Turns at low IAS

[old man emu]

2 hours ago, Thruster88 said:

A 3kg mass will have 30 N of force due to gravity, there is no 0.3kg anywhere

I can see that the problem with you blokes is that you cannot read. I started to post by defining the word "weight"

 

3 hours ago, old man emu said:

"Weight" is the layman's term for expressing the magnitude of the Force which is directly dependant on the mass of of an object and the acceleration due to gravity in a relationship that can be expressed algebraically as F = ma.

 Then I said, 

 

3 hours ago, old man emu said:

If we determine the "weight" of the object, to be 3 kg,

If we now put on our lab coats and become scientists, we will start talking in terms of Newtons. The scale shows us that the object exerts a force of 3 Newtons on the weighing mechanism.  Therefore in the equation F=ma, it is F that equals 3. We agree that a is an acceleration of 9.81 metres per second every second. If, for simplicity's sake, we round 9.81 to 10, then 3 = m.10. Therefore m = 3/10 which is 0.3.

 

Mass: If you could count up the number of protons, neutrons, and electrons in an object, this would be a measure of the mass. The mass is essentially "how much stuff" is in an object. 

 

Weight: There is a gravitational interaction between objects that have mass. If you consider an object interacting with the Earth ie affected by gravity, this force is called the weight. The unit for weight is the Newton.

 

I agree that if an object exerts a force of 30N, then it contains mass equal to 3 kg. But I never said that. I said that the Force (weight, whatever) was 3 kg. Read what I say, because I do think about what I write.

 

1 hour ago, APenNameAndThatA said:

OME compares his theories favourably to those of Einstein and Darwin and b) still believes that his angle of attack measuring device might work. Have I got that right OME? 

 

Scientific theories are the most reliable, rigorous, and comprehensive form of scientific knowledge, in contrast to more common uses of the word "theory" that imply that something is unproven or speculative. Lacking the facilities to test my theory, I cannot completely dismiss my device as ineffective. Until those tests are done, it still remains a theoretical use of the bubble in the tube.

23 hours ago, Student Pilot said:

This thread has just become one giant pocket pissing contest.

I agree, and I think I'm the urinal. 

 

 

[aro]

On 06/03/2021 at 5:05 PM, Student Pilot said:

Couple of things, a spirit level is open to flight forces and doesn't remain level. Bob Hoover demonstration of the roll while pouring a jug of water being an example. If an aircraft cannot maintain altitude it can just descend without stalling.

That's the point I think. APenNameAndThatA was listing things that OME has posted that are not actually true.

 

I'm sorry if OME feels picked on. What do you suggest should be done when incorrect information is posted to the Student Pilot area?

 

I have a growing suspicion that OME is trolling us with deliberately false theories. If so the joke is on us I guess. But it is a bit unfair to student pilots who might be trying to learn this stuff, and unfair to the owner of the site who is trying to create a useful resource.

[Student Pilot]

Windup

[Bruce Tuncks]

I gotta defend OME. I reckon his stuff is standard mechanics, like they once taught in physics classes. Can you give an example of a " false theory?"

 

 

[aro]

7 hours ago, old man emu said:

if an aircraft cannot maintain altitude it simply means that the Lift is insufficient to balance firstly the force of gravity and aircraft mass, plus any other detractors you want to add to the effects of gravity. All things being equal, ie wing area and air density, you can have an airspeed that is insufficient to produce the required amount of Lift while maintaining a "straight and level" angle of attack.

A "straight and level angle of attack" is an example of something that doesn't actually exist. With enough power you can fly straight and level at any angle of attack from VNE through to stall speed.

 

I'm not sure that your understanding of angle of attack is correct. What do you think the angle of attack will be at 60 knots cruise? 60 knots climb? 60 knots glide? Pulling 4G at 120 knots 3/4 of the way around a loop? All will be the same angle of attack. What do you think your bubble AOA indicator will show?

 

Descent doesn't mean lift is insufficient. Lift doesn't change significantly in a climb, descent or straight and level. (Ignoring the vertical components of thrust and drag, which actually reduce lift required for both climb and descent).

 

Climb and descent are a result of power settings. Descent means that you have insufficient power to overcome drag, climb means you have more power than drag. They are not an increase or decrease in lift.

[aro]

24 minutes ago, Bruce Tuncks said:

I gotta defend OME. I reckon his stuff is standard mechanics, like they once taught in physics classes. Can you give an example of a " false theory?"

