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Author Topic: Airworthiness Certificate(s); fuel capacity  (Read 86942 times)

Gary LaPook

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Re: Airworthiness Certificate(s); fuel capacity
« Reply #30 on: November 30, 2011, 07:35:46 PM »

Gary,
I'm still not clear what your point is.  The historical reality was that the plane used the full runway as reported by witnesses; you calculate that it should have or would have or could have needed less.  So . . . . ?

LTM,
Mona

The data available to the planners showed that there was a large safety margin for the takeoff at Lae. However, we know, after the fact, that the takeoff was anything but easy, it was what is technically known as a "hairy takeoff" and the plane barely got off the ground before the end of the 3,000 foot long runway. I can see how some might look at the actual takeoff and conclude that more power was needed from the engines or that the plane was terribly overloaded. Look at the the video of the takeoff, watch it a few times. (Notice that Noonan doesn't appear to be drunk.)
http://tighar.org/Projects/Earhart/ameliavideo.html

Then read the attached pages from Report 487.

Then watch the video again. Can you figure out why the takeoff used so much runway?

However, before the fact, the planners had no reason to suspect that it would be such a "hairy takeoff" so no reason to try to get more  more power out of the  engines.

gl
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Mona Kendrick

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Re: Airworthiness Certificate(s); fuel capacity
« Reply #31 on: November 30, 2011, 08:30:40 PM »






Then read the attached pages from Report 487.




  Hmm.  That summary says nothing about how much distance to expect between takeoff and the point where the plane should be able to start climbing out of ground effect.
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Gary LaPook

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Re: Airworthiness Certificate(s); fuel capacity
« Reply #32 on: November 30, 2011, 11:30:14 PM »






Then read the attached pages from Report 487.




  Hmm.  That summary says nothing about how much distance to expect between takeoff and the point where the plane should be able to start climbing out of ground effect.
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Today "takeoff distance" is the distance from brake release until climbing to 50 feet but it is clear from report 487 that it meant "ground run", from brake release until the wheels come off the ground. Collopy said the wheels "had not left the ground" until 50 yards short of the end of the runway so the ground run was 2850 feet. Chatter said the "run" was 850 yards making the ground run 2550 feet. Either of these observations are significantly longer than the 1840 feet calculated from the information in report 487.
Didn't you notice anything else?

gl
« Last Edit: December 01, 2011, 12:37:04 AM by Gary LaPook »
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Mona Kendrick

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Re: Airworthiness Certificate(s); fuel capacity
« Reply #33 on: December 01, 2011, 01:28:03 AM »











 
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Didn't you notice anything else?



    I note that the flaps don't appear to be extended, although it's hard to be sure because the images are so fuzzy.  If they were indeed up, that raises the question of why she might not choose to use them despite the 30 degree recommendation in report 487.  The answer may be in this excerpt from a letter Clarence Johnson wrote her during preparations for the world flight:

  The use of 10 to 30 degrees of wingflap with takeoff power will reduce the takeoff run about 20%.  If a normal, good runway is available, with a length of 3000 feet (for the heavier loads), no wingflap is required or recommended as the ship will take off in 2000 feet with a load of 14,000#.  The greatest danger in using wingflaps on takeoff lies in the reduction of directional control at the beginning of the run, and in retracting the wingflaps after takeoff.   (Pg. 44, Kelley: More Than My Share of It All)

--Mona
   
 
« Last Edit: December 01, 2011, 01:32:06 AM by Mona Kendrick »
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Gary LaPook

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Re: Airworthiness Certificate(s); fuel capacity
« Reply #34 on: December 01, 2011, 03:02:20 AM »


Didn't you notice anything else?


    I note that the flaps don't appear to be extended, although it's hard to be sure because the images are so fuzzy.

Maybe I have a clearer image but it is clear to me that the flaps were not set
to 30 degrees at the time of the takeoff in Lae. I am attaching two photos from
Purdue to help you evaluate the flap position in the takeoff video. The first
one shows the trailing edge of the right wing's top surface. (flap.jpg) Notice
there is no outline of the flap itself because the flaps on the Electra 10 are
split flaps, only the bottom surface of the wing deflects downward. The second
picture (flap down2.jpg) shows the left flap lowered, you can see it extending
downward from the bottom surface of the wing. The outboard edge of the flap is
aligned with the "1" in the registration number painted on the bottom of the
left wing. Note how the split flap looks. Since the flap surface is separated
from the top surface of the wing, this creates a thick dark area as seen from
behind due to the upper surface of the wing staying fixed and the bottom
surface, the flap, splitting and deflecting downward.

