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Where are you Amelia?

Old 21st Jul 2017, 01:27
  #41 (permalink)  
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Not sure if they were adopting this principle but for navigation over vast areas of ocean or desert it was usual to pick an en route diversion point, if they couldn't carry round trip fuel, at the diversion point one either had to have a positive current position to continue or divert to an easily located diversion field. Missing the Ontario should have been the heads up?
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Old 21st Jul 2017, 01:49
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the only way to conserve fuel [into a headwind] is to ease the Throttles
????

You add a bit of power to increase your groundspeed against a headwind. One thing you do not do is reduce below max range speed/power. Any such increase is actually quite minor: something of the order of a quarter of the headwind component.

The reason why we know that there was no diversion to Gardner/Saipan/Lae/whatever is that we have the radio logs. We know that when they found themselves at where they thought Howland should be they reacted by first circling and then trogging back and forth on the sunrise LOP (NNW/SSE).

If they had intended to divert to any of the suggested alternates she quite certainly would have said so when commencing the div and also would have tried to contact Ontario on the way back. No such transmissions were made, so the diverting theory is obviously misguided and devoid of supporting factual data.

As to the thread title question: I think it is pretty clear that they were well North of intended track and quite probably short of Howland longitudinally. By quite a long way too because they were unable to see the very conspicuous smoke signal from Itasca.

We know that they were already North of track from the earwitness on the tramp steamer and the absence of earwitnesses on Ontario. If they misidentified Ontario when they were actually looking at the steamer Myrtlebank or the lights of the strip-mining on Nauru then it's likely that they would have compounded the error by correcting for it in the opposite way, ie sending them even further off-track to the North.
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Old 21st Jul 2017, 01:57
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Originally Posted by David Billings View Post

You base distance on HF Signal strength ??? How does that work ?
It is a bunch of BS, the people who heard her estimated her to be no more than 100 miles away based on radio technology at the time. Also you want me believe that they were hundreds of miles short of Howland island - this is like saying that Noonan had no clue what he was doing. So it is a bunch of 'religious' beliefs, trying to navigate around the facts and bending them to make your theory fit. If Ric Gillespie was here who would be arguing that he has all the proofs that they flew to Gardner Island, you really deserve each other. And with this 'easing throttles' you clearly have no clue about flying airplanes, if you ease throttles beyond your max endurance - you actually make situation worse.

Originally Posted by Cazalet33 View Post
By quite a long way too because they were unable to see the very conspicuous smoke signal from Itasca.
.
They had no chance seeing this smoke with the typical cloud coverage. You would have to be very, very close to actually see it and then you would probably see the island too.
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Old 21st Jul 2017, 02:43
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Originally Posted by porterhouse View Post
It is a bunch of BS, the people who heard her estimated her to be no more than 100 miles away based on radio technology at the time....
See my earlier post re sunspot activity of the time - based on this well recorded data I suggest that determining distance on signal strength at that time on that frequency could have been somewhat fraught to say the least!

@David Billings. I quite understand the LiDAR approach but suggest a magnetic survey could have some particular advantages - it's probably worth a read to get a grasp of the principles.

I interpret that you are funding much of this exploration yourself and/or that funds are limited? You may find a basic gradiometer could be carried by a drone and would survey significant area with relative ease. Using Snuffler or similar you could plot the resultant data to give a mag anomaly map; an aircraft would be a significant anomaly.

FP.
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Old 21st Jul 2017, 13:13
  #45 (permalink)  
 
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For Mr. Porterhouse...

Expert Aviator 'Porterhouse' writes:

"It is a bunch of BS" :

You are after all, entitled to an opinion...rude as it is.

"...the people who heard her estimated her to be no more than 100 miles away based on radio technology at the time." :

Based on HF S5, you mean, which is not a true gauge and could mean they were hundreds of miles away at the time. Even radio experts say that distance cannot be measured by HF strengths and it has been said here (twice), 1937 was an unusual year for sunspot activity.

