Advanced search  
Pages: [1] 2 3 ... 5   Go Down

Author Topic: What happened with the moon  (Read 56141 times)

Chris Johnson

  • T5
  • *****
  • Posts: 1069
  • Trying to give a fig but would settle for $100,000
What happened with the moon
« on: September 26, 2013, 01:00:19 PM »

Why didn't/couldn't FN take shots at the moon to correct their position?

Cloud - well there are reports of clouds to the NW but TIGHAR has then South of Howland, they confirm seeing island and vessel so visibility may not have been an issue.

Fred - lets not go there, he made the rest of the flight OK

Equipment failure - 2 devices so would be very bad luck.

Anything in the achieves strike you?
Logged

Randy Conrad

  • TIGHAR member
  • *
  • Posts: 308
Re: What happened with the moon
« Reply #1 on: September 26, 2013, 04:02:10 PM »

In reference to Chris's question...I myself pondered on something similar to the thought of what happened or what would happen if Fred looked out his window and was taking a reading off of the Sun or Moon, but didnt notice that he was looking at a reflection on the wing of the plane? Is it possible Ric of this actually happening? Afterall, Caroline Kennedy's brother was killed in a situation where he thought were lights, but was the reflection off of the surface of the ocean. Yet, Amelia is up in the pilots seat, and he's in the back...supposedly...Fred thinks he sees the moon...and so does Amelia...it's quite late...very tired...my eyes are growing weiry...He gives her the reading...but doesnt notice that he was looking at the reflection of the moon in the wing of the aircraft. She takes it for granted that he gave her the right reading and sticks to it. So they continue flying. What I'm wanting to know Ric and others...is it possible for this to happen...and actually how far off would this take her? Let me know...Thanks!!!!
Logged

JNev

  • T5
  • *****
  • Posts: 778
  • It's a GOOD thing to be in the cornfield...
Re: What happened with the moon
« Reply #2 on: September 26, 2013, 04:16:39 PM »

If he didn't, my first thought is 'cloud cover', the most common reason for not being able to make a shot.
- Jeff Neville

Former Member 3074R
 
Logged

Chris Owens

  • T2
  • **
  • Posts: 64
Re: What happened with the moon
« Reply #3 on: September 26, 2013, 09:38:52 PM »

I myself pondered on something similar to the thought of what happened or what would happen if Fred looked out his window and was taking a reading off of the Sun or Moon, but didnt notice that he was looking at a reflection on the wing of the plane?

This is extremely unlikely for the reason that celestial navigation depends upon very precise measurements of angles (that's why a sextant is such a fussy piece of equipment and why taking a sight, especially on a moving object like a ship or airplane, is as much art as it is science.)  Consider standing on the equator at 6:00 AM watching the sun rise (sun is at zero degrees)..  A quarter away around the Earth to the east of you (6500 miles away or so) at the same instant, it's noon: another observer measures the sun right over head, at 90 degrees.  A one degree error in measuring the altitude of the sun is over 70 miles error in your position (I'm oversimplifying the math here to the point of being factually wrong, but you get the idea.)  Sighting a reflection rather than the real object wouldn't just be a little bit off, it would be way off, to the point that the numbers wouldn't make sense when you tried to do the calculations.   Beyond that,  the reflection of the moon (for example, on the surface of the water or of the wing) is actually *below* the horizon -- it would be physically impossible to point your sextant at it without turning the sextant upside down, which would clue you in instantly that you were pointing it at the wrong thing.

Logged

JNev

  • T5
  • *****
  • Posts: 778
  • It's a GOOD thing to be in the cornfield...
Re: What happened with the moon
« Reply #4 on: September 27, 2013, 07:49:43 AM »

I don't know, Chris.  I do know where Itasca said there were clouds such that might obscure the moon from being shot.

I also know where Itasca said there were 'stellar' conditions throughout the night for celestial navigation.

I guess we're stuck with 'what happened to the moon', or 'what happened to Fred', or 'what happened to Fred's octant (and preventer?)', etc.  'Clouds' are simply the first thing that comes to mind for failing to make a shot; as you have noted, there could be other reasons.  For now, and perhaps forever, it is a mystery.
- Jeff Neville

Former Member 3074R
 
Logged

JNev

  • T5
  • *****
  • Posts: 778
  • It's a GOOD thing to be in the cornfield...
Re: What happened with the moon
« Reply #5 on: September 27, 2013, 09:26:19 AM »

OK ***** Dump Question/Statement Time *****

Would it be practical to actualy take moon/star shots but not use them until later into the flight?

