B738SFP - reduced tail clearance - but why?
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B738SFP - reduced tail clearance - but why?
FCTM states for Take-off Flap 1 that B738SFP has 18cm less clearance than "normal" B738 (53cm vs. 33cm) and also needs 0,6 degrees more lift-off attitude.
now you might say:
"thats because the LE devices are sequenced different"
but according to my company's system book, there is NO difference in the LE devices for Flap 1 (LE Flaps 'full extended' + LE slats only 'extended').
you get the LE slats to "full extended" when
- B738 past the Flap 5 position
- B738SFP past the Flap 25
where's my glitch? what did i miss?
now you might say:
"thats because the LE devices are sequenced different"
but according to my company's system book, there is NO difference in the LE devices for Flap 1 (LE Flaps 'full extended' + LE slats only 'extended').
you get the LE slats to "full extended" when
- B738 past the Flap 5 position
- B738SFP past the Flap 25
where's my glitch? what did i miss?
Last edited by FCS Explorer; 18th May 2007 at 15:46. Reason: formating
The whole idea behind the 800SFP is to take-off or land with the same weight in a shorter distance. In the landing & stopping case this is achieved partially by improving the braking performance by reducing the gear splay, the idle thrust delay time and making the ground spoilers more effective.
In the take-off and landing case the slats are now sealed up to the 15 position (previously 10), this gives more lift at lower AoA. The other improvements in lift (ie reduction in Vr & Vref & dist reqd) can only be made by allowing an inc AoA, because the wing is unaltered. The increased AoA reduces tail clearance which is why the aircraft has a two position tailskid which extends further on landing.
These features are also standard on the -900ER and some may become available on -700s.
In the take-off and landing case the slats are now sealed up to the 15 position (previously 10), this gives more lift at lower AoA. The other improvements in lift (ie reduction in Vr & Vref & dist reqd) can only be made by allowing an inc AoA, because the wing is unaltered. The increased AoA reduces tail clearance which is why the aircraft has a two position tailskid which extends further on landing.
These features are also standard on the -900ER and some may become available on -700s.
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ok, thanks for shedding some light on this issue.
next question:
The increased AoA reduces tail clearance which is why the aircraft has a two position tailskid which extends further on landing.
it "extends further on landing" ? it really moves? with some tiny motor? or is this just a misunderstanding?
next question:
The increased AoA reduces tail clearance which is why the aircraft has a two position tailskid which extends further on landing.
it "extends further on landing" ? it really moves? with some tiny motor? or is this just a misunderstanding?
Last edited by FCS Explorer; 18th May 2007 at 23:52.
Captain SandL,
Good explanation. Although this makes me guilty of thread drift, can you also provide any enlightenment on the vertical situation indicator.
These have recently appeared on new aeroplanes in my company's fleet, with as yet no explanation of how they work, or what they are telling you.
BSD.
Good explanation. Although this makes me guilty of thread drift, can you also provide any enlightenment on the vertical situation indicator.
These have recently appeared on new aeroplanes in my company's fleet, with as yet no explanation of how they work, or what they are telling you.
BSD.
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vertical situation indicator
if u mean that profile thing that comes up on 2nd push of CTR-button on nav-display:
we have those. and sorry to say, no explanation needed since completely useless. nice toy, especially on a non-prec, but no one's using it.
magenta show what u put/got in box, a/c symbol, trendline derived from vert speed.
we have those. and sorry to say, no explanation needed since completely useless. nice toy, especially on a non-prec, but no one's using it.
magenta show what u put/got in box, a/c symbol, trendline derived from vert speed.
