Author Topic: How do pilots know the plane is going to stall?  (Read 3524 times)

Offline Tupac

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Re: How do pilots know the plane is going to stall?
« Reply #60 on: April 30, 2012, 02:24:21 PM »
You can hear 100 knots in a skyhawk much easier than 70 - you can hear 140 even better.

You need instruction in the art of a wildlife clearing pass.
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Offline colmbo

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Re: How do pilots know the plane is going to stall?
« Reply #61 on: April 30, 2012, 02:39:00 PM »
You can hear 100 knots in a skyhawk much easier than 70 - you can hear 140 even better.

The 206 I flew most of my jump loads in had around 11000 hours on it, there was no insulation in the cabin other than some carpet glued to the inside of the skin.

During a descent with airspeed well into the yellow arc the noise was inescapable.

Left slips sounded different than right slips.

Put some G on the airplane and the wing root vents would make a little moaning sound.

The airplane will tell you what's happening if you listen to it.
Columbo

"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."

Fate whispers to the warrior "You cannot withstand the storm" and the warrior whispers back "I AM THE STORM"

Offline VonMessa

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Re: How do pilots know the plane is going to stall?
« Reply #62 on: April 30, 2012, 03:00:10 PM »
The 206 I flew most of my jump loads in had around 11000 hours on it, there was no insulation in the cabin other than some carpet glued to the inside of the skin.

During a descent with airspeed well into the yellow arc the noise was inescapable.

Left slips sounded different than right slips.

Put some G on the airplane and the wing root vents would make a little moaning sound.

The airplane will tell you what's happening if you listen to it.

I have heard older instructors refer to this as  using the most "important" instrument, "paying attention to what your arse is telling you" or flying by the seat of your pants  :rofl

Something that is really important when your instruments decide to fail you
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Offline earl1937

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Re: How do pilots know the plane is going to stall?
« Reply #63 on: April 30, 2012, 03:33:31 PM »
The 206 I flew most of my jump loads in had around 11000 hours on it, there was no insulation in the cabin other than some carpet glued to the inside of the skin.

During a descent with airspeed well into the yellow arc the noise was inescapable.

Left slips sounded different than right slips.

Put some G on the airplane and the wing root vents would make a little moaning sound.

The airplane will tell you what's happening if you listen to it.
You speak the truth, even if some these guys don't comprehend what you are saying. Funny thing, not one person posting to this thread ever mentions how sloppy the controls get at slow speeds. Contarty to what some people say, aircraft certified in the "Normal" category does not have control centering springs. All I have ever flow, controls returned to the neutral position through slip stream over them! I know the B-24 that you flew had hydraulic boosted controls, did you have any control feel at all? but the 29's I flew did not! Whew! Sometimes in crosswinds, it was a wrestling match, with both the A/C and myself on the controls!
Blue Skies and wind at my back and wish that for all!!!

Offline colmbo

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Re: How do pilots know the plane is going to stall?
« Reply #64 on: April 30, 2012, 05:45:17 PM »
  I know the B-24 that you flew had hydraulic boosted controls, did you have any control feel at all? but the 29's I flew did not! Whew! Sometimes in crosswinds, it was a wrestling match, with both the A/C and myself on the controls!

B-24 was all manual as well...no hydraulic boost for the controls...although she could use it!!!  Rudder very stiff, elevator as well, ailerons not so bad -- at least not when compared to the B-17.

Engine-out drills would leave your rudder leg quivering.  After my type rating checkride I could barely walk -- seems the check pilot didn't realize the airplane actually had 4 engines!!

The B-17 has a low rate of roll, was the B-29 like that as well?
Columbo

"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."

Fate whispers to the warrior "You cannot withstand the storm" and the warrior whispers back "I AM THE STORM"

Offline Oldman731

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Re: How do pilots know the plane is going to stall?
« Reply #65 on: April 30, 2012, 06:36:49 PM »
B-24 was all manual as well...no hydraulic boost for the controls...although she could use it!!!  Rudder very stiff, elevator as well, ailerons not so bad -- at least not when compared to the B-17.

Engine-out drills would leave your rudder leg quivering.  After my type rating checkride I could barely walk -- seems the check pilot didn't realize the airplane actually had 4 engines!!

The B-17 has a low rate of roll, was the B-29 like that as well?


Please keep this up, you two.