I would say it's about 95% standard mechanics, 5% major errors or misunderstandings.

 

An example from the previously linked Social Australia post (where we can't comment)   :

 

Quote

As it sits on the surface, the object has an amount of inertia equal to its mass multiplied by the acceleration due to gravity, ma. Now, tie a string to the object and pull on the string towards you. The string will become straight and the pull is the centripetal force which we call "Tension" in this case. The object will not move until the Tension is greater than the inertia of the object.

In fact, inertia is mass. An object has the same inertia with or without gravity.

 

Assuming the force is lifting the object against gravity (it is not centripetal force unless the object is travelling in a circle), the object will move when the tension exceeds the force of gravity. How fast it accelerates depends on the inertia (mass) of the object and how much the tension exceeds the force of gravity, i.e. the net force.

 

 

[APenNameAndThatA]

1 hour ago, Bruce Tuncks said:

I gotta defend OME. I reckon his stuff is standard mechanics, like they once taught in physics classes. Can you give an example of a " false theory?"

 

 

He just said that something with a weight of 3 kg has a mass of 0.3 kg. Insists on it no less.  And his AOA meter can’t work. A theory is false if it is obviously wrong. 

[APenNameAndThatA]

1 hour ago, Bruce Tuncks said:

I gotta defend OME. I reckon his stuff is standard mechanics, like they once taught in physics classes. Can you give an example of a " false theory?"

 

 

It would be standard mechanics if he understood it

 

4 hours ago, old man emu said:

I can see that the problem with you blokes is that you cannot read. I started to post by defining the word "weight"

 

 Then I said, 

 

If we now put on our lab coats and become scientists, we will start talking in terms of Newtons. The scale shows us that the object exerts a force of 3 Newtons on the weighing mechanism.  Therefore in the equation F=ma, it is F that equals 3. We agree that a is an acceleration of 9.81 metres per second every second. If, for simplicity's sake, we round 9.81 to 10, then 3 = m.10. Therefore m = 3/10 which is 0.3.

 

Mass: If you could count up the number of protons, neutrons, and electrons in an object, this would be a measure of the mass. The mass is essentially "how much stuff" is in an object. 

 

Weight: There is a gravitational interaction between objects that have mass. If you consider an object interacting with the Earth ie affected by gravity, this force is called the weight. The unit for weight is the Newton.

 

I agree that if an object exerts a force of 30N, then it contains mass equal to 3 kg. But I never said that. I said that the Force (weight, whatever) was 3 kg. Read what I say, because I do think about what I write.

 

Scientific theories are the most reliable, rigorous, and comprehensive form of scientific knowledge, in contrast to more common uses of the word "theory" that imply that something is unproven or speculative. Lacking the facilities to test my theory, I cannot completely dismiss my device as ineffective. Until those tests are done, it still remains a theoretical use of the bubble in the tube.

I agree, and I think I'm the urinal. 

 

 

If something has a mass of 3 kg, it exerts 30 N of force, not 3. If you don’t believe me, speak to a high school physics teacher. 
 

And speak to a flying instructor about your AoA device. 

[old man emu]

1 hour ago, aro said:

An example from the previously linked Social Australia post (where we can't comment) 

You mean this one? https://www.socialaustralia.com.au/topic/1408-centrifuges/?tab=comments#comment-50048 Doesn't seem to be closed to further comment. If it is, please advise Ian to open it up. I was hoping for the discussion of that topic to move over there.

 

2 hours ago, aro said:

A "straight and level angle of attack" is an example of something that doesn't actually exist

Then why do aircraft designers go to all the trouble of instructing draughtsmen to design wing attachment points so that the chord line of the wing is at approximately +4 degrees above the longitudinal axis of the aircraft?

 

 In aerodynamics, angle of attack specifies the angle between the chord line of the wing of a fixed-wing aircraft and the vector representing the relative motion between the aircraft and the atmosphere.  The term "straight and level" implies that the aircraft is not turning, not altering altitude. That's the condition most people want to be in when cruising from A to B. In straight and level flight, all the vertical forces acting on the aircraft are balanced. This graph shows that at an angle of attack of about +4.5 degrees, the Coefficient of Lift has a value of one (1).

That coefficient is neither reducing nor increasing the lift for a given combination of air density, airspeed, or wing area. As you pointed out, an aircraft can fly within a large range of angles of attack, and those conditions you described do occur. "Straight and Level" is one of the conditions within that range.

