Advanced search  
Pages: [1] 2   Go Down

Author Topic: The Cooper Report and the 3105 Donut - why did AE quit transmitting?  (Read 28920 times)

JNev

  • T5
  • *****
  • Posts: 778
  • It's a GOOD thing to be in the cornfield...

If this belongs in Radio Reflections or somewhere else, my apologies - please feel free to move it, Marty or whomever.

So moved.

Mulling over how AE and FN may have gotten to Gardner when they did not find Howland I landed on the Cooper Report in Research Document #38 - a fascinating and lucid accounting by a contemporary witness of apparently excellent character and skill.  I'm probably re-capping something already covered here somewhere, and if so, my apologies.

Looks like the 3105 Donut got replaced by the 350 NM cone of silence after 043 that fateful day. 

Thoughts, anyone?
- Jeff Neville

Former Member 3074R
 
« Last Edit: September 26, 2013, 10:30:38 AM by Jeff Neville »
Logged

Martin X. Moleski, SJ

  • Administrator
  • *
  • Posts: 2961
Re: The Cooper Report and the 3105 Donut - why did AE quit transmitting?
« Reply #1 on: March 22, 2011, 01:10:00 PM »

That said, if the The 3105 Donut (Tracks Vol. 24, Oct. 2008) is true, and I believe it is a rational explanation of how AE's tranmitter was behaving, why didn't AE continue to transmit - and Itasca receive - as she finally tracked to the southeast toward Gardner?

You don't seem to be paying attention to the full contents of the last transmission: "Will repeat this on 6210" suggests that AE was switching to her daytime frequency.  The maxim she was following was, "The higher the sun, the higher the frequency."  She did not hear anything from the Itasca on 3105, so she did not hear them asking her not to change frequency.  If she did switch frequencies as she announced she was going to do, then all 3105 donut considerations go out the window from then on.  You then have to deal with the vagaries of her daytime frequency.

She was not heard on that frequency until 0418 GMT--four hours and eighteen minutes after 0000 GMT, her takeoff time from Lae.  That suggests to me that there was something odd about her daytime setup.  Whatever it was that kept Lae from hearing her for four hours may also have kept the Itasca from hearing her at all.  She might have reached Niku two or three hours after the last transmission.
LTM,

           Marty
           TIGHAR #2359A
 
Logged

Steve D. Burk

  • TIGHAR member
  • *
  • Posts: 25
Re: The Cooper Report and the 3105 Donut - why did AE quit transmitting?
« Reply #2 on: April 01, 2012, 04:22:07 PM »

I tend to agree with much of Jeff's original post on this topic.  Given that AE was low on fuel and lost, had only two voice transmission frequencies available to her (3105 and 6210), and her final transmission was judged by those who heard it to sound "frantic", it strikes me as highly unlikely that she would doggedly stick to transmitting only on her daytime frequency of 6210.  Her transmissions received by Itasca had gotten progressively stronger over several hours, reaching strength 5 in her final transmission.  And then absolutely zip.  She had only said she would repeat her final message on 6210.  Did she then fly for several hours afterward without anyone hearing from her ---and with her only attempting to contact Itasca on a single frequency despite their desperate state?  Seems highly unlikely to me.  What am I missing?
Logged

Brad Beeching

  • T3
  • ***
  • Posts: 158
Re: The Cooper Report and the 3105 Donut - why did AE quit transmitting?
« Reply #3 on: April 01, 2012, 08:23:27 PM »

It is only speculation on my part, but the only answer that makes any sense to me and the only answer to the question of "Why did Amelia quit transmitting?" has to be is.. she didn't. I cannot believe she would have quit trying to contact Itasca or Howland or anyone else who could hear her. I think the problem was that no one heard her. Is that due to them listening on the wrong time schedule? Listening on the wrong frequency at the wrong time schedule? I do not know, But in the post loss receptions, some who heard her transmissions reported only a carrier wave or just a hum or garbled voice. Perhaps she had a problem with the transmitter as well as the problems associated with the loss of the recieving antenna?

