Advanced search  
Pages: 1 [2] 3   Go Down

Author Topic: LOP nonsense  (Read 28892 times)

Mona Kendrick

  • T2
  • **
  • Posts: 71
Re: LOP nonsense
« Reply #15 on: August 31, 2011, 03:11:45 PM »







 He hit his aiming point - Dingle Bay, Ireland - right on the nose after 1,700 miles of DR.
[/quote]

     Or did he?  The navigation log, which could have substantiated his extraordinary claim, was allegedly stolen from the plane at Le Bourget.  In the absence of position fixes over the ocean, he'd need more or less continually updated wind information to keep a good DR course.  He said in The Spirit of St. Louis that he was unable to use the drift meter, which is unsurprising since there was no  autopilot or co-pilot to hold the unstable plane steady while readings were taken.  That leaves eyeball estimates of wind direction and velocity over the wavecaps -- but only in VFR conditions or when the cloud bases were high enough to drop below to get a good look at the water; many hours were spent in or above clouds.
     This is not to say that AE and FN couldn't DR for 350 nm with reasonable accuracy.  But, in Lindbergh's case, 1700 nm?  Particularly since he was in a sleep-deprived stupor much of the time?  I'd be interested in hearing estimates of probability from the professional navigators on the Forum.

LTM,
Mona
Logged

Ric Gillespie

  • Executive Director
  • Administrator
  • *
  • Posts: 5428
  • "Do not try. Do or do not. There is no try" Yoda
Re: LOP nonsense
« Reply #16 on: August 31, 2011, 06:12:37 PM »

He hit his aiming point - Dingle Bay, Ireland - right on the nose after 1,700 miles of DR.

     Or did he? The navigation log, which could have substantiated his extraordinary claim, was allegedly stolen from the plane at Le Bourget.

[/quote]

Your'e suggesting that Slim wasn't telling the truth?

     This is not to say that AE and FN couldn't DR for 350 nm with reasonable accuracy.  But, in Lindbergh's case, 1700 nm?  Particularly since he was in a sleep-deprived stupor much of the time?  I'd be interested in hearing estimates of probability from the professional navigators on the Forum.

Do we have professional navigators on the forum?  We have people who pontificate about navigation but I don't know of anyone who makes his or her living as a navigator.
Logged

Mona Kendrick

  • T2
  • **
  • Posts: 71
Re: LOP nonsense
« Reply #17 on: August 31, 2011, 07:51:15 PM »

OK, how about ex-Air Force navigators?

Mona
Logged

Gary LaPook

  • T5
  • *****
  • Posts: 1624
Re: LOP nonsense
« Reply #18 on: September 01, 2011, 12:03:00 AM »

This needs to be straightened out.
Gary LaPook has been on something of a campaign to discredit TIGHAR's hypothesis that Earhart and Noonan ran down the 157 337 line and landed at Gardner/Nikumaroro.

On his website at https://sites.google.com/site/fredienoonan/discussions/why-it-was-not-possible-to-follow-lop-to-nikumaroro he writes:
"Contrary to TIGHAR's premise, there was no way to navigate along the "157º-337º LOP" to Nikumaroro  (I have written countless posts about this, the navigation is quite simple even though to non navigators it might sound complicated. To a navigator it is no more complex than getting in your car and driving to the supermarket to get a gallon of milk) so they did _not_ end up on that island."

Unfortunately, Gary has a gross misunderstanding of TIGHAR's hypothesis.  We are not suggesting that Earhart or Noonan navigated down the line using celestial navigation to stay on course. As Gary points out, again and again, there is no way to do that.  It is TIGHAR's hypothesis that, upon reaching the LOP calculated to fall through Howland Island, and not seeing Howland Island, AE and FN turned and flew first northwestward, then southeastward along the line by means of the the only navigation method available to to them at that time - dead reckoning.   As Lindbergh once said, "The only thing wrong with dead reckoning is the name."  He used it to cross 1,700 miles of trackless ocean from St. John's Newfoundland and hit Dingle Bay, Ireland on the button.  To suggest that a navigator of Noonan's caliber could not dead reckon a few hundred miles - perhaps as few as 150 miles - with decent accuracy is, frankly, nonsense.

---------------------------------------------------------

 Ric, you will have to forgive me if I didn’t understand that you were not claiming that they had a
method by which they could determine that they were staying on the LOP and using this method
to fly along the LOP to Niku. My misunderstanding started when I read an article written by you
and published in the April 1992 issue of "Life.Magazine" On page 70 of that issue you wrote:

"Using celestial tables, Gannon pointed out that on the morning of July 2, 1937, the rising sun
would have provided the precise line of position Earhart said she was running. By flying
southeast along that line, Noonan could be sure that, even if he missed Howland, he would reach
an island in the Phoenix group in about two hours."

