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Amelia Earhart Search Forum => Aircraft & Powerplant, Performance and Operations => Topic started by: Ric Gillespie on November 02, 2011, 12:48:29 PM

Title: Fuel System Research Bulletin
Post by: Ric Gillespie on November 02, 2011, 12:48:29 PM
A new Research Bulletin describing the evolution of the fuel system aboard NR16020is now up on the TIGHAR website.  Click on the link here (http://tighar.org/Projects/Earhart/Archives/Research/Bulletins/61_FuelSystem/61_FuelSystem.htm)
Title: Re: Fuel System Research Bulletin
Post by: Martin X. Moleski, SJ on November 02, 2011, 02:00:46 PM
A new Research Bulletin describing the evolution of the fuel system aboard NR16020is now up on the TIGHAR website.  Click on the link here (http://tighar.org/Projects/Earhart/Archives/Research/Bulletins/61_FuelSystem/61_FuelSystem.htm)

There seems to be a small discrepancy in the drawings.

Fuselage tank #5 in one drawing is shown as 70 gallons.

On the "rear floor valve" fuel selector gauge in the same drawing, fuselage fuel tank #5 is reported as 149 gallons.

(http://tighar.org/Projects/Earhart/Archives/Research/Bulletins/61_FuelSystem/09fuelsystemschematic.jpg)

(http://tighar.org/Projects/Earhart/Archives/Research/Bulletins/61_FuelSystem/09a_valvesystem.jpg)
Title: Re: Fuel System Research Bulletin
Post by: Gary LaPook on November 02, 2011, 02:22:03 PM
A new Research Bulletin describing the evolution of the fuel system aboard NR16020is now up on the TIGHAR website.  Click on the link here (http://tighar.org/Projects/Earhart/Archives/Research/Bulletins/61_FuelSystem/61_FuelSystem.htm)
-----------------
These are my two posts of today and yesterday on the "Mystery rods" thread that describe the use of the fuel system.

Contrary to modern twin engined planes the Electra had a fuel system that fed both engines from the same tank. The right valve under the throttles is a standard Electra valve, with "right engine on," "left engine on," "both engines on ," and "both engines off" positions choosing which engine is to receive fuel from the fuel system. The left valve is in series with the right valve and is also almost standard, it selects the fuel tank to use, "right 97 gal. wing tank,"  "left  97 gal wing tank," "right 102 gal wing tank," "left 102 gal wing fuel tank," "off," and then the added position of "fuselage tanks." When in the "fuselage tanks" position it then opens the port to a third valve that selects which of the fuselage tanks to use. If it was desired to use fuel from one of the two forward 118 gallon tanks then the third valve was turned to "off" and fourth valve was opened to chose "right" or "left."

The above description is quite straight forward and should not confuse anybody.

Now looking at the rest of the fuel plumbing diagram in the Electra we come to the confusing part. There are two additional valves, the first labeled "stripping valve" and the one just below it on the diagram labeled "...RD," the rest of the label that is cut off is "forward floor valve." This valve duplicates the left valve on the instrument panel (this is the upper left valve on the diagram that is cut off) and both of these valves are connected in parallel allowing selecting any of the fuel tanks. This second valve is used to transfer fuel INTO a selected fuel tank. The valve on the instrument panel selects the tank that fuel is drawn OUT OF to go to the engines. The forward floor valve is connected to the stripping valve and the stripping valve selects where the fuel to be transferred comes from, either from the wobble pump or from the tank selected for supplying fuel to the engine.

Two examples will make this clear. Let's say all the fuel from the number 5 fuselage tank has been used up. Earhart then switches the left fuel selector valve away from the "fuselage" position to one of the wing tank positions to keep the engines running. She then sets the stripping valve to the wobble pump position and sets the forward floor valve to one of the wing tanks positions and then pumps the handle to move the remaining fuel from the depleted fuselage tank into the selected wing tank. After this is completed she then sets both of these valves back to off. (Note, only fuel from the fuselage tanks can be moved with the wobble pump and it can only be sent to a wing tank. Also, the plane must be using a wing tank during this operation, not one of the fuselage tanks. )





gl
Title: Re: Fuel System Research Bulletin
Post by: Chuck Varney on November 02, 2011, 03:46:01 PM

There seems to be a small discrepancy in the drawings.

Fuselage tank #5 in one drawing is shown as 70 gallons.

On the "rear floor valve" fuel selector gauge in the same drawing, fuselage fuel tank #5 is reported as 149 gallons.

Marty,

The discrepancy originated with Lockheed. See the blueprint (http://earchives.lib.purdue.edu/cdm4/item_viewer.php?CISOROOT=/earhart&CISOPTR=3683&DMSCALE=50&DMWIDTH=600&DMHEIGHT=600&DMX=0&DMY=1402&DMMODE=viewer&DMTEXT=%20lockheed%20electra&REC=13&DMTHUMB=1&DMROTATE=0) in the Purdue collection, where the #5 FUSELAGE 149 GAL switch sector is shown linked to the tank labeled #5 FUSELAGE 70 GAL.

