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Author Topic: Course lines, speed lines, where's Howland, and... where did she go?  (Read 101503 times)

Gary LaPook

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Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #15 on: December 10, 2011, 04:18:43 AM »

Rabaul still looks much scarier to me!  After just a few minutes in the air.....no more land in site. 
A lot of land nearby with a departure from Lae.  Still sticking to my opinion on that as a safer departure point.   Give me more land to fly by or over until I have to face the loneliness of open water.   
I take it you haven't done much flying over the ocean.
Based on her earlier flights, Earhart didn't share your aversion to water. When she flew solo across the Atlantic she departed from Newfoundland and I can tell you there is no land after you "coast out" and go "feet wet" after departing from there. She also flew solo from Hawaii to California, again no land to follow after departure. Then she flew from California to Hawaii on the first attempt, again no land after you put the coast of California behind you. Later, on the second attempt, they flew from Natal to Dakar, guess what, no land after takeoff on that leg either.
So whatever reason she chose to not depart from Rabaul, it was not that she was afraid of having no land in front of her after takeoff.

gl
« Last Edit: December 10, 2011, 11:39:04 PM by Gary LaPook »
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Ric Gillespie

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Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #16 on: December 10, 2011, 06:30:17 AM »

Ric sez: "At most destinations Earhart had pre-positioned her own fuel.  It's not clear whether that was true at Lae."
Interesting, I wasn't aware of that.  Did she have drums of fuel from a reliable source sent to those locations, or pay to have fuel sent to those locations (by the lowest bidder?), or was fuel "pre-paid" at the various airports, trusting it to be of good enough quality?

She had drums of fuel with her name on them pre-positioned at her planned destinations.
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Heath Smith

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Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #17 on: December 10, 2011, 07:43:54 AM »

Looks like Google Earth strikes again. From 1,000 feet the horizon is only 41.6 SM away so anything at sea level beyond that distance is hidden behind the curve of the Earth. If Howland was 20 feet tall then this would add to the distance that you could see the top of that tree by 5.9 SM making a maximum that it might be possible to see Howland 47.5 SM (41.3 NM) no matter how good the meteorological visibility happens to be and it is never that good over the ocean.

Gary,

Thank you for the information. I found an online calculate here that takes in to account other factors.

http://mintaka.sdsu.edu/GF/explain/atmos_refr/altitudes.html

Playing with different values of altitude, the island should have been visible at 50 miles. At an altitude of 1500 feet, the observable distance is 60 miles. At 2000ft, 68 miles.

Do we believe that they maintained a constant 1000ft altitude while attempting to find Howland or was there any evidence that she attempted to climb a bit to increase their odds of seeing the island?

Thanks.
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Rich Ramsey

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Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #18 on: December 10, 2011, 08:37:12 AM »

I'm just gonna through this out there and run. As I am not a Pilot or a navigator (just someone interested in flying and this mystery). If it was cloudy and she was at 1000 feet isn't it possible she just flew right over Howland and didn't know it? IF not right over it, close enough were should should see it but didn't?
"Hang Tough"
Rich
 
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John Ousterhout

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Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #19 on: December 10, 2011, 08:53:47 AM »

There were a number of people on Howland looking and listening for the approaching Lockheed.  I think it's safe to say that they would have heard it if it was within 10 miles, and possibly much, much further.  She missed seeing it by more than 10 miles, possibly more than a much greater distance, or someone would have heard her engines.

Scattered clouds play hob with a pilot's ability to spot a distant island, from what I've read.  They also make a star sight difficult unless you can get above them or in a large open space.  The navigator needs to be certain of which star he is seeing, and a minute or two after that to take an elevation.
Cheers,
JohnO
 
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Irvine John Donald

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Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #20 on: December 10, 2011, 08:57:02 AM »

Hi Rich.  I believe the weather at Howland was clear. If I'm wrong I will be corrected. And Itasca was creating smoke as a beacon.

However, please keep thinking " out of the box" and don't run.  While the really knowledgable guys on this forum will occasionally hand out a tongue lashing they can't actually hurt you!  LOL.

To Johns point about watchers I would add that even if the watchers had heard her they couldn't communicate with her. No way to say something like "you're passing to the north.". That would have been an even sadder ending if they had heard the plane.
Respectfully Submitted;

Irv
 
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Ric Gillespie

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Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #21 on: December 10, 2011, 09:45:51 AM »

I believe the weather at Howland was clear. If I'm wrong I will be corrected.

Happy to oblige. See the Itasca Deck Log
Sky conditions that morning during the period in question were 4/10ths to 3/10ths cloud cover.

And Itasca was creating smoke as a beacon.

