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Author Topic: Flying north and south on the line 157 337 (LOP revisited)  (Read 27582 times)

William Thaxton

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Marty,
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Were you using voice?

Yes.  I'm no great shakes at Morse code, either

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In this case, you die? 

 i wasn't quite looking at someting that radical.  After all, I've personally spent quite a few hours "out of contact" and I'm not dead yet.  I was referring to procedural steps such as "any station" broadcasts or "in the blind" broadcasts.  Just another of those things I was trained to do by aviators who were near contempararies of AE & FN.

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Maybe.  The problem with "false positives" is that some positives are very weak.  Both a real transmission from the downed aircraft and a false interpretation of background noise might sound a great deal alike.  In other words, the premise of your objection (false transmissions can sound just like real transmissions) cuts both ways; the existence of false positives can't be used to exclude true positives.

What you are saying is true but it doesn't exactly describe the case we have.  In the AE situation, radio operators were actively and consciously seeking transmissions from AE.  That creates a powerful incentive to "hear" AE in any transmission that can't be positively identified as something else.  Could some of these unmodulated transmissions have been from AE?  Yes.  Is that more likely than a spate of wishful thinking?  Take it from a guy who has spent many a nonproductive hour trying to answer sunspots.  I have serious doubts.

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The might also have tried tuning their DF equipment to 3105 kcs.  This is pure speculation, since we do not know exactly how the radio system was set up.  What I am trying to say is that they heard a transmission while using the loop antenna; why they didn't try using the loop on 3105 kcs (or lower) baffles me.

This gets into an area I have been trying to puzzle out and which, frankly, bothers me a bit.  Why 157/337?  First problem, this is consistently referred to as an LOP which really doesn't fit the general case definitions.  Simply put, you don't "fly" an LOP (except in certain very specific circumstances).  You "fly" a course line.  An LOP is a single element of determining position which must be combined with a second LOP to provide a position fix.  The most common and generally understood example might be latitude and longitude.  If you are at 0 degrees latitude, you are somewhere on the equator.  Unfortunately, that information yeilds a possible position error of roughly 12,500 miles.  You could be anywhere on the equator.  Only when this information is combined with a second LOP, let's say 0 degrees longitude, do you know you are on the equator due south of London.  It takes a minimum of two LOPs to determine a fix.  Once you have a fix (known position), you can determine a course (something you would fly).  Now we're finally getting to the point (sorry it took so long).  AE & FN reported they were flying a course 157/337.  That means FN had managed a fix of some sort.  The possibilities are pretty limited.  Since it was daylight, the only celestial fix available would have been a "sun line" and those are notoriously inaccurate in equatorial areas (hence the message about FN needing the stars).  Second choice would have been dead reckoning and the limitations of that method have been talked to death.  When all is considered, it would seem the third option is the one which best fits known facts and that third option is an RDF bearing.  An RDF bearing would provide a single LOP (NOT a fix), would explain the rather specific 157/337 course line, and would explain why FN was unsure which direction to head on the course line (without a second LOP to provide a true fix the transmitting station could have been anywhere within reception range in either direction along that bearing).  Short answer: I would find it reasonable to consider the possibility that AE & FN DID take an RDF bearing and were attempting to fly a course based on that bearing.  I know the evidence is less than thin, but I haven't come up with another way to make the other known pieces of the puzzle fit.

Just my thoughts and sorry to be so long winded.

William
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Martin X. Moleski, SJ

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Re: Flying north and south on the line 157 337 (LOP revisited)
« Reply #1 on: May 13, 2012, 08:42:17 PM »

What you are saying is true but it doesn't exactly describe the case we have.  In the AE situation, radio operators were actively and consciously seeking transmissions from AE.  That creates a powerful incentive to "hear" AE in any transmission that can't be positively identified as something else.  Could some of these unmodulated transmissions have been from AE?  Yes.  Is that more likely than a spate of wishful thinking?  Take it from a guy who has spent many a nonproductive hour trying to answer sunspots.  I have serious doubts.

Fair enough.  I don't doubt all the post-loss radio messages.  Given a poor location, the possibility of a jerry-rigged antenna, transmitting from the water, etc., I don't find it hard to imagine that transmissions from the plane (if any occurred) might be hard to hear and interpret.

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This gets into an area I have been trying to puzzle out and which, frankly, bothers me a bit.  Why 157/337?

This has been discussed at some length.