Chuck
Title: Re: Fuel System Research Bulletin
Post by: Martin X. Moleski, SJ on November 02, 2011, 04:22:19 PM

There seems to be a small discrepancy in the drawings.

Fuselage tank #5 in one drawing is shown as 70 gallons.

On the "rear floor valve" fuel selector gauge in the same drawing, fuselage fuel tank #5 is reported as 149 gallons.

The discrepancy originated with Lockheed. See the blueprint (http://earchives.lib.purdue.edu/cdm4/item_viewer.php?CISOROOT=/earhart&CISOPTR=3683&DMSCALE=50&DMWIDTH=600&DMHEIGHT=600&DMX=0&DMY=1402&DMMODE=viewer&DMTEXT=%20lockheed%20electra&REC=13&DMTHUMB=1&DMROTATE=0) in the Purdue collection, where the #5 FUSELAGE 149 GAL switch sector is shown linked to the tank labeled #5 FUSELAGE 70 GAL.

Thanks for confirming that the discrepancy is in the original drawings.

I couldn't see it clearly in the image that shows the tank as 70 gallons--the label for the tank is clear, but the drawing of the valve was a little too fuzzy for me to be sure that it read "149 gallons."
Title: Re: Fuel System Research Bulletin
Post by: John Ousterhout on November 03, 2011, 06:35:41 AM
I was searching on the web for any details of 1937 dump valves and stumbled upon this interesting article about the new Electra as a British passenger airliner.  It includes a nicely detailed drawing of the cockpit, which includes a reference to the fuel dump valve handle, located next to the pilots' seat, but does not show what it looked like or describe it in any detail.
http://www.flightglobal.com/pdfarchive/view/1937/1937%20-%201026.html

Title: Re: Fuel System Research Bulletin
Post by: Ric Gillespie on November 03, 2011, 06:44:01 AM
It includes a nicely detailed drawing of the cockpit, which includes a reference to the fuel dump valve handle, located next to the pilots' seat, but does not show what it looked like or describe it in any detail.

The cockpit in the article is, of course, quite different from Earhart's with respect to instruments and their location, but the basic controls are the same.
The reference to the fuel dump confirms that even the standard airplane had that capability.  Earhart's Electra, BTW, did not have de-icer boots.
Title: Re: Fuel System Research Bulletin
Post by: John Ousterhout on November 03, 2011, 07:57:49 AM
gl comments: "...(The wobble pump is operated with the lever with the white handle sticking up from the floor in front of the fuel selector valves and is shown just to the right of Earhart's knee in this photo.)..."

This creates another discrepancy - according to the drawing in the www.flightglobal.com archive I linked to earlier, that lever is the brake control.  Is the "emergency fuel pump" in the drawing the same as the wobble pump?  If so, then it's the black handle to the right of the throttles.  'Seems rather awkward to me.

Title: Re: Fuel System Research Bulletin
Post by: Ric Gillespie on November 03, 2011, 10:23:04 AM
The big handle (aka "Johnson Bar") in the middle is the brake, sometimes called the "emergency brake."  The Lockheed 10 Operating Manual says:

"Operation of brakes: Differential action is obtained by pressure on either right or left rudder toe brake pedal after the emergency brake has been pulled back about 3 notches."
Title: Re: Fuel System Research Bulletin
Post by: John Ousterhout on November 04, 2011, 06:49:38 AM
Gary,  please clarify something for me - the hand pump pushes fuel towards a Tee which splits it towards the Stripping Valve and towards the Engine Selector Valve. When you say "... the hand pump cannot be used as an emergency pump", and "that surprises me", you seem to imply expectation of some other arrangement.  Are you surprised that the fuel route to the Stripping Valve cannot be blocked, so the Hand Pump would force fuel towards the Engine Selector Valve?  As it appears, the best it could do is to present fuel to the Engine Selector Valve at near zero pressure.  I am ignorant of the fuel pump and carburetor arrangement on the engines, so I cannot offer any opinion of the effectiveness of this arrangement.  Do they have mechanical fuel pumps like on an old automobile engine? In normal conditions, how do the engines draw fuel from the Engine Selector Valve, and how would an "emergency pump" help?
Title: Re: Fuel System Research Bulletin
Post by: Gary LaPook on November 04, 2011, 08:23:04 AM
Gary,  please clarify something for me - the hand pump pushes fuel towards a Tee which splits it towards the Stripping Valve and towards the Engine Selector Valve. When you say "... the hand pump cannot be used as an emergency pump", and "that surprises me", you seem to imply expectation of some other arrangement.  Are you surprised that the fuel route to the Stripping Valve cannot be blocked, so the Hand Pump would force fuel towards the Engine Selector Valve?  As it appears, the best it could do is to present fuel to the Engine Selector Valve at near zero pressure.  I am ignorant of the fuel pump and carburetor arrangement on the engines, so I cannot offer any opinion of the effectiveness of this arrangement.  Do they have mechanical fuel pumps like on an old automobile engine? In normal conditions, how do the engines draw fuel from the Engine Selector Valve, and how would an "emergency pump" help?
-----------------------------
I see where I went wrong. I was looking at the fuel system blue print here:
http://earchives.lib.purdue.edu/cdm4/item_viewer.php?CISOROOT=/earhart&CISOPTR=3683&CISOBOX=1&REC=8