- oldman

Offline colmbo

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Re: How do pilots know the plane is going to stall?
« Reply #66 on: April 30, 2012, 07:09:48 PM »
Funny thing, not one person posting to this thread ever mentions how sloppy the controls get at slow speeds.

I thought about it, does that count?  :D

Control feel is certainly another way the airplane "talks to you".  As you get slow  you find you have the stick/yoke way back in your lap to increase pitch (or maintain a pitch attitude).  It takes more aileron or rudder to get a response and control pressures are reduced.
Columbo

"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."

Fate whispers to the warrior "You cannot withstand the storm" and the warrior whispers back "I AM THE STORM"

Offline Seanaldinho

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Re: How do pilots know the plane is going to stall?
« Reply #67 on: April 30, 2012, 08:50:03 PM »
I did say in my post that you lose control authority...

Another thing is a lower level of control authority (in other words the controls dont effect the movement of the plane as much as they do while in normal flight, in contrast at higher speeds the controls have more authority which can lead to overcontrolling)

Offline pembquist

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Re: How do pilots know the plane is going to stall?
« Reply #68 on: April 30, 2012, 08:50:19 PM »
You speak the truth, even if some these guys don't comprehend what you are saying. Funny thing, not one person posting to this thread ever mentions how sloppy the controls get at slow speeds.

You'll have to give props to Seanaldinho who mentions "less control authority" and to Hawkeye61 who mentions "controls get mushy" back on page 2.   I think the OP was curious about accelerated stalls though.  Generally speaking if a plane has a benign 1g stall does it behave well approaching a higher g stall?
Pies not kicks.

Offline Seanaldinho

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Re: How do pilots know the plane is going to stall?
« Reply #69 on: April 30, 2012, 08:51:29 PM »
You'll have to give props to Seanaldinho who mentions "less control authority" and to Hawkeye61 who mentions "controls get mushy" back on page 2.   I think the OP was curious about accelerated stalls though.  Generally speaking if a plane has a benign 1g stall does it behave well approaching a higher g stall?

Thank you sir  :aok

Offline earl1937

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Re: How do pilots know the plane is going to stall?
« Reply #70 on: May 01, 2012, 02:00:39 PM »
B-24 was all manual as well...no hydraulic boost for the controls...although she could use it!!!  Rudder very stiff, elevator as well, ailerons not so bad -- at least not when compared to the B-17.

Engine-out drills would leave your rudder leg quivering.  After my type rating checkride I could barely walk -- seems the check pilot didn't realize the airplane actually had 4 engines!!

The B-17 has a low rate of roll, was the B-29 like that as well?
Yes, the 29 had a slow roll rate, and to stop a bank angle where you wanted it, usually required a opposite control input. Most of the heavy iron I ever flew, DC-3, DC-6B and C-46, just returning the controls to neutral was enough to stop the bank angle where you wanted it.The 29 was very sloppy below 120 kts IAS, with everything hangin out! 1 and 2 engine out drills on one side or the other was a terror, until you employed the trim, then it wasn't to bad. One of the problems with the 29 was those big ole "fowler" flaps, which would cause a great deal of "float" or ground effect and if you had a crosswind, sometimes things could get very hairy!! Going into Tinian one rainy night, with #1 caged and a 30 to 40 knot, 25 degree from the right, crosswind, we actually ran off the runway during roll out and "washed" out the nose gear, but we were almost stopped when it "caved". The 29's I flew were "B" models with the -57 engines and new clyinder baffling and they were pretty good engines. This same engine when on to service C-97's, Boeing "stratocruisers", Lockheed L1049's "Connies" and DC-7B & C models. Millions of people flew over seas via United, American, TWA, Easteren and a number of trans-ocean carriers. Guys, didn't mean to slight anyones post about controls, 78 year eyes don't always take in everything they should! The orginal thread has brough a lot comments, great reading and wish we could have more like this.

Anyone know what a "A" and "N" quadrant is and a "Cone of silence"?
« Last Edit: May 01, 2012, 02:10:09 PM by earl1937 »
Blue Skies and wind at my back and wish that for all!!!

Offline Brooke

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Re: How do pilots know the plane is going to stall?
« Reply #71 on: May 01, 2012, 03:28:04 PM »
Anyone know what a "A" and "N" quadrant is and a "Cone of silence"?

