An observation about Attitude Indicators on aircraft.

Quote from: Jonny B Smart on April 06, 2017, 04:48:57 AM

"My son's playground ball is round. How could we have a round ball if the Earth is flat. If he Earth were flat, wouldn't his ball be shaped like a pancake?" (This is what you sound like to us.)

yeah exactly, why are some fruits round? If they grow on a flat earth, shouldn't they be flat? I'm surprised these people can even work their computers to watch their youtube "proofs".

This topic is about "Attitude Indicators on aircraft" so what about the instructions actually given to pilots.
In this case, it is on the "Head up display" version of the flight instruments.

More evidence the Horizon does not remain at eye level as you gain altitude.

The bit about the HUD instructions starts at about 0:44 secs in.

There is more than one way to "see curvature". There is a little horizontal curvature at 45,000 ft,

but an easily measurable "dip angle to the horizon" caused by the curvature of the going away from the observer.

See what you think.

I dropped a straight edge along the horizons shown, and did a measurement, at 1:50, between the horizon line indicator, and the actual earth horizon in the distance, and all were straight across, I did not observe any curvature when I used a straight edge.

"caused by the curvature of the going away from the observer"

You're dealing with perspective going away. The floor of the observer will rise up to the vanishing point, giving the observer the illusion the water/land reaches an apex of a curvature. We can observe the phenomenon on straight level railroad tracks, that we absolutely know is not going over any curvature. I have surveyed along RR tracks, and they're pretty horizontally level, not perfect, there are little dips and rises, but I've never measured a constant curvature along RR tracks. That doesn't prove the earth is flat, just saying RR tracks are laid on excavated surfaces that try to maintain a surface that is horizontally level, flat, a plane. A curve is not a flat level plane.

This carpenter's level:

http://sherpapreview-standard.s3-website-us-east-1.amazonaws.com/Preview/2012/08/15__04_18_30/13056_Left0000.jpg753c0e88-0a96-450c-bea2-42ccbac68698Large.jpg

...works, based on water being straight, level flat across its surface. Notice the liquid in the left and right sights, the water surface is horizontally level to earth's plane surface. This level could not work if water bowed across its surface. We would never understand what horizontally level means if not for the surface of water.

Quote from: rabinoz on April 06, 2017, 05:08:07 AM

This topic is about "Attitude Indicators on aircraft" so what about the instructions actually given to pilots.
In this case, it is on the "Head up display" version of the flight instruments.

More evidence the Horizon does not remain at eye level as you gain altitude.

The bit about the HUD instructions starts at about 0:44 secs in.

There is more than one way to "see curvature". There is a little horizontal curvature at 45,000 ft,

but an easily measurable "dip angle to the horizon" caused by the curvature of the going away from the observer.

See what you think.

I dropped a straight edge along the horizons shown, and did a measurement, at 1:50, between the horizon line indicator, and the actual earth horizon in the distance, and all were straight across, I did not observe any curvature when I used a straight edge.

"caused by the curvature of the going away from the observer"

You're dealing with perspective going away. The floor of the observer will rise up to the vanishing point, giving the observer the illusion the water/land reaches an apex of a curvature. We can observe the phenomenon on straight level railroad tracks, that we absolutely know is not going over any curvature. I have surveyed along RR tracks, and they're pretty horizontally level, not perfect, there are little dips and rises, but I've never measured a constant curvature along RR tracks. That doesn't prove the earth is flat, just saying RR tracks are laid on excavated surfaces that try to maintain a surface that is horizontally level, flat, a plane. A curve is not a flat level plane.

This carpenter's level:

http://sherpapreview-standard.s3-website-us-east-1.amazonaws.com/Preview/2012/08/15__04_18_30/13056_Left0000.jpg753c0e88-0a96-450c-bea2-42ccbac68698Large.jpg

...works, based on water being straight, level flat across its surface. Notice the liquid in the left and right sights, the water surface is horizontally level to earth's plane surface. This level could not work if water bowed across its surface. We would never understand what horizontally level means if not for the surface of water.

Quote from: physical observer on April 06, 2017, 06:05:16 AM

Quote from: rabinoz on April 06, 2017, 05:08:07 AM

This topic is about "Attitude Indicators on aircraft" so what about the instructions actually given to pilots.
In this case, it is on the "Head up display" version of the flight instruments.

More evidence the Horizon does not remain at eye level as you gain altitude.

The bit about the HUD instructions starts at about 0:44 secs in.