and the "hand" was cut off from "fuel pump" so I thought that this was a mechanical or electrical pump. Now that I have looked at the drawing I see that it is the standard hand pump which is used, according to the Electra operating manual, for pumping up pressure for starting the engines and, probably for emergencies. (I say "probably" because we don't know the capacity of that hand pump and whether it can supply fuel at a rate sufficient to keep an engine running nor does the Electra manual mention using in for emergencies.)

Looking further, I looked at my Wasp maintenance manual and it shows that each engine has its own engine driven mechanical pump, see attached scan (the S3H2 engine shown is the same as Earhart's S3H1 except that there is an angled adapter block for mounting the carburetor so that the carb remains horizontal while the engine is mounted at an angle for use in a helicopter), so the line between the hand pump and the engines would be under suction, not pressure so this changes my analysis.

Looking at the stripping valve, placing it in the "standard" position would allow the engines to draw fuel through the "forward floor valve" from any tank at the same time the engines were drawing fuel through the "control stand selector valve" although I don't see any reason to have this capability or reason to do it. So this position could not be used to transfer fuel between tanks.

Placing the "stripping valve" in the "wobble pump" position allows the wobble pump to "strip" any remaining fuel from the fuselage tanks and move it to the wing tanks. The "T" junction you pointed to is in the supply side of the wobble pump plumbing so the fuel moves in the opposite direction than you were thinking. After all, that is the purpose of the "stripping" system.

So, a separate wobble pump was added to the plane so it was not operated with the "hand fuel pump" handle on the right side of the panel as I had thought but the wobble pump handle does not appear to be shown in any of the photos either.

gl
Title: Re: Fuel System Research Bulletin
Post by: Gary LaPook on November 04, 2011, 08:33:12 AM
I was searching on the web for any details of 1937 dump valves and stumbled upon this interesting article about the new Electra as a British passenger airliner.  It includes a nicely detailed drawing of the cockpit, which includes a reference to the fuel dump valve handle, located next to the pilots' seat, but does not show what it looked like or describe it in any detail.
http://www.flightglobal.com/pdfarchive/view/1937/1937%20-%201026.html (http://www.flightglobal.com/pdfarchive/view/1937/1937%20-%201026.html)
---------------------------
Fuel dump valves were standard on the Electra and were "T" pull handles located on the floor under the pilot's seat. To operate them the pilot pulled them up which opened a dump valve in the chosen wing tank. Once opened they could not be closed and all the fuel from that tank would be dumped. Since this is, obviously, a critical operation, the handles were "safetied" so that they could not be inadvertently pulled. The reason for dumping fuel was for dealing with the loss of an engine since the plane might not be able to maintain altitude on one engine without losing weight.

gl
Title: Re: Fuel System Research Bulletin
Post by: John Ousterhout on November 04, 2011, 08:42:12 AM
Gary, thanks for the clarification.  You're a great resource.
Regarding the standard Electra dump valves, do you have any idea if the handles might have been the same as the ones on the ends of the mystery rods?
Title: Re: Fuel System Research Bulletin
Post by: Gary LaPook on November 04, 2011, 09:36:10 AM
Gary, thanks for the clarification.  You're a great resource.
Regarding the standard Electra dump valves, do you have any idea if the handles might have been the same as the ones on the ends of the mystery rods?
--------------
Hmmmm, interesting. I would suspect not since I believe the dump valves were activated by pull cables, not rigid rods.
gl
Title: Re: Fuel System Research Bulletin
Post by: Chris Johnson on November 04, 2011, 10:01:36 AM
Gary, thanks for the clarification.  You're a great resource.
Regarding the standard Electra dump valves, do you have any idea if the handles might have been the same as the ones on the ends of the mystery rods?
--------------
Hmmmm, interesting. I would suspect not since I believe the dump valves were activated by pull cables, not rigid rods.
gl

Could they have replaced the cables with the rods to prevent accidental dumping if the cable was snagged?

