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Author Topic: Working the Flight backwards  (Read 106764 times)

Martin X. Moleski, SJ

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Re: Working the Flight backwards
« Reply #15 on: September 06, 2011, 05:50:58 AM »

... IF she did have a tailwind, it could have increased her range ...

If wishes were horses, then beggars would ride.

If my grandmother had wheels, she would be a bicycle.

The ETA for the flight was eighteen hours after takeoff:

"Finally, just before 8:00 PM aboard Itasca, official notification of Earhart’s departure arrived from Lae, via Samoa: 'Urgent, Black, Itasca . . . Amelia Earhart left Lae at 10 AM local time July 2nd. Due Howland Island 18 hours time.' This information presented a new picture. The plane had left Lae two hours earlier than previously reported, and the eighteen-hour time-en-route estimate indicated that Earhart anticipated lighter headwinds than predicted in the most recent forecast. Itasca should now expect the plane to arrive at around 6:30 AM" (Finding Amelia, p. 85).

The actual arrival in the vicinity of Howland took nineteen hours ("We must be on you" at 1912 GMT).  That suggests headwinds rather than tailwinds.
LTM,

           Marty
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Ric Gillespie

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Re: Working the Flight backwards
« Reply #16 on: September 06, 2011, 06:47:37 AM »

There is still confusion about the LOP.
1. Credible reports of overcast conditions during the night mean that Fred was not able to maintain an accurate course for Howland using celestial navigation.
2. After sunrise Fred takes his observation.  He already knows that the sun will come at 67° True so he knows that his Line of Position will be 157° - 337°.  His after-sunrise observation lets him draw that line on his map and shows him how far along he is in an east-west sense.  He has no way knowing where he is in a north-south sense.
3. Having drawn his 157-337 line on the chart ("I'm somewhere on this line.") he draws another 157-337 line that passes through Howland.  He then measures the distance between the two parallel lines.  Now he knows how far it is from the line he is on to the line that passes through Howland.
4. Next question: How long will it take to cover that distance?  For that he needs to know the airplane's ground speed and that means getting an accurate handle on what the wind is doing (something he has not been able to do all night).  Now that it's daylight he can estimate the wind by watching the wave tops on the ocean or using his drift meter.
5. Now he can estimate at what time they will reach the line that passes through Howland. That time turns out to be 19:00 Greenwich.  He tells AE (probably with a note)  "ETA 1900."  He, of course, means that they'll reach the line at 19:00.  If they're bang on course they'll also reach Howland at 19:00, but Fred has been DRing all night without a celestial fix. He knows it would be amazing if they are still exactly on course.   Amelia doesn't understand the nuance.  All she knows is that Fred says ETA 1900.
6.  Amelia tries repeatedly to get Itasca to take a bearing on her but gets no reply.
7. 19:00 comes but Howland is not there and, at 19:12, Amelia radios, "We must be on you but cannot see you."  Fred knows that it's not true that "we must be on you" but he's not the one on the radio.  He knows that what they have to do now is DR their way up and down the line to find Howland.
8. He has Amelia fly northwest first and at 20:00 she tries to use her loop antenna, but no luck.  Fred has her turn around and they retrace their steps, DRing southeast and still hoping that they'll find Howland.
9.  Amelia finally understands what they're doing and why and at 20:13 radios "We are on the line 157 -337" and says she'll repeat this on her other frequency, but before she does she decides to explain further and at 20:25 radios, "We are running on line north and south."  Then she changes frequencies and nothing more is heard.
10. Noonan knows that all of the other islands on or near the LOP are southeast of Howland.  That's why he goes northwest first. But everything they do is in hopes of finding Howland.  At no point do they decide to "go for" some other island. 
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Martin X. Moleski, SJ

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Re: Working the Flight backwards
« Reply #17 on: September 06, 2011, 07:13:56 AM »

There is still confusion about the LOP.  ...

As long as there are newcomers to this one-room schoolhouse, there will be confusion.

Thanks for the narrative.  I've added it to the Ameliapedia article about the last transmission.
LTM,

           Marty
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Irvine John Donald

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Re: Working the Flight backwards
« Reply #18 on: September 06, 2011, 07:50:39 AM »

I thought the sunline represented the first real "position" that Fred had after flying through the night. If he had been able to get a position earlier, Amelia would have radioed it. So, I was assuming that he could not get a celestrial position, and was flying on compass only. Assuming that they ..............  landed. Given the evidence, I think Rics reef landing theory is correct, and the Electra is down there.