 

2 hours ago, aro said:

Lift doesn't change significantly in a climb, descent or straight and level.

Medic!!! He's shot himself in the foot!

 

Doesn"t change significantly? We could work it out, and I agree that the magnitude would not be massive, but change it does.

2 hours ago, aro said:

Climb and descent are a result of power settings

Power setting are how thrust is produced. Thrust results in velocity. Velocity is a factor in the creation of Lift. Change the velocity and you change the lift FOR A GIVEN AoA. When you demonstrate the stalling characteristics of your plane, what exactly is the exercise all about? I'd say that it is to show the dangers of stalling the aircraft at low altitude where recovery cannot be completed. Have you ever simply gone hands off and reduced power? The nose won't go up to the degree it does when you are demonstrating stalls and stall recovery. The aircraft, which has an intitial horizontal velocity will follow a ballistic trajectory.

This simple trajectory is likely to be modified by the longitudinal stability designed into the aircraft.

 

Now, aro, you questioned my qualifications to post stuff about the motion of aircraft. Will these suffice?

Bachelor of Science in Agriculture - where I learned to research topics and draw conclusions from that research, Plus experience in experimental design.

Traffic Accident Reconstruction Specialist - Application of the Newtonian Laws of Motion, including conservation of momentum and energy.

Passed several Commercial Licence Theory Examinations 

Unrestricted Private Pilot's Licence 

Practical Aircraft Maintenance experience.

Practical general automotive experience.

 

I think that will do. 

 

[APenNameAndThatA]

1 hour ago, Bruce Tuncks said:

I gotta defend OME. I reckon his stuff is standard mechanics, like they once taught in physics classes. Can you give an example of a " false theory?"

 

 

Here’s a list of false theories. 

Do you understand that QNH changes Vso? Do you understand that V speed is based on TAS? Do you understand that centrifugal force does not exist? Do you understand that a spirit level can determine AOA? Do you understand that the best AOA of an aeroplane can be determined with the aeroplane static on the ground and a spirit level? Do you understand that sonething with a weight of 3 kg has a mass of 0.3 kg? Do you understand that if a trimmed aircraft loses power it will slow down? So you understand that if an aircraft has its nose above a certain angle it will stall? Do you understand that if an airplane cannot maintain altitude it means that it has stalled? 

[APenNameAndThatA]

11 minutes ago, old man emu said:

You mean this one? https://www.socialaustralia.com.au/topic/1408-centrifuges/?tab=comments#comment-50048 Doesn't seem to be closed to further comment. If it is, please advise Ian to open it up. I was hoping for the discussion of that topic to move over there.

 

Then why do aircraft designers go to all the trouble of instructing draughtsmen to design wing attachment points so that the chord line of the wing is at approximately +4 degrees above the longitudinal axis of the aircraft?

 

 In aerodynamics, angle of attack specifies the angle between the chord line of the wing of a fixed-wing aircraft and the vector representing the relative motion between the aircraft and the atmosphere.  The term "straight and level" implies that the aircraft is not turning, not altering altitude. That's the condition most people want to be in when cruising from A to B. In straight and level flight, all the vertical forces acting on the aircraft are balanced. This graph shows that at an angle of attack of about +4.5 degrees, the Coefficient of Lift has a value of one (1).

That coefficient is neither reducing nor increasing the lift for a given combination of air density, airspeed, or wing area. As you pointed out, an aircraft can fly within a large range of angles of attack, and those conditions you described do occur. "Straight and Level" is one of the conditions within that range.

 

Medic!!! He's shot himself in the foot!

 

Doesn"t change significantly? We could work it out, and I agree that the magnitude would not be massive, but change it does.

Power setting are how thrust is produced. Thrust results in velocity. Velocity is a factor in the creation of Lift. Change the velocity and you change the lift FOR A GIVEN AoA. When you demonstrate the stalling characteristics of your plane, what exactly is the exercise all about? I'd say that it is to show the dangers of stalling the aircraft at low altitude where recovery cannot be completed. Have you ever simply gone hands off and reduced power? The nose won't go up to the degree it does when you are demonstrating stalls and stall recovery. The aircraft, which has an intitial horizontal velocity will follow a ballistic trajectory.

http://www.physicsclassroom.com/Class/vectors/u3l2a5.gif

This simple trajectory is likely to be modified by the longitudinal stability designed into the aircraft.