Maybe, maybe not.  Itasca could only make smoke by changing the fuel/air mixture in her boilers and she could only did that for a limited time without really scewing up the boiler tubes.   According to the Deck Log she began "laying down heavy smoke" at 0614.  By the time Earhart was thought to be close - an hour and a half later - Itasca may no longer have been able to make smoke without causing permanent damage to her propulsion system.
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Irvine John Donald

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Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #22 on: December 10, 2011, 10:28:39 AM »

Thanks Ric. What does "cloud cover" mean?  What would the base of the clouds be?  Under AE's reported altitude of 1000 feet?  Or over? 
Respectfully Submitted;

Irv
 
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Ric Gillespie

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Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #23 on: December 10, 2011, 10:47:40 AM »

Cloud cover means the percentage of the sky that is covered by clouds.  3/10ths cloud cover means that about a third of the sky is covered by clouds.
What the deck log describes is a very typical morning out there - a broken or scattered deck of cumulus with bases at about a thousand feet.  As the day warms up the bases gradually rise to maybe 2,500 feet and some of the clouds build into rain squalls.

If Earhart hopes to find land she needs to stay under the bases. 
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Irvine John Donald

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Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #24 on: December 10, 2011, 10:57:25 AM »

Ahh. Okay. I thought of cloud cover as that very high solid grey stuff.  So she was flying at or, presumably, just under the cloud base for visual searching.
Respectfully Submitted;

Irv
 
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Gary LaPook

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Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #25 on: December 10, 2011, 01:33:07 PM »

There were a number of people on Howland looking and listening for the approaching Lockheed.  I think it's safe to say that they would have heard it if it was within 10 miles, and possibly much, much further.  She missed seeing it by more than 10 miles, possibly more than a much greater distance, or someone would have heard her engines.

Scattered clouds play hob with a pilot's ability to spot a distant island, from what I've read.  They also make a star sight difficult unless you can get above them or in a large open space.  The navigator needs to be certain of which star he is seeing, and a minute or two after that to take an elevation.
It's pretty easy to be certain that you are looking at the sun and the moon. The moon was also available that morning and its placement in the sky provided a line of position running mainly east-west so would let Noonan know how far north and south they were just like the 157-337 LOP (mainly north-south) let them know how far east or west they were. Because of the moon, and the fact that Itasca reported clear skies to the south, Noonan taking a sight on the moon would have prevented them from flying very far south of Howland and would have kept them from ending up on Gardner.

The Itasca radio log records "partly cloudy" report from Earhart at 1623 Z (look at the 0453 Itasca time entry in Itasca number 2 radio log) so even if Noonan had been prevented earlier from getting star sights by "overcast" conditions you can bet you last dollar that they were going to maneuver the plane in that area to allow Noonan to get a star fix around 1623 Z. They reported "must be on you" at 1912 Z, less than three hours later. At a ground speed of 125 mph the plane covered about 375 SM during that period. The generally accepted estimate of uncertainty of dead reckoning is 10% of distance covered so their position was unlikely to be in error more than 38 SM (and probably much less) at 1912 Z so they would not have been near Gardner.

See standard flight navigation texts available here, (I don't make this stuff up):
https://sites.google.com/site/fredienoonan/topics/accuracy-of-dead-reckoning

https://sites.google.com/site/fredienoonan/topics/accuracy-of-celestial-fixes

https://sites.google.com/site/fredienoonan/topics/landfall-procedure

And an explanation here:

https://sites.google.com/site/fredienoonan/discussions/navigation-to-howland-island

gl


gl
« Last Edit: December 10, 2011, 10:56:14 PM by Gary LaPook »
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Gary LaPook

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Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #26 on: December 10, 2011, 02:08:51 PM »

I believe the weather at Howland was clear. If I'm wrong I will be corrected.

Happy to oblige. See the Itasca Deck Log
Sky conditions that morning during the period in question were 4/10ths to 3/10ths cloud cover.

And Itasca was creating smoke as a beacon.

Maybe, maybe not.  Itasca could only make smoke by changing the fuel/air mixture in her boilers and she could only did that for a limited time without really scewing up the boiler tubes.   According to the Deck Log she began "laying down heavy smoke" at 0614.  By the time Earhart was thought to be close - an hour and a half later - Itasca may no longer have been able to make smoke without causing permanent damage to her propulsion system.

That "scare story" comes from Bob Brandenburg,  TIGHAR's radio expert, not a boiler operations expert.

See what I wrote about this before at: https://tighar.org/smf/index.php/topic,383.msg4989.html#msg4989

and: https://tighar.org/smf/index.php/topic,383.msg5025.html#msg5025

I don't claim to be a boiler operations expert (though I do have quite a bit of knowledge about marine steam engines and boilers,) but I can read, and I posted  excerpt's from the Navy's standard textbooks on this subject on my prior post. Neither Admiral Knight nor the writers of the Navy Boilerman training text are trying to "advance the theory" of a Gardner landing.