There is more than one way to "see curvature". There is a little horizontal curvature at 45,000 ft,

but an easily measurable "dip angle to the horizon" caused by the curvature of the going away from the observer.

See what you think.

I dropped a straight edge along the horizons shown, and did a measurement, at 1:50, between the horizon line indicator, and the actual earth horizon in the distance, and all were straight across, I did not observe any curvature when I used a straight edge.

"caused by the curvature of the going away from the observer"

You're dealing with perspective going away. The floor of the observer will rise up to the vanishing point, giving the observer the illusion the water/land reaches an apex of a curvature. We can observe the phenomenon on straight level railroad tracks, that we absolutely know is not going over any curvature. I have surveyed along RR tracks, and they're pretty horizontally level, not perfect, there are little dips and rises, but I've never measured a constant curvature along RR tracks. That doesn't prove the earth is flat, just saying RR tracks are laid on excavated surfaces that try to maintain a surface that is horizontally level, flat, a plane. A curve is not a flat level plane.

This carpenter's level:

http://sherpapreview-standard.s3-website-us-east-1.amazonaws.com/Preview/2012/08/15__04_18_30/13056_Left0000.jpg753c0e88-0a96-450c-bea2-42ccbac68698Large.jpg

...works, based on water being straight, level flat across its surface. Notice the liquid in the left and right sights, the water surface is horizontally level to earth's plane surface. This level could not work if water bowed across its surface. We would never understand what horizontally level means if not for the surface of water.

You do understand the size of the earth and how it affects measurements?

Quote from: inquisitive on April 06, 2017, 09:46:18 AM

Quote from: physical observer on April 06, 2017, 06:05:16 AM

Quote from: rabinoz on April 06, 2017, 05:08:07 AM

This topic is about "Attitude Indicators on aircraft" so what about the instructions actually given to pilots.
In this case, it is on the "Head up display" version of the flight instruments.

More evidence the Horizon does not remain at eye level as you gain altitude.

The bit about the HUD instructions starts at about 0:44 secs in.

There is more than one way to "see curvature". There is a little horizontal curvature at 45,000 ft,

but an easily measurable "dip angle to the horizon" caused by the curvature of the going away from the observer.

See what you think.

I dropped a straight edge along the horizons shown, and did a measurement, at 1:50, between the horizon line indicator, and the actual earth horizon in the distance, and all were straight across, I did not observe any curvature when I used a straight edge.

"caused by the curvature of the going away from the observer"

You're dealing with perspective going away. The floor of the observer will rise up to the vanishing point, giving the observer the illusion the water/land reaches an apex of a curvature. We can observe the phenomenon on straight level railroad tracks, that we absolutely know is not going over any curvature. I have surveyed along RR tracks, and they're pretty horizontally level, not perfect, there are little dips and rises, but I've never measured a constant curvature along RR tracks. That doesn't prove the earth is flat, just saying RR tracks are laid on excavated surfaces that try to maintain a surface that is horizontally level, flat, a plane. A curve is not a flat level plane.

This carpenter's level:

http://sherpapreview-standard.s3-website-us-east-1.amazonaws.com/Preview/2012/08/15__04_18_30/13056_Left0000.jpg753c0e88-0a96-450c-bea2-42ccbac68698Large.jpg

...works, based on water being straight, level flat across its surface. Notice the liquid in the left and right sights, the water surface is horizontally level to earth's plane surface. This level could not work if water bowed across its surface. We would never understand what horizontally level means if not for the surface of water.

You do understand the size of the earth and how it affects measurements?

If the earth is a sphere, then it is not a horizontal line, like shown on the attitude indicator. It then scares me to think pilots are flying their craft thinking the land beneath is horizontally flat. If pilots are flying over a curved earth, their instruments would indicate that curve, but it doesn't, does it?

Quote from: inquisitive on April 06, 2017, 09:46:18 AM

Quote from: physical observer on April 06, 2017, 06:05:16 AM

Quote from: rabinoz on April 06, 2017, 05:08:07 AM

This topic is about "Attitude Indicators on aircraft" so what about the instructions actually given to pilots.
In this case, it is on the "Head up display" version of the flight instruments.

More evidence the Horizon does not remain at eye level as you gain altitude.

The bit about the HUD instructions starts at about 0:44 secs in.

There is more than one way to "see curvature". There is a little horizontal curvature at 45,000 ft,

but an easily measurable "dip angle to the horizon" caused by the curvature of the going away from the observer.