"Also you want me believe that they were hundreds of miles short of Howland island - this is like saying that Noonan had no clue what he was doing." :

I am not asking you to believe anything. It is plainly obvious from your way of speaking to other people that you know everything there is to know about aviation, so what is the point of conversing with you ? No point at all so this will be the last time. I am merely saying that the Groundspeeds point to a different operating mode compared to other LD flights made. Certainly, I do think that there was a miscalculation as to how far they had reached. YOU as an expert, may have a different opinion, to which you are entitled.

"So it is a bunch of 'religious' beliefs, trying to navigate around the facts and bending them to make your theory fit." :

The only facts in the New Britain Project are the detail surrounding the find of an all-metal, unpainted, twin-engined aircraft powered by P&W "Wasp" engines, with no military insignia, seen by an Australian WWII patrol and the appearance discovered years later of cryptic letters and numbers on a map from that era, used by the particular unit, which, had surprisingly enough detail information to identify the cryptic info as being of Earhart's Electra.... due to this astounding find, research went from there. The explanation of how it "could" get to be there is a HYPOTHESIS and is open to discussion and criticism, which I expect and do not mind. What I do mind, however, is people who tend to be bl--dy rude, such as you are. You are entitled to an opinion, but don't abuse the entitlement. Work your own aerodynamic and power usage formulas and see what you get if it is within your expert comprehension to do so.

" If Ric Gillespie was here who would be arguing that he has all the proofs that they flew to Gardner Island, you really deserve each other." :

Now you have upset me. "Deserve each other" ??? Mentioning Gillespie in the same breath as myself... Wow, you are quite a nasty pugnacious little man aren't you ? Dear Oh, Dear...

"And with this 'easing throttles' you clearly have no clue about flying airplanes, if you ease throttles beyond your max endurance - you actually make situation worse.":

Now there's a thing.... Do you have in your possession a Flight Manual for the Lockheed Electra 10A aircraft ? If you have, turn to Page 35A. Now, I mentioned that I had read somewhere that Clarence "Kelly" Johnson (in 1936) had advised Earhart to 'lean off' into an adverse headwind. Read Page 35A.... You don't have it ? I'll tell you what it says.... It says specifically that pilots should increase speed into an adverse headwind. Loose leaf Page 35A Amendment is printed in Courier Font. Courier Font was invented post-WWII and Lockheed felt it necessary to inform and instruct pilots to increase speed into an adverse (extra value to the flight planning) headwind. I didn't say "I" would lean off or ease the throttles. If you have a copy of "Last Flight" written by Earhart, on Page 33, it gives an indication that she could well be using lean of peak and if she did use lean of peak she would not be able to lean any more now would she ? The only way after that to use "less" gas would be to retard (ease) the throttles slightly. I obtained that AFM for the Electra 10A about twenty years ago from Lockheed at Marietta and was struck by the fact that Lockheed found it really necessary to include the point about increasing speed into a headwind years after production of the Electra had ended... Then again, that might be because of an incident in a flight or U.S Companies were facing more and more litigation over products (i.e: could be a reason why).

Have a nice expert aviator day.

Last edited by David Billings; 21st Jul 2017 at 13:24.
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Old 21st Jul 2017, 17:37
  #46 (permalink)  
 
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They had no chance seeing this smoke with the typical cloud coverage. You would have to be very, very close to actually see it and then you would probably see the island too.
The master of Itasca disagreed with your idea. He reckoned that the smoke plume was at least thirty miles long and was highly conspicuous to a distance of at least ten miles.

That's one of the reasons why I believe that they were more than 60 miles short when they thought they were "on top" of the island.

There are several reasons why I'm sure they were to the Nor'ard of intended track. For one thing, we know that the weather was a bit thick to the NorthWest but clear to the South.

That's entirely consistent with her having to descend to 1,000' to attempt to get visual with the island/ship/smoke. It also strongly suggests that they had not been able to note the exact time of sunrise of the upper or lower limb of the sun. Without that observation, and a precise note of the time of that observation, the 157/337 LOP was worse than useless. It was a trap.