Thanks Tom.  I also believe the TIGHAR theory and expect the Electra to be found off the reef.
Youre right that we should be thinking in 1937 terms which is why I also say let's put our mindset into terms of being in survivor mode.

The navigation used has so many variables and so many opinions that I thoughtbto look at it from a non technical way. IF, and many will say its a big IF, we assume the theory is correct then they landed on Gardner.  IMHO they did not make the decision to fly to Gardner.  Once they realized they could not find Howland they had to also realize they were lost. If Fred's navigation was right then Howland had to be nearby.  What would the conversation in the Electra have been?  I think AE would have listened to Fred and thats why they flew south on the LOP. The best chance of hitting an island.  In survivor mode, and knowing Howland was the best site, then any island would suffice. So they head south on the 157 LOP.  Its likely that Gardner was the first.  They land.  No matter what all the theories say, if we believe the theory then we must believe Gardner WAS the final stop.  How the got there from the route to Howland is the question everyone seems to be asking. I believe we draw a straight line on the recipricol course to 157. Thats the 337 line back to where it intersects the course to Howland.  Thats where they were when they decided to fly south.  Its just not as clean and simple as that I know but it might be.
Would they have found a different island first and decided not to land but find somewhere better?  Not likely. They are in survivor mode with ever lower gas supply. If they were further east when they turned south on the LOP then they would have potentially reached other islands first.  Look at the Gardner group on the map.  Fred was probably expecting to see other islands before seeing Gardner.  They would have been watching their gas supply dwindle away.  Then Gardner pops up. They likely didn't know it was Gardner at first but Fred should have been able to get that figured out in short order. They land, believing the US Coastguard and navy will find them.
All this means is that no matter what all the theories are you should just draw the line backwards north from Gardner along 337. Thats the "likely" intersection point where they turned.
No further flying east. No further flying around looking for Howland. No more discussion in the cockpit. For all we know AE and FN were blaming each other over the failure to find Howland and they weren't thinking rationally. We just don't know. Our belief in the theory is they landed on Gardner. It doesn't matter what else we "think" happened. They obviously had the gas, the charts and the determination to find land. Any land at this point.
Now we just work it backwards. We find that point where they turned south and ask "so why couldn't they find Howland? Why are they here when they turn south?"
Of course this is only if you believe in the TIGHAR theory.  :)

I just read Ric's latest post.  Ric's points are well made and I agree that all of them probably transpired. The main point is his point number 10.  At no point did they decide to ""go for" some other island". I think he means "going for" a "specific" island by name. I believe they were looking for "any" island once they turned south. At some point in that cockpit they knew they were lost and Ric's description of likely actions is tame compared to the "panic" I would have been in. Don't forget the radio message "suggested" AE's voice had some "anxiety" showing.
I still don't understand why they weren't blasting the entire Pacific with radio transmissions?  In survivor mode wouldn't they be trying to get any contact?  Knowing they are headed away from Howland wouldn't they be trying to tell Itasca they decided to head south so please come that way to pick them up?  Wouldn't they (AE) be using the radio to try to raise a ship or land based radio? To raise anybody?  Why no messages?  That doesn't fit the survivor mode. Unless the radio had issues.
Respectfully Submitted;

Irv
 
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Irvine John Donald

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Re: Working the Flight backwards
« Reply #19 on: September 06, 2011, 08:08:19 AM »

There is still confusion about the LOP.
1. Credible reports of overcast conditions during the night.........
10. Noonan knows that all of the other islands on or near the LOP are southeast of Howland.  That's why he goes northwest first. But everything they do is in hopes of finding Howland.  At no point do they decide to "go for" some other island.

I also believe that Ric's point ten would lead to a point 11. 

11.  After a reasonable period of flying south looking for Howland, FN would have told AE they were now looking for any island.  The gas supply would have backed that up.

But still thinking they were looking for Howland three hours after turning south?  I'm thinking no. 
Respectfully Submitted;

Irv
 
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Martin X. Moleski, SJ

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Re: Working the Flight backwards
« Reply #20 on: September 06, 2011, 08:11:18 AM »

... We find that point where they turned south ...

Randy Jacobson's Monte Carlo Simulation put that location SSW of Howland.

Quote
I still don't understand why they weren't blasting the entire Pacific with radio transmissions?

What makes you think that they weren't?

Radios often have problems with propagation.

Post-loss radio messages.
LTM,

           Marty
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Irvine John Donald

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Re: Working the Flight backwards
« Reply #21 on: September 06, 2011, 08:49:51 AM »

I believe they were Marty. My "survivor mode theory" suggests they would be using the radio extensively while frantically scanning for land or ships. Adrenaline would be pumping. FN would be taking fixes. But we "suspect" a broken antennae and poor planning prevented them from connecting with Itasca.