See what you think.

I dropped a straight edge along the horizons shown, and did a measurement, at 1:50, between the horizon line indicator, and the actual earth horizon in the distance, and all were straight across, I did not observe any curvature when I used a straight edge.

"caused by the curvature of the going away from the observer"

You're dealing with perspective going away. The floor of the observer will rise up to the vanishing point, giving the observer the illusion the water/land reaches an apex of a curvature. We can observe the phenomenon on straight level railroad tracks, that we absolutely know is not going over any curvature. I have surveyed along RR tracks, and they're pretty horizontally level, not perfect, there are little dips and rises, but I've never measured a constant curvature along RR tracks. That doesn't prove the earth is flat, just saying RR tracks are laid on excavated surfaces that try to maintain a surface that is horizontally level, flat, a plane. A curve is not a flat level plane.

This carpenter's level:

http://sherpapreview-standard.s3-website-us-east-1.amazonaws.com/Preview/2012/08/15__04_18_30/13056_Left0000.jpg753c0e88-0a96-450c-bea2-42ccbac68698Large.jpg

...works, based on water being straight, level flat across its surface. Notice the liquid in the left and right sights, the water surface is horizontally level to earth's plane surface. This level could not work if water bowed across its surface. We would never understand what horizontally level means if not for the surface of water.

You do understand the size of the earth and how it affects measurements?

If the earth is a sphere, then it is not a horizontal line, like shown on the attitude indicator. It then scares me to think pilots are flying their craft thinking the land beneath is horizontally flat. If pilots are flying over a curved earth, their instruments would indicate that curve, but it doesn't, does it?

Quote from: kennykirklan on April 06, 2017, 05:02:15 AM

Quote from: Jonny B Smart on April 06, 2017, 04:48:57 AM

"My son's playground ball is round. How could we have a round ball if the Earth is flat. If he Earth were flat, wouldn't his ball be shaped like a pancake?" (This is what you sound like to us.)

yeah exactly, why are some fruits round? If they grow on a flat earth, shouldn't they be flat? I'm surprised these people can even work their computers to watch their youtube "proofs".

Fruit is round, so earth is round? What a sorry analogy.

Yep, the curvature just can't be detected, can it? You know why, because it is not there. Your need to insult shows your failure in supporting your claim.

I'll be waiting for your visual evidence concerning water.

You're dealing with perspective going away. The floor of the observer will rise up to the vanishing point, giving the observer the illusion the water/land reaches an apex of a curvature.

that we absolutely know is not going over any curvature.

and they're pretty horizontally level

but I've never measured a constant curvature along RR tracks.

just saying RR tracks are laid on excavated surfaces that try to maintain a surface that is horizontally level, flat, a plane. A curve is not a flat level plane.

This carpenter's level:

...works, based on water being straight, level flat across its surface.

Notice the liquid in the left and right sights, the water surface is horizontally level to earth's plane surface.

This level could not work if water bowed across its surface. We would never understand what horizontally level means if not for the surface of water.

If the earth is a sphere, then it is not a horizontal line, like shown on the attitude indicator. It then scares me to think pilots are flying their craft thinking the land beneath is horizontally flat. If pilots are flying over a curved earth, their instruments would indicate that curve, but it doesn't, does it?

PO

After your total ignorance and dismissing of Newton's Laws in the other thread earlier I wasn't going to get involved with you again but hey-ho. I have a certain interest in this subject.

Firstly curvature. You DO see it all the time....going away from you. The horizon in all directions is the same distance so no wonder it looks flat! You effectively ARE on a flat earth with a radius of 3 miles (sea level). You have to go really high and effectively be looking down on the earth to see the curve.

Anyway, back to aircraft artificial horizons. I'll be doing some "practical study" later whilst piloting a Boeing 777-200 ER from Far East Asia back to Europe. I don't doubt that the line on the glass cockpit Attitude Indicator has been "drawn" straight, but then the curve would be pretty tricky to draw given that it's radius would be 6400kms and the instrument is only a few inches across - maybe you own a big enough compass, I don't, but hey, I've only been a commercial pilot for 28 years so perhaps you know more than me.