 

Now, aro, you questioned my qualifications to post stuff about the motion of aircraft. Will these suffice?

Bachelor of Science in Agriculture - where I learned to research topics and draw conclusions from that research, Plus experience in experimental design.

Traffic Accident Reconstruction Specialist - Application of the Newtonian Laws of Motion, including conservation of momentum and energy.

Passed several Commercial Licence Theory Examinations 

Unrestricted Private Pilot's Licence 

Practical Aircraft Maintenance experience.

Practical general automotive experience.

 

I think that will do. 

 

It is true that a spirit level will work to determine aoa is straight and level flight. Same as a artificial horison could. But straight and level flight is not where you need to measure aoa. 

[old man emu]

5 minutes ago, APenNameAndThatA said:

And speak to a flying instructor about your AoA device. 

Speak to a LAME about how a slip indicator is fitted to an aircraft. Which axis it aligned with?

 

16 minutes ago, APenNameAndThatA said:

If something has a mass of 3 kg, it exerts 30 N of force,

Of course it does. But how much mass acted upon by an acceleration of 9.81 m/s/s exerts a force on a weighing device of 3 kgs?  Don't forget that I was at pains to say I was talking about "weight" in layman's terms as opposed to Force in physacist's terms.

[old man emu]

3 minutes ago, APenNameAndThatA said:

It is true that a spirit level will work to determine aoa is straight and level flight. Same as a artificial horison could. But straight and level flight is not where you need to measure aoa. 

Thank the Deities we finally agree on something. But who ever said in the original discussion that we were talking about straight and level flight? I'm sure that the discussion was about flying at AoAs close to the stalling angle, and I think it was also in relation to circuit work. And I reiterate, straight and level flight is one condition of AoA in a range of AoA's that it is possible to fly at aircraft at.

[aro]

10 minutes ago, old man emu said:

Then why do aircraft designers go to all the trouble of instructing draughtsmen to design wing attachment points so that the chord line of the wing is at approximately +4 degrees above the longitudinal axis of the aircraft?

Because that is the most efficient angle of attack for cruise flight.

 

11 minutes ago, old man emu said:

As you pointed out, an aircraft can fly within a large range of angles of attack, and those conditions you described do occur. "Straight and Level" is one of the conditions within that range.

Straight and level is not an angle of attack.

 

12 minutes ago, old man emu said:

Doesn"t change significantly? We could work it out, and I agree that the magnitude would not be massive, but change it does.

The point is climbing and descending is not a result of more or less left. When climbing, lift is less than in straight and level flight.

 

15 minutes ago, old man emu said:

Power setting are how thrust is produced. Thrust results in velocity. Velocity is a factor in the creation of Lift. Change the velocity and you change the lift FOR A GIVEN AoA. When you demonstrate the stalling characteristics of your plane, what exactly is the exercise all about? I'd say that it is to show the dangers of stalling the aircraft at low altitude where recovery cannot be completed. Have you ever simply gone hands off and reduced power? The nose won't go up to the degree it does when you are demonstrating stalls and stall recovery. The aircraft, which has an intitial horizontal velocity will follow a ballistic trajectory.

It will descend. It is hopefully not a ballistic trajectory. The actual behaviour is typically adjusted by modifying the thrust line of the engine in the design/testing 

phase.

 

Climb comes from excess power. Best climb speed is maximum excess power. Descent comes from insufficient power.

 

18 minutes ago, old man emu said:

Now, aro, you questioned my qualifications to post stuff about the motion of aircraft. Will these suffice?

 

So your aerodynamics is basically PPL? Why do you think that prevents people questioning your information?

 

 

 

[aro]

2 minutes ago, old man emu said:

Thank the Deities we finally agree on something. But who ever said in the original discussion that we were talking about straight and level flight? I'm sure that the discussion was about flying at AoAs close to the stalling angle, and I think it was also in relation to circuit work.

There's the problem. It won't work in a descent, which is an important part of circuit work. If the reading is totally different in a climb and in a descent at the same AOA, it is not an AOA indicator.

 

You need to measure AOA in relation to the aircraft. But the spirit level reading is influenced by both gravity and the acceleration of the aircraft. Gravity moves around relative to the aircraft as the attitude changes.

 

A spirit level is in principle the same mechanism as your inner ear. We know that the inner ear is unreliable and subject to illusions due to acceleration etc. Your proposed AOA indicator suffers the same problems.