Only from the show "Get Smart". :)  Thanks for the stories, Earl! <S>

Offline Oldman731

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Re: How do pilots know the plane is going to stall?
« Reply #72 on: May 01, 2012, 03:29:47 PM »
Only from the show "Get Smart". :)  Thanks for the stories, Earl! <S>

Just in case you were confusing this with something else, Earl:

http://www.youtube.com/watch?v=uqcSWI6Ppks

And thanks for the information, both you and Colmbo.

- oldman

Offline colmbo

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Re: How do pilots know the plane is going to stall?
« Reply #73 on: May 01, 2012, 07:58:03 PM »

Anyone know what a "A" and "N" quadrant is and a "Cone of silence"?

Old radio navigation system having four courses (denoted by the Cone of Silence).  You listened to a morse coded signal (A or N) to determine which side you were on, right in the middle was the null tone or "cone of silence".  I think the 4 courses were north, south, east or west and you had to be somewhat oriented to figure out which side you were on and which direction to the station.

Never used one, just remember hearing about them.

From your statements about the B-29 roll I'm guessing it was just a Boeing thing.  The B-17 was very slow to roll and the ailerons were very heavy.  Working the airplane in close to make airshow passes routinely called for full aileron to get enough roll rate.  The B-17 could be challenging in a crosswind but overall is an honest airplane.  Just for relaxed, fun flying the B-17 beats the B-24.  The B-24 could be a bit of a beast...but that's what makes her fun, gives you a sense of accomplishment when you do things well in the Liberator.

Even though the B-17 is a taildragger the B-24 is harder to taxi.  She has a castoring, non steerable nosewheel so when slow you have to use the brakes to steer.  The brakes on these old airplanes work off of the aircraft hydraulic system/accumulator.  They are expander tube brakes -- there is kind of an inner tube around the brake pucks that is filled with hydraulic fluid to activate the brakes.  Since it takes a moment to fill this tube there is a slight delay when using the brakes.  The first time user will press the brakes and if used to modern brake systems will notice nothing happens so will press a bit harder on the brakes then finally when the expander tube fills you've now applied more brake than needed.  In the B-24 the main wheels are just slightly behind the center of gravity so the airplane is tail heavy on the ground.  If you get ham footed on the brakes the nose will start bobbing down with braking then rebound up as you release.  If you get a bit out of synch you could probably bounce the nosewheel off the ground, although I've never heard of that happening.  What does happen is as the nose bobs back up the weight on the nosewheel is reduced and that castoring wheel will turn left or right a bit and as the weight comes back on the nose you dart off in whichever direction the airplane has decided to take you.  The Liberator can make a grown man cry like a little girl within 50' or less when you first learn to taxi her.  :D

Once you get used to her you can drive her around like a sportscar --- well, like a 65000 pound 67' long, 110' wide sportscar.  What many of us did was instead of pressing with your foot to apply brakes (when using for directional control) was to just curl your toes down -- that little bit of pressure would be enough to open the flow valve to the brake and gently apply just enough to ease her around the corner as you taxi.  When taxiing along a taxiway we'd taxi with a bit of speed to get the rudders working (also bumping the power up on #2 and #3 helps to get more air over the rudder) then you didn't need brakes to steer.  You can also steer with power but have to be careful because each time you add power to turn you also pick up a bit more speed.

Using brakes and power it is possible to "back up" in the B-17.  Think about it.....
Columbo

"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."

Fate whispers to the warrior "You cannot withstand the storm" and the warrior whispers back "I AM THE STORM"

Offline earl1937

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Re: How do pilots know the plane is going to stall?
« Reply #74 on: May 01, 2012, 08:46:36 PM »
Old radio navigation system having four courses (denoted by the Cone of Silence).  You listened to a morse coded signal (A or N) to determine which side you were on, right in the middle was the null tone or "cone of silence".  I think the 4 courses were north, south, east or west and you had to be somewhat oriented to figure out which side you were on and which direction to the station.

Never used one, just remember hearing about them.

From your statements about the B-29 roll I'm guessing it was just a Boeing thing.  The B-17 was very slow to roll and the ailerons were very heavy.  Working the airplane in close to make airshow passes routinely called for full aileron to get enough roll rate.  The B-17 could be challenging in a crosswind but overall is an honest airplane.  Just for relaxed, fun flying the B-17 beats the B-24.  The B-24 could be a bit of a beast...but that's what makes her fun, gives you a sense of accomplishment when you do things well in the Liberator.