I noticed that you did not say Noonan would just fly that heading but that he would fly "along
that line
" which I read as clearly intimating that Noonan had some way to stay on the LOP.


Then on February 26, 2002 you responded to my post:

“Date:         Tue, 26 Feb 2002 12:23:34 EST
From:         Gary LaPook
Subject:      Re: Celestial navigation and post-loss messages.

But, since they were following their plan to go to the Phoenix islands, they
didn't need to fix their position after they arrived, all they had to say is "we
on one of the Phoenix islands, probably Gardner, come and get us."

gl
**************************************************************************
From Ric

Their plan was not to go to the Phoenix Islands.  Their plan was to run
southeastward on the LOP
in hopes of hitting one of the islands known to be
on that line  - namely - Howland, Baker, Gardner, and as we've only recently
realized, Atafu (Duke of York).

So here you are, running down the LOP, watching and hoping for an island, and
it's taking FOREVER, and you're wondering, "

I recently watched the show,  "The Real Amelia Earhart" (2006) on the National Geographic
Channel and  at 21 minutes into the show they show a chart with the LOP through Howland and
Nikumaroro

Narrator:

"Gillespie thinks it makes prefect navigational sense for Earhart and Noonan to aim for Gardner
Island, now known as Nikumaroro, located in the Phoenix Island chain."

Gillespie:

"If Earhart is lost, the only piece of information she has is that she is on a navigational line that
falls through Howland Island. She also knows there are other islands on that line so if she flies
southeastward on that line she is guaranteed of hitting land."

And in your recent movie, “Finding Amelia,” about eight minutes into the show you say that
navigators came to you and told you about Noonan's technique. Then a map was put up showing
the LOP through Howland and Gardner.

The Narrator says:

"If Amelia and Fred couldn't find Howland they could have followed this line south and
reached another island, Gardner, now called Nikumaroro."

Then you say:

"And my first reaction is, first of all, these guys know what they are talking about, these are real
navigators..."

You didn’t take this opportunity to point out that the narrator was wrong, that they could not
have followed this line south.

To make sure I got it right I decided to look up the definition of the word “along” to make sure
that I had the proper understanding of that word. There are a number of dictionaries available
online at: http://www.onelook.com where I input “along” and got many definitions, all similar to
these:

-------------------------------------------------------------------------------------------
1. moving on or beside a line

        a.
      moving forward on a line, road, path, etc. toward one end of it

      Mrs. Klein was hurrying along the path toward us.

     
      b.
      moving from one place to another while staying near the side or edge of something

      They were sailing along the southern coast of Australia.
     
2. used for showing where someone or something is

        a.
      continuing in a line on or beside a road, river, wall, etc.

      The stores along 5th Avenue were brightly lit for Christmas.

      a line of trees along the river bank

      b.
      at a place on or beside a road, river, etc.

      The sound of gunfire was coming from somewhere along the road.

 
From a different dictionary:

PREPOSITION:

   1. Over the length of: walked along the path.
   2. On a line or course parallel and close to; continuously beside: rowed along the shore; the
trees along the avenue.

http://www.onelook.com/?w=along&ls=a

------------------------------------------------------------------------------

I also looked up “followed” and a typical definitions is:


Travel along a certain course

“Follow the road”

“Follow the trail”

Synonyms: travel along



Based on all of these statements, you can understand why I thought you still believed that they
had some way to follow along the LOP to Niku and that they were not just dead reckoning. You
can also see how an average viewer of these TV shows could also conclude that your point
was that they would have been able to easily determine that they were staying on the LOP and
tracking it to Niku.

Anyway, it is good that we are finally in agreement that there was no way for Noonan to
determine that they were staying on the original LOP and following along that LOP all the way to
Niku so if they ended up on Niku it was only by dead reckoning those 350 nautical miles.

gl
« Last Edit: September 01, 2011, 02:17:11 AM by Gary LaPook »
Logged

Thom Boughton

  • T2
  • **
  • Posts: 89
  • Infinite Rider on The Big Dogma
Re: LOP nonsense
« Reply #19 on: September 01, 2011, 01:33:29 AM »

Do we have professional navigators on the forum?  We have people who pontificate about navigation but I don't know of anyone who makes his or her living as a navigator.