[old man emu]

7 minutes ago, aro said:

So your aerodynamics is basically PPL? Why do you think that prevents people questioning your information?

Based on my experience in one field of physics, I have developed the ability to understand the descriptions and calculations involved in other fields. Since this forum is not for aerodynamics engineers, by more for laypersons, I deliberately step away from the really deep stuff, that is now more applicable to aircraft that no one here is likely to fly.  

 

I attempt to simplify what I am saying , but it seems that it is not simple enough for some.

[old man emu]

3 minutes ago, aro said:

There's the problem. It won't work in a descent

I've just about had enough of your unsubstantiated claims. Put up or shut up.

[aro]

1 minute ago, old man emu said:

I've just about had enough of your unsubstantiated claims. Put up or shut up.

OK... lets say we climb an aircraft at 60 knots with an angle of climb of 5 degrees. Then we reduce power to descend at an angle of 5 degrees at the same 60 knots.

 

The airspeed is the same. The angle of attack must therefore be the same. What do you expect your indicator to show? I would expect it to show a change of 10 degrees, where the correct indication would be a change of zero.

[APenNameAndThatA]

2 hours ago, aro said:

OK... lets say we climb an aircraft at 60 knots with an angle of climb of 5 degrees. Then we reduce power to descend at an angle of 5 degrees at the same 60 knots.

 

The airspeed is the same. The angle of attack must therefore be the same. What do you expect your indicator to show? I would expect it to show a change of 10 degrees, where the correct indication would be a change of zero.

I’ve already tried that line of reasoning. For example, that if an aircraft was flying vertically straight up, the AOA indicator would show an angle of attack of 90 degrees. 

[Mike Gearon]

I’m sad/ ashamed about 2 things.

 

1. Like a car accident I’ve returned to look at the thread. Interesting to learn OME history on this subject. That’s a good depth of knowledge. 

 

2. My wife watches Married at First Sight and I watched it with her last night.

 

AOA indicator... Okay. I’ve not seen the original thread. I’ve gathered enough flying knowledge now to be slightly dangerous. on that subject...Im going to look around for a more modern version of Stick and Rudder. Any suggestions appreciated....

 

I’m okay with the spirit level approach as long as the data goes to a chip that has software and an algorithm that gathers data right up until the stall warning goes off such as accelerometers on 3 axis, speed data, attitude and any others the aircraft has on offer to feed to the  software. Then bring in the good old fashioned Cessna vacuum stall warning indicator along with the spirit level. Have the little nerdy computer brain deal with all that and set off a noise and light alert.

 

 

 

 

Edited March 7, 2021 by Mike Gearon

[aro]

55 minutes ago, Mike Gearon said:

Interesting to learn OME history on this subject. That’s a good depth of knowledge.

Two things are glaringly missing:

Physics, and aerodynamics past PPL level. I don't see any more qualifications than many other posters to the site.

 

The traffic accident reconstruction is interesting, it maybe explains some of the errors e.g. the reference to ballistic trajectories.

 

A car that leaves the ground in an accident will follow a ballistic trajectory. A ballistic trajectory in an aircraft is unusual e.g. the Vomit Comet, some aerobatics perhaps, or floating dog videos.

 

A stalled aircraft will not follow a ballistic trajectory. Nor will an aircraft when you reduce power.

 

Most of OME's errors are year 11 physics and BAK level stuff.

 

1 hour ago, Mike Gearon said:

I’m okay with the spirit level approach as long as the data goes to a chip that has software and an algorithm that gathers data right up until the stall warning goes off such as accelerometers on 3 axis, speed data, attitude and any others the aircraft has on offer to feed to the  software.

Your Dynon, Garmin etc. EFIS has all that information. They can't use it to generate AOA information. They require additional information e.g. pressure sensors at an angle to the airflow for AOA. More advanced systems use a vane on the outside of the aircraft, i.e. direct reading of AOA.

 

 

[APenNameAndThatA]

1 hour ago, Mike Gearon said:

I’m sad/ ashamed about 2 things.

 

1. Like a car accident I’ve returned to look at the thread. Interesting to learn OME history on this subject. That’s a good depth of knowledge. 

 

2. My wife watches Married at First Sight and I watched it with her last night.

 

AOA indicator... Okay. I’ve not seen the original thread. I’ve gathered enough flying knowledge now to be slightly dangerous. on that subject...Im going to look around for a more modern version of Stick and Rudder. Any suggestions appreciated....