My thinking is that if people had to climb over the tanks to get from the cockpit to the rear of the plane wire cables might easily be caught by someone scrambling.
Title: Re: Fuel System Research Bulletin
Post by: John Ousterhout on November 04, 2011, 12:51:40 PM
Although I'm nearly convinced that the mystery rods activated dump valves, the fact that the could work as both pull and push-rods raises a question: were they supposed to be able to push, as well as pull?  The cable-operated dump valves locked open, if I understand correctly.  If I were designing similar valves for the aux. tanks, but wanted to protect the cables, I'd route them along the tops of the tanks, under the platform, not angled up over the tops like the mystery rods.  Then again, rods would be perfectly functional, and generally would have less friction than cables, if that was an important factor.
Can anyone suggest a different function for the mystery rods?  Also, why only 3, when there were 6 tanks?
Title: Re: Fuel System Research Bulletin
Post by: Gary LaPook on November 04, 2011, 06:40:44 PM
Although I'm nearly convinced that the mystery rods activated dump valves, the fact that the could work as both pull and push-rods raises a question: were they supposed to be able to push, as well as pull?  The cable-operated dump valves locked open, if I understand correctly.  If I were designing similar valves for the aux. tanks, but wanted to protect the cables, I'd route them along the tops of the tanks, under the platform, not angled up over the tops like the mystery rods.  Then again, rods would be perfectly functional, and generally would have less friction than cables, if that was an important factor.
Can anyone suggest a different function for the mystery rods?  Also, why only 3, when there were 6 tanks?
-----------------------------
The only reason to activate the dump valves is after an engine failure and it is a one way trip, you want to get rid of as much weight as possible to keep from crashing so there would never be a reason to try to close the valves once they were opened so pull cables are the way to go. The cables are inside flexible protective housings so you don't have to worry about inadvertent activation.  The standard dump handles are protected from inadvertent activation by safeties. If the rods were for dump valves then it looks like an accident just waiting to happen. In addition to the small handles at the cockpit ends there are also those big handles sticking out just waiting for someone crawling past to accidentally dump the fuel. Hmmm, maybe that is why they ran out of fuel after only 20 hours.

gl
Title: Re: Fuel System Research Bulletin
Post by: Ricker H Jones on November 05, 2011, 09:54:38 AM
Looking at Ric's evolution of the fuel system (http://tighar.org/Projects/Earhart/Archives/Research/Bulletins/61_FuelSystem/61_FuelSystem.htm), the photo with the photographer taking a picture shows that the cockpit door has been hung with the cut-out in the door for the rods already made.  In the photo with AE looking aft over the first iteration of the installed tanks (with the two filler necks and a manifold system going to the tanks)  a rod is shown attached to one of the tanks. (it passes between AE's arm and belt).  Could these rods have operated valves on the filling manifold to close off a quarantined tank and prevent it from being filled? 
Title: Possible Dump valve design question
Post by: John Ousterhout on November 06, 2011, 07:26:19 AM
Gary (or anyone else who knows) - is there anything like a "standard" fuel dump valve design that Lockheed might have used, if they used dump valve on the auxiliary tanks?  I read a snippet from a different book about Earhart that mentioned the dump valves would have been pushed open by sea water pressure during a water landing.  How can we evaluate this possibility if we know nothing about the valves?  Can dump valves be opened by external pressure this way?
Title: Re: Possible Dump valve design question
Post by: Ric Gillespie on November 06, 2011, 07:43:21 AM
I read a snippet from a different book about Earhart that mentioned the dump valves would have been pushed open by sea water pressure during a water landing. 

Ah yes ... "would have" ... a guess masquerading as a fact.
Title: Re: Fuel System Research Bulletin
Post by: Harry Howe, Jr. on November 06, 2011, 12:46:18 PM

Of course nothing would prevent the "Rods" from being able to be Push/Pull  and/or  "Twist".

Does/Did anyone, including AE and FN really know the total fuel at Take-Off?

Using the numbers listed on the valve diagrams, it looks like a total of 1151 gallons if tank #5 had 70 and 1230gallons if tank #5 had 149.  But, the Chater report talks about all tanks being full except for the 81 galon tank that was half full.  What 81 gallon tank was he reporting on?

Can anyone clear this up?
Title: Re: Fuel System Research Bulletin
Post by: Ric Gillespie on November 06, 2011, 05:16:15 PM
Does/Did anyone, including AE and FN really know the total fuel at Take-Off?

I don't know any way of answering that question without being there.  We know that Chater (http://tighar.org/Projects/Earhart/Archives/Documents/Chater_Report.html) and Collopy (http://tighar.org/Projects/Earhart/Archives/Documents/Collopy_Letter.html) were both under the impression that there was a total of 1,100 U.S. gallons of gasoline aboard the airplane when it left Lae. I think it's safe to assume that AE and FN also believed that to be true. 

Using the numbers listed on the valve diagrams, it looks like a total of 1151 gallons if tank #5 had 70 and 1230gallons if tank #5 had 149.

According to both the November 1936 and May 1937 inspections, Tank #5 had a maximum capacity of 70 gallons and the aircraft's total fuel capacity was 1,151 U.S. gallons.  That seems pretty well settled.
 