Shots are used 'when taken'; they are charted *and* useful later - in the sense of  that the earlier fix provides a position from whence one has come.  In that sense they are useful *later*. 

But that usefulness is very limited -

The pilot would have proceeded by dead reckoning after the last fix.  That includes the pilot factoring into her heading drift correction, etc.  Typically the flight would have proceeded by DR until the next fix.  The idea is then to get a new fix when able; a new fix is needed to validate one's then-present position.  DR alone cannot account for undetected changes in wind, etc. along the way since the last fix. 

If one cannot get a new fix later in the flight, then one is stuck at the mercies of DR and it's potential errors, i.e. winds having changed along the way since the last fix, etc.

There's more to it.  Fred also had a drift meter, so when he could see an object below - a ship, marker of some sort, etc. he might have gotten a good idea of what the actual drift was along the way since the last fix.  We don't know how much he was able to use it, for sure.  Had he been able to use it, the information should have been helpful to the DR exercise by amending drift and speed by having sorted out the winds aloft by drift observations.

We do know that during the night earlier in the flight Earhart reported overcast conditions - not good for getting star fixes.  We also know that she later in the night she reported improved conditions, so Fred may well have gotten a fix somewhere in that break.
- Jeff Neville

Former Member 3074R
 
« Last Edit: September 27, 2013, 09:36:50 AM by Jeff Neville »
Logged

Chris Owens

  • T2
  • **
  • Posts: 64
Re: What happened with the moon
« Reply #6 on: September 27, 2013, 09:26:53 AM »

OK ***** Dump Question/Statement Time *****

Would it be practical to actualy take moon/star shots but not use them until later into the flight?

In some sense you always use an observation "later" if for no other reason than it takes some time (especially before the days of portable programmable calculators) to convert a sight to a line of position (navigators call this "reducing" a sight.) 


Typically, you might do this:  Take a sight, plot it, wait a little bit, take another sight (either on the same celestial object or another one), plot the second sight.  At this point you know: 
  • I was on this line (call it "line A") at noon
  • I was on that line (call it "line B") at 12:15
  • Between noon and 12:15, I was flying due East at 200 knots, and I think the wind was out of the East at 20 knots, so I think I was moving due East over the ground at about 180 knots, which means that at 12:15 I must have been about 45 miles East of where I was at noon.
  • So, I can draw a new line (call it "line A2") that is parallel to line A, but 45 miles East of line A.  I was probably somewhere on line A2 at 12:15, but I'm less confident about that than I am about Lines A or B, because it requires a guess about wind speed and direction.
  • If I chose my sights well, lines A2 and B will cross at an angle (as opposed to being parallel or nearly parallel, so I'm pretty sure that at 12:15 I was at the point where Lines A2 and B cross.

Now I'm probably not going to get this all plotted on my chart until 12:30 or so.....   it's all true whether I plot the lines at 12:30 or at 4 in the afternoon, but, of course, the data becomes less and less useful as it gets older.
Logged

JNev

  • T5
  • *****
  • Posts: 778
  • It's a GOOD thing to be in the cornfield...
Re: What happened with the moon
« Reply #7 on: September 27, 2013, 09:46:35 AM »

So Fred may have taken shots but winds may have forced the plane'southward'?

Would a pilot be asked to correct the flight path as they go along or would there be another stratergy?

BTW as you may see I don't really have a scobbie doo (thats a clue) about CN :)

Fred may have taken shots and gotten fixes; after shots taken and during dead reckoning efforts, winds could have 'forced' the plane south, north, slowed it, or sped it up.  There can be any number of combinations of those vectors, depending on where the winds were from.

The pilot would be asked to adjust heading if the navigator had new information that indicated a correction was needed.  That would mean having obtained a 'new' fix, or perhaps some drift observations that suggested that wind conditions had changed measurably.

We don't know where the winds might have been coming from.  Except for one early report from the plane reporting winds of 24 knots, all we have are ground observations.  We also do not know of any radical changes - the weather was reasonably settled as I understand it. 
- Jeff Neville

Former Member 3074R
 
Logged

Alex Fox

  • T1
  • *
  • Posts: 39
Re: What happened with the moon
« Reply #8 on: September 27, 2013, 12:19:45 PM »

Maybe the moon was fine, and Fred was fine, but his charts were wrong.  I know, the charts are ground already treaded on this forum, and we don't know what charts he was using. 