But Itasca could hear them. Why then wouldn't Itasca hear them while headed south on the LOP. Other than the one message that says they were on the LOP we have silence?  Meaning they didn't use the radio again?  That doesn't fit. So assuming they were transmitting why didn't anyone hear them?  Further radio problems?  Lack of radios being monitored? (no scanning mode in those days). As I asked in a previous post, is it possible that by turning south the broken antenna is transmitting differently than when travelling west to east?  If the radio wasn't working then how were the post loss signals made?  Repairs by AE and FN?  If FN was hurt could AE do it?  We think FN was hurt based on signals from a radio with a broken antenna that is mounted on the belly of the aircraft (unless she switched to her upper body loop antenna) which is on the ground and not 10,000 feet in the air.  If those messages could be heard then why not in the air travelling south on the LOP from 1,000 foot altitude?  Landed and on her wheels the highest antenna is no more than 30' off the ground and we heard from that position.

We have signals before turning south and after landing but nothing in between when its the most critical for them to get info out? 
Respectfully Submitted;

Irv
 
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Martin X. Moleski, SJ

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Re: Working the Flight backwards
« Reply #22 on: September 06, 2011, 09:25:49 AM »

... we "suspect" a broken antennae and poor planning prevented them from connecting with Itasca.

The (theoretically) "lost antenna" would explain the inability of AE and FN to receive messages.  It does not explain the failure of the Itasca to hear any more messages after AE switched to her daytime frequency.

The assertion that planning for the flight was fatally flawed is more than a suspicion.  It is demonstrable that AE did not understand or communicate the limits of her equipment and the limits of the Itasca's equipment

Quote
But Itasca could hear them. Why then wouldn't Itasca hear them while headed south on the LOP.

Please look up in this thread.  I've already given you a link to answer that question.  AE changed frequencies.  There are problems with radio propagation at different times of day on different frequencies.  You may not like that answer, but it would be a courtesy to recognize that an answer has been given to your question.

Quote
... is it possible that by turning south the broken antenna is transmitting differently than when traveling west to east?

The antenna that seems to have broken on takeoff was for RECEIVING, not transmitting.

Quote
If the radio wasn't working then how were the post loss signals made?

We know that the transmitter was working.

Transmitters SEND signals.

Receivers RECEIVE signals.

They are two different parts of the radio system.

One part was broken (receiving).  One part was not (transmitting).
LTM,

           Marty
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Ric Gillespie

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Re: Working the Flight backwards
« Reply #23 on: September 06, 2011, 09:52:07 AM »

Knowing they are headed away from Howland wouldn't they be trying to tell Itasca they decided to head south so please come that way to pick them up?

At what point would they know that they were headed away from Howland, and how would they know that?

  Wouldn't they (AE) be using the radio to try to raise a ship or land based radio? To raise anybody?  Why no messages?  That doesn't fit the survivor mode. Unless the radio had issues.

The issue was frequencies.  The airplane's radio had the ability to transmit on only three frequencies - 3105 KhZ, 6210 KHz, and 500 KHz.
All ships monitored 500 Khz as a "calling" and emergency frequency, but 500 kHz was code-only and AE and FN did  not know Morse code and the aircraft had insufficient antenna to put out a meaningful signal on 500 kHz.
The other two frequencies were aviation-only voice frequencies and, at that time, no one but Itasca was listening on those frequencies anywhere in the central Pacific.
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Irvine John Donald

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Re: Working the Flight backwards
« Reply #24 on: September 06, 2011, 10:17:46 AM »

Thanks Marty for those clarifications. I apologize for not formally acknowledging your answer.

I respectfully submit that I do not necessarily "accept" all answers given as being unquestionably correct. If I do then I am mentally dead. 

I accept your response to the radio regarding transmitter working but receiving isn't. Glad you clarified that for me.

Question Marty.  Can AE tell if she is transmitting correctly?  A light or gauge to indicate she is transmitting?
Respectfully Submitted;

Irv
 
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Erik

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Re: Working the Flight backwards
« Reply #25 on: September 06, 2011, 10:20:45 AM »

With all the arguments and speculation over the accuracy needed to be able to find Gardner from LOP , I have not really seen any mention of the 'vertical height' being a benefit.   This is especially true for the navigational accuracy (or inaccuracy) that would be needed to reliably find Gardner.  From looking below, it doesn't appear that a whole lot of science would be needed!