Anyway, concerning the flight. The routing westward will be basically a great circle route between departure and arrival. This will get modified due to prevailing winds and temperatures, overflight charges, political considerations for possible diversions, forecast CAT etc etc. That's all been done presuming the earth is a sphere. This generates planned true and magnetic headings across diverging lines of longitude. I appreciate the flat earth map does approximate to a projected globe in the northern hempisphere but it still has those lines of longitude like spokes of a wheel, always at the same angle to each other. The real world isn't like that which is why we're trained to work out initial true/mag tracks between waypoints using a round earth model. But maybe you know more about it than I do.

In reality we will primarily use gps - you know that info from satellites orbiting the round earth. As a back up and cross check we'll align our IRS (inertial reference system) which is a 3axis gyro stabilised set of orthogonally mounted accelerometers. We tell it where it is to start with (using a spherical earth lat/long coordinate system) then the computer integrates twice to go from acceleration, to speed, to position. There we go with that pesky Newtonian calculus again but it seems to work! Luck maybe? Perhaps you know more than Newton.

If we don't like that it's down to VOR/DME/NDB fixing, the max ranges of which are calculated assuming the earth is round as it's basically the same as line of sight, i.e. From what altitude can I receive that station. Actually it is odd that line of sight ranges increase with altitude isn't it? It shouldn't make any difference on a flat earth. Perhaps you know more than I do.

And before you ask, no you don't really see the curve at 40,000 feet. The radius of the earth is 6400kms so popping up another 10 doesn't do much. It does make the horizon about 200 nautical miles away though. We do see some cool sunrises and sunsets though, and the Milky Way over Australia is awesome. Odd how flying from say over Broome to Sydney takes the time it says on the flight plan though - it looks a bloodily long way on a flat earth map. Perhaps you know more about it?

Anyway, it all starts with lobbing a load of fuel into the engines, firing them up and opening the taps. Those big Rolls Royce Trents are awesome. The fuel burns, the mix heats up, gets ejected out of the back, add the thrust from the huge front fan and hey ho Newton's 3rd law sends us forward. Who'd of thought it? At Vr we use the horizontal stabiliser to change the attitude, increasing the angle of attack of the wing, then Mr Bernoulli takes over and we get lift and we're away. Now call me controversial but the FOUR forces acting on the aircraft are lift opposing gravity, and thrust opposing drag. At least I think that's it. Perhaps you know more than I do.

As we climb gravity makes the air less dense changing the angles of attack for a given lift and changing the high speed Mach buffet and the low speed stall speeds. As the aircraft gets lighter we need less angle of attack to balance the decreasing gravitational tug which also gives less induced drag (form drag stays roughly the same).

I could go on but I think most here will be getting the idea that this is all predicated on the round earth model. Now I know you're not going to bother to try and understand but I just needed to get it off my chest! Oh and no we don't consciously pitch over to follow the curve. It's too gradual. We fly an assigned pressure altitude in the cruise based on 1013 hpa pressure. As we all do that it keeps us vertically separated from other aircraft. In reality we're all moving up and down a bit as the density of the air beneath the aircraft changes.

And relax.

Z
BAC1-11
B737 200-500
MD DC-10
B777 200-300

Quote from: physical observer on April 06, 2017, 06:05:16 AM

I dropped a straight edge along the horizons shown, and did a measurement, at 1:50, between the horizon line indicator, and the actual earth horizon in the distance, and all were straight across, I did not observe any curvature when I used a straight edge.

"caused by the curvature of the going away from the observer"

You're dealing with perspective going away. The floor of the observer will rise up to the vanishing point, giving the observer the illusion the water/land reaches an apex of a curvature. We can observe the phenomenon on straight level railroad tracks, that we absolutely know is not going over any curvature. I have surveyed along RR tracks, and they're pretty horizontally level, not perfect, there are little dips and rises, but I've never measured a constant curvature along RR tracks. That doesn't prove the earth is flat, just saying RR tracks are laid on excavated surfaces that try to maintain a surface that is horizontally level, flat, a plane. A curve is not a flat level plane.

This carpenter's level:

http://sherpapreview-standard.s3-website-us-east-1.amazonaws.com/Preview/2012/08/15__04_18_30/13056_Left0000.jpg753c0e88-0a96-450c-bea2-42ccbac68698Large.jpg

...works, based on water being straight, level flat across its surface. Notice the liquid in the left and right sights, the water surface is horizontally level to earth's plane surface. This level could not work if water bowed across its surface. We would never understand what horizontally level means if not for the surface of water.

can you give us the exact brand and part number of you straight edge?
i like to get information of the fabrication tolerance and surface tolerance of that straight edge.
because if you try to check a radius of 6372km with a straight edge that is only 6in long these tolerances matter.

for example: we had to fabricate one time a Part that had a tolerance of 0.01mm over a length of 12m for flatness.
we needed special equipment to check this part.

