bbc article

[richie conroy]

Ric how long would high tide be at its highest for, an would it be possible wen high tide receeded an batterys gettin low amelia could have tryed to fly plane around island to charge batterys  but as gone down before getting to were she took off from an ditching it out beyond reef ?

[Ric Gillespie]

She did not need to fly the plane to recharge the batteries.  She could recharge at 900 RPM (little more than a fast idle) burning only 6 gallons per hour. All she needed was for the water to be low enough for the prop to clear.

[Chris Johnson]

She did not need to fly the plane to recharge the batteries.  She could recharge at 900 RPM (little more than a fast idle) burning only 6 gallons per hour. All she needed was for the water to be low enough for the prop to clear.

When you say clear, do you mean totaly clear of the water or could she run the prop in shallow water?

[Ric Gillespie]

When you say clear, do you mean totaly clear of the water or could she run the prop in shallow water?

Totally clear.  Airplane propeller tips bend if they hit anything hard - and water, at that speed, is like concrete. If the tip is bent the prop becomes unbalanced. An out of balance prop will set up vibration that can tear an engine off its mounts.

[Rich Ramsey]

This is a total Newbie question but if they had the mean's couldn't they remove the Prop and run the engine that way to recharge the batteries?

[Ric Gillespie]

This is a total Newbie question but if they had the mean's couldn't they remove the Prop and run the engine that way to recharge the batteries?

Nope.  You can't run an airplane engine without the prop. The engine would tear itself to pieces. The prop acts as a flywheel. 

[Dan Swift]

Confirming what Ric said.  Can't run without the prop...needs the resistance and the balance.  And it would rip things apart if it started to strike the water at the bottom of its rotation...even at only 900RPMs. 
Those old radials only cruised at about 2,000 rpms (someone confirm that for me), so 900 pretty fast actually.  Makes me wonder if AE tried to stay on the radio too long and the prop did start making contact with the water.  It very well could have been the end of the engine and there fore the end of the radio transmissions.  Another "could of / I wonder if" statement.  Sorry!   

[Ric Gillespie]

Full throttle for Earhart at sea level was 28.5 inches of manifold pressure and 2050 RPM

[Rich Ramsey]

I thought that would be the answer but I wasn't sure. No harm in checking.  As to your "wonder if"... if I only had a time machine. I would so pick this point and place in time. Just so I can know, I wouldn't change anything, just the need to know the truth.

Thanks for the info.

[Dan Swift]

Wow Ric!  No wonder she almost crashed into the sea off Lae!  That lack of power plus 6600 extra lbs. of gas!

[Gary LaPook]

Full throttle for Earhart at sea level was 28.5 inches of manifold pressure and 2050 RPM

-------------------------------------------------------
I thought takeoff power was 35.5 inches and 2250 rpm and maximum continuous power was
32.5 inches and 2200 rpm.

gl

[Gary LaPook]

prob been asked before but i haven't come across it yet in forums, i wonder y amelia or fred didnt do a SOS or HELP in the sand around island

There's no sand on that beach.  It's all coral rubble.  The might have laid out a message with cut vegetation but they they would have to be expecting an aerial search and, as  far as they knew, theirs was the only airplane in that part of the world.

or stay were they could be seen if a plane flew over ?

Again, there was no reason for them to expect an aerial search.

---------------------------------------------------

Good point  so they would have been expecting a shipborne search.

This also further disproves the "get lost so the Navy can search the Mandates" theory since the Lexington was not conveniently located  at the time. For the "Mandates search" plan the Lexington would have been at Pearl or Lahaina Roads, not 3,000 miles away in San Diego.

gl

[JNev]

Full throttle for Earhart at sea level was 28.5 inches of manifold pressure and 2050 RPM

-------------------------------------------------------
I thought takeoff power was 35.5 inches and 2250 rpm and maximum continuous power was
32.5 inches and 2200 rpm.

gl

Depends on where you look -

Engine performance limits according to FAA TC Data Sheet #590 for the L-10E are as follows -

Engines:
2 P&W Wasps S3H1

Placard Limits:
Maximum, except takeoff
Below 4000 ft. pressure alt.
     30-1/2 in. Hg., 2000 rpm (450 hp)
4000 ft. pressure alt. and up
     29 in. Hg., 2000 rpm (450 hp)
Takeoff (one minute)
     34-1/2 in. Hg., 2200 rpm (550 hp)

This is at "Revision 0" for the L-10E TC Data Sheet, which remains unrevised to this day.