  But, the Chater report talks about all tanks being full except for the 81 galon tank that was half full.  What 81 gallon tank was he reporting on?

Nice catch Harry. I've been waiting for someone to spot that discrepancy in the Chater report.  Bob Brandenburg and I went 'round and 'round with it last summer.

Chater says, "July 1st — after the machine was tested the Vacuum Oil Co.’s representatives filled all tanks in the machine with 87 octane fuel with the exception of one 81 gallon tank which already contained 100 octane for taking off purposes. This tank was approximately half full and it can be safely estimated that on leaving Lae the tank at least 40 gallons of 100 octane fuel – (100 octane fuel is not obtainable in Lae). A total of 654 imperial gallons was filled into the tanks of the Lockheed after the test flight was completed. This would indicate that 1,100 US gallons was carried by the machine when it took off for Howland Island."

The airplane did have an 81 gallon tank in each wing as you can see from the diagrams in the Fuel System Research Bulletin. (http://tighar.org/Projects/Earhart/Archives/Research/Bulletins/61_FuelSystem/61_FuelSystem.htm)  The trouble is, each 81 gallon tank shared a fueling port AND a fuel gauge with the 16 gallon tank in that wing.  As shown in the Fueling Form in that bulletin, for fueling purposes, each wing had a 97 gallon tank.  So how could Chater (or anyone for that matter) know that one of the 81 gallons tanks was half full?  As far as we know, there was no way to "stick" those tanks.  The Kollsman fuel gauges for those tanks read from 0 to 100 gallons in five gallon increments.  Apparently one 97 gallon tank (81 + 16) - we don't know which wing - was dedicated to 100 octane.  If you looked at the gauge for that tank and it read 40 gallons you'd know that the 16 gallon tank was dry and the 81 gallon tank was about half full.
Title: Re: Fuel System Research Bulletin
Post by: Gary LaPook on November 07, 2011, 03:26:51 AM
Does/Did anyone, including AE and FN really know the total fuel at Take-Off?

I don't know any way of answering that question without being there.  We know that Chater (http://tighar.org/Projects/Earhart/Archives/Documents/Chater_Report.html) and Collopy (http://tighar.org/Projects/Earhart/Archives/Documents/Collopy_Letter.html) were both under the impression that there was a total of 1,100 U.S. gallons of gasoline aboard the airplane when it left Lae. I think it's safe to assume that AE and FN also believed that to be true. 

Using the numbers listed on the valve diagrams, it looks like a total of 1151 gallons if tank #5 had 70 and 1230gallons if tank #5 had 149.

According to both the November 1936 and May 1937 inspections, Tank #5 had a maximum capacity of 70 gallons and the aircraft's total fuel capacity was 1,151 U.S. gallons.  That seems pretty well settled.
 
  But, the Chater report talks about all tanks being full except for the 81 galon tank that was half full.  What 81 gallon tank was he reporting on?

Nice catch Harry. I've been waiting for someone to spot that discrepancy in the Chater report.  Bob Brandenburg and I went 'round and 'round with it last summer.

Chater says, "July 1st — after the machine was tested the Vacuum Oil Co.’s representatives filled all tanks in the machine with 87 octane fuel with the exception of one 81 gallon tank which already contained 100 octane for taking off purposes. This tank was approximately half full and it can be safely estimated that on leaving Lae the tank at least 40 gallons of 100 octane fuel – (100 octane fuel is not obtainable in Lae). A total of 654 imperial gallons was filled into the tanks of the Lockheed after the test flight was completed. This would indicate that 1,100 US gallons was carried by the machine when it took off for Howland Island."

The airplane did have an 81 gallon tank in each wing as you can see from the diagrams in the Fuel System Research Bulletin. (http://tighar.org/Projects/Earhart/Archives/Research/Bulletins/61_FuelSystem/61_FuelSystem.htm)  The trouble is, each 81 gallon tank shared a fueling port AND a fuel gauge with the 16 gallon tank in that wing.  As shown in the Fueling Form in that bulletin, for fueling purposes, each wing had a 97 gallon tank.  So how could Chater (or anyone for that matter) know that one of the 81 gallons tanks was half full?  As far as we know, there was no way to "stick" those tanks.  The Kollsman fuel gauges for those tanks read from 0 to 100 gallons in five gallon increments.  Apparently one 97 gallon tank (81 + 16) - we don't know which wing - was dedicated to 100 octane.  If you looked at the gauge for that tank and it read 40 gallons you'd know that the 16 gallon tank was dry and the 81 gallon tank was about half full.
------------------------------------------------------
There is definitely a conflict in the evidence regarding the fuel on board. The tanks only held 1151 U.S. gallons so that puts an absolute top limit on the gas in the plane. Chatter said that 654 Imperial gallons (785 U.S. gallons) were put into the tanks so this puts an absolute floor on the fuel load of 785 U.S. gallons.