"caused by the curvature of the going away from the observer"

You're dealing with perspective going away. The floor of the observer will rise up to the vanishing point, giving the observer the illusion the water/land reaches an apex of a curvature. We can observe the phenomenon on straight level railroad tracks, that we absolutely know is not going over any curvature. I have surveyed along RR tracks, and they're pretty horizontally level, not perfect, there are little dips and rises, but I've never measured a constant curvature along RR tracks. That doesn't prove the earth is flat, just saying RR tracks are laid on excavated surfaces that try to maintain a surface that is horizontally level, flat, a plane. A curve is not a flat level plane.

This carpenter's level:

...works, based on water being straight, level flat across its surface. Notice the liquid in the left and right sights, the water surface is horizontally level to earth's plane surface. This level could not work if water bowed across its surface. We would never understand what horizontally level means if not for the surface of water.

The centre might be a whole 0.000000051 mm above the ends! 

Quote from: southern hemispherer on April 05, 2017, 11:24:47 AM

Do you have an attitude indicator in your car? Seeing that you see as much curvature from ground level as from an aeroplane, why don't you invest in one, Mr physical observer?

Why is the indicator line straight across, level and not curved like the ball earth? Your answer didn't answer the query.

Quote from: physical observer on April 05, 2017, 01:45:56 PM

Quote from: southern hemispherer on April 05, 2017, 11:24:47 AM

Do you have an attitude indicator in your car? Seeing that you see as much curvature from ground level as from an aeroplane, why don't you invest in one, Mr physical observer?

Why is the indicator line straight across, level and not curved like the ball earth? Your answer didn't answer the query.

Couldn't have said it better

The AI is not an earth model. The purpose of the instrument is to show the plane's attitude in relation to the horizon. At the aircraft scale and typical altitude, straight is functional.

The only time a plane would see curve is 60000feet+. Hardly any planes go that high - and, even if they did, the curve would be so subtle that a straight line on the AI would still work fine.

Mechanical gyro AIs in most commercial and military aircraft are backup instruments. Certainly wouldn't be a primary instrument in an aircraft travelling at an altitude where curvature could be viewed.

So a simple answer to your question is: there's no point manufacturing something that functionally provides no advantage and is barely relevant to a handful of aircraft that don't need it.

The earth is massive, when will that truth sink into FE people?

If the earth is a sphere, then it is not a horizontal line, like shown on the attitude indicator. It then scares me to think pilots are flying their craft thinking the land beneath is horizontally flat. If pilots are flying over a curved earth, their instruments would indicate that curve, but it doesn't, does it?

PO

After your total ignorance and dismissing of Newton's Laws in the other thread earlier I wasn't going to get involved with you again but hey-ho. I have a certain interest in this subject.

Firstly curvature. You DO see it all the time....going away from you. The horizon in all directions is the same distance so no wonder it looks flat! You effectively ARE on a flat earth with a radius of 3 miles (sea level). You have to go really high and effectively be looking down on the earth to see the curve.

Anyway, back to aircraft artificial horizons. I'll be doing some "practical study" later whilst piloting a Boeing 777-200 ER from Far East Asia back to Europe. I don't doubt that the line on the glass cockpit Attitude Indicator has been "drawn" straight, but then the curve would be pretty tricky to draw given that it's radius would be 6400kms and the instrument is only a few inches across - maybe you own a big enough compass, I don't, but hey, I've only been a commercial pilot for 28 years so perhaps you know more than me.

Anyway, concerning the flight. The routing westward will be basically a great circle route between departure and arrival. This will get modified due to prevailing winds and temperatures, overflight charges, political considerations for possible diversions, forecast CAT etc etc. That's all been done presuming the earth is a sphere. This generates planned true and magnetic headings across diverging lines of longitude. I appreciate the flat earth map does approximate to a projected globe in the northern hempisphere but it still has those lines of longitude like spokes of a wheel, always at the same angle to each other. The real world isn't like that which is why we're trained to work out initial true/mag tracks between waypoints using a round earth model. But maybe you know more about it than I do.