Even though the B-17 is a taildragger the B-24 is harder to taxi.  She has a castoring, non steerable nosewheel so when slow you have to use the brakes to steer.  The brakes on these old airplanes work off of the aircraft hydraulic system/accumulator.  They are expander tube brakes -- there is kind of an inner tube around the brake pucks that is filled with hydraulic fluid to activate the brakes.  Since it takes a moment to fill this tube there is a slight delay when using the brakes.  The first time user will press the brakes and if used to modern brake systems will notice nothing happens so will press a bit harder on the brakes then finally when the expander tube fills you've now applied more brake than needed.  In the B-24 the main wheels are just slightly behind the center of gravity so the airplane is tail heavy on the ground.  If you get ham footed on the brakes the nose will start bobbing down with braking then rebound up as you release.  If you get a bit out of synch you could probably bounce the nosewheel off the ground, although I've never heard of that happening.  What does happen is as the nose bobs back up the weight on the nosewheel is reduced and that castoring wheel will turn left or right a bit and as the weight comes back on the nose you dart off in whichever direction the airplane has decided to take you.  The Liberator can make a grown man cry like a little girl within 50' or less when you first learn to taxi her.  :D

Once you get used to her you can drive her around like a sportscar --- well, like a 65000 pound 67' long, 110' wide sportscar.  What many of us did was instead of pressing with your foot to apply brakes (when using for directional control) was to just curl your toes down -- that little bit of pressure would be enough to open the flow valve to the brake and gently apply just enough to ease her around the corner as you taxi.  When taxiing along a taxiway we'd taxi with a bit of speed to get the rudders working (also bumping the power up on #2 and #3 helps to get more air over the rudder) then you didn't need brakes to steer.  You can also steer with power but have to be careful because each time you add power to turn you also pick up a bit more speed.

Using brakes and power it is possible to "back up" in the B-17.  Think about it.....
Was not aware the 17 had "reversable" props! We used power on 1 and 4 to help with taxiing, but the 29 was a docil ground hog! "A" and "N" quadrant was as you point out, a 4 "legged" radio range. First thing you had to do is orientate yourself by first "ident" which quadrant you were in! Lets say for discussion, dash-dot. Then you flew what ever heading you wanted to and turned your radio down to where you could barely hear the dast-dot. If the signal dies, you were generally going "away" from the station. Do a 180 and listen again and if sound increased, you were generally going towards the station. (Your car radio will do the same thing today) You had no choice at his point but to continue your heading until you heard a steady tone, which would occur as your crossed the "A" and "N' signals which would now be joined and you would get a steady "tone". Then it was a simple matter to keep bracketing this tone until the signal got louder and louder and as you crossed the transmitter site, you would enter the "cone" of silence. The higher you were, the wider the "cone" of silents. This was the first navigational system in the U.S., pioneered by the old "Air Mail" system and was installed by the U.S. government so as to have fast and timely mail delivery. Then the airline pioneers started flying and of course the rest is history as they say. Those guys flying mail planes were really brave pilots. After finding the cone of silence and not knowing how low the clouds were, they would select one of the four legs, execute a "procedure" turn, descending all the time until they broke out of the bottom of the clouds or crashed into a mountain. There was actually a "flare" system in use prior to the introduction of "low" frequency navigation, where the government had employees actually light large bon fires every 30 miles or so. Not sure on the distance between fires, but you get the idea. If it was IFR conditions, they just waited on the ground until the weather cleared. I had the honor of knowing a wise old gentleman by the name of W.W. Taylor, who in his early sixties, gave me several lessons in a J-3 in 1948. He was a early airmail pilot and he told me he knew where all the Railroad stations were along his route he flew and where the fields were that he could land in. He would walk to the station and have them telegraph ahead to see what the weather was where he was going, if there was a doubt about the weather ahead. He also said he knew where he could land and get fuel for his aircraft. Wow, would that have not been some exciting times to be flying? Bywinged aircraft, flying wires for braces, struts, only thing I ever flew was the famous PT-17 steerman and if you couldn't hear what was about to happen when you slowed down, you were in for one hellav surprise. I would advise anyone reading this to make every effort to find one of the old steermans and beg or pay for a ride! It will really make you appreciate why it was always regarded as the best "basic" trainer every built. (Don't mean to slight the T-6, but it had a closed cockpit, which you could open in flight, but still nothing like the old steerman)!
« Last Edit: May 01, 2012, 09:00:36 PM by earl1937 »
Blue Skies and wind at my back and wish that for all!!!