At the locus the fair weather cumulus was variable in extent and height was described as "low" in the deck log of Itasca. Have a look for yourself at the log and note that "amount" is in tenths, not oktas. Times are ship's time. Earhart reported 200 miles to run at 06:12 ship's time and that's when Itasca started making smoke. Cloud was between 2 and 3 10ths over the relevant time period. In modern parlance we'd call that "few".

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Old 22nd Jul 2017, 03:25
  #47 (permalink)  
 
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If you have a copy of "Last Flight" written by Earhart, on Page 33, it gives an indication that she could well be using lean of peak and if she did use lean of peak she would not be able to lean any more now would she ? The only way after that to use "less" gas would be to retard (ease) the throttles slightly.
Except that if she tried that in a headwind she would in fact use more fuel. If she were to "ease the throttles" ie reduce power and therefore fly slower she would increase fuel consumption per Nautical mile (ie an adverse specific ground range). Between Emelia, Noonan and the various advisers along the way, they should have understood this and actually increased power slightly in a headwind in order to decrease fuel consumption/nm.

Last edited by psycho joe; 22nd Jul 2017 at 05:37.
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Old 22nd Jul 2017, 15:26
  #48 (permalink)  
 
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He reckoned that the smoke plume was at least thirty miles long and was highly conspicuous to a distance of at least ten miles.
Viewed from the bridge of a ship (sea level). Yes, no problem with that opinion. However from the cramped tiny cockpit of the Lockheed possibly flying towards the morning sun reflecting off the ocean and seen between hundreds of fair weather Cumulus dotting the ocean. A different view altogether.
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Old 23rd Jul 2017, 13:25
  #49 (permalink)  
 
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From 1,000' below the couple of oktas of cumulus within ten or twenty miles of Howland, she'd have seen the massive smoke signal from Itasca quite easily. Sure, the island would have been a bugger to spot from much more than five to ten miles away, but she knew that. It was the ship and its huge smoke plume that she was looking for. That's a very different visual cue from an island which looks like a cumulus shadow.

Here's a snippet I found when researching in the Purdue files. She wrote a first draft of her memoirs in the interregnum between her first and second RTW attempts. Here's what she said of her solo flight from Hawaii to California:

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Old 24th Jul 2017, 04:38
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She would have arrived in the Howland is area with about an hours fuel. The fuel had been sitting in lae for some time . It would have lost performance. Power is mass flow . Lae temps would men less mass due to the expansion relative to temp. Neither knew morse code. Due to an error of installation and consequent incompatibility with antenna loading and frequency they could transmit but not receive. They were tracked across the pacific.The personnel on the ground in their eagerness turned on the primitive NDB to early. With the range considerably reduced as the battery voltage had dropped. It would have given every indication to ground personnel it was transmitting.
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Old 24th Jul 2017, 06:47
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Originally Posted by greg47 View Post
She would have arrived in the Howland is area with about an hours fuel. The fuel had been sitting in lae for some time . It would have lost performance. Power is mass flow . Lae temps would men less mass due to the expansion relative to temp. Neither knew morse code. Due to an error of installation and consequent incompatibility with antenna loading and frequency they could transmit but not receive. They were tracked across the pacific.The personnel on the ground in their eagerness turned on the primitive NDB to early. With the range considerably reduced as the battery voltage had dropped. It would have given every indication to ground personnel it was transmitting.
I would suggest that her aircraft had a still air range of at least 4,000 statute miles and she could have quite probably rung out another 200 odd miles if she was utilising the techniques she had learnt from proving flights with Pratt and Whitney and from conversations with Charles Lindberg. She should have had plenty of fuel for Plan B, the Gilbert Islands, and if the headwinds had been strong enough for her to fall well short of Howland, possibly enough, or almost enough to make it back to New Britain with a good tailwind.Going by her fuel usage to Hawaii on her first attempt, she was using a lot less fuel than planned.
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Old 24th Jul 2017, 07:36
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The fuel had been sitting in lae for some time . It would have lost performance
Not so. Lae was a major airport at the time. Established in 1927 to support the goldfields at Wau and Bulolo, regular scheduled QANTAS flights to Australia were running also at the time of Amelias visit. So fuel aplenty and fresh.
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Old 26th Jul 2017, 23:20
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There was no possibility of diversion. That's why she didn't divert.