The TC Data Sheet E-143 for the engine is another matter - but there are two points to consider:

1 - the data sheet information for the airplane with installed engines is always / would have been the controlling data for NR16020, and

2 - the engine data sheet was revised as late as August 7, 1973, so performance upgrades may have (probably did) happened (happen).  I did not delve into the original or previous revisions of engine TC Data Sheet E-143 to see, but that is common enough. 

Anyway, some of your numbers may be found there, especially given the conditions provided by "Note 5" therein -

Rating:
(Impeller gear ratio) - 10:1 (this is for the integral supercharger - Jeff)
Maximum continuous, hp., rpm, in. Hg., at:
     Critical altitude (ft.) - 550-2200-32.5-5000
           ("Critical altitude" power means making 550 hp at 2200 rpm and 32.5 in. Hg. at 5000 ft. press. alt. - Jeff)     
     Sea level pressure altitude (ft.) - 550-2200-34.0-S.L.
          (meaning 550 hp at 2200 rpm and 34.0 in. Hg. at Sea Level)
Takeoff (5 minutes), hp., rpm, in. Hg., at:
     Critical altitude (ft.) - 600-2250-35.5-3000
          (Meaning 600 hp at 2250 rpm at 35.5 in. Hg. at 3000 ft. press. alt. - Jeff)
     Sea level pressure altitude (ft.) - 600-2250-36.0-S.L. (See Note 5)
          (Meaning 600 hp. at 2250 rpm at 36 in. Hg. manifold press. at sea level for 5 minutes; Note 5 stipulates "best power mixture strength and 450 degrees F cylinder head temperature" limits and increased Critical Altitude / higher manifold pressure limits with the use of 91/96 octane fuel - Jeff)

Unless AE had some amending data that I do not know about regarding her permissible performance parameters, the data we see in L-10E TCDS 590 above is what she would have been governed by - for good reason: detonation and high temps result from running above those numbers and those things destroy cylinders, etc. very quickly.  I believe the "Lockheed Report 487: Range Study of Lockheed Electra Bimotor Airplane" document bears-out that AE was bound by what we see in the L-10E TCDS.

LTM -

[Ric Gillespie]

Full throttle for Earhart at sea level was 28.5 inches of manifold pressure and 2050 RPM

-------------------------------------------------------
I thought takeoff power was 35.5 inches and 2250 rpm and maximum continuous power was
32.5 inches and 2200 rpm.

gl

Engine performance limits according to FAA TC Data Sheet #590 for the L-10E are as follows -

Engines:
2 P&W Wasps S3H1

Placard Limits:
Maximum, except takeoff
Below 4000 ft. pressure alt.
     30-1/2 in. Hg., 2000 rpm (450 hp)
4000 ft. pressure alt. and up
     29 in. Hg., 2000 rpm (450 hp)
Takeoff (one minute)
     34-1/2 in. Hg., 2200 rpm (550 hp)

My mistake. My numbers were Johnson's recommendations for the first hour of flight. 

I have a 1946 Pratt & Whitney "Specific Operating Instructions" for the S3H1 engine that shows "Take-off (5 min) 600 bhp, 2250 RPM at Sea Level."

[richie conroy]

av read thru quite allot ov tighar's,  previous forum posts an am unable to find a list of every single item found at seven site if 1 exists ?

also has some looked thru luke field inventory an gallaghers invenory from when he died ?