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Author Topic: Course lines, speed lines, where's Howland, and... where did she go?  (Read 66615 times)

Gary LaPook

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Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #30 on: December 10, 2011, 04:20:39 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."
------------------------
But radio log 2 was made as a cleaned up copy of the raw log very shortly later. The person typing up log 2 had the opportunity to ask Bellarts at that time, when the facts were the most clear in his head, what Bellarts actually meant by what he had typed in the raw log. Since log 2 does not have dashes over the "part cldy"  entry, Bellarts must have clarified this as being what he had heard.

Any other explanation must include that Bellarts was smoking dope at the time and just dreamed up that entry in the raw log.

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

It just occurred to me that it may actually have been Bellarts that typed up log 2 so he would have known what he had heard as logged on the raw log when he typed up log 2.
gl
« Last Edit: December 10, 2011, 11:05:31 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 #31 on: December 10, 2011, 04:29:56 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.
The short answer is "Yes." We know this because Noonan had taken even higher sights using the same octant and shooting through the same windows in the same airplane on the flight to Hawaii and on the leg from Natal to Dakar. I posted a complete explanation of this before at:

https://tighar.org/smf/index.php/topic,383.msg5653.html#msg5653

gl
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Gary LaPook

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Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #32 on: December 10, 2011, 04:37:11 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
Here is a photo of what it probably looked like:
https://tighar.org/smf/index.php?action=dlattach;topic=452.0;attach=171
I also posted a photo of land ten miles ahead on this post:
https://tighar.org/smf/index.php/topic,447.msg5573.html#msg5573


gl
« Last Edit: December 10, 2011, 05:09:17 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 #33 on: December 10, 2011, 04:40:45 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?



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




LTM,
 
     ....tb
According to Itasca's deck log, visibility that whole morning was "9" - the maximum on the scale, defined as "Prominent objects visible above 20 miles."

gl
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Gary LaPook

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Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #34 on: December 10, 2011, 04:52:54 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.
They were also looking for a ship, see:
https://tighar.org/smf/index.php/topic,383.msg5585.html#msg5585

gl
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John Ousterhout

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Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #35 on: December 10, 2011, 05:28:26 PM »

" I posted a complete explanation of this before at:
https://tighar.org/smf/index.php/topic,383.msg5653.html#msg5653"
thx gl, excellant link.  Sun and moon in good positions for fixes at an appropriate time (good planning?).  'Hard to imagine FN didn't have appropriate tables. 'Got any suggestions where they went wrong from your POV?
We seem to have drifted from "last takeoff footage" a bit ourselves.
Cheers,
JohnO
 
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Thom Boughton

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Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #36 on: December 10, 2011, 05:48:11 PM »

According to Itasca's deck log, visibility that whole morning was "9" - the maximum on the scale, defined as "Prominent objects visible above 20 miles."


Ahh!   So it does.  I missed the legend on the prior page.

One wonders what 'Prominent Objects' they found over twenty miles away to identify in the middle of the ocean other than Howland itself.  Anyone know how far offshore Itasca was parked?  Otherwise, all you had to identify was water.  Either way, this problem would be the same no matter how you logged the observation.



LTM,
 
    ....tb


TIGHAR #3159R
 
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Heath Smith

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Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #37 on: December 10, 2011, 07:47:16 PM »


Over at the U.S. Coast Guard website, there is a PDF that contains the history of the Itasca. There are a couple pages about Earhart and Howland.

http://www.uscg.mil/history/webcutters/Itasca_1930.pdf

"The flying conditions within a radius of 40 miles of Howland Island were excellent with an east wind of 8 to 13 miles per hour, the sea smooth and ceiling unlimited as far as could be observed.  The sun was rising clear and bright, with the island, the ship and the smoke screen in its glare.  Visibility to the north and west was excellent to the horizon, but beyond that continuous banks of heavy cumulus clouds were visible.  The plane's transmissions had indicated a flight through cloudy and overcast skies throughout the night and morning, and that dead reckoning distance had been accomplished.  The plane's signal strength had been high and unchanged during the last hour of transmission, and its line of position had indicated that the dead reckoning had run correct.  Throughout the proceeding night stellar navigating possibilities south and east of Howland and close to Howland had been excellent."
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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 #38 on: December 10, 2011, 09:21:03 PM »