Start with this article and its links.  If you are not satisfied, then please read the four threads in the Celestial Choir board.  If that still doesn't satisfy, please start a new thread there.

I'm not going to answer any of your questions until you've done your homework.   :)

If anybody else tries to answer them, I'll create a new thread in the Celestial Choir, in spite of the likelihood that it will duplicate existing threads. 
LTM,

           Marty
           TIGHAR #2359A
 
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William Thaxton

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Re: Flying north and south on the line 157 337 (LOP revisited)
« Reply #2 on: May 15, 2012, 05:23:31 PM »

Hi, Marty

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I'm not going to answer any of your questions until you've done your homework.   

I caught the little smiley face but we do need to keep the record straight.  I don't expect an "answer" because I'm not asking a question.  I am stating that I don't find the arguments for 157/337 "LOP" to be compelling.  With the information available to FN I just can't conceive why an experienced navigator would use the amateur set of actions required to end up flying an advanced LOP (terrible technique, by the way) and having no idea of a preferred direction.

As for my homework, I started that back in the 1970s when I spent 4 years flying for the USAF Navigator Training School (Mather AFB, CA).  I continued my education by logging another 7000 or so flying hours in transport aircraft mostly without navigator support.  In the process, I've circled the world several times, navigated under Capricorn, flown in both polar regions, and made landfall on every continent.  All without ever being seriously lost.  Since retirement, I've kept my hand in through marine navigation.  I use GPS, but I don't trust GPS.  I never get out of sight of my home dock without current, prepared, route specific charts.

Hope that didn't come across as too "snippy".  You don't know my background or abilities and would have no reason to be familiar with that information.  I do not consider myself to be an expert navigator but I do know enough to raise the flag when available information just doesn't add up. 

Here's how it plays out in my mind:  even a marginal navigator who "shot" a sunline (that's the 157/337 LOP) at sunrise would know that he had a second LOP available just by checking his watch (longitude determination is almost exclusively a function of time).  We now have a two point fix for even a marginal navigator.  Not a great fix, but better than no fix.  An experienced navigator, after a night of refining his course line based on night celestial fixes, would have added a third LOP based on his refined course line and viola!  A classic, three LOP fix!  With all this information available, it would make no sense to just "press on" toward an "advanced LOP" without making some course correction which would provide a direction of turn once the presumed LOP was intercepted.  That just doesn't work for me.

In any case, just my opinion and I hope I haven't offended anyone by expressing it.  I've read a good part of the Celestial threads and I see more questions than answers.  I just can't add "experienced navigator" and "information available" to come up with "on the advanced LOP and don't know which way to go".

Enough rambling for now.

William
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Martin X. Moleski, SJ

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Re: Flying north and south on the line 157 337 (LOP revisited)
« Reply #3 on: May 15, 2012, 06:50:17 PM »

I caught the little smiley face but we do need to keep the record straight.  I don't expect an "answer" because I'm not asking a question.  I am stating that I don't find the arguments for 157/337 "LOP" to be compelling.  With the information available to FN I just can't conceive why an experienced navigator would use the amateur set of actions required to end up
flying an advanced LOP (terrible technique, by the way) and having no idea of a preferred direction.

OK. 

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As for my homework, I started that back in the 1970s when I spent 4 years flying for the USAF Navigator Training School (Mather AFB, CA).  I continued my education by logging another 7000 or so flying hours in transport aircraft mostly without navigator support.  In the process, I've circled the world several times, navigated under Capricorn, flown in both polar regions, and made landfall on every continent.  All without ever being seriously lost.  Since retirement, I've kept my hand in through marine navigation.  I use GPS, but I don't trust GPS.  I never get out of sight of my home dock without current, prepared, route specific charts.

Hope that didn't come across as too "snippy".  You don't know my background or abilities and would have no reason to be familiar with that information.  I do not consider myself to be an expert navigator but I do know enough to raise the flag when available information just doesn't add up. 

I wasn't questioning your background or abilities.  I was wondering whether you were familiar with the discussion.  It's gone on a long time.  You are not the first professional navigator to look at the data, such as it is.  There are questions about which reasonable people may reasonably disagree.

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Here's how it plays out in my mind:  even a marginal navigator who "shot" a sunline (that's the 157/337 LOP) at sunrise would know that he had a second LOP available just by checking his watch (longitude determination is almost exclusively a function of time).  We now have a two point fix for even a marginal navigator.