Here's food for thought...

If I am not mistaken, the elevation of NW end of the island combined with the height of the buka trees would put a total vertical height of 100' feet or so.  Combine that with a horizontal width of 1/4 - 1/2 mile profile from the NW end.  This gives you an object sticking up from the horizon with dimensions approximately 100' x 2500' in size.    It's not a ship blowing smoke, but it would seem hard to miss an object that size.

I am assuming that they had binoculars, but even if not, I would guess that an object of that size on the horizon would be fairly noticable even from far distances.  With or without cloud cover.  Does anyone by chance have any real pictures of a similar island from open ocean? 

Just for kicks, I created a vertical object 100' x 2500' in google earth, drew an approximate line from Gardner to Howland, and then estimated flying altitude that might seem reasonable.  Here is what it might look like from a sampling of several different pespectives.  Of course this is just a simulation, but you get the idea.

Gardner from 50 miles out on LOP at 3000' altitude


Gardner from 25 miles out on LOP at 1500' altitude


Gardner from 10 miles out on LOP at 1000' altitude


It would seem to me that Gardner would be fairly easy to spot, even with crude DR techniques. 

Comments? 
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Irvine John Donald

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Re: Working the Flight backwards
« Reply #26 on: September 06, 2011, 10:39:59 AM »

Very interesting. If you leave the altitude at 1,000 feet then what can you see from 50 miles and 25 miles out.

I believe they were not specifically trying to find Gardner.  Ric believes they were looking still for Howland. My theory is that after flying three hours south they, at some point Ric, must have realized that they weren't anywhere near Howland and needed someplace to land.  But both those theories would have the two travellers scanning the water for land or ships. Is it best to do so from 1,000 feet or 10,000 feet? Keeping in mind the trade off of elevation over aircraft performance (endurance).  I believe opinion in this forum is to choose 1,000 feet.
Respectfully Submitted;

Irv
 
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Ric Gillespie

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Re: Working the Flight backwards
« Reply #27 on: September 06, 2011, 10:42:33 AM »

Question Marty.  Can AE tell if she is transmitting correctly?  A light or gauge to indicate she is transmitting?

Interesting question. In flight? Probably not unless the ammeter flickers.  On the ground?  She should hear the dynamotor kick in when she transmits.  But all those things tell her is that the power is going to the transmitter.  I don't know how she'd be able to confirm that the antenna was radiating.
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Irvine John Donald

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Re: Working the Flight backwards
« Reply #28 on: September 06, 2011, 11:02:53 AM »

Knowing they are headed away from Howland wouldn't they be trying to tell Itasca they decided to head south so please come that way to pick them up?

At what point would they know that they were headed away from Howland, and how would they know that? ..........

Thanks Ric.

How would they know the were headed away from Howland?  Hmm.  Good point and i believe the answer is that they didn't. Your description says that FN told AE to first fly north but, finding no Howland, FN then instructed her to fly south. We don't know this for sure, but if the entire TIGHAR theory is right then they got to Gardner somehow.  But you're surmissing Ric that at a point while travelling NW he tells her to turn around and head SE. (See section 8 of previous post).  Based on what facts would he tell her to turn?  They fly NW from 19:12 to 20:00.  Approximately 45 mins. Then they head south. They know they didn't see Howland while flying 45 minutes NW so its not likely they expected to see Howland until at least minute 46 on thr trip back.  Unless of course they missed it. I'm not suggesting they wouldnt be looking during that first 45 minutes on SE route.  But now we fly for three hours south?  Still looking for Howland??  I respectfully suggest that at about an hour after turning SE on the LOP that they came to the realization that they missed Howland and now it was time to find any island or ship.
Respectfully Submitted;

Irv
 
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Ric Gillespie

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Re: Working the Flight backwards
« Reply #29 on: September 06, 2011, 11:12:10 AM »

Is it best to do so from 1,000 feet or 10,000 feet?

The issue is clouds.  The Itasca deck log that morning recorded scattered cumulus clouds.  A noon observation on Howland recorded the bases at 2,650 feet.  That's a very typical central Pacific morning.  Some wisps of cloud appear at ballpark 1,200 feet just as dawn first begins to color the sky.  By the time the sun is up there's a well-defined scattered cumulus deck.  By mid-day the clouds have grown and bases have risen to about 2,500 feet.  By late afternoon there may or may not be some isolated squalls around.

If you're flying above a scattered deck everything except what is directly beneath you is hidden.  If you're looking for an airport (or an island) you have to stay below the bases. 
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