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AuthorTopic: Course lines, speed lines, where's Howland, and... where did she go?  (Read 86293 times)

Gary LaPook

• T5
• Posts: 1624
Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #90 on: December 17, 2011, 01:32:55 AM »

Gary
3.  202 miles to the vicinty of Howland  then 44 to 66miles (20-30 minutes at 134 nph) WNW of where they expected to see Howland, then they circled back towards Howland and continued on to Gardiner.
5. Why do you have them flying an additional 44 to 66 miles if you think they were only 202 miles south-southeast of Howland when they intercepted the LOP? Why don't they turn around after just flying the 202 miles to Howland? Doesn't this just waste time and fuel?
gl
« Last Edit: December 17, 2011, 01:51:36 AM by Gary LaPook »
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Gary LaPook

• T5
• Posts: 1624
Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #91 on: December 17, 2011, 01:46:30 AM »

No, 1800 GCT (0600 Howland time).

I believe that in 1937, Itasca time was offset from GMT by 11.5 hours.

GMT - 11.5 = Itasca time.

See Randy Jacobson's explanation of the 1937 time zones, which is essential for understanding The Jacobson Databases, which, in turn, underlie much of TIGHAR's research into the fatal flight and post-loss radio messages.

I've tried to copy Jacobson's table into a new article in the Ameliapedia.  I've also done my level best to calculate the Itasca time for the transmission timeline
• I can't explain why Jacobson used a convention that is the opposite of the current UTC convention. Perhaps that reflects how time zones were calculated in the GMT/Zulu days.
• I don't trust my math.

Another maddening wrinkle: the Howland log was kept on GMZ-10.5 while the Itasca was on GMZ-11.5.
I take it you are confused by the sign convention. For navigation purposes it is important to be able to determine Zulu time which is the entering argument for the Nautical Almanac. The navigation and navy sign convention makes this easy. You start with the local time shown on the ship's clocks and then apply the Zone Description which then gives you Zulu (GMT) time. For instance, the navigator on the Itasca takes an observation of the sun at 0815 ship's time. He then applies the Zone Description of + 11:30 and determines the GMT of the observation as 1945 Z which is the value he needs to enter his Nautical Almanac. The ships are not concerned with determining the time at other locations other than at Greenwich.

Other users are interested in converting GMT to local time so they use a reversed sign for the conversion factor. Using the same values as above, 1945 Z minus 11:30 makes the time on Itasca 0815.
See my prior post:
https://tighar.org/smf/index.php/topic,433.msg5362.html#msg5362

gl
« Last Edit: December 17, 2011, 01:50:43 AM by Gary LaPook »
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John Ousterhout

• T4
• Posts: 487
Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #92 on: December 17, 2011, 07:28:53 AM »

Jeff, et al;
GL has his own web pages presenting his ideas about the flight:
Those are good pages to visit to identify what points are weell supported, and what points are open to interpretation, and what points are based on assumptions.
Cheers,
JohnO

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Irvine John Donald

• T5
• Posts: 597
Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #93 on: December 17, 2011, 08:00:50 AM »

Hi John

To save us all some time can you point us to the part of Gary's website that says what he believes happened?  I see lots of sections on why TIGHAR is wrong but nothing leaps out on Gary's hypothesis.
Respectfully Submitted;

Irv

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John Ousterhout

• T4
• Posts: 487
Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #94 on: December 17, 2011, 08:37:24 AM »

Here's the closest I've found to Gary stating what he believe happened:
"It is most likely that they had planned to use the radio as the primary, or preferred, method for finding Howland since it is easier to use and saves you the time and distance necessary for the landfall procedure. However, the celestial landfall procedure is accurate enough, by itself, to find Howland so was perfectly adequate as a backup, or secondary, method for completing the flight. When they failed to get the radio signals at the point that they had that expected to be able to receive them, they would have turned to commence the landfall procedure with the knowledge that if they did start receiving the radio signals they could abandon the landfall at that point and turn and follow the radio bearings directly to the island. There is no other explanation for their report of being on the 157-337 line except that they were flying the landfall since that line has absolutely no relevance to any other approach."
I take Gary's statement to mean that he believes the flight most likely continued to try to navigate towards Howland until they ran out of fuel.  He's obviously spent a lot of time and effort considering the various evidence and hypotheses', so he makes a very good foil to sharpen any other hypothesis.  I'm glad he participates here, regardless of how irritating he may be at times, and I encourage TIGHAR folks to visit his pages for a different and thoughtful perspective.
Note that I don't think he is "right", any more than I think TIGHAR is "right".  That is a decision to be made if and when the Electra is found.
Cheers,
JohnO

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Irvine John Donald

• T5
• Posts: 597
Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #95 on: December 17, 2011, 10:45:07 AM »

Hi John. Thanks for that info. It helps and your encouragement to others to go and visit Gary's site is appropriate. I have been to his site myself on several occasions but always come away feeling that the site is setup to say why TIGHAR is wrong in its thinking. Not "but here's what I, Gary Lapook, think".