I believe you have made a mistake in your assessment of the situation.  The sunline is a LOP, and the chronometer gives you longitude--but the longitude is not a LOP that crosses the LOP derived from the sunline.  You do not know where you are on the LOP; you know how far east or west that slanted line is from Greenwich.

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Not a great fix, but better than no fix.

One line does not make a fix.

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An experienced navigator, after a night of refining his course line based on night celestial fixes, would have added a third LOP based on his refined course line and viola!  A classic, three LOP fix!

The French word is "voila."  A "viola" is a stringed instrument slightly larger than a violin, often used in string quartets.

You have given a classic "coulda, woulda, shoulda" argument.  You've told us what you would have done and therefore what you think Fred did so.  Maybe your scenario is correct; maybe not.  If he did do as you presume he would have, then there must have been some other error in navigation that kept him from finding Howland.

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With all this information available, it would make no sense to just "press on" toward an "advanced LOP" without making some course correction which would provide a direction of turn once the presumed LOP was intercepted.  That just doesn't work for me.

OK.  Then you need some other explanation for AE's last transmission, which, near as anyone can tell, gives the bearing of a LOP that matches what would have been expected in that region at that time of year and near dawn: "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]."

I grant you that I couldn't navigate my way out of a paper bag if you spotted me my first LOP.  But it sounds a lot like a LOP derived from an early observation of the sun, and it sounds as though they don't know which way Howland is from where they think they are. 

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In any case, just my opinion and I hope I haven't offended anyone by expressing it.  I've read a good part of the Celestial threads and I see more questions than answers. 

This is a discussion forum.  When you express an opinion, you should expect others to pitch in theirs.  That's how the Forum works, for good or ill.

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I just can't add "experienced navigator" and "information available" to come up with "on the advanced LOP and don't know which way to go".

There may be other explanations for what AE said.  My opinion is that she probably told the truth about what they were doing, as she understood it.
LTM,

           Marty
           TIGHAR #2359A
 
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William Thaxton

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Re: Flying north and south on the line 157 337 (LOP revisited)
« Reply #4 on: May 16, 2012, 03:04:45 PM »

Hi, Marty

I'll start with apologies in case I've come on too strong.  I'm certain there are some holes in my analysis (in fact, GL has already pointed out a historical note of which I wasn't aware but it really makes no difference to the basic concept).  I agree we are working from very limited information and, at this point, I STILL support testing of the Niku hypothesis.  My real point is that some of the pieces just don't fit.  When pieces of a hypothesis don't fit it is time to figure out "why" and revise the hypothesis.  Could be some sort of very minor variation or could be something more significant.  I don't pretend to know which but I do know we are unlikely to find out unless we are willing to question everything.

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I believe you have made a mistake in your assessment of the situation.  The sunline is a LOP, and the chronometer gives you longitude--but the longitude is not a LOP that crosses the LOP derived from the sunline.  You do not know where you are on the LOP; you know how far east or west that slanted line is from Greenwich.

Sorry, Marty, but a line of longitude is, most definately, an LOP.  Take a look at your globe.  See those long lines running north and south and passing through both poles?  Those are lines of longitude (which, by the way, constitute great circles of the earth).  Note that they run true north and south (180/360).  The sunline based LOP we have been discussing is the collection of points which constitute a line at a right angle to the observed azimuth of the sun, in this case 157/337.  Since these lines are, by definition, not parallel they must cross at some point.  That point is called a fix.  In this case, it isn't a particularly desirable fix because the intercept angle of the two LOPs is too shallow (only 23 degrees), but it is still a valid fix.

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One line does not make a fix.


Absolutely true, but we have two lines!  And, as I mentioned later, a point based on DR.  I have also learned that the moon was still above the horizion at the time in question so that adds a 4th bit of information.  Do you begin to see why I'm having a bit of trouble with the idea that FN was, basically, wandering around lost?

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The French word is "voila."  A "viola" is a stringed instrument slightly larger than a violin, often used in string quartets.
 

DARN!  You caught me!  I believe I said that my morse code was no great shakes, well the same goes for my spelling and my French.

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You have given a classic "coulda, woulda, shoulda" argument.  You've told us what you would have done and therefore what you think Fred did so.