She'd massively blown her fuel reserve quite early in the flight, even before whatever nav bust(s) occurred.

We have very little actual track data and most of that is a bit flaky, but let's look at the numbers.

Depart 00:00z from Lae. We know the position of the end of the runway, thanks to Google Earth, to be 6 44.3'N 147 00.0'E. Noonan would have used the published co-ords of Lae which were 6 45'N 147 01'E.

At 04:18z she said she was at 7,000' and declared a speed of 140, but didn't give a position. It's unclear whether 140 was in mph or in knots and even less clear whether it referred to IAS or TAS or G/S. We can only conjecture with that data, but any such conjecture is unfruitful. The altitude is presumably to stay above the weather, but it blows any chance of adhering to the economical fuel plan which required staying down at 2,000' feet for the first 9 hours and only climbing to 8,000' after 17 hours of flight.


At 05:19z she gives an altitude of 10,000' and a position of 7 3'N 150 7'E. The altitude is credible, though surprising. The position is clearly bollocks. If you want to mallet a square peg into a round hole you can substitute any Lat or Long (or both) into any theorised position for that time, but the more intellectually honest thing to do would be to set the false data to one side and move on. Her altitude of 10,000' shows that she'd massively blown her fuel budget in the very heavy climb. She shouldn't have been above 2,000' on the fuel plan at this point and shouldn't have been as high as 8,000' until about 18:00z. 10,000' was clearly necessary to remain VMC on top, but she paid a huge price in fuel to get that high so early in the flight.

Her position report of 07:18z at 8,000' at 4 33'S 159 07'E is the only one of the entire flight which we can in any way corroborate. It is entirely consistent with the known nav plan and it is almost certainly based on a sunset shot. My own calculation produces a sunset time of 07:19:27z would have been observable on Noonan's bubble sextant at that place and aircraft altitude. This raises an interesting question as to whether Noonan's chronometer was correct. We know that he'd been unable to get a radio time signal at Lae to check the index and rate of his chronometers.

Her zero wind estimate for the flight was 18 hours. Her departure message gave an ETA of 19:00 which was based on the forecast headwinds in the first and second halves of the flight.

At 17:45 she declared her belief that she was approximately 200 miles from Howland.

At 18:15 it was 100 miles to go.

At 19:12 she believed that she should be "on top" of Howland. She declares low fuel state and estimates only half an hour left. That is presumably at cruise power and we can presume that she then pulled the power back to max endurance and quite probably had Noonan scavenging the last dregs of fuel from the emptied tanks.

At 20:13 she makes what was to be her final call. She says that they are still running "North and South" along the 155/337 LOP.

No diversion. No fuel to attempt one either.
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Old 26th Jul 2017, 23:57
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I'll tell you what it says.... It says specifically that pilots should increase speed into an adverse headwind. Loose leaf Page 35A Amendment is printed in Courier Font. Courier Font was invented post-WWII and Lockheed felt it necessary to inform and instruct pilots to increase speed into an adverse (extra value to the flight planning) headwind. I didn't say "I" would lean off or ease the throttles. If you have a copy of "Last Flight" written by Earhart, on Page 33, it gives an indication that she could well be using lean of peak and if she did use lean of peak she would not be able to lean any more now would she ? The only way after that to use "less" gas would be to retard (ease) the throttles slightly. I obtained that AFM for the Electra 10A about twenty years ago from Lockheed at Marietta and was struck by the fact that Lockheed found it really necessary to include the point about increasing speed into a headwind years after production of the Electra had ended.
The Billings hypothesis appears to suggest that Earhart did not know the basic airmanship knowledge that you increase airspeed into a headwind for max range by pushing the throttles up. He appears to suggest that this was not written by Lockheed until after the War and by inference he appears to suggest that she did not know this fairly basic piece of airmanship and engine handling. I say bollocks!