Brad
Brad

#4327R
 
« Last Edit: April 01, 2012, 08:43:23 PM by Brad Beeching »
Logged

Steve D. Burk

  • TIGHAR member
  • *
  • Posts: 25
Re: The Cooper Report and the 3105 Donut - why did AE quit transmitting?
« Reply #4 on: April 02, 2012, 09:02:39 AM »

The two major possibilities seem to be: (1) after her final transmission on 3105, AE switched to 6210 and, for whatever reason, there was a problem with 6210 and it was never received by Itasca or those in the vicinity.  In this scenario AE flies on for several more hours and never transmits again on 3105 while in the air; or (2) after her final transmission on 3105 the Electra ran out of gas and the "crash and sink" scenario occurs very quickly since she was flying at 1000 ft.  Given the circumstances, I find scenario (1) highly improbable.  That is, AE could not afford to simply casually continue transmitting at regular, rather widely spaced intervals on a single frequency as if it was business as usual.  The Itasca and others knew the situation was dire and they were listening intently on 3105 and 6210 (not just listening at predetermined intervals of time), but her transmission went abruptly from signal level 5 to nothing on any frequency.  One can forcefully argue that she couldn't possibly have run out of gas (although AE herself said she was low on fuel and sounded absolutely frantic in her final transmission), but that assertion has its own set of requirements and unknowns (she definitely started with 1100 gal; she didn't encounter strong headwinds, etc.).  As much as I find the post-flight research fascinating ---at this point in my understanding, I am unable to get over the hurdles outlined above.
Logged

Jeff Victor Hayden

  • T5
  • *****
  • Posts: 1387
Re: The Cooper Report and the 3105 Donut - why did AE quit transmitting?
« Reply #5 on: April 02, 2012, 10:53:37 AM »

It would appear that the communications problems which dogged the approach to and, failed location of Howland continued on until, well we don't know , landing, ditching? Does that sound plausible? Sounds plausible, neither AE or Itasca could get the other to do what they requested regarding frequencies in a consistent and reliable manner. Perhaps she was transmitting, on the wrong frequency and, maybe Itasca was listening, on the wrong frequency?
This must be the place
 
Logged

Steve D. Burk

  • TIGHAR member
  • *
  • Posts: 25
Re: The Cooper Report and the 3105 Donut - why did AE quit transmitting?
« Reply #6 on: April 02, 2012, 11:21:56 AM »

She could only transmit by voice on two frequencies (3105 and 6210) and the Itasca and others were monitoring both of these.  As she approached Howland the strength of her transmissions on 3105 as recorded by Itasca grew progressively from level 1 to 5 over a several hour period, then abruptly they never heard further from her in the air again on either 3105 or 6210.  Her transmission went from almost overloading the Itasca speaker to zip---no fading back from signal level 5 to lower values.  True, two-way voice communication was never established.  Although Itasca heard her signal progressively increase in strength as she approached, they never heard it progressively decrease as she, presumably according to the TIGHAR scenario, flew SE for several hours.  Is that because she switched to 6210 and never used 3105 again (and there was some unknown problem with 6210)?  With only two choices of frequencies, lost, low on fuel, and desperate it seems unlikely to me that she bet everything on her "daytime" frequency of 6210 and never tried 3105 again.  At least that is my take.
Logged

Jeff Victor Hayden

  • T5
  • *****
  • Posts: 1387
Re: The Cooper Report and the 3105 Donut - why did AE quit transmitting?
« Reply #7 on: April 02, 2012, 12:24:32 PM »

Good points and well put Steve. Another scenario would be that after getting nowhere with comms on 3105 and 6210 she may have concluded that Itasca couldn't hear her (wrongly) so didn't bother wasting any more time/effort and simply concentrated on getting the airplane on Terra Firma. Given the fuel situation establishing comms could wait until they were safely on the ground. On the other hand they may have just ridden it into the ocean.
This must be the place
 
« Last Edit: April 02, 2012, 01:23:28 PM by Jeff Victor Hayden »
Logged

Steve D. Burk

  • TIGHAR member
  • *
  • Posts: 25
Re: The Cooper Report and the 3105 Donut - why did AE quit transmitting?
« Reply #8 on: April 02, 2012, 01:38:13 PM »

Jeff: Actually AE did acknowledge hearing signals from Itasca only 45 min. before her final transmission!  Here is a quote from p.97 of the hardback version of Ric Gillespie's "Finding Amelia":
"Although he could not send the long count Earhart requested, Galten immediately responded with a series of As on 7500 kilocycles and, at 8:00 am, was rewarded with a direct response from Earhart on 3105:"KHAQQ calling Itasca.  We received your signals but unable to get a minimum. Please take a bearing on us and answer 3105 with voice."  This was both good news and bad news.  For the first time Earhart had heard Itasca's signals, but she had not been able to take a bearing using her own direction finder."

