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Author Topic: Battery life on AE's plane?  (Read 31790 times)

Dan Swift

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Re: Battery life on AE's plane?
« Reply #15 on: December 30, 2010, 01:57:50 PM »

As a pilot myself, I have concluded that Amelia was deficient in two areas:  1.  She was not a great  pilot.  2. She thought she was a great pilot.  A very dangerous combination usually resulting in death by crash at some point.  She would have thought she could do anything in an airplane. 
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Ted G Campbell

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Re: Battery life on AE's plane?
« Reply #16 on: December 30, 2010, 07:59:19 PM »

This is what would have run through my mind on arriving at Niku flying the Lockheed.

A low level flyover to assess the landing zone near the Norwich City – flat, easy access to the up beach parking area (near the trees) and near an easily identifiable landmark i.e. the ship.

If I could get the plane on the ground in tact – landing gear down – and out of the danger of the water surrounding the island there just might be a chance to contact rescue, get refueled and fly out of the mess I’ve found myself in.

I would have landed with the ocean to my left trying to keep the ship as close as I can to my rollout (thus enhancing my visibility from either the sea or air).

I am afraid that as AE rolled out she caught the left gear in a hole under the waterline, the plane took a hard left turn either twisting off the left gear or damaging it to the point of no return.  The spin was so violent that FE was thrown into the side wall with subsequent head injury.

The plane is now pointed into the surf and unable to be moved.  The right engine is still above the water line when the tide is in and is able to run when the tide is out.  When the tide is out we can still get into the plane to run it and transmit the radio.  It’s only a matter of time before the plane heads into the ocean.  Each time I run it for the radio it inches further toward the sea – the brakes are fading because I am losing hydraulic fluid out of the damaged left gear.  Finally, no control on forward motion when I run up the engine and there-she-goes.

Ted Campbell
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Nancy Marilyn Gould

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Re: Battery life on AE's plane?
« Reply #17 on: January 04, 2011, 07:27:59 PM »

As a pilot myself, I have concluded that Amelia was deficient in two areas:  1.  She was not a great  pilot.  2. She thought she was a great pilot.  A very dangerous combination usually resulting in death by crash at some point.  She would have thought she could do anything in an airplane. 

Judgment is always better in hindsight.  When I was learning to fly, I had the advantage of learning from many, many prior aircraft accidents.  In fact, that's what a good pilot does:  read up on aircraft accidents and learn from them.  But Amelia was a pioneer.  She really didn't have much history to go on.  Plus a lot less was known back then about instrument flying and the instruments themselves were a lot more complicated.
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Randy Conrad

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Re: Battery life on AE's plane?
« Reply #18 on: January 05, 2011, 12:31:49 AM »

Ric and Gang...

 Hey fellas!!! Over the course of the past twenty years I've had the opportunity to work for the best battery manufacturing plant in the world!!! One of the things I do know is that salt water is not good for any battery. However, I'm sure that as Ric has mentioned that distress signals could have been made before the plane was taken and pulled over the reefs edge!!! Anyway, for alot of our overseas markets we have to concentrate on making sure the posts are greased thoroughly to keep them from corroding and to make sure that acid levels are at their finest. We also primarily concentrate on DI water usage!!! Getting back with the salt water, the battery or batteries don't necessarily have to sit in salt water to get ruined. Just the air itself from the ocean can have a significant effect on performance and the life of the battery. Afterall, she did fly over much of the ocean, and probably took on alot of salty air from the ocean. As for the battery life...It depends on the care of the battery...What shape it was in before her last port of call...Did her and Fred check this...Were there any cracks or leaks coming from the battery!!!! In most good cases as I have learned over the years...A good battery can last for hours....Anywhere from 4-6 hours without charging!!!! But, it depends on the total integrity of the battery...Such as the plates, terminals, acid levels, clean posts, and container integrity. Anyway, as in most cases when we run our batteries down in our cars..We have to usually charge them or jump start them with another battery source and then drive the car for quite some time to recharge the system...Such would be the case if her battery was down...But, if it wasn't///Good question Ric....How many batteries does the Electra have in it...and how many batteries can you get by with running it at half to full capacity? Also, if there is more than one battery...how many batteries does it take to just operate the radio alone??? Has your staff looked into this? Anyway, this is totally exciting and very resourceful in a way!!!! You also have to remember that whatever fluid she might have had in those batteries is all she can run with, unless she had extra acid laying in the plane...which I highly doubt...and if she did add salt water...then she definately would be sitting for awhile!!! Anyway, need to run a series of tests on running an Electra with just a small portion of batteries to the normal usage and how many batteries can you run the radio off of!!!!
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Ric Gillespie

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Re: Battery life on AE's plane?
« Reply #19 on: January 05, 2011, 06:42:09 AM »

Bob Brandenburg has done extensive work on battery life aboard the Electra and, with the cooperation and assistance of Covington Aircraft Engines in Okmulgee, OK, I ran tests using a Pratt & Whitney R-1340 engine connected to an Eclipse generator just like the one on Earhart's Electra. We were able to confirm Paul Mantz' comment in 1937 that Earhart should have been able to charge her batteries by running the starboard engine at 900 RPM burning 6 gallons of fuel per hour. We'll have a full report on the battery research and its impact on the post-loss radio signals question.
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Dan Swift

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Re: Battery life on AE's plane?
« Reply #20 on: January 05, 2011, 01:15:52 PM »

Bob Brandenburg's analysis is humbling - excellent.  The cluster / block nature of the transmissions supports what a pilot would do, IMO. 

As others have pointed out, no, AE was not a 'great' pilot - and while she no doubt suffered from some degree of believing she was a great pilot, she would have had some firm working knowledge of generator / battery capability by the time of a Gardner arrival, as would have FN most likely.  Even a rudementary grasp would have been sharpened as one realized the cause and effect of diminishing batteries and relatively slow restoration rates, and even dim memories of things told and warned-of in an earlier time would likely have come to the fore in AE's mind as she struggled to transmit from the Electra.

A reef landing would not have been terribly hard after the pilot dragged the 'field' a time or two to understand what was there.  It is often the psychological barriers that create the worst hazards and when we 'have the picture' a landing is easier.  AE may not have been a great pilot, but she managed to get the Electra airborne out of Lae with a huge load of fuel - she would have been far lighter and easier to handle by the time of reaching that reef.

I share the belief that the airplane eventually went off the reef - but have no idea that it was by her own power.  I don't know of the Electra having a complex hydraulic braking system that would compromise both sides if a gear were damaged or torn away - in 1937 it may have just been a larger version of the simple master-slave system on each side that we see on lighter planes today, each independent of the other.  Does anyone out there know the details on that?  Can be found out if it becomes an important point I guess.

If the right gear remained intact and the right engine thereby supported clear of the reef, the right brake should have been sufficient to hold at reasonable thrust for recharging the batteries.  If not, some form of chocking the wheel would have come into play if it were me struggling with the beast (maybe that's how FN's head injury occurred... ; ) - that's just bad, sorry).

The main point seems to be however that it was likely that AE got the chance to make those transmissions, however imperfectly the whole flight had been handled, and the pattern we can identify from the evidence supports the power curve Bob Brandenburg so ably discerned from what we can know of the Electra's systems and what was reported. 

AE had a reasonable chance to do what is believed was done; at some point the airplane was lost - brakes and chocks are no match for much of a storm that could have come and gone, washing that shoreline with violent surf for a few hours. 

Tangled wreckage at the teeth of the surf may have been what Emily S. and others reported knowing about - perhaps it was the rusting gear of the Electra, just barely jutting above the surf at very low tides where it came to rest for some years before finally sliding off to the deep during some big storm.

LTM -

My Piper products, and most civil aircraft I have ever flown, have independent braking systems for left and right side.  In fact I blew a wheel cylinder on landing one day in a good cross wind on a relatively short field.  Got a bit hairy trying to stop, and keep the plane on the runway, with only one side breaking!  Turning during taxiing was a bit interesting too.  So, she should have been able to hold the airplane with right engine running and only right brakes.  I would think. 
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Christophe Blondel

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Re: Battery life on AE's plane?
« Reply #21 on: January 17, 2011, 03:44:38 PM »


Each time I run it for the radio it inches further toward the sea – the brakes are fading because I am losing hydraulic fluid out of the damaged left gear.  Finally, no control on forward motion when I run up the engine and there-she-goes.


I would not imagine the accident that way, for I cannot imagine that AE would have left the plane inch toward the sea every time she ran the engine without having tried to stop it with whatever she could find to be put in front of the wheels.

I would imagine instead that for all but the last of her emission days, everything runs OK, the Electra remains stable. On the fourth or fifth day however (sorry, I did not take the time to check that in the post-loss radio-call journal), may be because the high tide is everyday a bit higher (isn't it ?), maybe because she runs the engine everyday a little faster to compensate for the decreased efficiency of battery charging due to the salt water spray that progressively shortens out the electrical circuit, maybe because the brakes have been weakened by their stay in water, maybe because of all causes together ... Suddenly the plane leaps forward and turns left to the open sea before she can stop the engine. Accidents of that sort may happen so suddenly that even professionals get trapped (Airbus broke an A340 that way in Toulouse only three years ago!)

It may be at this very time that Noonan gets hurt. I cannot easily imagine that a landing so successful that it left the plane able to operate one engine would hurt anybody who had his or her belt fastened. In contradistinction they probably did not have their seat belts fastened just for making radio calls ...

It may be on this day that Betty hears what is actually AE’s last call. Doesn’t the info stand somewhere on the forum that there was no engine noise in the background? Anyway Betty hears AE crying. That does not seem consistent with the attitude of an aviation pioneer, but would be the reaction of anybody who has just made his or her plane fall from the coral platform where it had safely stood since its so successful landing. The catastrophe has just happened! Now the plane maybe hanging on the coral edge just by one wheel, with only a few hours of emission left depending on the charge of the batteries, if it does not slip completely into water before that time. And the rising tide (which should not be a problem if the plane was still on the coral plateau) makes things worse: Betty says she hears AE ‘having trouble getting water so high the plane was slipping’.

Finally the coral edge acts as a saw that separates the plane in two parts, one that remains on coral, progressively torn to pieces that will give the few aluminum artifacts found ashore and eventually the ‘wheel of fortune’, and the other that sinks down the coral cliff, where we all hope to find it in a not too far future.

Christophe (who, as a glider pilot, will not blame anybody for the way (s)he runs his or her engines)
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Dan Swift

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Re: Battery life on AE's plane?
« Reply #22 on: January 18, 2011, 11:31:12 AM »

Seems more likely to me that the transmissions stopped because they just exhausted the little fuel left.  And a storm, or high winds, resulting in high tides just swept the Electra off the reef.  It could have moved it a little bit towards the reef everyday...no doubt.  Then one day a rough tide....gone. 
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Stephen Hinkle

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Re: Battery life on AE's plane?
« Reply #23 on: February 26, 2011, 06:38:54 PM »

The radio could have consumed batteries fast without the engine running.   The radios back then were tube type, and it appeared from the schematics, one of them used a Dynamotor power supply to turn 12V into 1050V.  The combination of the tube filaments (a 282A is a 10V tube at 3.0 Amps each and one of her radios uses 4 of them, plus 2 6L6s at 0.9A at 6.3V).   This doesn't count the amperage of the Dynamotor or the current required to turn 12V into 1050V, which is a multiple of 87.5.  So even if the plate current of the entire radio was 200ma (which it could be more or less), this would draw 17.5 amps at 12V not including the dynamotor or filaments at 100% transformer efficiency, which most are less than that.     If you add the filaments and 200ma B+ together, you get over 30 amps of consumption!

http://www.nj7p.org/Tube4.php?tube=282A
http://www.nj7p.org/Tube4.php?tube=6L6
http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/ElectraRadios/Schematic2.html\

I would be willing to think that this radio would flatten the batteries quickly.
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Lars Chr. Ødegaard

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Re: Battery life on AE's plane?
« Reply #24 on: March 02, 2011, 01:04:56 PM »

From what  i remember, the radio drew 60-something amps when transmitting. I am also pretty certain this is more that the generators max output, which in practice means that you would drain the batteries even with the engine(s) running. I've heard a couple of stories from the 50s and 60s about people waiting in their cars for some time with the engine idling, headlights, (tube)radio and ventilation blower on, and when they stepped on the brakes to put it in gear, the brake lights made the battery voltage drop to the point where the engine died. The old DC generators, at least in cars,  were nowhere near as efficient as the alternators we know today, and it would take a long time just to regenerate the power used to start an engine. The aircraft engines obviously had magneto ignition that would keep them running without any battery power, but they still has to be started. I'm not claiming to be an expert, but my guess is that even if the gas tanks were full when they landed, they would run out of power after a few hours transmission time anyway if they started and stopped the engines each time.
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