Isn't this CG PDF contradictory to what the deck log said. See Ric's reply 75 at top of this page. 3/10ths to 4/10ths cloud cover.   Should I presume the deck log is likely to be accurate versus an interpreted narrative written later for a history chapter?
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 #39 on: December 10, 2011, 10:52:51 PM »

Isn't this CG PDF contradictory to what the deck log said. See Ric's reply 75 at top of this page. 3/10ths to 4/10ths cloud cover.   Should I presume the deck log is likely to be accurate versus an interpreted narrative written later for a history chapter?
No, because scattered cloud do not constitute a "ceiling," only "broken" or "overcast" constitute a ceiling. As long as less than 6/10 of the sky is covered by clouds there is no ceiling.

gl
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Gary LaPook

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Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #40 on: December 10, 2011, 11:21:37 PM »

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.   
BTW sight is spelled s-i-g-h-t.
S-i-t-e means a particular location such as a site for a concert.
Site also means, in the artillery, the difference in the height above sea level between the guns and the target, and this must be allowed for in computing quadrant elevation.

gl
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Gary LaPook

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Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #41 on: December 10, 2011, 11:52:18 PM »

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.
That calculator is much more complicated than is needed for this discussion especially since you do not know the lapse rate. That calculator is appropriate for surveyors with sophisticated instruments. United States Navy Hydrographic Office Publication Number 9, the standard navigation reference text book in the United States, commonly known as "Bowditch," gives the formula as 1.317 times the square root of the height of eye in feet.

gl
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Gary LaPook

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Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #42 on: December 11, 2011, 12:37:54 AM »

Gary,
All I am saying is, I wasn't around in 1937....so I do not know how accurate forecasting winds aloft was....especially in the middle of the Pacific Ocean.  A Pilot knows their limitations better than anyone else.  I am saying that, if I were in the position AE was in, with available Navigation at the time, I would have wanted to fly over as much land as possible until I headed out over the open ocean.  Very seldom winds aloft actually were the same as forcasted when I flew long trips. 

Better question might be how many 2,500 mile trips had she flown over an ocean and ended up at the right place?     

And great point:  Noonan didn't find Howland...did he?   

Too bad AE couldn't push the mic button on her yoke and just say "Lae Ground....Electra 16020 IFR Howland Island"...and get her clearance instructions, route, initial altitude assignment, initial frequency, and her transponder code....and take off with clearance from the Lae tower.  And then get those vectors to the approach at Howland....and they both live happily ever after.   Not so much!
"Electra November Romeo one six zero two zero" (remember, you must use the "November" when flying internationally) "radar contact lost, resume own navigation, report Itasca outbound." Now what are you going to do?

gl
« Last Edit: December 11, 2011, 12:45:31 AM 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 #43 on: December 11, 2011, 02:59:47 AM »


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.
gl
As an example of the measures that Noonan would have taken to get a celestial fix when the sky was partly cloudy around 1623 Z (0453 Itasca time), I am attaching an excerpt from the book Seaplane Solo by Sir Francis Chichester about the first crossing of the Tasman Sea in 1931. Chichester was flying solo in a Gypsy Moth open cockpit biplane across the 1,450 miles of the Tasman sea in a plane that couldn't carry enough fuel to go that far. He decided to land at the two tiny islands in the Tasman Sea, Norfolk and Lord Howe, but there were no radio stations to help him find those fly-specks. He decided to develop and use the procedure of using a sextant to make a single line of position sun line approach to each of these islands. Chichester is credited with being the person who invented this procedure which was later used by the Air Force, the Navy and by Noonan while flying to Howland. This excerpt shows the desperate measures Chichester had to use to get an observation of the sun through a very small hole in the overcast so he could determine when to make the turn onto the LOP that would take him to Lord Howe. Noonan would have done the same.
gl
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Ric Gillespie

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Re: Course lines, speed lines, where's Howland, and... where did she go?
« Reply #44 on: December 11, 2011, 08:17:21 AM »

Gary, you wrote:
As an example of the measures that Noonan would have taken to get a celestial fix when the sky was partly cloudy  ....  Noonan would have done the same.

Gary, why didn't you write:
As an example of the measures that Noonan took to get a celestial fix when the sky was partly cloudy ... Noonan did the same.
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