Experiment & Questions

[Learning2Fly]

^ Right, but again, the small forces over extended periods would confuse the instrument.

For example, a rotation of +/-1 or 2 degrees in pitch, or bank over 20 miles of ground would activate the erection system.

The ADI would self correct with the force of gravity, and the scenario repeats constantly over the entire flight.

At best, the ADI is very inaccurate instrument...at least within a small window of precision.

I found these last night and leafed through pages of each using key search words. I'll keep them by the bed side!

Fundamentals of High Accuracy Inertial Navigation
https://books.google.ca/books?id=2hJTDp ... on&f=false

Automatic Control of Aircraft and Missiles
https://books.google.ca/books/about/Aut ... &q&f=false

[PilotDAR]

For example, a rotation of +/-1 or 2 degrees in pitch, or bank over 20 miles of ground would activate the erection system.

The ADI would self correct with the force of gravity, and the scenario repeats constantly over the entire flight.

Yes.

Right, but again, the small forces over extended periods would confuse the instrument.....

.....At best, the ADI is very inaccurate instrument...at least within a small window of precision.

No.

Airworthy aircraft parts and systems do not get confused, are inaccurate, nor have small windows of precision. They will work correctly through their full operating range, or they are not certified for installation.

It seems to me that you should stop thinking about this, and simply accept that these instruments work perfectly fine as intended, and pilots should fly with reference to them with confidence. In the case of a system failure, means are in place for a pilot to detect that, but it will not result in the aircraft being cast away from earth into space!

[digits_]

I found these last night and leafed through pages of each using key search words. I'll keep them by the bed side!

Fundamentals of High Accuracy Inertial Navigation
https://books.google.ca/books?id=2hJTDp ... on&f=false

Automatic Control of Aircraft and Missiles
https://books.google.ca/books/about/Aut ... &q&f=false

And that is probably the core of your problems. Leafing throuh, using key search words, is not how you study and learn new concepts. You have to actually thorougly read and understand what is written. And read it again.

Inertial Navigation works on a different principle than an attitude indicator and will not help you understand the air vane technique mentioned before.

[Learning2Fly]

It seems to me that you should stop thinking about this, and simply accept that these instruments work perfectly fine as intended

No, I think I should continue thinking about this and you should as well.

You're not accounting for the small, constant forces that I have described which will confuse the instrument.

If you think the rate of change, and change of forces on the gimbal will vary based on aircraft speed, then you must agree
the instrument must be able to correct for a 0.00001 degree of change per minute to 8 degrees per minute (value referenced by Photofly).

If you are flying level at speed X, and gravity is forcing a correction of 4 degrees per minute, there is still a window of 4 degrees per minute
that can be added by slight rotations that will activate the erection system. Unless you tell me that your aircraft would never pitch or roll
at a rate of 1,2,3 degrees over 20 miles...

More to the first point, I fell upon this video just now to help explain my argument. Well damn, now I'm really looking for your answers.
This guy is stating that a constant rate of climb would require yoke inputs to maintain the pitch because we all agree that gravity allows
us to fly level without nosing down.

I've time marked this video and it's about 45 seconds of your time. Explain this to agree with the gravity concept of flying level please:
[youtube]https://youtu.be/5kYekbGBzEY?t=24m00s[/youtube]

[digits_]

https://youtu.be/5kYekbGBzEY?t=24m00s

How do you expect to ever understand the answers to your questions if you keep watching/trusting movies that start from a flawed premise: the earth is flat?

[Learning2Fly]

https://youtu.be/5kYekbGBzEY?t=24m00s

How do you expect to ever understand the answers to your questions if you keep watching/trusting movies that start from a flawed premise: the earth is flat?

He asks a valid question:

Why are you not making constant corrections on the yoke (pulling back) to maintain a constant rate of climb (pitch)?

ie: no elevator inputs during climb, no trim, etc. the ADI must show a trend toward the horizon, VSI should show an increased rate of climb as more ground is covered

Surely, someone can verify this during their next flight?

ETA: add VSI should increase rate of climb over distance.

[PilotDAR]

which will confuse the instrument.

Very simply, I trust what I see. In 7500 hours of flying, I have seen exactly three confused attitude indicators. Two were explained as a result of vacuum pump failure, and one internal bearing failure. Even after aerobatics, and toppling the AI, they're not confused, they are righting themselves with the intended function. Instruments which get confused don't get certified, which I know, 'cause I'm a guy who certifies such things!

[digits_]

Why are you not making constant corrections on the yoke (pulling back) to maintain a constant rate of climb (pitch)?

You are. You can trim to neutralize the forces, or just keep the pressure manually if you don't trim.