 

I’m okay with the spirit level approach as long as the data goes to a chip that has software and an algorithm that gathers data right up until the stall warning goes off such as accelerometers on 3 axis, speed data, attitude and any others the aircraft has on offer to feed to the  software. Then bring in the good old fashioned Cessna vacuum stall warning indicator along with the spirit level. Have the little nerdy computer brain deal with all that and set off a noise and light alert.

 

 

 

 

I had no idea that OME's ideas could be so seductive. I'm genuinely shocked, actually. You might be okay with a spirit level being linked to chips, but Dynon, Garmin, Cessan and EVERYBODY else is not. The Dynon has accelerometers but needs an external pitot tube to calculate AOA. Why do you think that is? It's because its the only way you can do it. 

 

Open question to everyone: if an aircraft was flying vertically straight up, what AOA would a spirit level show? 

[old man emu]

4 hours ago, Mike Gearon said:

Okay. I’ve not seen the original thread

Mike,

It seems that you are not Robinson Crusoe there. In that thread I described the whole process of setting up the device. I'll not repost it here. What is happening is that people are dropping in with comments akin to "That's B...sh!t" without providing a countering argument from which their point of view can be assessed.

 

The spirit level approach might seem steampunk to people who have been brought up with the convenience of digital devices, but digital devices are simply versions of steam driven devices. Neither is good nor bad.

 

Here, on the wingtip, 

is a common tool used in aviation which is somewhat related to the ball in a tube. Can anyone prove that they don't do their intended job?

 

 

 

11 hours ago, APenNameAndThatA said:

I’ve already tried that line of reasoning. For example, that if an aircraft was flying vertically straight up, the AOA indicator would show an angle of attack of 90 degrees. 

That comment is taking the context of the argument to an absurd extreme. Actually, a spirit level in an aircraft going vertical in either direction would stop at the end of its range of travel. If that range extended to 90 degrees, yes it would show that. However, I, foolishly, expected to be directing my posts to people who fly aircraft within a limited range of movement around the lateral axis of the aircraft. If you can get a Foxbat, or a C-172 to fly vertically upwards, or vertically downwards (without exceeding Vne) then my suggested device is not for you. If, however, one's particular operations require flight at AoAs close to the stalling AoA, then the suggested device might prove useful.

 

3 hours ago, aro said:

A stalled aircraft will not follow a ballistic trajectory.

aro, there's an outbreak of headlice at a local primary school. Can you attend because you're blood good at nit-picking. However, you are not much good are reading, so don't volunteer as a teacher's aide.

 

In relation to the path an aircraft would follow if the power was reduce when the aircraft was in "straight and level" flight, I said, and highlighted, 

15 hours ago, old man emu said:

This simple trajectory is likely to be modified by the longitudinal stability designed into the aircraft.

For your benefit I know I should have listed all the things that would alter that trajectory from the theoretical, but there are other readers here.

 

3 hours ago, aro said:

Physics, and aerodynamics past PPL level. I don't see any more qualifications than many other posters to the site.

 

Did you study trigonometry in school? Most people did. And when was the last time most people used what they learned in school? When they completed the last trigonometry exam question when they were in school. In my line of work, I had to use trigonometry as a basic tool. Admittedly, it was at the simple end of the spectrum, but so is the basic physics of flight. Also I had to apply the Laws of Motion and understand things like inertia, centripetal force, centre of mass, impulse and so on. These were my tools of trade, so I know how to use them, the same way as an aircraft woodworker knows how to make scarf joint in a spar, or an welder can join pieces of metal.

 

14 hours ago, aro said:

You need to measure AOA in relation to the aircraft.

That statement clearly indicates that you have not even had the courtesy to read the description of the set up. Until you do, don't say anything more.

 

14 hours ago, aro said:

Gravity moves around relative to the aircraft as the attitude changes.

Can I have some of what you are smoking? Most physicists will say that, in relation to the planet, the acceleration due to gravity is a vector directed towards the centre of the planet. Since the aircraft and the planet are as one with respect to astronomic bodies, one can discount the effects of the gravitational forces exerted by those bodies.