While I won't lay claim to being a professional navigator, I am (or rather I was) a professional pilot with a certain amount of training in Celestial Navigation.  Navigation in general being part and parcel of the responsibilities of a pilot, I will make the following statement with more than a small amount of confidence:

Who can say what contingency plans Noonan had in his back pocket? I can't believe he didn't have something in terms of a Plan B.  But unless I missed something along the way (high probability, no doubt), nobody knows for sure.  Therefore I can't/won't speak to his intentions.  But if we do make the assumption that this was the plan...it was not in the least difficult to do so, regardless what some of those hereabouts might espouse. 

While I would not wish to attempt finding (any part of) Ireland strictly by means of Dead Reckoning....finding a point which is only 150 to 200 miles away via Dead Reckoning is a compleatly different proposition altogether.  Especially at the cruise speeds of an Electra, Dead Reckoning from Howland to Gardner would be barely more than childs' play for Noonan.  If you can't hold a heading for between 60 and 90 minutes, then you're in the wrong line of work.

I won't try reading the mans mind....but if this was his "out" (and it does at least seem to be an obvious one), it was an easy out.



....TB


TIGHAR #3159R
 
Logged

Chris Johnson

  • T5
  • *****
  • Posts: 1069
  • Trying to give a fig but would settle for $100,000
Re: LOP nonsense
« Reply #20 on: September 01, 2011, 02:29:00 AM »

Idiots tutorial in Dead Reckoning anybody? (but please don't start a navigational war over my simple request for help  :) )
Logged

Gary LaPook

  • T5
  • *****
  • Posts: 1624
Re: LOP nonsense
« Reply #21 on: September 01, 2011, 04:37:37 AM »

Idiots tutorial in Dead Reckoning anybody? (but please don't start a navigational war over my simple request for help  :) )

--------------------------------

That's easy, it means figuring out where you are by keeping track of the direction and distance you have traveled from your starting point. Let's say you are in the middle of a featureless desert and you know your exact position by looking at your fiend's GPS that provides your coordinates within one-tenth of a mile. You mark this position on your chart. Now you leave your friend (and his GPS) behind and start walking straight east by looking at your compass and you count your steps. After you have counted the number of steps that you normally walk in one mile you stop. You should now be one mile straight east from your starting position so you draw a line on your chart starting from the previously marked starting position and extending straight east. You then measure one mile along this line and make a mark on the line, this is your current position and you can then read out its coordinates from your chart. Pretty simple.

The next question that you have to think about is how accurately do you know your present position? First thing to realize is that since you only knew your starting position within ten meters that you cannot possibly know you present position to an accuracy greater than the accuracy of your starting position. If, instead of being exactly at the coordinates read out from the GPS, and that you plotted on your chart, you were actually 0.1 miles north of those coordinates when you started then you will be 0.1 miles north of the position that you marked on your chart. But that is only if you did a perfect job of walking straight east and only if you did a perfect job of counting your steps and there was no variation in your stride, not even the tinniest little bit. You think back and you remember that the compass needle wobbled around a bit and you had to go around some big rocks along the way so maybe you did not maintain a straight east path perfectly and maybe you did not walk exactly one mile. Because of these imperfections in maintaining a course and in calculating the distance traveled you realize that there is some uncertainty in the present position, you cannot be certain that you are at the exact coordinates where you marked the position on the chart. You may have wandered a little bit off to one side, to the north or to the south, and you may have stopped a little short of a mile or you may have walked a little bit further than one mile. You say to yourself "although I can't be certain that I did a perfect job of this dead reckoning I do feel very confident that I must have walked at least 0.9 miles and I know I couldn't have walked more than 1.1 miles. And although the compass needle moved around a bit (and I didn't watch it at all times) I don't think that I could have wandered more than 6 degrees off to one side or the other." So based on your thinking your are confident that you couldn't be more than one tenth of a mile from your plotted position, 10% of the distance you walked. This works because the tangent of 6 degrees is 0.1 so the possible error to the right or to the left is also 10% of the distance traveled. But don't forget the original uncertainty of 0.1 miles in the starting position which you must add to the uncertainty caused by walking. With this understanding you can draw a circle around the position you have marked your chart with a radius of 0.2 miles , one tenth of a mile from walking and one tenth of a mile uncertainty in the starting position, and be very confident that your real position must be somewhere within the circle that you have just drawn.

