Why does an airplane fly?

meritflyer · November 6th, 2006, 19:34

Seems to be a misunderstood subject in the instructor community. Most consider it a debatable one as well. Newtonian theory? Bernoulli? Both?

Discuss..

Gonzo · November 6th, 2006, 19:40

As a wise ex-Airbus employee once told planes fly because of magic

amorris311 · November 6th, 2006, 19:41

i believe it.

themctm · November 6th, 2006, 19:44

To be honest I rely on the FAA for all explanations...

USMCmech · November 6th, 2006, 19:44

Money, lots of Money.

meritflyer · November 6th, 2006, 20:06

Quote:

Originally Posted by USMCmech

Money, lots of Money.

Ding! Ding! Ding!

meritflyer · November 6th, 2006, 20:07

Quote:

Originally Posted by themctm

To be honest I rely on the FAA for all explanations...

The Proficient Pilot by Capt. Barry Schiff.

BuickCFI · November 6th, 2006, 22:19

money and magic, only thing you ever need to know

seagull · November 7th, 2006, 06:32

The topic with my screen name above is a discussion on this, but there have been a lot of threads on this topic before, do a search of them and read up.

It is misunderstood, that's for sure!

Dazzler · November 8th, 2006, 22:17

Fixed wing aircraft fly because of money.
Rotary wing aircraft fly because they are so ugly the Earth repels them.

BuickCFI · November 8th, 2006, 23:03

Quote:

Originally Posted by Dazzler

Fixed wing aircraft fly because of money.
Rotary wing aircraft fly because they are so ugly the Earth repels them.

i love it

Champcar · November 8th, 2006, 23:35

I believe Bernoulli is the main cause of flight, newton may have some part in it.

seagull · November 9th, 2006, 06:08

Quote:

Originally Posted by Champcar

I believe Bernoulli is the main cause of flight, newton may have some part in it.

Depends on what you mean by this. If you mean it the way most do, the answer is "not".

JAM · November 9th, 2006, 11:37

Widely misunderstood. The sun is what makes airplanes fly. Ever notice there are many more airplanes flying when it's sunny?

TFaudree_ERAU · November 9th, 2006, 12:02

Quote:

Originally Posted by JAM

Widely misunderstood. The sun is what makes airplanes fly. Ever notice there are many more airplanes flying when it's sunny?

But you've shot down your own argument when you said "more airplanes". That means airplanes DO fly at night, so that rules out the sun theory.

My answer: Chuck Norris and a little bit of the Foo Fighters (Learn To Fly)

seagull · November 9th, 2006, 22:08

Actually, the answer is "what else do you expect them to do, they're airplanes! Do you expect them to bark at your neighbors? Sheesh!"

Dazzler · November 9th, 2006, 23:08

Quote:

Originally Posted by seagull

Actually, the answer is "what else do you expect them to do, they're airplanes! Do you expect them to bark at your neighbors? Sheesh!"

No, silly, cars do that!

perpetual · November 10th, 2006, 13:34

Airplanes fly the same as fish swim / interact with water...

resistance of two masses interacting....

Ian J · November 10th, 2006, 13:42

Quote:

Originally Posted by Dazzler

Fixed wing aircraft fly because of money.
Rotary wing aircraft fly because they are so ugly the Earth repels them.

No, rotary wing aircraft fly because they know if they don't, I'll roundhouse kick them into the stratoshere!

aviatorrbt · November 10th, 2006, 20:17

Quote:

Originally Posted by Dazzler

Fixed wing aircraft fly because of money.
Rotary wing aircraft fly because they are so ugly the Earth repels them.

aviatorrbt · November 10th, 2006, 20:18

Quote:

Originally Posted by ChinookDriver

No, rotary wing aircraft fly because they know if they don't, I'll roundhouse kick them into the stratoshere!

that could work too!

Sandesh · November 14th, 2006, 16:52

According to my instructor. In a climb it is mostly newton because of the AOA. The air is hitting the wing thus creating a force upward. But in Level or cruise, It is mostly bernouli which is the pressure difference. So its is a combo of both.

B767Driver · November 14th, 2006, 18:36

Quote:

Originally Posted by Sandesh

According to my instructor. In a climb it is mostly newton because of the AOA. The air is hitting the wing thus creating a force upward. But in Level or cruise, It is mostly bernouli which is the pressure difference. So its is a combo of both.

Uh-oh...you're going to raise Seagull's blood pressure!

Your understanding is normal...and I was a CFI for 15 years before I started to take an interest and learn more about aerodynamics. Mostly...because Seagull called me out on my misunderstood and misapplied physics of the subject. Then I took a deeper look at the physics involved...instead of the skin deep gloss over that most pilots get in pilot training.

Most FAA publications, industry journals and pilot training material will re-inforce what you stated above. As a matter of fact, I reviewed my CFI certificate on line this summer...and that's exactly what the author stated about lift production (also what the FAA teaches). But truth be told....an airplane produces lift because of the pressure differential formed due to the shape of the airfoil and how it causes air to flow around it. Not by forces formed by air impacting the surface and bouncing off of it.

Newton's 3rd law is a misapplication and is largely insignificant in lift production until you reach very high altitude, hypersonic flight. Here the air particles hitting the surface and bouncing off become more significant in comparison with the extremely low air pressure at high altitude...and will become a player in force development.

meritflyer · November 14th, 2006, 20:20

Capt. Barry Schiff also says lift is due to a combo of both Newtonian and Bernoulli in his book, The Proficient Pilot.