Both Collopy and Chatter state that the plane had 1100 U.S. gallons on board but there is a conflict in their statements. Collopy said that a 100 gallon tank was half full while Chatter said an 81 gallon tank was half full. There are no 100 gallon or 81 gallon tanks in the fuselage but there are 102 gallon and 81 gallon tanks in each of the wings. Earhart lost control of the plane on takeoff from Hawaii so she would be loath to have a lateral fuel imbalance on takeoff at Lae so is likely that she wouldn't just leave one tank in just one of the wings half full but would leave a tank on the other side half full also. Supporting this theory is the discrepancy in the size of the tanks described by Chatter and Collopy. If one of them looked in the tank and passed the information on the other guy then they would have the exact same size for the tank so it didn't happen this way. If they each looked in the same tank that was half full then, again,  they would have stated the same size. Based on this it is reasonable that they were each looking in different tanks, one in the right wing and one in the left wing. They both said they saw a tank half full and even if they talked to each other neither would have reason to realize that the other guy was talking about a different tank since they both calculated 1100 gallons total. It is like the old story of the three blind men examining an elephant. Based on this I believe that it is quite likely that they only had about 1050 U.S. gallons on board when they took off from Lae.

gl
Title: Re: Fuel System Research Bulletin
Post by: Ric Gillespie on November 07, 2011, 09:11:29 AM
Both Collopy and Chatter state that the plane had 1100 U.S. gallons on board but there is a conflict in their statements.

Yes, but easily explainable without jumping to the conclusion that they were wrong.

Collopy said that a 100 gallon tank was half full while Chatter said an 81 gallon tank was half full. There are no 100 gallon or 81 gallon tanks in the fuselage but there are 102 gallon and 81 gallon tanks in each of the wings.

True.

Earhart lost control of the plane on takeoff from Hawaii so she would be loath to have a lateral fuel imbalance on takeoff at Lae so is likely that she wouldn't just leave one tank in just one of the wings half full but would leave a tank on the other side half full also.

How can you possibly know what Earhart would be loath to do?  I imagine that you would be loath to set off to fly around the world in 1937 without knowing Morse code.  I sure would. The 81 and 102 gallon wing tanks were in the center section inboard of the engines and gear.  A 300 lb. discrepancy side-to-side that close to the fuselage and inboard of the gear in a 15,000 airplane is hardly worth worrying about.

Supporting this theory is the discrepancy in the size of the tanks described by Chatter and Collopy. If one of them looked in the tank and passed the information on the other guy then they would have the exact same size for the tank so it didn't happen this way.

There was no way to "look in the tanks."  The tanks were buried in the wings. As shown in the Fuel System (http://tighar.org/Projects/Earhart/Archives/Research/Bulletins/61_FuelSystem/61_FuelSystem.htm) research bulletin, the 16 and 81 gallon tanks share a filler port.  For fueling and fuel gauge purposes the two tanks are treated like a single 97 gallon tank.

If they each looked in the same tank that was half full then, again,  they would have stated the same size. Based on this it is reasonable that they were each looking in different tanks, one in the right wing and one in the left wing. They both said they saw a tank half full ...


No they didn't.  Neither one of them said anything about seeing a tank half full.  Chater (http://tighar.org/Projects/Earhart/Archives/Documents/Chater_Report.html) said, "This tank was approximately half full and it can be safely estimated that on leaving Lae the tank at least 40 gallons of 100 octane fuel ..."  He didn't say how he knew the tank was approximately half full.  Collopy (http://tighar.org/Projects/Earhart/Archives/Documents/Collopy_Letter.html) said, "One tank contained only 50 gallons of its total capacity of 100 gallons." Ditto.

If the wing tanks were not full, the only way to know how much fuel was in them was from the fuel gauges. From photos of the Electra cockpit it appears that the the fuel gauge for each of the "97 gallon" tanks was a Kollsman 180.  The gauge read from 0 to 100 gallons in five gallon increments (even though the combined tanks held only 97 gallons).  Chater looks at the gauge and sees that it reads roughly 50 gallons.  He knows that the gauge is actually for two tanks, a 16 and an 81, because he has a Lockheed Electra of his own.  If the gauge is reading 50 gallons then the 16 gallon tank is empty and the 81 gallon tank is down about 34 gallons - about 47 gallons remaining.  So he says, "This tank was approximately half full and it can be safely estimated that on leaving Lae the tank at least 40 gallons of 100 octane fuel ..." Safe guess. 
Collopy looks at same gauge and sees the same thing but Collopy doesn't know the particulars of the Lockheed 10.  All he knows is that the gauge goes from 0 to 100 gallons and that the needle reads about 50, so he says, "One tank contained only 50 gallons of its total capacity of 100 gallons."

Based on this I believe that it is quite likely that they only had about 1050 U.S. gallons on board when they took off from Lae.

I think it's more likely that the actual load was more like 1,107 U.S. gallons but 1,100 is a safe conservative figure.

Ric
Title: Re: Fuel System Research Bulletin
Post by: Gary LaPook on November 08, 2011, 12:06:18 AM
--------------------
O.K. Ric, I'll buy that, it makes sense to me.

gl
Title: Re: Fuel System Research Bulletin
Post by: Richard C Cooke on November 21, 2011, 08:30:54 AM
Collopy looks at same gauge and sees the same thing but Collopy doesn't know the particulars of the Lockheed 10.  All he knows is that the gauge goes from 0 to 100 gallons and that the needle reads about 50, so he says, "One tank contained only 50 gallons of its total capacity of 100 gallons."
Collopy's telegram reports what Noonan told him about the fuel onboard:

"According to Captain Noonan the total fuel capacity of the aircraft was 1150 U.S. Gallons and oil 64 U.S. Gallons. They left Lae with a total of 1100 U.S. Gallons of fuel and 64 U.S. Gallons of oil. One tank contained only 50 gallons of its total capacity of 100 gallons. This tank contained 100 octane fuel and they considered the 50 gallons of this fuel sufficient for the take-off from Lae."

There is no suggestion that he personally checked the plane, and the numbers are nice round ones ie: 1150, 1100, 100 and 50 which is what he would remember from a conversation with Noonan, rather than an engineering or maintenance report giving exact numbers.

Richard Cooke
Title: Re: Fuel System Research Bulletin
Post by: Ric Gillespie on November 21, 2011, 09:10:57 AM
There is no suggestion that he personally checked the plane, and the numbers are nice round ones ie: 1150, 1100, 100 and 50 which is what he would remember from a conversation with Noonan, rather than an engineering or maintenance report giving exact numbers.

Thanks Richard.  I think that's a good observation.
Title: Re: Fuel System Research Bulletin
Post by: richie conroy on December 01, 2011, 02:48:30 PM
i come across this picture so thought i would post it as u can see the rods an rods connected in upright position goin to black box or pump  :)

Title: Re: Fuel System Research Bulletin
Post by: Chuck Varney on December 02, 2011, 07:59:31 AM
Ric,

The photo that Richie Conroy attached to Reply #29 shows a piece of equipment mounted atop the starboard 118-gallon tank.

Do you know what it is?

Chuck
Title: Re: Fuel System Research Bulletin
Post by: Ric Gillespie on December 02, 2011, 08:26:14 AM
Ric,

The photo that Richie Conroy attached to Reply #29 shows a piece of equipment mounted atop the starboard 118-gallon tank.

Do you know what it is?

Chuck

Short answer: No.
The key question is:  When was the photo taken?
I think I see part of the Hooven Radio Compass at lower right. That would date the photo to some time between October 1936 and early March '37 before the change to the Bendix loop.
Title: Re: Fuel System Research Bulletin
Post by: John Ousterhout on December 02, 2011, 08:45:27 AM
The presence of upholstery/lining material indicates an early photo (or maybe not, see additional discussion below).  The hand-written notes on the tanks seems likely to indicate the picture taken shortly after their installation - later photos show no notes written on them, and the lining was stripped out of the fuselage.  The mystery box on top of the starboard tank is directly under the Hooven radio compass antenna, so I assume it contains electronics associated with the antenna.

from TIGHAR research bulletin November 1, 2011:
"In October 1936, Earhart flew the Electra to Wright-Patterson AFB in Dayton, Ohio where inventor Fred Hooven installed and tested his Radio Compass, later known as an Automatic Direction Finder or ADF.  The receiver was mounted on one of the fuselage tanks forward on the starboard side and the loop antenna was housed in a faired dome on top of the cabin."
Title: Re: Fuel System Research Bulletin
Post by: Chuck Varney on December 02, 2011, 10:25:29 AM
Thanks, Ric and John.

Ric, I don't know the photo's true date, but I found a copy of it here (http://shineyourlight-shineyourlight.blogspot.com/2011/08/history-of-flight.html), where the caption says ". . probably taken in early 1937. . ". 

Perhaps the Hooven setup was still installed when the Conroy photo was taken, but I couldn't convince myself of that. See the attachment, where I have put the Conroy photo together with one that shows the Hooven receiver and the cabling to it and to the loop.  Note that the latter photo does not include the equipment atop the starboard 118-gallon tank.

What did the Bendix loop coupler enclosure look like?

John, you wrote:

Quote
The presence of upholstery/lining material indicates an early photo.  The hand-written notes on the tanks also indicate the picture taken shortly after installation - later photos show no notes written on them, and the lining was stripped out of the fuselage.

Don’t you have your liner / no-liner chronology reversed? What specific photos are you referring to as being later and having neither writing on the tanks nor a cabin liner installed?

Quote
The mystery box is directly under the Hooven radio compass antenna. . .