Partially true, at least.  I would say it diverges from the "classic" in two areas.  First, I was trained in much the same way that FN was trained and, in some cases, by people who were near contemparies of FN.  It isn't hard to make the case that two people with similar training placed in a similar situation would act in a similar fashion.  In other words, I'm not presenting what I might have done from a vacuum but from the perspective of one with experience similar to that of FN.  Secondly, in a broader sense basic cellestial and DR navigation itself hasn't changed much in the last couple of hundred years.  In fact, the major change in the last 500 or so years has been a reliable method for determining longitude (the chronometer).  Other than that we're still using centuries old techniques.  "Why?", you ask?  Because they work.  Those who used inferior techniques didn't make it home so only the superior techniques were passed on.  That makes it less a case of what "I" would have done and more a case of what a trained navigator would have done.  "Coulda, woulda, shoulda"?  Yes.  But that leaves the REAL question of why an experienced navigator might do otherwise and that question is the one we need to answer.

I can actually come up with several alternative scenarios to explain the "157/337" and am even willing to accept that it is based on a sunline LOP.  What simply won't float is that FN didn't know which way to turn.  The only way I can make that work is if the 157/337 line were based on something OTHER THAN his sunline LOP.  If it were an advanced LOP, FN sould have known which way to turn.

As for what AE did or didn't know or understand, I'm less conflicted.  She really doesn't seem to have been all that great a pilot and certainly wasn't what I would refer to as a "professional".  Too many questionable decisions for me to rank her as much more than a "driver".

Enough "opinion" for now,
William
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Martin X. Moleski, SJ

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Re: Flying north and south on the line 157 337 (LOP revisited)
« Reply #5 on: May 16, 2012, 04:06:46 PM »

My real point is that some of the pieces just don't fit.  When pieces of a hypothesis don't fit it is time to figure out "why" and revise the hypothesis.  Could be some sort of very minor variation or could be something more significant.  I don't pretend to know which but I do know we are unlikely to find out unless we are willing to question everything.

I'm grateful that you don't mind me questioning your line of reasoning.

It's part of "everything."

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Sorry, Marty, but a line of longitude is, most definately, an LOP.  Take a look at your globe.  See those long lines running north and south and passing through both poles?  Those are lines of longitude (which, by the way, constitute great circles of the earth).  Note that they run true north and south (180/360).

Yes, I understand what a line of longitude is.

And I understand the idea that a chronometer synchronized with GMT is used to determined longitude.  I've read the book twice.

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The sunline based LOP we have been discussing is the collection of points which constitute a line at a right angle to the observed azimuth of the sun, in this case 157/337.  Since these lines are, by definition, not parallel they must cross at some point.

Yes, I understand how a LOP is derived from a celestial observation.

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That point is called a fix.

Mathematically, it is a point.  Topographically, it is a region.  There is a whole branch of science devoted to measurement.  The iron law of measurement is that all measurements are accompanied by an error bar; there is a limit to the precision of the instrument.  At a given time on a chronometer, your "line of longitude" is not a line but a band as broad as the plus-minus precision of your instrument.  If you only have a second hand, the limit of the instrument is plus-minus one second, assuming that the chronometer is in perfect synch with GMT.  The limits of precision of the sextant depend on how fine the lines are that are engraved on it.  Then there is the question of eye height when making the observation, which brings in the limits of precision in the altimeter (not shown in this drawing).


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In this case, it isn't a particularly desirable fix because the intercept angle of the two LOPs is too shallow (only 23 degrees), but it is still a valid fix.

I agree that you have to draw your sun-LOP through the longitude you've determined from your chronometer--it's the only way to put the sun-LOP on your chart.

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One line does not make a fix.


Absolutely true, but we have two lines!  And, as I mentioned later, a point based on DR.

Yes--accompanied by another large error bar. 

The accumulation of uncertainties would be reduced by more sitings, but you never get down to the purity of mathematical lines and points.

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I have also learned that the moon was still above the horizion at the time in question so that adds a 4th bit of information. Do you begin to see why I'm having a bit of trouble with the idea that FN was, basically, wandering around lost?

The thought that he was "wandering around lost" derives from two pieces of evidence:

- It sounds that way in AE's last transmission.

- They never arrived at Howland.

Maybe Fred did aim for an offset.

Maybe he didn't.

Until we find his charts, we won't know for sure.

Whatever method he used, Howland didn't turn up where he expected it to.  "We must be on you but cannot see you."

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What simply won't float is that FN didn't know which way to turn.

OK.  We can give up that idea.  AE still said they were searching "the line" ... "north and south."  They made the turn as Fred calculated, got to where Howland should have been, and didn't see it.  Gary says at this point that they coulda, shoulda, woulda done a box search, and got lost about four hours later, with Fred doing constant updates of sun and moon LOPs all the way.  TIGHAR's theory, as yet unproven to the degree that will stand up in the court of Idiots United, is that they found their way to Niku, by one means or another.

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The only way I can make that work is if the 157/337 line were based on something OTHER THAN his sunline LOP.  If it were an advanced LOP, FN sould have known which way to turn.

What the professional navigators who started this whole question in the 1980s noticed was that the line in the last transmission is the LOP that would be expected from a sun sight near dawn.  If you've got an alternative explanation for how AE picked those numbers, have at it. 

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As for what AE did or didn't know or understand, I'm less conflicted.  She really doesn't seem to have been all that great a pilot and certainly wasn't what I would refer to as a "professional".  Too many questionable decisions for me to rank her as much more than a "driver".

And an extremely photogenic driver at that.   :)
LTM,

           Marty
           TIGHAR #2359A
 
« Last Edit: May 16, 2012, 04:24:17 PM by Martin X. Moleski, SJ »
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William Thaxton

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Re: Flying north and south on the line 157 337 (LOP revisited)
« Reply #6 on: May 22, 2012, 04:24:04 PM »

Well, Marty, I spent the last hour answering you latest and was ready to post when the cat stepped on the keyboard.  I'll try to get back to it later but everything has zoomed off to the cyber waste bin for now.

William
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Martin X. Moleski, SJ

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Re: Flying north and south on the line 157 337 (LOP revisited)
« Reply #7 on: May 22, 2012, 05:05:57 PM »

Well, Marty, I spent the last hour answering you latest and was ready to post when the cat stepped on the keyboard.  I'll try to get back to it later but everything has zoomed off to the cyber waste bin for now.

BTDT, without the help of any pets. 

Condolences.
LTM,

           Marty
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John Ousterhout

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Re: Flying north and south on the line 157 337 (LOP revisited)
« Reply #8 on: May 23, 2012, 09:24:22 AM »

A couple thoughts come to mind after reading the above:
The initial direction to turn upon reaching an advanced LOP would likely have been to the South, assuming Fred intentionally aimed for an intercept North of Howland as has been suggested by GL and others.  'Makes perfect sense to me.
The flight "down" the LOP would have likely relied on Ded Reckoning, Radio Direction Finding, and visual observation to try to find Howland.  The distance flown from arrival at the LOP to the "must be on you" location is not known, but has been suggested to be no more than 100 miles.  Even if they arrived south of Howland (due to unaccounted-for DR errors), and then turned south, they would not have travelled more than 1/3rd the distance from Howland to Gardner before concluding they had missed Howland and Baker.
Gary has reasonably suggested they would then have flown some sort of search pattern for as long as they could.
Martin has nicely illustrated the shape of the area of navigational uncertainty, above, bounded by two principal error bars.
Here's my point - if the area of uncertainty is roughly a skinny rectangle, and a navigator knew it, then what is the "best" shape of search pattern?  Gary suggested an expanding square, but wouldn't an expanding rectangle be "better"?  If the rectangle was very long and skinny like Martin's example, then the implied pattern would consist of relatively long legs on one axis, with short turn-around legs on the cross axis.
Comments invited.
Cheers,
JohnO
 
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William Thaxton

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Re: Flying north and south on the line 157 337 (LOP revisited)
« Reply #9 on: May 23, 2012, 09:56:08 AM »

Back again, Marty, and the cat is outside (I hope!).

Here's a shorter version of what I wrote last night (I have to get to work shortly and am a bit pressed for time):

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Mathematically, it is a point.  Topographically, it is a region.  There is a whole branch of science devoted to measurement.

True, Marty, but not important to this discussion.  We are discussing air navigation, not pure mathematics.  In air navigation, information used to develop either an LOP or a fix point is considered to be precise for the purpose of plotting that information.  The admitted (and inherent) error values are not considered until all LOPs or points are plotted.  The region of probability is then defined by a polygon which incorporates all points or LOP intersections.  The classic is a "three star fix" which will yield a triangle.  The actual position is then assumed to be the center of that polygon unless the navigator in question has reason to believe one or more of the generated points/LOPs have a greater accuracy than others.  The position is then "weighted" (what is called "navigator judgement").  It actually makes sense from a pure math standpoint, too.  The region defined by each LOP/point and the associated error values constitutes a set of points.  The actual position (or region in which the position lies) must be defined by the subset of points which satisfy the calculation associated with ALL plotted LOPs/points. That subset will lie within the region bounded by the polygon generated by the plotted points and points of intersection of plotted LOPs.  What you describe in your post actually reduces to a four LOP fix with the four LOPs defined by the extreme error values (+ or -) assigned to each of the two measured LOPs.  Since the measured LOPs will cross at the center of our quadralateral, the point of intersection is assumed to be our "fix".

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The thought that he was "wandering around lost" derives from two pieces of evidence:

- It sounds that way in AE's last transmission.

- They never arrived at Howland.

Maybe Fred did aim for an offset.

Maybe he didn't.

Until we find his charts, we won't know for sure.

Whatever method he used, Howland didn't turn up where he expected it to.  "We must be on you but cannot see you."



Since there was question about which way to search along "the line", it would indicate that FN did NOT use the offset method.  The whole purpose of the offset is to know which way to search.  Additionally, the search along "the line" seems to say that FN put a great deal of faith in his determination of longitude but not as much in his determination of latitude. AE reports searching "north and south" which would vary latitude considerably but have a minimal effect on longitude.

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Gary says at this point that they coulda, shoulda, woulda done a box search

Actually, Gary is arguing that an experienced navigator would have commenced a box search.  And that plays to the crux of my questions about this whole thing.  Perhaps we would be better served to explain why an experienced navigator did NOT institute an expanding square search pattern (the classic and accepted procedure). 

In summary, we have evidence that FN was, at best, uncertain of his position.  It would also appear that FN decided not to use the accepted, classic procedure for this situation.  We are then asked to accept that an experienced navigator used this uncertain position as the starting point in his search for a flyspeck located almost 300 miles away, thereby abandoning a larger target with prepared support facilities and distancing himself from rescue forces and the presumed initial search area.  AE and FN might have been flying a sunline based LOP but that doesn't explain why they abandoned their best estimated position, avoided accepted procedure, and flew away from their primary support area.  There just has to be something we're missing here.

As for the court of Idiots United, I may well be a member but I still support the search at Gardner and that is, primarily, because I don't see a better option on the table just now.  If AE and FN ditched somewhere in the area it is unlikely we will ever find the wreckage and know for sure.  While I do consider the evidence for Gardner to be pretty thin, at least it is evidence and should be explored.  Where I differ is that I think we haven't asked the right question just yet.  "Why did AE and FN ignore standard procedure, fly away from their best estimated position, prepared support, and potential SAR forces."  Answer that question and you may be on to something.

By the way, I may be slow but I finally caught the "SJ" after your name.  It explains a lot, at least to me, about the way you approach this discussion.  Keep us honest!

William
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William Thaxton

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Re: Flying north and south on the line 157 337 (LOP revisited)
« Reply #10 on: May 23, 2012, 10:02:54 AM »

John,
Your analysis is essentially correct.  Just be advised that "square" or "expanding square" is not definatively descriptive.  An experienced navigator might well take into account several factors and use judgement to "skew" the actual geometric figure to fit the situation.  In other words, if you were reasonably sure of your longitude (or even the advanced LOP based on sunline), you might extend the search north and south to cover uncertainty in latitude, thereby flying an "expanding rectangle" search. 

William
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Martin X. Moleski, SJ

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Re: Flying north and south on the line 157 337 (LOP revisited)
« Reply #11 on: May 23, 2012, 05:17:10 PM »

What you describe in your post actually reduces to a four LOP fix with the four LOPs defined by the extreme error values (+ or -) assigned to each of the two measured LOPs.  Since the measured LOPs will cross at the center of our quadralateral, the point of intersection is assumed to be our "fix".

The time LOP gives you longitude; the LOP derived from the sun sighting tells you that you are on that line somewhere;  nothing from the intersection of the two tells you how far north or south to draw the intersection.  Because of the limits of the instrument and the tables used in navigation, the slanted rectangle is a huge region.  There is not just one point where the time LOP and the sextant LOP cross each other; it is a whole line running from the northernmost point on the earth from which the sextant sighting could be made at that time of day to the southernmost point.  Of course, a navigator should have an idea of latitude from a previous sighting advanced by dead reckoning, but the line from the watch and the line from the sextant do not supply that information.

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The thought that he was "wandering around lost" derives from two pieces of evidence:

- It sounds that way in AE's last transmission.

- They never arrived at Howland.

Maybe Fred did aim for an offset.

Maybe he didn't.

Until we find his charts, we won't know for sure.

Whatever method he used, Howland didn't turn up where he expected it to.  "We must be on you but cannot see you."


Since there was question about which way to search along "the line", it would indicate that FN did NOT use the offset method.  The whole purpose of the offset is to know which way to search.  Additionally, the search along "the line" seems to say that FN put a great deal of faith in his determination of longitude but not as much in his determination of latitude. AE reports searching "north and south" which would vary latitude considerably but have a minimal effect on longitude.


Yes, that fits with my understanding that there is a very large north-south region where one would expect the same sextant reading at the same time of day.

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Gary says at this point that they coulda, shoulda, woulda done a box search

Actually, Gary is arguing that an experienced navigator would have commenced a box search.  And that plays to the crux of my questions about this whole thing.  Perhaps we would be better served to explain why an experienced navigator did NOT institute an expanding square search pattern (the classic and accepted procedure). 

In summary, we have evidence that FN was, at best, uncertain of his position.  It would also appear that FN decided not to use the accepted, classic procedure for this situation.  We are then asked to accept that an experienced navigator used this uncertain position as the starting point in his search for a flyspeck located almost 300 miles away, thereby abandoning a larger target with prepared support facilities and distancing himself from rescue forces and the presumed initial search area.

Heading south on the 337-157 LOP is searching for Howland first.  After they've gone as far north as they dared and didn't find the island (perhaps turning north on the LOP, then saying, "We must be on you but cannot see you" some time later), they then head south.  In that direction are Howland, Baker, and the Phoenix group; on the 337 bearing, there is nothing.

No one has yet drawn the chart for a four- or five-hour box search that still misses Howland and Baker.  I'm looking forward to the calculation.  I accept the fact that I may have to draw my own chart ...

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AE and FN might have been flying a sunline based LOP but that doesn't explain why they abandoned their best estimated position, avoided accepted procedure, and flew away from their primary support area.  There just has to be something we're missing here.

If I'm not mistaken, we're missing a twin-engine passenger plane with two souls on board.   :D

Gary says that Fred should have gotten a fresh sunline periodically (every fifteen minutes or so?) that would have let him refine his position, albeit with absolutely minimal differences between one angle of observation and the next.  In other words, he may have been lost latitudinally around 2013 GMT, but he shouldn't have been as lost an hour later.

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As for the court of Idiots United, I may well be a member but I still support the search at Gardner and that is, primarily, because I don't see a better option on the table just now.  If AE and FN ditched somewhere in the area it is unlikely we will ever find the wreckage and know for sure.  While I do consider the evidence for Gardner to be pretty thin, at least it is evidence and should be explored.  Where I differ is that I think we haven't asked the right question just yet.  "Why did AE and FN ignore standard procedure, fly away from their best estimated position, prepared support, and potential SAR forces."  Answer that question and you may be on to something.

Why did AE and FN depart from Lae without confirming that their RDF worked on the frequency they planned to ask for?

Why did AE and FN not try tuning their RDF system to 3105 kcs?

Why didn't AE know that the Itasca could not DF on 3105 kcs?

Why didn't AE understand that she needed to transmit long enough for a ground station to get a bearing on her?

Why didn't they explicitly tell their support crew what plan B was?

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By the way, I may be slow but I finally caught the "SJ" after your name.  It explains a lot, at least to me, about the way you approach this discussion.  Keep us honest!

I have to keep myself honest first.  That's the hard part.   :-\
LTM,

           Marty
           TIGHAR #2359A
 
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John Ousterhout

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Re: Flying north and south on the line 157 337 (LOP revisited)
« Reply #12 on: May 23, 2012, 08:55:09 PM »

"Why did AE and FN ignore standard procedure..."
As I understand it, there was NO "standard procedure" in 1937.

"... and potential SAR forces."
SAR (Search And Rescue) did not exist yet.

