Never flown one but am aware of the twin Beech's rudder blanking tendencies - my uncle instructed in C-45's and spoke of this in detail to me.
Never heard of that in the L10. Not to say it didn't happen to have similar characteristics - maybe so, maybe not. But among other things, Johnson was a consumate aero engineer for the day and I doubt he'd of given imperiliing advice. Earhart's mishap at Luke Field likely had far more to do with mishandling with differential power than with rudder blanking if Mantz's own observations and comments are to hold any weight (and I don't know that she'd used flaps there anyway).
I'm perplexed that anyone would suggest that 'flaps on takeoff' are an odd thing: that's a common take-off configuration for many types, especially where heavy loads, short fields and soft fields are concerned. I have flown a number of types where it was 'standard' - Cessna Cardinal RG: 10 degrees for take-off is normal; Maule M4-220C: 20 degrees normal, etc.
If anyone would like to have a brief and impressive study into "why this is so", have a gander at the
excellent training film Tim Gard shared a few days ago. It involves the B-17 and three point take-offs, but it is the aero/early lift vs. wheel drag equation that is so important here.
The B-17 is a different case (has to do with its design ground attitude more than flaps), but adding flaps provides a similar benefit in the equation: adding flaps increases camber and effective cord, which increases lift; in most types it adds earlier aero lift which = earlier weight off wheels (less wheel drag), and in turn = shorter ground roll. Stall margins are also typically improved (which fits the lift / drag / speed relationship). In short, the sooner the ship can gain ground effect and begin to accelerate more rapidly, the less field length that is needed for a safe take-off. Also, the more altitude as one leaves the end of the runway.
Gary LaPook wrote on this point several times - many times containing lots of fascinating detail. While Gary and I didn't always agree on every technical point, I respect that he's an experienced pilot and instructor, and in my view
he nailed the flaps vs. no flaps equation in a number of posts, perhaps this one is a clear example (you'll have to read through it to get to it, so I quoted it below as well).
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.
Who knows why Earhart didn't follow the recommendations of arguably the finest and most innovative aero engineer the industry saw for decades: could have been anything from simple oversight (which is so simply apparent I tend to believe it - and that's not to scathe the dead lady) to distrust of herself or the machine somehow. Judging by how long the ground roll was and her continued dependence on ground effect once past the end of the runway (by settling to that height above the water), I'd say she'd have been well served to have used flaps - just as Kelly believed. Looking at it anew, it was an unnecessarily close thing after all.
Yes, she pulled it off - it was gutsy, and she made it (I've given credit for that before this string somewhere); but as Ric noted earlier, the flight came very close to ending in the waters off the end of Lae's runway. Then we'd of had a very different story about her and wouldn't be here on this forum talking about her in all probability; not that we're not most all capable of arguing over that ending as well, had we no other hangar flying to do...