In reality we will primarily use gps - you know that info from satellites orbiting the round earth. As a back up and cross check we'll align our IRS (inertial reference system) which is a 3axis gyro stabilised set of orthogonally mounted accelerometers. We tell it where it is to start with (using a spherical earth lat/long coordinate system) then the computer integrates twice to go from acceleration, to speed, to position. There we go with that pesky Newtonian calculus again but it seems to work! Luck maybe? Perhaps you know more than Newton.

If we don't like that it's down to VOR/DME/NDB fixing, the max ranges of which are calculated assuming the earth is round as it's basically the same as line of sight, i.e. From what altitude can I receive that station. Actually it is odd that line of sight ranges increase with altitude isn't it? It shouldn't make any difference on a flat earth. Perhaps you know more than I do.

And before you ask, no you don't really see the curve at 40,000 feet. The radius of the earth is 6400kms so popping up another 10 doesn't do much. It does make the horizon about 200 nautical miles away though. We do see some cool sunrises and sunsets though, and the Milky Way over Australia is awesome. Odd how flying from say over Broome to Sydney takes the time it says on the flight plan though - it looks a bloodily long way on a flat earth map. Perhaps you know more about it?

Anyway, it all starts with lobbing a load of fuel into the engines, firing them up and opening the taps. Those big Rolls Royce Trents are awesome. The fuel burns, the mix heats up, gets ejected out of the back, add the thrust from the huge front fan and hey ho Newton's 3rd law sends us forward. Who'd of thought it? At Vr we use the horizontal stabiliser to change the attitude, increasing the angle of attack of the wing, then Mr Bernoulli takes over and we get lift and we're away. Now call me controversial but the FOUR forces acting on the aircraft are lift opposing gravity, and thrust opposing drag. At least I think that's it. Perhaps you know more than I do.

As we climb gravity makes the air less dense changing the angles of attack for a given lift and changing the high speed Mach buffet and the low speed stall speeds. As the aircraft gets lighter we need less angle of attack to balance the decreasing gravitational tug which also gives less induced drag (form drag stays roughly the same).

I could go on but I think most here will be getting the idea that this is all predicated on the round earth model. Now I know you're not going to bother to try and understand but I just needed to get it off my chest! Oh and no we don't consciously pitch over to follow the curve. It's too gradual. We fly an assigned pressure altitude in the cruise based on 1013 hpa pressure. As we all do that it keeps us vertically separated from other aircraft. In reality we're all moving up and down a bit as the density of the air beneath the aircraft changes.

And relax.

Z
BAC1-11
B737 200-500
MD DC-10
B777 200-300

PO

After your total ignorance and dismissing of Newton's Laws in the other thread earlier I wasn't going to get involved with you again but hey-ho. I have a certain interest in this subject.

Firstly curvature. You DO see it all the time....going away from you. The horizon in all directions is the same distance so no wonder it looks flat! You effectively ARE on a flat earth with a radius of 3 miles (sea level). You have to go really high and effectively be looking down on the earth to see the curve.

Anyway, back to aircraft artificial horizons. I'll be doing some "practical study" later whilst piloting a Boeing 777-200 ER from Far East Asia back to Europe. I don't doubt that the line on the glass cockpit Attitude Indicator has been "drawn" straight, but then the curve would be pretty tricky to draw given that it's radius would be 6400kms and the instrument is only a few inches across - maybe you own a big enough compass, I don't, but hey, I've only been a commercial pilot for 28 years so perhaps you know more than me.

Anyway, concerning the flight. The routing westward will be basically a great circle route between departure and arrival. This will get modified due to prevailing winds and temperatures, overflight charges, political considerations for possible diversions, forecast CAT etc etc. That's all been done presuming the earth is a sphere. This generates planned true and magnetic headings across diverging lines of longitude. I appreciate the flat earth map does approximate to a projected globe in the northern hempisphere but it still has those lines of longitude like spokes of a wheel, always at the same angle to each other. The real world isn't like that which is why we're trained to work out initial true/mag tracks between waypoints using a round earth model. But maybe you know more about it than I do.

In reality we will primarily use gps - you know that info from satellites orbiting the round earth. As a back up and cross check we'll align our IRS (inertial reference system) which is a 3axis gyro stabilised set of orthogonally mounted accelerometers. We tell it where it is to start with (using a spherical earth lat/long coordinate system) then the computer integrates twice to go from acceleration, to speed, to position. There we go with that pesky Newtonian calculus again but it seems to work! Luck maybe? Perhaps you know more than Newton.