I couldn't find an actual photo of an Electra 10 in flight with the flaps down.
I did find a you tube video showing a computer animated landing of the plane
which does show clearly what the flaps look like when they are lowered. This
animation looks to be accurate and looks like some of the computer animated
trial exhibits prepared for me by accident reconstructionists trial experts.
Look at this video and then look at the takeoff video again and I think you will
be convinced that the flaps were not extended for the Lae takeoff.


http://www.youtube.com/watch?v=zk2rjEDtjdM&feature=related

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

ADDED:

Here is a link to an Electra flying by with the flaps both up and down, it is easy to detect the difference.

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

Quote
If they were indeed up, that raises the question of why she might not choose to use them despite the 30 degree recommendation in report 487.  The answer may be in this excerpt from a letter Clarence Johnson wrote her during preparations for the world flight:

  The use of 10 to 30 degrees of wingflap with takeoff power will reduce the takeoff run about 20%.  If a normal, good runway is available, with a length of 3000 feet (for the heavier loads), no wingflap is required or recommended as the ship will take off in 2000 feet with a load of 14,000#.  The greatest danger in using wingflaps on takeoff lies in the reduction of directional control at the beginning of the run, and in retracting the wingflaps after takeoff.   (Pg. 44, Kelley: More Than My Share of It All)

--Mona   
 
Or she simply forgot. Either way, following the procedure in report 487 would have shaved about 500 feet off the takeoff roll and so it would not have been nearly as hair raising for the observers and for the people in the plane and would not have provided ammunition for those who speculate about engine switches, spy missions or gold bullion smuggling.

Before anybody accuses me of being critical of the flying abilities of Earhart or of women pilots in general, I must point out that these types of accidents happen all the time, almost always involving male pilots. A quick check of the NTSB website shows two FATAL accidents in 2009 alone caused by attempting to take off from a short runway without properly setting the flaps for a short field takeoff.

http://dms.ntsb.gov/aviation/AccidentReports/o1p0cgqeqsuxb5555aopug551/D12012011120000.pdf

http://dms.ntsb.gov/aviation/AccidentReports/14mmym55xqfv2q55eznk1d551/X12012011120000.pdf
gl
« Last Edit: December 27, 2011, 12:42:42 AM by Gary LaPook »
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Mona Kendrick

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Re: Airworthiness Certificate(s); fuel capacity
« Reply #35 on: December 01, 2011, 10:42:40 AM »

     I agree, this is an interesting catch and a neat explanation for the long run.  Seems like the question of whether to use flaps for the Lae takeoff may have been a tough call  -- Minimize the takeoff run at the cost of some directional control?  Or maximize directional control at the cost of some extra takeoff distance?  I think I too might choose the latter if I'd recently experienced a groundloop.

LTM,
Mona
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Gary LaPook

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Re: Airworthiness Certificate(s); fuel capacity
« Reply #36 on: December 02, 2011, 12:12:40 AM »



If they were indeed up, that raises the question of why she might not choose to use them despite the 30 degree recommendation in report 487.  The answer may be in this excerpt from a letter Clarence Johnson wrote her during preparations for the world flight:

  The use of 10 to 30 degrees of wingflap with takeoff power will reduce the takeoff run about 20%.  If a normal, good runway is available, with a length of 3000 feet (for the heavier loads), no wingflap is required or recommended as the ship will take off in 2000 feet with a load of 14,000#.  The greatest danger in using wingflaps on takeoff lies in the reduction of directional control at the beginning of the run, and in retracting the wingflaps after takeoff.   (Pg. 44, Kelley: More Than My Share of It All)

--Mona   
 
Or she simply forgot. Either way, following the procedure in report 487 would have shaved about 500 feet off the takeoff roll and so it would not have been nearly as hair raising for the observers and for the people in the plane and would not have provided ammunition for those who speculate about engine switches, spy missions or gold bullion smuggling.

gl
What Johnson said was correct for a 14,000 pound takeoff without flaps but was definitely NOT TRUE for a 15,000 pound takeoff which takes significantly more than 2,000 feet at standard conditions and even more at the 2,000 foot density altitude at Lae. According to report 487, it takes 2,600 feet to take off without flaps at 16,500 pounds at a sea level density altitude. Doing the same calculations we did before, we find that a takeoff at Lae at a density altitude of 2,000 feet and 15,000 pounds without flaps results in a ground run of 2,278 feet. Lest you think that this is all just theoretical mumbo-jumbo, this calculation agrees quite closely with Chatter's observation of 2,550 feet, a difference of only 272 feet, less than a 12% difference thus Chatter's observation confirms the accuracy of this calculation. (I accept Chatter's report as more accurate in all of it's detail compared to Collopy's short letter.)