Your entry above has your interpretation of what you believe Gary thinks. It doesn't point to the Lapook hypothesis. What we would like to hear from Gary is his hypothesis or theory and not a rehash of why TIGHAR is wrong.  In a court a prosecutor has to prove what happened using evidence. To different degrees of certainty depending on the court. A defense lawyer needs to only show that the prosecutor is wrong to win his case.  I feel that's what Gary tries to do.  What I would like to see is Gary to take off his lawyer's hat and just render his personal opinion on what happened. No judge, no jury, no court decision.  Just one of a bunch of guys sitting around a kitchen table sharing his thoughts over a beer.  No condemnation, no insults, no judgement. Gary's current method of trying to convince us TIGHAR is wrong is dead ending because he isn't putting an alternative forward.  Ric has passion and conviction in his hypothesis. Gary seems to have that same passion and conviction for disproving Ric. What drives that passion?  Gary??
Respectfully Submitted;

Irv

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Heath Smith

• T4
• Posts: 391
Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #96 on: December 17, 2011, 12:45:05 PM »

I am still trying to understand why Eahart and Noonan selected the 157/337 "line" which I believe everyone assumes to be the Advanced Line of Position described here:

If they did establish their own LOP at sunrise, and there seems to be considerable debate whether that was even possible, why follow the ALOP at all? Was it because they were on a 247/67 heading that is 90 degrees from the 157/337 LOP at Howland and they made that heading change when they set their own LOP at sunrise?

Reliance on being able to see the sunrise in advance, with unknown weather conditions ahead, at pre-dawn, would seem to be very risky. Perhaps it was a backup plane in case Fred could not establish celestial navigation? There must have been some pre-planning going on there to intercept this ALOP from the start, regardless of the celestial navigation, and ability to establish a LOP. If both failed, would they have been forced to falling back to estimates based on the compass heading and timepiece as the last resort? Given that they had no ability to measure the head winds (short of dropping flares) do we believe it had been that been for them?

I like the idea of an offset as this seems to be the most logical thing to do (even for a layperson like myself), ensuring that you hit hand if you somehow drifted North. Do not go directly for the target but hit this line a bit South to ensure success of hitting something sooner or later. I cannot see a reasonable argument that suggests that they did not do this to some degree.

Maybe it was not the midpoint between Howland and Gardner, but it was somewhere on that line based on Fred's confidence level.
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Harry Howe, Jr.

• T5
• Posts: 576
• Nuclear Physicist(Ret) Pilot(Ret) Scuba(Ret)
Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #97 on: December 17, 2011, 01:22:33 PM »

Gary
5.  They flew the 200 or so miles on the LOP towards where they expected Howland to be, didn't spot it, radioed in "we must be on you...",  continued on the LOP for 20 to 30 minutes and still didn't spot it so they decided to return along the 337 to 157 course and after they travelled 20 to 30 minutes back to where they had expected Howland to be and still not spotting it radioed "running N and S on the line 157/337" and continued on to the Phoenix Island group (Gardiner?)

We must bare in mind that there is a  chance that FN's chart had Howland mislocated by 5 nm to the west of its "true" position.  Why did they miss Howland? We'll probably never know.
No Worries Mates
LTM   Harry (TIGHAR #3244R)

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Martin X. Moleski, SJ

• Posts: 2982
Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #98 on: December 17, 2011, 01:28:01 PM »

Reliance on being able to see the sunrise in advance, with unknown weather conditions ahead, at pre-dawn, would seem to be very risky. Perhaps it was a backup plane in case Fred could not establish celestial navigation?

Observing the time of sunrise from a particular alititude is celestial navigation.  The sun is just one of the heavenly bodies that can be used to generate a line of position.

Quote
There must have been some pre-planning going on there to intercept this ALOP from the start,

Not necessarily.  It was one tool in Fred's arsenal, I believe.