I agree that the box is near where the Hooven loop antenna would have been installed, but I find the Conroy photo extent too limited to determine whether the Hooven equipment was actually in place when the photo was taken.

Chuck
Title: Re: Fuel System Research Bulletin
Post by: John Ousterhout on December 02, 2011, 11:51:04 AM
The same Research Report of November 1, 2011 "The Fuel System of NR16020" goes on to say: " The Hooven Radio Compass was removed the first week of March 1937. The cabin has been furnished with a cloth headliner."
Yeah, I'm sure I've got my "liner" history backwards. 
The significance and timing of the hand written notes on the tanks is my own conjecture. I imagine the individual tanks may have been identified with such hand written notes during construction.  That's a common way to keep track of things, especially customized items that someone else may be installing.  Some time after installation the notes might have been cleaned off.
Title: Re: Fuel System Research Bulletin
Post by: richie conroy on December 02, 2011, 11:53:50 AM
is there evidence the belly antenna on the electra was replaced after the crash ?

cant remember if i have read it had, or its not mentioned in the repair list  ::)
Title: Re: Fuel System Research Bulletin
Post by: Martin X. Moleski, SJ on December 02, 2011, 12:01:03 PM
is there evidence the belly antenna on the electra was replaced after the crash ?

I think I've got a decent history of the antennas (http://tighar.org/wiki/Antennas) on the wiki.

The answer is "yes."
Title: Re: Fuel System Research Bulletin
Post by: Chuck Varney on December 04, 2011, 12:59:34 PM
In replies #31 and #34 of this thread, I asked:

1. In the photo that Richie Conroy attached to Reply #29, what is the equipment item mounted above the starboard 118-gallon tank?

2. What did the enclosure for the Bendix loop antenna coupler look like?

Since posting the questions I’ve found a photo that suggests that the item mounted above the tank is the Bendix loop coupler.

See the attachment, which combines a crop from the Reply #29 photo with a crop from a photo showing Cyril Remmlein holding a Bendix loop coupler, the latter photo from the book by the Long’s.  In the two crops, note the crinkle finish, the mounting plate at top of enclosure, and the cable connector at top right of front panel.

If the loop coupler supposition is correct, the photo dates to 6 March 1937, or after, and begs two more questions:

3. What are the front panel details for the coupler (labels, purpose of switches, other controls and connectors)?

4. What is it that is partially revealed at bottom-right in the Reply #29 photo?

Chuck
Title: Re: Fuel System Research Bulletin
Post by: Ricker H Jones on December 07, 2011, 04:16:17 PM
This frame from a film clip Richie posted on another thread shows what could be  fuel drains on the belly of the Electra.
 
(http://www.criticalpast.com/app_old/cpdata2/65675063657/big/65675063657_000551_3.jpg)
Title: Re: Fuel System Research Bulletin
Post by: Ric Gillespie on December 07, 2011, 05:05:47 PM
This frame from a film clip Richie posted on another thread shows what could be  fuel drains on the belly of the Electra.

The Harney Drawings have little rearward-facing openings on the belly that he labeled "fuel drains."
Title: Re: Fuel System Research Bulletin
Post by: richie conroy on December 07, 2011, 06:08:32 PM
i thought or assumed,  the fuel was sucked out via a hoover like system i.e siphoning,

could it be possible they drained what they could, of fuel from these ports to start the camp fires ?

mind u saying that, if they had fuel to start fires they could ov started one instantly when planes flew over to generate a smoke signal to planes over head!!!!!!

think i answered me own question there  :) 
Title: Re: Fuel System Research Bulletin
Post by: richie conroy on December 07, 2011, 06:19:42 PM
is it also possible, that the navigator's door to an from plane was left open from noonan's exit an the weight ov water in rear ov plane made it role back off reef ?
Title: Re: Fuel System Research Bulletin
Post by: John Ousterhout on February 26, 2012, 08:08:26 AM
Richie found a reference by AE mentioning the dump valves.  No details, but we might conclude that the tanks actually had them.

http://tighar.org/smf/index.php/topic,592.msg10723.html#new
Post #260
Title: Re: Fuel System Research Bulletin
Post by: Gary LaPook on February 26, 2012, 10:57:20 AM
Richie found a reference by AE mentioning the dump valves.  No details, but we might conclude that the tanks actually had them.

http://tighar.org/smf/index.php/topic,592.msg10723.html#new
Post #260
Duh!
  The "dump valves" wording is on page 70 of Last Flight and we all missed it. Standard Electras came with dump valves for the inboard wing tanks which were to be operated in the event of an engine failure so that the airplane could maintain flight on just the one remaining engine because weight is critical in this situation. And that is for a plane that is not operating above the standard maximum weight of 10,500 pounds so it counts in spades for a plane that might be 6,000 pounds above that weight, like Earhart's. So it certainly makes even more sense that her plane had dump valves for the fuselage tanks too. I think we have found the answer to the mystery of those "mystery rods."

gl