But if we're looking for a third option to the "where was the moon/where was Fred" debate...
#4317
 
Logged

JNev

  • T5
  • *****
  • Posts: 778
  • It's a GOOD thing to be in the cornfield...
Re: What happened with the moon
« Reply #9 on: September 27, 2013, 04:12:13 PM »

Maybe the moon was fine, and Fred was fine, but his charts were wrong.  I know, the charts are ground already treaded on this forum, and we don't know what charts he was using. 

But if we're looking for a third option to the "where was the moon/where was Fred" debate...

A third option like that does not seem to relate to whether Fred shot the moon or not.  If one must, however, then a 'third option' to 'where was the moon/where was Fred' discussion would seem to warrant another string, perhaps called 'what and where were Fred's charts', IMHO. 

Not saying it's not an interesting pursuit - but I am not sure it would yield much.  For one thing, I believe TIGHAR has done an outstanding job of looking into Earhart and Noonan's route planning and it seems reasonably likely that Fred did use something on the order of established charts and information of the time that would have provided reasonable positions for islands, etc.  You will see in that information that a 5 NM error may have existed as to Howland Island's position, depending on whether Fred had updated information or not - but that hardly seem material in my view, or TIGHAR's I believe.

Fred is also on record as having used reliable charts for certain other crossings, so we at least have a record of Fred's realizing the importance of acceptable charts, IMO.

Just MHO - YMMV, of course.
- Jeff Neville

Former Member 3074R
 
« Last Edit: September 27, 2013, 04:15:36 PM by Jeff Neville »
Logged

JNev

  • T5
  • *****
  • Posts: 778
  • It's a GOOD thing to be in the cornfield...
Re: What happened with the moon
« Reply #10 on: September 27, 2013, 04:33:28 PM »

OK long week and late night this side of the pond but........

does it make a difference that FN plotted PanAm routes via the west coast rather than the final flight via East?????

Not really - it is the very same skill set. 
- Jeff Neville

Former Member 3074R
 
Logged

Alex Fox

  • T1
  • *
  • Posts: 39
Re: What happened with the moon
« Reply #11 on: September 27, 2013, 04:37:54 PM »

A third option like that does not seem to relate to whether Fred shot the moon or not. 

It's a different subject, but I brought it up because the thread seemed to imply something was either wrong with the moon or Fred.  But if his charts were off, then he could have been perfectly conscious/competent, and the moon perfectly visible, and they'd still be lost.
#4317
 
« Last Edit: September 27, 2013, 05:05:21 PM by Jeff Neville »
Logged

JNev

  • T5
  • *****
  • Posts: 778
  • It's a GOOD thing to be in the cornfield...
Re: What happened with the moon
« Reply #12 on: September 27, 2013, 05:06:49 PM »

A third option like that does not seem to relate to whether Fred shot the moon or not. 

It's a different subject, but I brought it up because the thread seemed to imply something was either wrong with the moon or Fred.  But if his charts were off, then he could have been perfectly conscious/competent, and the moon perfectly visible, and they'd still be lost.

Whoops - sorry Alex - I meant to 'quote' and answer your post, but accidentally hit 'modify', so you'll notice an 'edited' notation.

I retracted my 'modification' and 'quoted' in a new reply, more appropriately of course.

My apologies.

Now -

It directly questions whether something went wrong with being able to shoot the moon (I think the moon was OK...), or with Fred, or anything else.  In that sense I see your point, but the charts have been a well-established factor so far as I can tell - a 5 NM error could have been the case, but that would hardly explain the debacle of that day.  Unless of course a 5 NM margin really was the tragic difference somehow - not likely so far as I can tell.
- Jeff Neville

Former Member 3074R
 
Logged

John Ousterhout

  • T4
  • ****
  • Posts: 487
Re: What happened with the moon
« Reply #13 on: September 27, 2013, 07:56:10 PM »

"...Unless of course a 5 NM margin really was the tragic difference somehow - not likely so far as I can tell."
In a different thread I discovered that an aircraft similar to the Lockheed 10 became impossible to hear at a distance significantly less than 5 miles.  If Amelia had flown within visual distance of Howland, she would not yet been within hearing distance.  By the same token, she wouldn't have heard a search aircraft overhead until it was within about 60 seconds of arrival.
Cheers,
JohnO
 
Logged

richie conroy

  • T5
  • *****
  • Posts: 1412
Re: What happened with the moon
« Reply #14 on: September 27, 2013, 08:01:57 PM »

And there is the possibility that the few seconds the plane could be heard from afar she was on radio to Howland/itasca taking all plane watchers off guard

Richie
We are an echo of the past


Member# 416
 
Logged
Pages: [1] 2 3 ... 5   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