[Learning2Fly]

Digits,

According to the engineer in the video, the trim will require resetting constantly.

You can't just aim the aircraft without elevator inputs because the Earth continues to curve, and gravity will continue to pull the aircraft off pitch.

If you were to neutralize the force, the elevator would be angled in which case the aircraft would have a higher rate of climb.

Agree?

[digits_]

Digits,

According to the engineer in the video, the trim will require resetting constantly.

You can't just aim the aircraft without elevator inputs because the Earth continues to curve, and gravity will continue to pull the aircraft off pitch.

If you were to neutralize the force, the elevator would be angled in which case the aircraft would have a higher rate of climb.

Agree?

Read the previous posts. No I don't agree. That is incorrect.

[Learning2Fly]

Digits,

According to the engineer in the video, the trim will require resetting constantly.

You can't just aim the aircraft without elevator inputs because the Earth continues to curve, and gravity will continue to pull the aircraft off pitch.

If you were to neutralize the force, the elevator would be angled in which case the aircraft would have a higher rate of climb.

Agree?

Read the previous posts. No I don't agree. That is incorrect.

So then your ascent is not a straight line from the tangent, it is curving down as you are climbing...but the ADI doesn't follow this trend.

Agree? If so:

why does the ADI not trend toward the horizon as you steady climb, but the ADI will remain steady in level flight?

[Chris M]

So then your ascent is not a straight line from the tangent, it is curving down as you are climbing...but the ADI doesn't follow this trend.

Agree? If so:

why does the ADI not trend toward the horizon as you steady climb, but the ADI will remain steady in level flight?

Correct. On a large scale the climb is a round profile at a constantly diverging distance from the Earth below.

The AI displays the angle between the aircraft and the earth directly below. That angle is constant throughout the climb.

The above is stated assuming the aircraft is performing a theoretically ideal climb, one with a constant rate and ground speed all the way up. Reality will differ.

[PilotDAR]

the trim will require resetting constantly.

So you could run out of trim, before you ran low on fuel? I must flight plan a route only so long as can be flown before I run out of trim range! I've never seen that in a flight manual!

[Learning2Fly]

the trim will require resetting constantly.

So you could run out of trim, before you ran low on fuel? I must flight plan a route only so long as can be flown before I run out of trim range! I've never seen that in a flight manual!

Then our perception of constant climb cannot be a straight line as shown in the video.

It must be a curved trajectory.

Now I'm going the instruments and math as I don't believe the ADI, and VSI agree with a
'constant rate of climb' model of a curved line.

Time for some scale drawings and math?

[7ECA]

Man, I'm wondering how any of us have managed to fly for any number of hours before running into all of these issues with trim, instruments, etc...

We all must be really friggin' lucky, or something. Maybe Murphy took a day off?

[C.W.E.]

If friction produces heat how long should it take for a dog to hump a pail of water to a boil?

[digits_]

If friction produces heat how long should it take for a dog to hump a pail of water to a boil?

It will never work as at a certain point you'll get an equilibrium between the heat the dog produces and the losses that occur from heat leaking into the environment.

[Learning2Fly]

If friction produces heat how long should it take for a dog to hump a pail of water to a boil?

Hey smart guy, can you tell me how the VSI indicates ft/min?

Apply your answer to a curved ascent, while gravity is pulling the aircraft over the curved Earth.

I don't ever remember the instructor drawing a curved line for climb in flight plan.

Do you?

[7ECA]

Hey smart guy, can you tell me how the VSI indicates ft/min?

Apply your answer to a curved ascent, while gravity is pulling the aircraft over the curved Earth.

I don't ever remember the instructor drawing a curved line for climb in flight plan.

Do you?

You must be a real joy in ground school.

Happen to have gone through a lot of instructors recently?

[youhavecontrol]

Learning2Fly, I decided to quote myself. It seems like that's all any of us are doing right now in a round-about way... just repeating ourselves hoping it'll stick. Maybe you'll understand it when you read it a second time:

Learning2Fly, in all honesty, it's clear that what you need is to discuss this in person with someone, over a whiteboard, who can break down each concept individually, rather than offer explanations piece by piece that get muddied by your own research. Every time an answer is given to you, you counter it with some piece of information with another logical flaw in it. Once that flaw is pointed out, it's as if you forget the first answer someone gave you and you are back to square one again... asking about altitude over distance. It's hopeless discussing in circles without drawing the bigger picture for you. You need a one-on-one lesson, not the internet.

I swear... the flat earth thing is one frustratingly huge echo-chamber where reason and clarity are totally lost with the rest of the crap bouncing around.

It reminds me of the airplane/treadmill thing all over again.