Here's what she was told, in writing, by Lockheed with the very specific topic of her proposed long range flight in mind:



Edited to add:

Not because she's a wumman or anything, but Kelly Johnson even drew her a nice little picture to clearly show the physics of the thing if the words were too complicated:

Last edited by Cazalet33; 27th Jul 2017 at 00:13.
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Old 27th Jul 2017, 04:59
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Lae position

A couple of posts previous Lae quoted as 6 degrees N or so! I would have thought 6 South would have been more like it! Typical winds in the dry season below 10,000' could be variable 10. Maybe very little night vertical development over the water with the ICZ to the North. British Phosphate Commission's "Myrtlebank" (NORAD)was in the area and could have been misidentified!! Residents on Nauru and locals at Tabitieua in the Gilbert's claim hearing an aircraft! So much conjecture, however a fascinating story. Good luck DB I admire your tenacity.
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Old 27th Jul 2017, 06:00
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Lae OLD

From GCmap.com Lae is 6 degrees 43' 59" S/146 degrees 59' 50" E so given a bit of track crawl down the centre of the Huon Gulf and a heavy aircraft her first position report is not too unreasonable.
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Old 27th Jul 2017, 06:27
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For Cazalet33

Thankyou Cazalet33 for a very forceful explanation of your Hypothesis of what happened and what should not have happened during the Last Flight. It is sometimes pleasant to read of other Hypotheses.

The Lockheed Report you refer to was made and written in 1936 as evidenced by the page date. There are later telegrams from C.L. Johnson in 1937 which stipulate different Power regimes and different heights and your display of Page 7 of LR487 is for a Gross Weight of 16,500 pounds and unlikely that Earhart attempted that AUW.

There is a Lockheed Regime which has 8000' after two hours and 10,000 feet after ten but there is also a notation that 1000' either side is not important. Climb outs would waste fuel at high power and the term cruise-climb would be more likely.

The Chater Report records Noonan's Chronometer as three seconds slow from two time signals.

In referring to the 0519 GMT PR call, I think you mean 7 deg 03' SOUTH 150 deg 07' E, instead of the North Latitude which would put them up in the Carolines. Can we then have a consideration by you that this recorded position included in The Chater Report is incorrect ?

NOTE: I work in Statute Miles (Sm) because by all accounts Earhart also did work in Statute Miles.

I recall that I measured this 7 deg 03' S, 150 deg 07' location on ONC M-14 as being only 215 Statute Miles from Lae (GE says 219) and at a position 60 Statute Miles south of the direct track line to Howland. If so, their G/S is only 42 Smph average, which surely cannot be correct unless they were going around in circles.....

In your consideration then, would it be possible for this particular PR Longitude to have been heard as 150 deg 07' when in reality it could very well be 157 deg 0' making the distance after 5:19 (or thereabouts) as 686 Sm for an Av. G/S of 129 Smph. Would you consider that a scratchy HF Tx made with a low tone American accent and heard by Australian Radio Operator Harry Balfour in Lae could erroneously be recorded as 150 deg 07' East Longitude ? Say 150-7, 150-7 to yourself a few times, you get the drift...

I, personally, believe it was recorded incorrectly and should be 157 deg 0' E Longitude which coupled with the South Latitude sits the PR very nicely over the landmark of Mount Maetambe on Choiseul Island.

Why fly ESE to Choiseul instead of ENE towards the Buka Gap ?

