (Gardner), where there was nothing.
When they made Niku, even though he was injured, he may have been able to get a fix on their location. As hs been theorized in another thread, maybe he knew their location and approximate flight time to Howland, or Canton. Maybe they were going to attempt that, and just ran out of time. The tides too the Electra over the reef, and Fred and Amelia were now real castaways.

Well, thats a theory-
Tom
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richie conroy

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Re: NR16020 end of the line - what happened?
« Reply #4 on: December 19, 2011, 10:49:57 AM »

can some one tell me if 137/375 would be on a LOP an were would it be on google earth ?
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richie conroy

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Re: NR16020 end of the line - what happened?
« Reply #5 on: December 19, 2011, 11:01:57 AM »

http://e-archives.lib.purdue.edu/cdm4/document.php?CISOROOT=/earhart&CISOPTR=2101&REC=4

i was just reading this an wondered wether these co ordinates put her near gardner ?
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Martin X. Moleski, SJ

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Re: NR16020 end of the line - what happened?
« Reply #6 on: December 19, 2011, 12:22:08 PM »

can some one tell me if 137/375 would be on a LOP an were would it be on google earth ?

157 and 337 are compass headings.

There are 360 degrees on a compass.

157 is approximately south-southeast.

337 is approximately north-northwest.

157 and 337 are "reciprocals" of each other.  157 is 180 degrees away from 337 and, of course,
337 is 180 degrees away from 157 (I know that is redundant, but still).



There are an infinite number of lines that can be drawn on the face of the earth.  From any point on earth, you may head toward 157 or 337 on your compass.

Here is a post with lots of pictures that may  help you visualize what the numbers mean.

The numbers you give (137/375) are not reciprocals of each other.  137 degrees on a compass is roughly south-east, while 375 is not found on the compass at all. The numbers run from 1 to 360; there is no "375" on the face of a compass.

The last recorded transmission from NR16020 says, ""We are on the line 157 337.  Will repeat the message.  We will repeat this on 6210 kcs.  Wait.  We are running [on] line [north and south]." Some professional navigators believe that gives a clue about a sighting that FN may have made at dawn.  Click on the link to the article about the last recorded transmission from NR16020 to see more pictures that may help you visualize the arguments being conducted here.
LTM,

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Bruce Thomas

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Re: NR16020 end of the line - what happened?
« Reply #7 on: December 19, 2011, 04:06:31 PM »

http://e-archives.lib.purdue.edu/cdm4/document.php?CISOROOT=/earhart&CISOPTR=2101&REC=4

i was just reading this an wondered wether these co ordinates put her near gardner ?
Richie, I had begun a reply to you earlier today that was similar to Marty's when you sent clarification (and the link) in your second message.  It made me sure that you already have a good understanding of the specifics of the 157/337 line.   

Thanks for the link to that strange handwritten letter -- once I read it, it was clear where you were coming from with those strange numbers, and that they weren't supposed to be reciprocal compass headings for a line of flight. 

The person who wrote that letter (it was received at Purdue University 5 days after AE and FN disappeared) seems to have heard or read something about Amelia sending an SOS with those numbers.  I can't recall ever reading anywhere else about a radio message with those numbers -- I cannot locate any of the entries in TIGHAR's "Post Loss Radio Signal Catalog" that speak about those numbers. 

The writer of the letter seems to have then applied strange numerological skills to interpret them.  Each number, she writes, references multiple people by name (AE, FN, GPP) -- including the letter writer herself and her boyfriend!  "179 means Marvin Lawrence Arrowsmith, my boyfriend and 16 means Charlotte Moeller my name."

Weird.
LTM,

Bruce
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« Last Edit: December 19, 2011, 04:09:52 PM by Bruce Thomas »
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JNev

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Re: NR16020 end of the line - what happened?
« Reply #8 on: December 19, 2011, 05:00:15 PM »

Richie,

"Where" depends on "time" - that is, the "line" can be placed as a matter of position in the sky of the heavenly body the shot is based on - and where the globe is under you depends on "time" (when the shot was made).

That's a pretty basic description - but Marty and Bruce have already touched on it: 157 - 337 are not coordinates that place you anywhere - they simply define reciprocal headings.  Those two headings are derived, in this case, from the sun rising at 67 degrees (90 degrees to the "line").  I believe Gary also has explained that extraction being possible up to about an hour after sunrise.  And, in this case - if you do go to "Google Earth" you could run a line through Howland island along the 157 - 337 reciprocal and you'd get the idea I think.

But to your point - the only "where" you can establish depends on "when" you made the shot to establish the line - and then it is only in east-west terms, no north-south comes out of that line.  That is another matter.  But that's why 157 - 337 does not establish a point you can go to on Google Earth, etc.

LTM -
- Jeff Neville

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« Last Edit: December 19, 2011, 05:47:00 PM by Jeff Neville »
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richie conroy

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Re: NR16020 end of the line - what happened?
« Reply #9 on: December 20, 2011, 05:01:29 AM »

thx for replys will look thru them.

as u all prob know nearest iv been to any plane is to go on holiday  :)

i just happened to Google Earhart SOS calls an the link was near the bottom

compared to the knowledge u guys have am pritty much out my depth but am willing to learn

an ye never know if some-think like that letter may lead to some-think 

gl  :)
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richie conroy

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richie conroy

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Re: NR16020 end of the line - what happened?
« Reply #11 on: December 21, 2011, 01:25:53 PM »



http://triggerpit.com/2011/11/06/spectacular-photos-iss-cosmonaut-fyodor-yurchikhin-50-pics/

this image is from the iss if u save it an open in paint or CS5 an invert u get a good image of were we think electra was  :)
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Martin X. Moleski, SJ

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« Last Edit: December 21, 2011, 01:46:14 PM by Martin X. Moleski, SJ »
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richie conroy

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Re: NR16020 end of the line - what happened?
« Reply #13 on: December 21, 2011, 01:57:25 PM »

if u open in paint an zoom in more were we think electra was, i swear u can see outline ov sumthink that was once there an marked the reef
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Ricker H Jones

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Re: NR16020 end of the line - what happened?
« Reply #14 on: December 21, 2011, 04:57:32 PM »

Good find, Richie.
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