You look on your chart and you see a water hole that you want to get to since you are thirsty. You measure the course from your current position and you see that it is still straight east and the distance is 3.5 miles. Since you got tired of counting your steps you decide to time this leg for one hour and ten minutes because you normally walk at three miles per hour. So again following your compass you walk east for one hour and ten minutes and then stop. You look around for that water hole and don't see it. Now you are worried since your canteen is empty. You think about it some more. You think that you just walked 3.5 miles so you figure that you should be within 10% of that distance or 0.35 miles from the water hole. But you realize that the error in the distance may be greater than 10% of the distance you walked because this time you didn't count your steps, you just timed it and maybe you didn't maintain a speed of exactly 3 miles per hour the whole time. But wait, that 0.35 uncertainty is only for this last leg and you must add the uncertainty of the starting position, 0.2 miles so now the radius of uncertainty has grown to 0.35 miles plus 0.2 miles, a total uncertainty 0.55 miles. That water hole could be more than a half mile away in almost any direction except behind you (or you would have found it by now.) You think, "in which direction should I search, should I go to the right or to the left, and it is now getting dark and I am mighty thirsty."

Good luck in finding that water hole.

And something else, if the GPS was not working right and gave you coordinates ten miles north of your actual position when you started then you would still be ten miles south of where you think you are and no where near that water hole.

This 10% of the distance traveled is a commonly accepted estimate of the uncertainty in dead reckoned in flight postions. See: https://sites.google.com/site/fredienoonan/topics/accuracy-of-dead-reckoning

If Noonan was trying to decide whether to abandon efforts to find Howland and instead to proceed to Gardner he would have taken this into consideration, that he could accumulate a DR error of 35 NM to the right or to the left while flying the 350 NM leg down to Gardner, errors large enough to keep them from spotting that island. In addition he realized that since he didn't know his starting position that his error when nearing Gardner could be much larger.

gl
« Last Edit: September 01, 2011, 04:42:17 AM by Gary LaPook »
Logged

Chris Johnson

  • T5
  • *****
  • Posts: 1069
  • Trying to give a fig but would settle for $100,000
Re: LOP nonsense
« Reply #22 on: September 01, 2011, 04:40:00 AM »

Thanks Gary,  just like navigating in Fog whilst out walking as i've used in questions on navigation myself.  Looks like I probably knew the answer to my question but couldn't see the wood for the trees  ::)
Logged

h.a.c. van asten

  • T4
  • ****
  • Posts: 322
Re: LOP nonsense
« Reply #23 on: September 01, 2011, 06:10:00 AM »

Yes . If a pilot announces "..but fuel is running low.." , but it is actually 120 galls remaining , 11% of his original store for a flight to somewhere else , that´s very bad dead reckoning .
Logged

Ric Gillespie

  • Executive Director
  • Administrator
  • *
  • Posts: 5428
  • "Do not try. Do or do not. There is no try" Yoda
Re: LOP nonsense
« Reply #24 on: September 01, 2011, 08:24:06 AM »

 Ric, you will have to forgive me if I didn’t understand that you were not claiming that they had a
method by which they could determine that they were staying on the LOP and using this method
to fly along the LOP to Niku.

Gary, all is forgiven.  I can understand how you may have misinterpreted what I meant but, as your exhaustive archive of quotes shows, I have never said that AE and FN used celestial observations to navigate their way "along" (or "down" or "southeastward" or "on") the LOP.   We don't need to burn any more bandwidth arguing about that.
Having reached what they believed was a 337 157 line that passed though Howland Island and not seeing Howland, they began searching for Howland by flying "north and south" on the line - at least that's what AE said they were doing.  I think, or at least hope, that we are in agreement that AE and FN could have reached Gardner by navigating down the 157° LOP by means of dead reckoning. We can disagree about how far they would have to go and how difficult it would be maintain a sufficiently accurate course to come within sight of Gardner - but once you acknowledge that it was possible you have to consider the other evidence that it did, in fact , happen.
Logged

Harry Howe, Jr.

  • T5
  • *****
  • Posts: 576
  • Nuclear Physicist(Ret) Pilot(Ret) Scuba(Ret)
Re: LOP nonsense
« Reply #25 on: September 01, 2011, 12:26:15 PM »



The walking in the desert with a compass in the hand is not an applicable analogy of the AE/FN situation. 
They had two compasses, one magnetic one radio, a directional Gyroscope, and an autopilot.  Also a drift indicator.  To have set the autopilot to fly a course of 337 to  157 (with a wind correction of course) and maintain that course for 3 hours wouldn't be a monumental feat for a pilot, even one of limited skills as AE.  The ten percent error  in DR doesn't apply to an autopilot guided flight.  They wouldn't have missed Gardner by 35 miles or even close to that.