Quote
I like the idea of an offset as this seems to be the most logical thing to do (even for a layperson like myself), ensuring that you hit hand if you somehow drifted North. Do not go directly for the target but hit this line a bit South to ensure success of hitting something sooner or later. I cannot see a reasonable argument that suggests that they did not do this to some degree.

This is a moot point.  It is something about which reasonable people can reasonably disagree and which makes absolutely no difference to deciding where to look for the pieces of the Electra.  Arguments about what our heroes coulda, shoulda, woulda done are incapable of resolution--unless, of course, someone finds Fred's charts from the fatal flight.
LTM,

Marty
TIGHAR #2359A

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Heath Smith

• T4
• Posts: 391
Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #99 on: December 17, 2011, 02:05:25 PM »

Quote
unless, of course, someone finds Fred's charts from the fatal flight.

Or models like the doughnut hole theory (or other radio models) could give credence to the idea.
« Last Edit: December 17, 2011, 02:49:51 PM by Heath Smith »
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Gary LaPook

• T5
• Posts: 1624
Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #100 on: December 17, 2011, 06:59:12 PM »

I am still trying to understand why Eahart and Noonan selected the 157/337 "line" which I believe everyone assumes to be the Advanced Line of Position described here:

If they did establish their own LOP at sunrise, and there seems to be considerable debate whether that was even possible, why follow the ALOP at all? Was it because they were on a 247/67 heading that is 90 degrees from the 157/337 LOP at Howland and they made that heading change when they set their own LOP at sunrise?

Reliance on being able to see the sunrise in advance, with unknown weather conditions ahead, at pre-dawn, would seem to be very risky. Perhaps it was a backup plane in case Fred could not establish celestial navigation? There must have been some pre-planning going on there to intercept this ALOP from the start, regardless of the celestial navigation, and ability to establish a LOP. If both failed, would they have been forced to falling back to estimates based on the compass heading and timepiece as the last resort? Given that they had no ability to measure the head winds (short of dropping flares) do we believe it had been that been for them?

I like the idea of an offset as this seems to be the most logical thing to do (even for a layperson like myself), ensuring that you hit hand if you somehow drifted North. Do not go directly for the target but hit this line a bit South to ensure success of hitting something sooner or later. I cannot see a reasonable argument that suggests that they did not do this to some degree.

Maybe it was not the midpoint between Howland and Gardner, but it was somewhere on that line based on Fred's confidence level.

gl
« Last Edit: December 17, 2011, 07:04:54 PM by Gary LaPook »
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Gary LaPook

• T5
• Posts: 1624
Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #101 on: December 18, 2011, 01:14:08 AM »

Gary
5.  They flew the 200 or so miles on the LOP towards where they expected Howland to be, didn't spot it, radioed in "we must be on you...",  continued on the LOP for 20 to 30 minutes and still didn't spot it so they decided to return along the 337 to 157 course and after they travelled 20 to 30 minutes back to where they had expected Howland to be and still not spotting it radioed "running N and S on the line 157/337" and continued on to the Phoenix Island group (Gardiner?)

But what you are saying doesn't make any sense, You had then aim for a spot 200 miles south-southeast on the LOP on the assumption that the uncertainty, or possible error, in the DR approaches 200 miles. But, they could be off course either to the right or to the left of the the 200 mile offset position along the LOP that you aimed for, so they might actually have intercepted the LOP 200 miles further out to the south-southeast, a  total of 400 miles from Howland. You then have them turning left and flying 200 miles along the LOP to the spot where they expect Howland to be. You then have them flying only 44 to 66 miles further prior to turning around but they actually must fly an additional 200 miles to ensure that they have flown far enough to find Howland because of the possiblity that they actually intercepted 400 miles from Howland.

gl
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Irvine John Donald

• T5
• Posts: 597
Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #102 on: December 18, 2011, 09:21:33 AM »

Well said Jeff. I second the motion. Gary??
Respectfully Submitted;

Irv

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Heath Smith

• T4
• Posts: 391
Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #103 on: December 18, 2011, 09:27:47 AM »

Gary,

---

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 landÃ­all.

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?

« Last Edit: December 18, 2011, 09:29:28 AM by Heath Smith »
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richie conroy

• T5
• Posts: 1412
Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #104 on: December 18, 2011, 11:29:18 AM »

i don't think Gary has any issue with the Gardner hyposis, he  is just trying to explain why he thinks Tighar theory ov the lop is wrong,

u only have to look at his website an see its mostly about the lop nothink else
We are an echo of the past

Member# 416

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