Simviation Forums

hello to all: I do not know if this fits in this catagory if it does not sorry about that:

I have an 737 mai I'm flying at 15 degree angle of slope gainning altitude the stjupid stall light sounds how I'm I suppose to get to my flight level if the stall button keeps going off like I said its only a 15 degree incline so its not much of an angle. something is wrong with this plane

this is the only plane is doing it, on all the other planes I have I can push the angle of attack up to 20 degrees some times 30 degrees with no stall going off I gain my flight level in no time.

bombardier

Ok, firstly, you are making the common mistake of confusing Angle off the Horizon with Angle of Attack. Angle off the Horizon, in this case about 15° you say, is merely a convenient reference to a fixed feature in the plane's environment...the horizon. You seem to have the nose 15° above that. All well and good, but totally irrelevant in this case. The STALL warning works off the ANGLE OF ATTACK. This is the angle at which the relative wind, or the wind the aircraft sees as it plows through the air strikes the wing.






As you can see, the slower you go, the more you pull up on the nose to maintain you climb angle, but this increases you angle of attack. You can have an increasing angle of attack with a constant pitch as shown in the second pic, above. Just need to slow down a triffle.

YOUR problem, as I see it, isn't the angle above the horizon, 15°, but in your case, your SPEED is too slow for the action you want to accomplish, in this case climbing at a certain VS, or Vertical Speed. Only one thing to do to solve the problem: SPEED UP! This will lower your AOA (Angle of Attack), thus removing the stall warning, which sounds to let you know the relative wind is getting ready to separate from the top of your wings, as shown in Figure 2. This happens, no lift, No lift, no fly, and you fall down and go BOOM!!

Hope that helps out a little bit
Pat☺

hello phontom tweak:

and again great explanation thanks for that.

so let me see the high pressure is on top of the wing the low pressure is under the wing so if the high and low pressure are the same no lift will result in a stall, stall causes plane go boom. I do not want plane to go boom that would be bad news.

if I reestablished the high pressure top and low pressure bottom of wind again result in lift then we pitch the nose back gently and not as steep and we should get to my fl soon.

bombardier

Ummm....not to quibble too much, but you have it backwards

The low pressure is on top, caused by Bournoulli's Theorem and the venturi effect: You speed up a specific volume of air, the pressure drops. It's how a carbeurator works. The air splits at the leading edge, and to keep up, the air above the wing goes faster, thus lowering the pressure there. SO, a wing is sucked from above and pushed from below. It's all relative. Rotary wing aircraft (helicopters) work the same, altho they move the wing through the air around the central mast, rather than moving the whole plane through the air. For an airfoil (wing) to function, however, the air needs to flow smoothly across both surfaces of the wing.



As you can see in the diagram, as AOA increases, eventually the air flow lifts from the upper surface of the wing, and swirls round and round. The pressure equalizes by filling in from the trailing edge (Nature abhors a vacuum!) and down you go.

So you have the right idea, but the details were reversed
Pat☺

hello phantom tweak:

do not worry about quibble, thats how we learn. in this case quibble is good with the post of high and low pressure.

I guess you know about now that I do not fly planes. but I did take some courses in ground school long time ago and forgot alot that were taught to me. one of the subjects was doing a stall in a simulator. and I see a stall on tv all the time and the stalls plane goes nose down straight down you looking at land comming up to you fast. when you lose lift and stalls you do not glide down the nose goes down quick streight down position.

but I still like to fly fsx.

bombardier

Not trying to confuse you but not all aircraft's stall the same way. The biggest difference is top wing versus bottom wing and than throw in a T tail and you really get some strange stalls. My first flight was in a Cessna a high wing aircraft and when it stalled it would try to fish tale down which can be dangerous. I latter flew a piper Cherokee a low wing aircraft and when it stalled it was like going over a small speed bump in a car. You hardly knew you had stalled
I believe it is Cessna that makes a small T tail aircraft that is a night mere to fly because of the lack of prop was over the tail. I can only imagine what a stall in that aircraft would be like.

hello garymbuska:

this jet a 737 mai I guess it was my fault, I flew it today over the ukraine and at first i pitched the nose too high and almost stalled. I got my a380 quantas at an iran airport one of the engines did not start up well. but seems ok now. I'm still a long ways from australia.

bombardier