Well, for one, it fits with Earhart and Noonan avoiding the reported LOW off the S.E. corner of New Britain Island. For two, it also fits very nicely with the port drift off the N.E. Track to Nukumanu Island, an obvious drift caused by the Easterly wind which in turn caused one of the (as you say) "NAV busts" and which put the Electra 21 Sm to the West of the Nukumanu Atoll. However, I do not think that the PR given by Earhart was a PR at 0718 GMT. For the third reason, you have to consider that if the reported LOW really was a bad tropical storm then they are headed towards the region of Mount Balbi (8,500') on Bougainville Island and unlikely to wish to be on instruments over there.

You mean that the Electra turned West and Noonan took a sunshot into the dying sun at that Lat/Long ?

I consider (my consideration) that in respect to the 0718 GMT call, Noonan needed to know where he had been "when" they sighted NUKUMANU off to their right and made that a Turnpoint, so the Turnpoint needed to be fixed and the only way to do that is to time the run to the Main Island of Nukumanu to the abeam point or overhead and estimate his distance by the timed run. This would then give him the chance of working "what the wind had been" which had caused him to drift by 21 Sm. To do that he has to work it out ....so in my consideration the Turnpoint was at ~0705 GMT and the Tx on the normal time of 18 minutes past the hour then reported the PR and the wind of 23 Knots. If you consider the context of Choiseul at 0518 GMT and the PR of 0718 GMT for the distance of 224 Sm the G/S of 112 Smph (97 Kts) average is way too low, I recall I worked that it was too low to remain in the air in cruise power at the weight. If you include the 21 Sm and the Lagoon and accept another few miles while Noonan ran the numbers the G/S comes up to around the 130 Smph Av. mark. More likely in an abeam wind.

Yes, agreed, her reporting of PR's was lousy.

Noonan had to have his distance from the Turnpoint at Nukumanu (the PR Lat/Long) because he had already fixed the distance NUK to Ontario and the "extra bit" of the (as you say) NAV bust, was needed so that he could work his G/S NUK to Ontario.

Ontario decklog was recording 20 Knots of wind from 090 degrees at 1030 GMT when they were going over so who knows what the wind was at 10,000 feet ? Noonan had the distance in mind but there was another complication. Ontario was recording a position at 1030 GMT which was 29 Sm to the East of the U.S. Navy designated position.

Now Cazalet33.... what complication would that cause ?

At this point in the flight, my belief is they should have called a stopper on it, turned back, waited out the dawn and landed back at LAE.... but it was a record setting flight wasn't it ?

Take note Cazalet33 and anybody else: I have NEVER, EVER, said that Earhart did not know about speeding up into a headwind. What I have said is that there is a written statement by C.L. Johnson in a telegram that he sent to Earhart which advises to lean-off into a headwind. The telegram is dated March 11th 1937 and it says:

WIRE FROM MARSHALL CONFIRMS MY RECOMMENDATIONS OF POWER AND FUEL CONSUMPTION STOP REMEMBER TO LEAN MIXTURE VERY SLOWLY STOP NINE HUNDRED GALLONS FUEL AMPLE FOR FORTY PERCENT EXCESS RANGE TO HONOLULU FOR CONDITIONS GIVEN IN WIRE THIS MORNING STOP IF NECESSARY MIXTURE CAN BE LEANED TO ZERO SEVEN ZERO ON LAST HALF OF FLIGHT IF EXCEPTIONAL HEAD WINDS EXIST STOP CHECK SPARKPLUGS etc, etc, etc....

Cambridge 070 indicates a mixture ratio of 14.3: 1

...and another thing: "Pulling Power Back, "Easing Throttles", "Retarding Throttles", "Throttling Back" "Reducing Power" will ALL cause less fuel to go into the engines and therefore less power produced. In the intended context that is what happens. Whether it will result in more fuel usage per Nautical Mile was not a mention in the context nor intended. I hope that is made clear.

Oh, by the way, can I have less of the bollocks please and more of your astute mind..... We are all interested in this Mystery but that expression serves no purpose. I deliberated long and hard before deciding to post and that sort of stuff turns me right off (as does arrogance).