Given that AE had heard Itasca's signals just 45 min. before her final (in-air) transmission, and considering her desperate plight, doesn't it seem a very strange time to totally abandon all attempts to make radio contact and fly off into the wild blue yonder for several more hours?
Logged

Gary LaPook

  • T5
  • *****
  • Posts: 1624
Re: The Cooper Report and the 3105 Donut - why did AE quit transmitting?
« Reply #9 on: April 02, 2012, 08:18:56 PM »

Good points and well put Steve. Another scenario would be that after getting nowhere with comms on 3105 and 6210 she may have concluded that Itasca couldn't hear her (wrongly) so didn't bother wasting any more time/effort and simply concentrated on getting the airplane on Terra Firma. Given the fuel situation establishing comms could wait until they were safely on the ground. On the other hand they may have just ridden it into the ocean.
Gee, that would be tough, having to push the button on the microphone while looking out the window while the autopilot holds that magic 157° heading. Golly, I don't see how any pilot would have been able to do that. After all, it's not like her life might depend on establishing communications with the Itasca.

Wait a second, let me think about that some more. Right, now I remember at least one occasion where I was talking into the microphone while looking out the window for other traffic, Oh! and hand flying the plane at the same time.

gl
« Last Edit: April 02, 2012, 08:21:59 PM by Gary LaPook »
Logged

Jeff Victor Hayden

  • T5
  • *****
  • Posts: 1387
Re: The Cooper Report and the 3105 Donut - why did AE quit transmitting?
« Reply #10 on: April 03, 2012, 03:51:50 AM »

No, I think you missed the point I was trying to make there Gary.
1. When low on fuel (gas?)would it not be wise to put it down somewhere as a priority?
2. Having trouble comminicating with Itasca was a distraction, many aircrashes are attributed to crew being distracted with some problem or another, meanwhile no one is actually flying the plane. I recall Eastern Airlines flight 401 where the whole crew concentrated their efforts on a 'faulty' landing gear light while the plane flew itself into the ground.
3. I'm sure it's easy to press a switch, look out of the windows and fly the plane at the same time  :), in normal circumstances ;)
This must be the place
 
Logged

John Ousterhout

  • T4
  • ****
  • Posts: 487
Re: The Cooper Report and the 3105 Donut - why did AE quit transmitting?
« Reply #11 on: April 03, 2012, 08:10:57 AM »

Changing transmission frequencies was pretty easy in the Lockheed - not much more than turning a 3-position switch.  However, changing the receiving frequency was more involved, requiring some "head-down" work to pick the band (she had just been listening on 7500 on the DR loop, then presumably changed to 6210), then dial in the frequency while reading the numbers on the dial, then possibly fine-tuning to get the best reception.  Sometime in there she also switched antennas, from the directional loop to the (possibly missing) belly antenna.
 She may have been preoccupied dialing in the receiver, trying to pick up Itasca, although I find it hard to believe she wouldn't continue to transmit "blind".  It seems that she didn't realize that she could receive ok on the loop, but not on the belly antenna.
Cheers,
JohnO
 
Logged

Martin X. Moleski, SJ

  • Administrator
  • *
  • Posts: 2961
Re: The Cooper Report and the 3105 Donut - why did AE quit transmitting?
« Reply #12 on: April 03, 2012, 08:41:53 AM »

It seems that she didn't realize that she could receive ok on the loop, but not on the belly antenna.

This, for me, is the most important mistake that AE and FN made with their radio equipment.

It seems to me that if she had simply tuned from 7500 kcs to 3105 kcs after hearing the letter A on her DF antenna, she ought to have been able to hear the Itasca's voice transmissions.  She and Fred seem not to have thought of trying a different frequency after 7500 kcs failed to give them a null.  It's very sad in hindsight.  I'm sure their decisions made sense to them at the time they made them.
LTM,

           Marty
           TIGHAR #2359A
 
Logged

Steve D. Burk

  • TIGHAR member
  • *
  • Posts: 25
Re: The Cooper Report and the 3105 Donut - why did AE quit transmitting?
« Reply #13 on: April 03, 2012, 08:51:40 AM »

But please reread my quote above of AE's transmission.  She says: "We received your signals but unable to get a minimum. Please take a bearing on us and answer 3105 with voice."  Clearly she was going to listen on 3105 after receiving the As.
Logged

Steve D. Burk

  • TIGHAR member
  • *
  • Posts: 25
Re: The Cooper Report and the 3105 Donut - why did AE quit transmitting?
« Reply #14 on: April 03, 2012, 09:06:13 AM »

Sorry --realized my mistake above immediately after posting.  AE no doubt switched back to the missing belly antenna and set the receiver to 3105 rather than using the loop antenna to receive 3105.
Logged
Pages: [1] 2   Go Up
 

Copyright 2019 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