Please remember that the prime function of an autopilot is to detect and correct for small deviations from a preset heading in order to maintain that heading.  That is what "George" (the autopilot) did.  Fred and Amelia monitored their progress (altitude, speed, fuel, engine performance, etc.)
No Worries Mates
LTM   Harry (TIGHAR #3244R)
 
Logged

Chris Johnson

  • T5
  • *****
  • Posts: 1069
  • Trying to give a fig but would settle for $100,000
Re: LOP nonsense
« Reply #26 on: September 01, 2011, 12:31:40 PM »



The walking in the desert with a compass in the hand is not an applicable analogy of the AE/FN situation. 
They had two compasses, one magnetic one radio, a directional Gyroscope, and an autopilot.  Also a drift indicator.  To have set the autopilot to fly a course of 337 to  157 (with a wind correction of course) and maintain that course for 3 hours wouldn't be a monumental feat for a pilot, even one of limited skills as AE.  The ten percent error  in DR doesn't apply to an autopilot guided flight.  They wouldn't have missed Gardner by 35 miles or even close to that.

Please remember that the prime function of an autopilot is to detect and correct for small deviations from a preset heading in order to maintain that heading.  That is what "George" (the autopilot) did.  Fred and Amelia monitored their progress (altitude, speed, fuel, engine performance, etc.)

To be fair to Gary he was replying to my request for a simple (idiots) example of DR and not necesserily referencing it to the AE/FN flight.

Buts its all interesting anyway :)
Logged

Harry Howe, Jr.

  • T5
  • *****
  • Posts: 576
  • Nuclear Physicist(Ret) Pilot(Ret) Scuba(Ret)
Re: LOP nonsense
« Reply #27 on: September 01, 2011, 01:57:14 PM »


Chris
But the context is the AE/FN  P&DR flight from Howland to Gardner.  Walking in the desert has nothing to do with aerial DR.
One of the first things I learned in Boy Scouts Orienteering was not to walk around looking at the moving needle on my compass.  I learned to plot a course from A to B, measure  a compass bearing. establish a waypoint, walk to that waypoint, establish  another wapoint on the bearing and so forth.

In the air over water of course you don't have waypoints so it is necessary to set your proposed course, correct for wind, set your autopllot, monitor your progress, correct your instruments as necessary. watch your speed and time, etc.
Lindbergh did it for 1700 miles in 1927, I think that even AE could do it for 400 miles.  And if she couldn't, then FN could.   And, more importantly, they did!
No Worries Mates
LTM   Harry (TIGHAR #3244R)
 
Logged

Chris Johnson

  • T5
  • *****
  • Posts: 1069
  • Trying to give a fig but would settle for $100,000
Re: LOP nonsense
« Reply #28 on: September 01, 2011, 02:22:37 PM »

And I agree! When I walk the moors of northern England and the mist drops we sight something and take a bearing on it with the compass and follow it.  Stop and do the same until we're where we want to go.

All I was saying was that Gary had replied to my "stupid" question and was not relating it to AE/FN or even promoting an alternative theory.

Anyway it looks like we've had a bit of a Forum Navigational Kiss and make up and as I don't anticipate ever having to plot a LOP or DR to a small island then I am more than happy with what I have learnet about navigation from many people on the forum.

I've got some more Irish Jokes to share if you want  :P

Forum forgive me for i am weak :)
« Last Edit: September 01, 2011, 03:03:36 PM by Chris Johnson »
Logged

Mona Kendrick

  • T2
  • **
  • Posts: 71
Re: LOP nonsense
« Reply #29 on: September 01, 2011, 02:25:03 PM »




I've got some more Irish Jokes to share if you want  :P
[/quote]

Please!  Let's hear them!

Mona
Logged
Pages: 1 [2] 3   Go Up
 

Copyright 2018 by TIGHAR, a non-profit foundation. No portion of the TIGHAR Website may be reproduced by xerographic, photographic, digital or any other means for any purpose. No portion of the TIGHAR Website may be stored in a retrieval system, copied, transmitted or transferred in any form or by any means, whether electronic, mechanical, digital, photographic, magnetic or otherwise, for any purpose without the express, written permission of TIGHAR. All rights reserved.

Contact us at: info@tighar.org • Phone: 610-467-1937 • Membership formwebmaster@tighar.org

Powered by MySQL SMF 2.0.15 | SMF © 2017, Simple Machines Powered by PHP