And the other independent witnesses on the scene all reported continuous smoke. So read the references and make up your own mind.

gl
« Last Edit: December 10, 2011, 11:00:07 PM by Gary LaPook »
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Thom Boughton

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Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #27 on: December 10, 2011, 03:12:42 PM »

Thanks Ric. What does "cloud cover" mean?  What would the base of the clouds be?  Under AE's reported altitude of 1000 feet?  Or over?



For those accustomed to reading such things, using what is in the log and doing a few quick computations to find some of the missing values, in present day (or nearly present day) terms, the Hourly weather report would today look something like this


 10SCT 9 008/81/77/0703/979

(OK...not really 'Today', I left it in the SA format. I've never liked the new METAR coding, but if someone is more accustomed to the ICAO way of things and wants it I'll convert it.)



The 2/10 to 3/10 cloud cover is today termed to be 'Scattered' (as Ric said).  In basic terms it means the sky is 20 to 30 percent covered by clouds.  In this case, it indicates that the clouds were cumuliform in nature which means they were lower clouds.  There were no actual recorded values for cloud height.  In THIS case, however, with the reported temperature and pressure ...and my calculated dewpoint value ... it is predictable that the bases were probably (roughy 85% probability) somewhere in the vicinity of 900 to 1000 ft.

I can say from experience that, with bright sunshine (as it appears there was at the time), the lower the clouds then the darker the shadows they cast on the water surface ...and therefore the more difficult it becomes to differentiate between cloud shadow and land mass.

The visibility was 9 (nautical, presumably) miles / millibar air pressure of 1008mb/ temp 81F (27C) / Dewpoint 77F (25C)/ Winds 070 (ENE) at 03Kts / Air Pressure 29.79 In. Hg


Comparing this observation to the earlier and later observations that day, it does appear to have been a fairly stable weather system.  Temps climb and fall as would thus be expected, as well as changes in pressure and and winds throughout the period shown.  Although it is interesting to note a 4 degree temperature/dewpoint spread with relatively light winds.  This not always, but sometimes, could indicate the possibility of fog and/or haze...there are other factors involved though. The visibility was reported to be 8 to 9 miles throughout the entire period, so it does not appear to have been a factor. 

If anything, conditions only got better as the clouds are later recorded as changing from cumulus to higher alto cumulus to cirrus ...which occur at much higher altitudes. Not to mention a steady rise in atmospheric air pressure.



LTM,
 
     ....tb



TIGHAR #3159R
 
« Last Edit: December 10, 2011, 03:16:05 PM by Thom Boughton »
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John Ousterhout

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Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #28 on: December 10, 2011, 03:27:20 PM »

gl sez: "Noonan taking a sight on the moon would have prevented them from flying very far south of Howland and would have kept them from ending up on Gardner."

Question: could Fred take a sight at extremely high elevation (adding a deadly serious meaning to "shoot the moon")? July 1, 1937, 13:03Z was the moon last quarter, making it near overhead at dawn.  I don't recall seeing a navigator's bubble on top of the Lockheed, so the range of sight elevations available may have been quite restricted.  I can imagine some extreme frustration onboard the aircraft if there were no good star sights available, yet a moon high in the sky that he couldn't shoot. I'd appreciate any thoughts.
Cheers,
JohnO
 
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Ric Gillespie

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Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #29 on: December 10, 2011, 03:32:33 PM »

It's pretty easy to be certain that you are looking at the sun and the moon. The moon was also available that morning and its placement in the sky provided a line of position running mainly east-west so would let Noonan know how far north and south they were just like the 157-337 LOP (mainly north-south) let them know how far east or west they were. Because of the moon, and the fact that Itasca reported clear skies to the south, Noonan taking a sight on the moon would have prevented them from flying very far south of Howland and would have kept them from ending up on Gardner.

That's a pretty good argument that he did not "shoot the moon" because he didn't reach Howland and he apparently did reach Gardner.

The Itasca radio log records "partly cloudy" report from Earhart at 1623 Z (look at the 0453 Itasca time entry in Itasca number 2 radio log) so even if Noonan had been prevented earlier from getting star sights by "overcast" conditions you can bet you last dollar that they were going to maneuver the plane in that area to allow Noonan to get a star fix around 1623 Z.

The Itasca Radio Log has always been interpreted that way but the raw log preserved by Bellarts is not that clear.  The log records that at 04:53 Itasca time, the operator sent Earhart the weather on 3105 in both morse code and voice ("fone").  Earhart seems to have "stepped on" that transmission and the operator typed on the same line (HEARD EARHART (PART CLDY). He then went back and typed dashes over the (PART CLDY), hit the carriage return, and continued the dashes through about half of the next line.  Why?  (The dark line under HEARD EARHART was added much later, probably by Bellarts.)Where the dashes a mistake?  Did he change his mind about what he had heard?  I don't know but there is certainly room to question whether Earhart said "partly cloudy."

« Last Edit: December 10, 2011, 04:05:48 PM by Ric Gillespie »
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