In the book "Airliner Color History: Boeing 737-100 and 200" by Michael Sharpe and Robbie Shaw there is a section called "A Pilot's View" written by captain Jack Brown. When describing the 737-200, he writes:
" It was certainly well-balanced and presented no unpredictable challenges to even an inexperienced pilot. Although I did not fly the aircraft, the -100 reportedly suffered from being excessively 'cruciform.'
Can anyone explain what this means? How does an aircraft "suffer" from being excessively cruciform." Thanks for any information or insight.
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Re: Boeing 737-100 "excessively cruciform" meaning?
I looked up the book and read the passage. All I can think of, is he's referring to the structure of the tail, which changed between the -100 and -200. The horizontal stabilizer sweep was increased and the area was increased as well. It might be that the elevation of the stabilizer relative to the wing, also may have changed. But am not sure about that.
Increasing the stabilizer sweep angle has some benefits. The center of tail lift moves backwards, which gives the stabilizer more leverage. And the range of stall angles increases, which gives the stabilizer more control margin if the main wing stalls. The cost of this is some loss of lift coefficient, which is why an area increase usually accompanies a sweep angle increase, to make up the loss of lift.
This is speculation, though, just trying to piece together an argument that makes sense. It may not be what he meant.
Increasing the stabilizer sweep angle has some benefits. The center of tail lift moves backwards, which gives the stabilizer more leverage. And the range of stall angles increases, which gives the stabilizer more control margin if the main wing stalls. The cost of this is some loss of lift coefficient, which is why an area increase usually accompanies a sweep angle increase, to make up the loss of lift.
This is speculation, though, just trying to piece together an argument that makes sense. It may not be what he meant.
Re: Boeing 737-100 "excessively cruciform" meaning?
Could he mean lack of pitch range? Not a pilot…forgive my nomenclature usage.
Re: Boeing 737-100 "excessively cruciform" meaning?
I means shaped like a cross. Most notably the square Templar or Maltese cross. So in reference to an airplane it means the wings are very close to the middle of the fuselage and are roughly the same width as the plane is long.
I'm guessing that it tends to move the center of lift to far forward.
I'm guessing that it tends to move the center of lift to far forward.
Re: Boeing 737-100 "excessively cruciform" meaning?
Dalmd88 wrote:I means shaped like a cross. Most notably the square Templar or Maltese cross. So in reference to an airplane it means the wings are very close to the middle of the fuselage and are roughly the same width as the plane is long.
I'm guessing that it tends to move the center of lift to far forward.
That may have been his intent. The -200 added 36" to the nose section and 40" to the tail section, over the -100. So only 4" shift in the relative wing position toward the nose. However for the -100, the wing span was essentially equal to the fuselage length.
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- convair880mfan
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Re: Boeing 737-100 "excessively cruciform" meaning?
I wonder if this is related to the comment of Captain Barry Schiff on the Boeing 720 [which is similar in cruciform shape to the 737 in some respects]:
"some pilots feel that [the] 7120 is not quite as easy to handle as the larger 707: The shorter fuselage of the airplane makes it slightly less stable." (1) Don't think this answers my question though.
1. Barry Schiff. The Boeing 707. Famous Aircraft Series. Fallbrook CA: Aero Publishers 1967. p. 70.
"some pilots feel that [the] 7120 is not quite as easy to handle as the larger 707: The shorter fuselage of the airplane makes it slightly less stable." (1) Don't think this answers my question though.
1. Barry Schiff. The Boeing 707. Famous Aircraft Series. Fallbrook CA: Aero Publishers 1967. p. 70.
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- Florianopolis
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Re: Boeing 737-100 "excessively cruciform" meaning?
Guys, couldn't he just be saying that the airplane was "cross", like it flew like it was in a bad mood ?
Re: Boeing 737-100 "excessively cruciform" meaning?
Is it possible that the guy was just kind of an idiot and he wrote in an excessively florid style?
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