Last edited by David Billings; 27th Jul 2017 at 06:45.
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Old 27th Jul 2017, 07:28
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S.S. Myrtlebank

Sundaun

The PR at 0718 GMT was given as 4 deg 33.5'S, 159 deg 07E.

NUKUMANU Island itself is at:

4 deg 37' S, 159 deg 28'E

The Position of the USS Ontario according to the US Navy was:

3 deg 05' S, 165 deg 00' E.

The deck log of the USS Ontario say that at 1030GMT it was at:

2 deg 56' 21"S, 165 deg 22' 54" E

The position given for the SS Myrtlebank was:

2 deg 20'S, 167 deg 10'E

If we leave NUKUMANU at say 0700 GMT and arrive over the Ontario at 1030, I make it say: 420 Sm for 3.5 Hours = a G/S of 120 Smph Av..

I make the distance LAE-ONTARIO 1363 Sm through the dogleg of Choiseul, plus the "NAV bust" and if they were at the Ontario at 1035GMT (lights in sight ahead at 1030 GMT), then the Average G/S over the distance is 128 Smph Their G/S is decaying.

The SS Myrtlebank was a further 145 miles to the East making the distance 565 Sm delivering a G/S of 161 Mph average.

If my start speed at Nukumanu is 130 Smph to average 161 over the sector , I have to be doing 192 Smph when I am overhead the Myrtlebank (Law of Averages)

Cazalet33 says she has already "busted" her fuel by climbing to 10,000' ...now she busts it again by opening the Taps.....if she wants to do 192 MPH !

On a Long Range Plan that would be the last thing to do.

I have looked very closely at the Groundspeeds and it is my belief that they were low compared to previous flights. Certainly "in the era" and "for the aircraft" being nobbled by a 26 mph wind at Nukumanu and forward certainly would get her attention and Fred's alarm !

My persistence.... well now I am sort of forcibly retired, I suppose I've got nothing better to do... it has only been 23 years.... I have a firm regard for the evidence that has kept me at it. Thanks for the kind remarks....

Last edited by David Billings; 27th Jul 2017 at 12:47.
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Old 27th Jul 2017, 07:54
  #59 (permalink)  
 
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...and another thing: "Pulling Power Back, "Easing Throttles", "Retarding Throttles", "Throttling Back" "Reducing Power" will ALL cause less fuel to go into the engines and therefore less power produced. In the intended context that is what happens. Whether it will result in more fuel usage per Nautical Mile was not a mention in the context nor intended. I hope that is made clear.
The idea that you have put forward, that reducing power will reduce fuel consumption is correct for maximising endurance, ie time in the air, but incorrect for best range, ie getting as far as possible with the fuel available in the tanks.

Leaning the fuel/air ratio to allow for the thinner air at alt will achieve a chemically balanced or stoichiometric ratio of fuel, which will result in reduced fuel consumption. This has nothing to do with wind.

Reducing, easing etc throttles will reduce power, and subsequently reduce speed. Whilst this will reduce fuel consumption/hour, the reduced groundspeed in a headwind means that the duration of the flight will be longer (compared to no wind or tailwind) and therefore the fuel consumed over a given distance will be greater. (Due to the fact that the aircraft is exposed to the headwind for a greater period of time.)

Otoh, increasing throttles (power) and flying faster in a headwind will reduce the time that the aircraft is exposed to the headwind and therefore reduce the overall fuel consumption for the entire trip, compared to flying slower. This is demonstrated very effectively in the charts above, and the physics would have been well understood at the time.

The idea that trip fuel can be reduced, or that range can be extended by reducing power in a headwind is incorrect.
psycho joe is offline  
Old 27th Jul 2017, 14:15
  #60 (permalink)  
 
Join Date: Apr 2008
Location: Australia
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The idea that trip fuel can be reduced, or that range can be extended by reducing power in a headwind is incorrect.
Not the whole story. It depends on what speed you were at when you made the power reduction.

If at the speed for best range, then yes, reducing power will reduce range. But if at a greater speed than that for best range, then reducing power will increase range.
FGD135 is offline  

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