It is interesting to look at what would have happened if Earhart had completely filled that tank, adding about 50 U.S. gallons weighing 300 pounds. A takeoff at 15,300 pounds without flaps would have taken 2,370 feet, only 92 feet longer. And if she had put the flaps down to the 30° position specified in report 487 the takeoff would have taken only 1,914 feet providing a 1,086 foot safety margin, 57% extra runway.

We know that Earhart did not fill that tank because she believed that she needed 100 octane fuel to get maximum power out of her engines but Pratt and Whitney documents show that the engines make full takeoff power of 600 horsepower using the 87 octane fuel available at Lae (Jeff Neville disputes this) so she could have filled that tank, made a safe takeoff, and then have an extra hour of flying endurance to find a safe place to land.

Just for the sake of argument, let's say that Neville is correct and that she could only get 550 horsepower from each engine using 87 octane fuel, how would this have affected the takeoff? The length of the takeoff run varies with the inverse of the ratio of the engine power. Report 487 shows 2,100 feet for standard conditions, 30° of flaps, and 16,500 pounds using the full power of 600 horsepower from each engine, a total of 1,200 horsepower so taking off with a total of 1,100 hp gives a takeoff distance 9% longer, 2,290 feet. We adjust this for the takeoff weight of 15,300 pounds as we did before and find 1,970 feet. We then increase this by 6% to account for the density altitude so the complete calculation gives 2,088 feet compared to 1,914 for 1,200 hp (we could have just multiplied the 1,914 by 1.09 too), only 174 feet longer and with 912 foot safety margin, 44% extra runway available. Doing the same calculation for the flaps up scenario produces a takeoff run of 2,585 but this would be cutting it close so Earhart would have to have remembered to set the flaps correctly.
So no matter how you figure it, Earhart unnecessarily left behind an hour's worth of fuel and this fuel could have made a significant difference in the end.

gl
« Last Edit: December 02, 2011, 02:00:34 AM by Gary LaPook »
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Thom Boughton

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Re: Airworthiness Certificate(s); fuel capacity
« Reply #37 on: December 02, 2011, 05:20:08 PM »

There is now incontrovertible proof that the plane did NOT land on Nikumororo. NBC news reported that the Airworthiness Certificate for the airplane was just discovered in California and that this Airworthiness Certificate must be carried in the plane at all times, so this means that the plane was secretly brought back to the U.S. and then disposed of. Since the plane made it back to the U.S. it could not possibly be found on Niku.


(chuckle)




Obviously the plane never left California by air.  I well remember my ground school instructor explaining that it wasn't horsepower, nor aerodynamics, nor even Bournoulli's principal that enabled an airplane to fly, it was the airworthiness certificate.  Without it, an airplane could not fly, and that was that!


Hmmm....I suspect your ground instructor must have been ex-military (those military guys tend to lead a sheltered existence and do not always get to see the whole picture) as it seems he is in need of a little refresher training.

For ANY pilot will tell you, without any hesitation or reservation of any sort, that there is one thing and only one thing that EVER makes an airplane fly......



....MONEY!!!    ;D ;D






LTM,

      ....twb
TIGHAR #3159R
 
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Gary LaPook

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Re: Airworthiness Certificate(s); fuel capacity
« Reply #38 on: December 04, 2011, 12:44:33 AM »


    I note that the flaps don't appear to be extended, although it's hard to be sure because the images are so fuzzy. 
--Mona
   
 
Here is a link to an Electra flying by with the flaps both up and down, it is easy to detect the difference.
http://www.youtube.com/watch?v=halcPvrj-hI&feature=related
gl
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Gary LaPook

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Re: Airworthiness Certificate(s); fuel capacity
« Reply #39 on: December 04, 2011, 11:57:19 AM »

There is now incontrovertible proof that the plane did NOT land on Nikumororo. NBC news reported that the Airworthiness Certificate for the airplane was just discovered in California and that this Airworthiness Certificate must be carried in the plane at all times, so this means that the plane was secretly brought back to the U.S. and then disposed of. Since the plane made it back to the U.S. it could not possibly be found on Niku.


(chuckle)




Obviously the plane never left California by air.  I well remember my ground school instructor explaining that it wasn't horsepower, nor aerodynamics, nor even Bournoulli's principal that enabled an airplane to fly, it was the airworthiness certificate.  Without it, an airplane could not fly, and that was that!


Hmmm....I suspect your ground instructor must have been ex-military (those military guys tend to lead a sheltered existence and do not always get to see the whole picture) as it seems he is in need of a little refresher training.

For ANY pilot will tell you, without any hesitation or reservation of any sort, that there is one thing and only one thing that EVER makes an airplane fly......



....MONEY!!!    ;D ;D






LTM,

      ....twb
Similarly, it is not the elevator nor the throttle that controls altitude. Altitude is actually controlled by oil pressure, when the oil pressure goes down to zero, the plane goes down to zero altitude.

gl
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Dan Swift

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Re: Airworthiness Certificate(s); fuel capacity
« Reply #40 on: December 06, 2011, 02:24:55 PM »

In the video, she appears to have 0 flaps, pulled hard off in ground affect, leveled off in ground affect to gain speed.  And she would have lost ground affect going over the cliff causing the drop down to the sea to avoid stalling. 
Just a 'hot and heavy' takeoff on a soft field.   
TIGHAR Member #4154
 
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Chris Austin

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Re: Airworthiness Certificate(s); fuel capacity
« Reply #41 on: December 07, 2011, 05:50:32 AM »

Similarly, it is not the elevator nor the throttle that controls altitude. Altitude is actually controlled by oil pressure, when the oil pressure goes down to zero, the plane goes down to zero altitude.

gl

Second that -

And the propeller's true purpose is to keep the pilot cool; watch the pilot sweat when it quits...

LTM -

I don't know if the guy was sweating, but listen to his breathing. Due to the lack of chat, I'd also assumed he was solo until it was on the ground! Sensible passenger - let him concentrate.

http://www.youtube.com/watch?v=t0txEC0Rhdg
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Irvine John Donald

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Re: Airworthiness Certificate(s); fuel capacity
« Reply #42 on: December 07, 2011, 06:40:50 AM »

I think Jeff is being more thoughtful in his reply #41 on page 3 of this thread. It's likely AE did not want to dilute her 100 octane believing she needed it for her take off at Howland. She didn't plan to get lost. She did have to plan on taking off from a newly constructed airfield on a very small island she had never been to before. No 100 octane on Lae to top up with?  Okay so she saves what she has of the fuel she believes will "boost" her takeoff for Howland. AE at this point is still planning to finish the trip.   Perhaps as Jeff observes, the discussion needs to be more practical and less technically oriented. Think in terms of AE and her planning the trip. Who said she planned on using the 100 octane for the takeoff at Lae where she knew exactly what runway length and condition were?
Respectfully Submitted;

Irv
 
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Gary LaPook

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Re: Airworthiness Certificate(s); fuel capacity
« Reply #43 on: December 07, 2011, 10:09:17 AM »

I think Jeff is being more thoughtful in his reply #41 on page 3 of this thread. It's likely AE did not want to dilute her 100 octane believing she needed it for her take off at Howland. She didn't plan to get lost. She did have to plan on taking off from a newly constructed airfield on a very small island she had never been to before. No 100 octane on Lae to top up with?  Okay so she saves what she has of the fuel she believes will "boost" her takeoff for Howland. AE at this point is still planning to finish the trip.   Perhaps as Jeff observes, the discussion needs to be more practical and less technically oriented. Think in terms of AE and her planning the trip. Who said she planned on using the 100 octane for the takeoff at Lae where she knew exactly what runway length and condition were?
The runway was longer at Howland.

gl
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Irvine John Donald

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Re: Airworthiness Certificate(s); fuel capacity
« Reply #44 on: December 07, 2011, 01:15:18 PM »

But the field was an unpaved, untested airfield on a very small island. AE knew there were no facilities there other than what Itasca would have. If she believed 100 octane would give her take off a boost, from a brand new unpaved runway that no aircraft had ever landed on or taken off from, then wouldn't she want to save the 100 octane for that takeoff?  Use all the runway at Lae with her regular fuel, believing she had ample fuel and reserve to make it to Howland. This, of course, is all theory as she never made it to Howland or radioed to say what she was planning.  I ask the pilots out there....  If you were doing this trip, and using the knowledge of 1937, what would you do?  Could you, or would you, trust that the Howland airfield was built as advertised?
Respectfully Submitted;

Irv
 
« Last Edit: December 07, 2011, 01:17:44 PM by Irvine John Donald »
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