It could be argued that disappearances like Fred and Amelia's indicated the need for "Standard Procedures" and coordinated SAR efforts, along with specific training for searchers and planners.  Those later efforts seem to me to have been well thought out, and Gary has ppresented many of them, but they didn't yet exist when Amelia lost contact and the Itasca had to decide what to do next.  Even radio procedures were not well established in her time, which should make us cautious when we apply current assumptions to what she "would have done".
Cheers,
JohnO
 
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William Thaxton

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Re: Flying north and south on the line 157 337 (LOP revisited)
« Reply #13 on: May 31, 2012, 08:35:03 PM »

Hi, John.

I've been away from my keyboard for several days and am just finding time to catch up.  It's going to take a bit to digest Marty's latest (frankly, I can't follow his objections) so I thought I'd answer you first.

About standard procedures:  Actually, standard procedures for locating difficult landfalls had existed for a couple of centuries by this time.  The fact that air navigation was new doesn't imply that navigation was new.  In fact, navigators were routinely finding difficult landfalls before there was even a reliable method of determining longitude.  FN wasn't being asked to do something new.  The precedent for some sort of area search was well established long before AE, FN, or aviation was born.  If there is an argument to be made, it is that AE and FN had an easier task because they had a higher "crows nest" and could search a greater area in less time.

Concerning SAR forces:  Just what would you call the US Coast Guard?  The USCG grew out of the life saving service and was established, at least in part, to provide rescue services.  On top of that, search and rescue was an established maritime procedure.   Remember the response and search for suvivors from the Titanic?  And that was a couple of decades prior.  The Itasca was in position to provide navigation support and immediately began a search when AE and FN were overdue.  US naval forces were also in the area and initiated an air search when AE and FN were overdue.  The only thing they DIDN'T do was use the acronym "SAR".  Did this incident lead to improved SAR procedures?  Probably!  Was search and rescue "invented" as a result of this incident?  NO!

Don't become a victim of the arrogance that everything of value was "invented" in the 20th and 21st centuries.  The world had gotten along fairly well for quite some time before the 20th century dawned.  The world had ben fairly well explored and mapped long before AE and FN made their flight.  What we've done, at least in the area of navigation, is improve on the broad strokes drawn by those who have gone before.

William
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John Hart

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Re: Flying north and south on the line 157 337 (LOP revisited)
« Reply #14 on: July 05, 2012, 05:09:33 PM »

I guess before I posted my rather basic discussion of what I would have expected FN to do at extended LOP I should have read this thread and joined in.  Sorry.  I am a single seat pilot that William may put in the category of "driver".  So I know my navigational analysis may be discredited by him, but I also have read a lot about how overwater navigation was done in those days.  In every case your process would be different if you were:

A.  Looking to make landfall on a continent or other large body of water.

B. Flying at high or low altitude (event horizon)

c.  Weather conditions

d.  Expected fuel state at arrival

On each of these there are judgement calls made based upon experience.  We need to remember that FN did not have the experience that was passed on to any of us still alive to be on this forum.  He was a pioneer and may have done something none of us would expect.  But a universal of flying over water I would think is to always make your error toward more/closer land.  I think FN knew what I know, that sometimes an island can be 5 miles away from you and unseen, especially in S Pacific.  He also knew he had a long DR leg and would need a significant fuel consuming offset to insure he was N of Howland (why offset S requiring a NNW run toward nothing if you miss?) especially if you missed the island on the SSE run down from the offset.  Why not try to do your best direct nav and then fly NNW briefly in case you missed S and then go SSE towards all the other options along the way?  He may have had a very high opinion of his ability to hit spot on too.  Problems is your event horizon at 1000 feet is minimal, the impact of heat and humidity decreases slant range visibility, tiny island can be hidden easily under a cloud shadow, and the 360 view out of an Electra is not great.  So good chance of missing even if you flew nearby.  Whether you had done an offset or not you would finish up flying 157 till the gas ran out based on the islands along that bearing.  Not some other COA.

But I will admit I depended on Litton and Honeywell to do most of my Navigating.  But I also looked out the window and made sure Hal was taking me where I wanted to go.  I have been flying over Mexico when I was not supposed to be even with an INS.  (The bombing range at Luke AFB is right on the Mexico border) An old fighter pilot in the group told us all we were S of where we thought we were (no GPS then) even before AWACS told us to work N we were in Mexico!  I never forgot that lesson...trust but verify.

Eventually I'll find all the stuff on here but I doubt it.  I bet I will find every though I might ever have here if I look long enough.  Your patience is appreciated.

JB
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