 

16 hours ago, aro said:

inertia is mass. An object has the same inertia with or without gravity

Inertia, is a property of an object by which it opposes any Force to put it in motion or, if it is moving, to accelerate it by changing the magnitude or direction of its velocity. Inertia is a passive property and does not enable a body to do anything except oppose forces. A moving body keeps moving not because of its inertia but only because of the absence of a force to slow it down, change its course, or speed it up. In that case, the object has zero inertia. If the object is subjected to the Force of gravity, then it attains inertia. If you take the case of an object motionless on a surface, then it also has no inertia because the force of gravity is mathematically negated by the resistance of the surface to further movement of the object. It is in an equilibrium of forces. If you apply another force to the object, you upset that equilibrium. The force changes the velocity of the object and you have unbalanced the sum of the forces in the system. 

 

 

 

[APenNameAndThatA]

4 hours ago, old man emu said:

Mike,

It seems that you are not Robinson Crusoe there. In that thread I described the whole process of setting up the device. I'll not repost it here. What is happening is that people are dropping in with comments akin to "That's B...sh!t" without providing a countering argument from which their point of view can be assessed.

 

The spirit level approach might seem steampunk to people who have been brought up with the convenience of digital devices, but digital devices are simply versions of steam driven devices. Neither is good nor bad.

 

Here, on the wingtip, 

is a common tool used in aviation which is somewhat related to the ball in a tube. Can anyone prove that they don't do their intended job?

 

 

 

That comment is taking the context of the argument to an absurd extreme. Actually, a spirit level in an aircraft going vertical in either direction would stop at the end of its range of travel. If that range extended to 90 degrees, yes it would show that. However, I, foolishly, expected to be directing my posts to people who fly aircraft within a limited range of movement around the lateral axis of the aircraft. If you can get a Foxbat, or a C-172 to fly vertically upwards, or vertically downwards (without exceeding Vne) then my suggested device is not for you. If, however, one's particular operations require flight at AoAs close to the stalling AoA, then the suggested device might prove useful.

 

aro, there's an outbreak of headlice at a local primary school. Can you attend because you're blood good at nit-picking. However, you are not much good are reading, so don't volunteer as a teacher's aide.

 

In relation to the path an aircraft would follow if the power was reduce when the aircraft was in "straight and level" flight, I said, and highlighted, 

For your benefit I know I should have listed all the things that would alter that trajectory from the theoretical, but there are other readers here.

 

Did you study trigonometry in school? Most people did. And when was the last time most people used what they learned in school? When they completed the last trigonometry exam question when they were in school. In my line of work, I had to use trigonometry as a basic tool. Admittedly, it was at the simple end of the spectrum, but so is the basic physics of flight. Also I had to apply the Laws of Motion and understand things like inertia, centripetal force, centre of mass, impulse and so on. These were my tools of trade, so I know how to use them, the same way as an aircraft woodworker knows how to make scarf joint in a spar, or an welder can join pieces of metal.

 

That statement clearly indicates that you have not even had the courtesy to read the description of the set up. Until you do, don't say anything more.

 

Can I have some of what you are smoking? Most physicists will say that, in relation to the planet, the acceleration due to gravity is a vector directed towards the centre of the planet. Since the aircraft and the planet are as one with respect to astronomic bodies, one can discount the effects of the gravitational forces exerted by those bodies.

 

Inertia, is a property of an object by which it opposes any Force to put it in motion or, if it is moving, to accelerate it by changing the magnitude or direction of its velocity. Inertia is a passive property and does not enable a body to do anything except oppose forces. A moving body keeps moving not because of its inertia but only because of the absence of a force to slow it down, change its course, or speed it up. In that case, the object has zero inertia. If the object is subjected to the Force of gravity, then it attains inertia. If you take the case of an object motionless on a surface, then it also has no inertia because the force of gravity is mathematically negated by the resistance of the surface to further movement of the object. It is in an equilibrium of forces. If you apply another force to the object, you upset that equilibrium. The force changes the velocity of the object and you have unbalanced the sum of the forces in the system. 

 

 

 

Okay, if he aircraft was flying nose down 30 degrees, steadily, what would the AOA meter say the AOA was? 

[Thruster88]

OME, if I fitted one off your spirit level AOA devices in the RV6a which sits level on the runway what angle of attack do you think it will indicate when the 180hp is fed to the constant speed prop. I am guessing at least 20°. Should I abort the takeoff given that most wings stall at about 16°?

 

Also can I use the spirit level in the turn coordinator to keep the wings level in cloud?