If we don't like that it's down to VOR/DME/NDB fixing, the max ranges of which are calculated assuming the earth is round as it's basically the same as line of sight, i.e. From what altitude can I receive that station. Actually it is odd that line of sight ranges increase with altitude isn't it? It shouldn't make any difference on a flat earth. Perhaps you know more than I do.

And before you ask, no you don't really see the curve at 40,000 feet. The radius of the earth is 6400kms so popping up another 10 doesn't do much. It does make the horizon about 200 nautical miles away though. We do see some cool sunrises and sunsets though, and the Milky Way over Australia is awesome. Odd how flying from say over Broome to Sydney takes the time it says on the flight plan though - it looks a bloodily long way on a flat earth map. Perhaps you know more about it?

Anyway, it all starts with lobbing a load of fuel into the engines, firing them up and opening the taps. Those big Rolls Royce Trents are awesome. The fuel burns, the mix heats up, gets ejected out of the back, add the thrust from the huge front fan and hey ho Newton's 3rd law sends us forward. Who'd of thought it? At Vr we use the horizontal stabiliser to change the attitude, increasing the angle of attack of the wing, then Mr Bernoulli takes over and we get lift and we're away. Now call me controversial but the FOUR forces acting on the aircraft are lift opposing gravity, and thrust opposing drag. At least I think that's it. Perhaps you know more than I do.

As we climb gravity makes the air less dense changing the angles of attack for a given lift and changing the high speed Mach buffet and the low speed stall speeds. As the aircraft gets lighter we need less angle of attack to balance the decreasing gravitational tug which also gives less induced drag (form drag stays roughly the same).

I could go on but I think most here will be getting the idea that this is all predicated on the round earth model. Now I know you're not going to bother to try and understand but I just needed to get it off my chest! Oh and no we don't consciously pitch over to follow the curve. It's too gradual. We fly an assigned pressure altitude in the cruise based on 1013 hpa pressure. As we all do that it keeps us vertically separated from other aircraft. In reality we're all moving up and down a bit as the density of the air beneath the aircraft changes.

And relax.

Z
BAC1-11
B737 200-500
MD DC-10
B777 200-300

https://www.reddit.com/r/mildlyinteresting/comments/5ba92u/mt_hood_casting_a_shadow_on_the_clouds_this/

Physical observation of Mount Hood (Oregon, USA) casting a shadow on the bottom of cloud at sunrise. Sun must be too low for flat Earth!

Quote from: Jonny B Smart on April 07, 2017, 04:21:04 AM

https://www.reddit.com/r/mildlyinteresting/comments/5ba92u/mt_hood_casting_a_shadow_on_the_clouds_this/

Physical observation of Mount Hood (Oregon, USA) casting a shadow on the bottom of cloud at sunrise. Sun must be too low for flat Earth!

This won't help because physical observer does not understand simple math. He will probably ask how does that prove that the sun is not near.

@physical observer Before you start arguing, learn some trignometry so that we can explain that.
https://www.khanacademy.org/math/geometry/hs-geo-trig/hs-geo-trig-ratios-intro/v/basic-trigonometry

The best post I've ever seen on a FE discussion. I'm suitably humbled with my PA28/C152 background.

Killed the FE debate dead - sleep tight flat earthers. Tomorrow might bring a fresh conspiracy for you.

Beautiful
Let me know if you ever fly out of KSLC.

Now that's all well and good, presenting facts based on proven scientific principles augmented by years of first hand experience that can be corroborated by the thousands of other commercial pilots currently flying in service......BUT.....when did facts ever matter on this forum? Never.
The crazy flat earth believers religiously disregard facts in favour of dreaming up wild notions based on more than the misfiring of their malfunctioning neutrons.
The very fact that they believe in a sun made of rock and metal and that penguins were 'manufactured' by ex nazis to feed Antartic guards who protect the infinite plane  says everything one needs to know about them........mad as a spherical bucket of pancakes.

There are FE pilots that correctly define the Earth's shape as flat. They have considered all evidence instead of RE pilots demonstrating their limited exposure to FET.

It really doesn't matter if you are piloting the plane or a passenger within.  It is the experience and interpretation of observation submitted by either that ultimately determines the best source for Earth shape data.

Those in the course of FET study will focus on such things as horizon and effects of atmospherics relative to Earth shape when looking out the craft window. Pilots and others necessarily focusing on criteria other than Earth shape are not as capable of defining Earth shape vis-a-vis their flight experience.