Flaps....

gay_pilot18

New Member
Quick question everybody why do most commerical aircraft have 40 degrees of flaps e.g MD-80/90, B-737 200-900,B-727,B-747.

But the Boeing 757/767/777 all have only 30 degrees of full flap.

Good question huh I hope to hear some really good informative answers cause well always wanted to know why.

Lastly I don't know much about Airbus aircraft why you ask......"cause well they suck" so if you were wondering that is why I didn't list any of them.Cause not sure if all there planes are have 40 degrees of flaps or not.

But hey if they do or don't let me know.
 
Well, this is a difficult question to answer, but here goes. The "degrees" of travel that a flap has really doesnt matter. This is because every aircraft has a different wing, and therefore, every different aircraft has different needs regarding high lift devices. You see, if you have more "flap surface" you dont necessarily need to deflect them so far down. But aircraft that dont have the room on the wing for a tremendous number of flap surfaces, are going to need to move the flaps they DO have, alot further to create the same effect. The purpose of flaps is to change the camber of the airfoil so as to make it more efficient at low speeds, so that you dont need so much Angle of Attack to keep the aircraft flying. But if the wing or airfoil is already designed for low speed efficiency, you dont really flaps as much. But if on the other hand, the aircraft has a very high speed wing, you are just gonna need more flaps to get it down to approach speeds. Its really an engineering question, not a question of standardization (ie: all our aircraft are gonna have 40 degrees of flaps.) I hope this helps.
 
It really isn't "degree" as it is a "position" I think.
 
Doug, you could be right. However, if it is a "position", then why not have setting such as: Flaps 1, 2, 3, 4, 5.......etc.?
 
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Lastly I don't know much about Airbus aircraft why you ask......"cause well they suck"

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So are you one of the Americans that think if it is made in America that it has to be better? If so, you are mistaken.
Also, to emphasize what Iain said, look at how many companies are buying their aircraft, enough said.
 
OK, lets chill with the airbus thing folks. True, the typical american mentality is that if it isnt made here, its no good. But everyone is entitled to an opinion. And here is mine, I dont like automation. Anything to take the pilots job away from him, OH sorry (make it easier), bothers me. Call me old school if you want. Airbus seems more prone to this. ie: sidestick computer flight controls, fly by wire useage, stuff like that. So far, i think Boeing is only using fly by wire on the 777.
 
Expect it on every new design that Boeing puts out. It's going to be on the 7E7, and it's a fact of life at this point. Look at when the 757/767 was designed and compare it to the A300, which has no FBW as I understand it. Boeing does not put it in the planes that are already certified but producing now because it would require recertification.

Cheers


John Herreshoff
 
*Sigh*...... I guess the ole stick-n-rudder skills are gonna be less and less important. Oh well, guess I can always have fun in GA aircraft.
 
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Airbus suck?? Hmmm - looking at the order numbers they are pretty popular.

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Popular doesn't mean everything....Chevrolet sells more units than Jaguar, but I'd rather own a Jag. Chevy has more orders, but IMHO they stink. Get what I'm laying down?
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Very true. Airbus adopted the "assembly line" mentality which allowed them to compete with Boeing quite well by lowering prices, Chevy style, but youre not getting the same kind of care and pride put into your aircraft. So Scarebus, Oops, sorry, Airbus may be popular with many companies these days, but they arent fooling me.
 
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Lastly I don't know much about Airbus aircraft why you ask......"cause well they suck" so if you were wondering that is why I didn't list any of them.Cause not sure if all there planes are have 40 degrees of flaps or not.

But hey if they do or don't let me know.

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The 320s have positions 1,2,3,& 4. I don't know what the angle of deflection is. I'm gonna say something that really pains me,but Airbuses don't "suck". They are pretty good and efficent airplanes. I did'nt like them at first because I was used to working around 737s all day long, were you just gas it up,load the passengers and go. The 320 is a lot more....complicated. But still a pretty cool airplane.
 
The Human Factors course I took explained why the Airbus's were having mishaps/accidents due to the automation. The training in automation wasn't taught very well. So when the computer would do something on its own, sometimes the pilot wouldn't understand what it was doing. The pilot would then try to counteract the computer and make the situation worse. We were taught more details on this but I can't remember them all. From what the class was told, the training is a lot better and there are less accidents due to the pilot knowing more about automation.


Baronman, I can't stand chevy's either, but look at the accords and camrys. They sell a lot, and IMO, they are great cars. But I understand your point of something selling well because of its prica and being a piece of crap.
 
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Doug, you could be right. However, if it is a "position", then why not have setting such as: Flaps 1, 2, 3, 4, 5.......etc.?

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Probably because it would be "unnatural"

Boeing always has flaps 1, 5, 15, 25, 30 (and sometimes 40)

MD products has 0/slats extend, 11, 15, a detent-selectable 16-23 range, 28, 40

McDonell-Douglas is a little weird!
 
WOW! Sounds like you could create a seperate ground-school, just for MD flaps! Thanks Doug, yeah, i guess it would be kind of unnatural.
 
And the worst part about moving the flap handle from 0/slats extend to flaps 11 is that the flaps will almost move as fast as you move the flap handle.

So if you slam it into the flaps 11 position, the aircraft is going to dramatically pitch up. We've got to slowly move the flap handle!

Does the pilot phrase "If it ain't Boeing, I ain't going" start to make a little more sense now?
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Yeah, that is a favorite phrase of mine actually. Which poses the question, are you pretty much stuck where you are for now Doug? Or is there an opportunity for you to move to some different equipment?
 
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are you pretty much stuck where you are for now Doug?

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Yup!

When things started getting hot -n heavy prior to 9/11 with upward movement, I was too lazy to bid off of the "mad dog" -- so when the backslide started, I was already in a relatively junior category.

Whenever things turn around, I think I need to get off of the MD-88/90 because I'm pretty much bored to death. Turning off the flight director, de-tuning the ILS freq and shooting a plain visual with no VASI while holding best speed to the marker hardly raises my blood pressure anymore!
 
Yeah, I can image. Well good luck with that, hope you can get into something that sets your hair on fire again. Im an intern at ACA right now, and it looks like im gonna have to donate a kidney to get into an RJ in the forseeable future. Oh well, guess we all gotta just ride this out!
 
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