It discusses in detail air striking the wing from underneath, air accelerating over the upper camber to produce a downward moment off the trailing edge, and the high/low pressure differential theory of static pressure and kinetic energy.

B767Driver · November 14th, 2006, 20:35

Quote:

Originally Posted by meritflyer

Capt. Barry Schiff also says lift is due to a combo of both Newtonian and Bernoulli in his book, The Proficient Pilot.

It discusses in detail air striking the wing from underneath, air accelerating over the upper camber to produce a downward moment off the trailing edge, and the high/low pressure differential theory of static pressure and kinetic energy.

It's no wonder we're all so confused.

There's an endless array of variations to the story.

I've been reading and asking pointed questions relating to fluid dynamics over the past couple of years...and those analysis discount the effect of bouncing air off the bottom of the wing as "statistically insignificant".

November 6th, 2006, 19:34	#1
meritflyer Old Skool Join Date: Dec 2005 Location: Winchestertonfieldville Posts: 6,802	Why does an airplane fly? Seems to be a misunderstood subject in the instructor community. Most consider it a debatable one as well. Newtonian theory? Bernoulli? Both? Discuss.. __________________ The simplest answer tends to be correct.

November 6th, 2006, 19:40	#2
Gonzo Old Skool Join Date: Sep 2005 Posts: 1,765	Re: Why does an airplane fly? As a wise ex-Airbus employee once told planes fly because of magic

November 6th, 2006, 19:41	#3
amorris311 Old Skool Join Date: Feb 2006 Location: Los Angeles soon to be phx Posts: 2,628	Re: Why does an airplane fly? i believe it.

November 6th, 2006, 19:44	#4
themctm Junior Member Join Date: Sep 2006 Posts: 87	Re: Why does an airplane fly? To be honest I rely on the FAA for all explanations...

November 6th, 2006, 19:44	#5
USMCmech Old Skool Join Date: May 2004 Location: Dallas TX Posts: 1,711	Re: Why does an airplane fly? Money, lots of Money. __________________ "You may all go to Hell, I shall go to Texas" David Crockett http://www.myspace.com/usmcmech96

November 6th, 2006, 22:19	#8
BuickCFI Old Skool Join Date: Feb 2006 Location: South of the Border Posts: 2,053	Re: Why does an airplane fly? money and magic, only thing you ever need to know __________________ CFI, CFII, MEI -Why is it when two planes almost hit each other it is called a near miss? Shouldn't it be called a near hit?

November 7th, 2006, 06:32	#9
seagull Old Skool Join Date: Sep 2001 Posts: 2,045	Re: Why does an airplane fly? The topic with my screen name above is a discussion on this, but there have been a lot of threads on this topic before, do a search of them and read up. It is misunderstood, that's for sure!

November 8th, 2006, 22:17	#10
Dazzler Senior Member Join Date: Jan 2004 Location: Minneapolis, MN Posts: 1,038	Re: Why does an airplane fly? Fixed wing aircraft fly because of money. Rotary wing aircraft fly because they are so ugly the Earth repels them. __________________ CSEL-IA AGI IGI CFI CFII Little children may destroy a house... But they make a home.

November 8th, 2006, 23:35	#12
Champcar Old Skool Join Date: Oct 2005 Location: KROC Posts: 2,245	Re: Why does an airplane fly? I believe Bernoulli is the main cause of flight, newton may have some part in it. __________________ Commercial Single/Multi Instrument IGI

November 9th, 2006, 11:37	#14
JAM Junior Member Join Date: Oct 2002 Location: Florida Posts: 246	Re: Why does an airplane fly? Widely misunderstood. The sun is what makes airplanes fly. Ever notice there are many more airplanes flying when it's sunny?

November 9th, 2006, 22:08	#16
seagull Old Skool Join Date: Sep 2001 Posts: 2,045	Re: Why does an airplane fly? Actually, the answer is "what else do you expect them to do, they're airplanes! Do you expect them to bark at your neighbors? Sheesh!"

November 10th, 2006, 13:34	#18
perpetual Junior Member Join Date: Mar 2002 Location: RKNN Posts: 185	Re: Why does an airplane fly? Airplanes fly the same as fish swim / interact with water... resistance of two masses interacting....

November 14th, 2006, 16:52	#22
Sandesh Junior Member Join Date: Dec 2004 Location: TEXAS Posts: 84	Re: Why does an airplane fly? According to my instructor. In a climb it is mostly newton because of the AOA. The air is hitting the wing thus creating a force upward. But in Level or cruise, It is mostly bernouli which is the pressure difference. So its is a combo of both. __________________ Status-Private Pilot w/Instrument Rating. Objective- Airline Pilot.

November 14th, 2006, 20:20	#24
meritflyer Old Skool Join Date: Dec 2005 Location: Winchestertonfieldville Posts: 6,802	Re: Why does an airplane fly? Capt. Barry Schiff also says lift is due to a combo of both Newtonian and Bernoulli in his book, The Proficient Pilot. It discusses in detail air striking the wing from underneath, air accelerating over the upper camber to produce a downward moment off the trailing edge, and the high/low pressure differential theory of static pressure and kinetic energy. __________________ The simplest answer tends to be correct.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode