physics question

SixPapaCharlie

SixPapaCharlie

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You are flying along in IMC and have a total instrument failure.
Vacuum pump, electric, and a bird hit the pitot tube. Part of it went into both static ports.

Fortunately you are flying to a child's birthday party and have a mylar helium filled balloon with you.

Keeping the balloon centered on the cabin ceiling you should be able to maintain level flight and also determine if your attitude changes correct?

Ascend, it moves forward. Pitch down, it moves back etc...

Would it work like that?
 
Forgot forward and back due to acceleration and deceleration.
 
Are you allowed at children's birthday parties?
 
SixPapaCharlie said:
You are flying along in IMC and have a total instrument failure.
Vacuum pump, electric, and a bird hit the pitot tube. Part of it went into both static ports.
Click to expand...

This is when you pull up the artificial "panel page" on your portable GPS/Tablet.
 
You just killed a billion dollar aviation instruments industry.
 
SixPapaCharlie said:
You are flying along in IMC and have a total instrument failure.
Vacuum pump, electric, and a bird hit the pitot tube. Part of it went into both static ports.

Fortunately you are flying to a child's birthday party and have a mylar helium filled balloon with you.

Keeping the balloon centered on the cabin ceiling you should be able to maintain level flight and also determine if your attitude changes correct?

Ascend, it moves forward. Pitch down, it moves back etc...

Would it work like that?
Click to expand...

No. It's like trying to fly with a spirit level.

Level turns don't move it. Poor coordination does. The effects of acceleration will totally screw you up.

It will naturally drive you into a spiral dive just like trying to fly by feel does.
 
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6PC may be on to something though. I don't think you could maintain level flight on the basis of keeping the balloon centered in its spot in the cockpit, BUT, it would act as sort of a crude "gyro", so you could paint a lubber line circling the balloon and it would act as an independent attitude reference. Because the balloon is tethered, there would be some effect from turns and acceleration, but as long as they are small, it might work adequately.

If you could untether it and have it float in free space, it might work fairly well.
 
Sac Arrow said:
6PC may be on to something though. I don't think you could maintain level flight on the basis of keeping the balloon centered in its spot in the cockpit, BUT, it would act as sort of a crude "gyro", so you could paint a lubber line circling the balloon and it would act as an independent attitude reference. Because the balloon is tethered, there would be some effect from turns and acceleration, but as long as they are small, it might work adequately.

If you could untether it and have it float in free space, it might work fairly well.
Click to expand...

This would work a lot better in a vacuum.
 
Sac Arrow said:
6PC may be on to something though. I don't think you could maintain level flight on the basis of keeping the balloon centered in its spot in the cockpit, BUT, it would act as sort of a crude "gyro", so you could paint a lubber line circling the balloon and it would act as an independent attitude reference. Because the balloon is tethered, there would be some effect from turns and acceleration, but as long as they are small, it might work adequately.

If you could untether it and have it float in free space, it might work fairly well.
Click to expand...
How would you tell the difference between diving and accelerating straight and level?
 
Jeff Oslick said:
This would work a lot better in a vacuum.
Click to expand...

Yes.

Lindberg said:
How would you tell the difference between diving and accelerating straight and level?
Click to expand...

Same way an AI would tell you. Balloon would be sideways in a dive. It would only give you attitude information reliably, to the extent that it isn't upset by contacting the cabin.
 
SixPapaCharlie said:
You are flying along in IMC and have a total instrument failure.
Vacuum pump, electric, and a bird hit the pitot tube. Part of it went into both static ports.
Click to expand...

If you have all those failures, face facts; it just isn't your day. (Or maybe it's going to be your day.):yikes:
 
I guess the question is, is it floating relative to earth, or the G force created by the plane(as in a turn)?

Somebody knows, not me. 6pc, you are just full of these!

:)
 
Sorry I meant untethered.
Like actually ON the ceiling
 
I prefer a 3/4 full mason jar of white lightning. When you can't keep the greasy side down, you can consume the instrument and not care.
 
MAKG1 said:
That's what I thought you meant.

It's a spirit level.
Click to expand...

But if in flying straight and level the balloon is centered right.
My goal isn't to navigate anywhere, just keep from spinning it in while I troubleshoot.

If I start to bank, the balloon would roll the opposite direction. No?
 
problem is.....the balloon's reference is not earth.....and you'd like to know your position relative to earth....
 
hate to spoil things, but why can't the pilots of real airplanes just open the aux. static port inside the plane or break the glass? hmmmmm Too simple?
 
If you ascend it will grow and maybe burst.
If you descend it will shrink and maybe fall to the floor, not sure.

How about just use your stratus/ipad/art horizon? Saves carrying kids around too!
 
A coordinated one g roll would keep the balloon in one place. Bad idea for a backup instrument.
 
FastEddieB said:
Have you ever transported helium balloons in a car?

What happens when you brake or accelerate is quite counterintuitive.
Click to expand...

Yep, balloon moves forward when you accelerate, back when you brake, my observation anyway.
 
SixPapaCharlie said:
You are flying along in IMC and have a total instrument failure.
Vacuum pump, electric, and a bird hit the pitot tube. Part of it went into both static ports.

Fortunately you are flying to a child's birthday party and have a mylar helium filled balloon with you.

Keeping the balloon centered on the cabin ceiling you should be able to maintain level flight and also determine if your attitude changes correct?

Ascend, it moves forward. Pitch down, it moves back etc...

Would it work like that?
Click to expand...

No, same reason kinestetic senses don't work, the vector angle of gravity is stable in coordinated flight. Your deck angle on climb and descent won't be significant enough to over come the friction of the balloon until the angles are high enough that you're in trouble. Better to get a cat or a duck for emergencies.
 
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PaulS said:
Yep, balloon moves forward when you accelerate, back when you brake, my observation anyway.
Click to expand...

Yep, your car is a big tank filled with fluid that has inertia. The car applies force to the fluid, and the fluid applies force to the balloons. The balloons follow the motion of the fluid and the vortexes from acceleration in a closed system.
 
FastEddieB said:
Have you ever transported helium balloons in a car?

What happens when you brake or accelerate is quite counterintuitive.
Click to expand...

It's obvious what happens. Air has mass as pilots are aware.
 
JOhnH said:
Are you sure about that? Or are you thinking about gravity instead of a vacuum?
Click to expand...

To figure this out, ask, "why does helium rise?" Because it's lighter (less dense) than the surrounding air, correct?

Well, in a vacuum where there would be no air for the helium to be lighter than, it would be the heaviest/most dense thing there, and gravity would bring it to the bottom of the chamber.

Of course technically as soon as anything is put in the vacuum, it's no longer a vacuum.
 
EdFred said:
To figure this out, ask, "why does helium rise?" Because it's lighter (less dense) than the surrounding air, correct?

Well, in a vacuum where there would be no air for the helium to be lighter than, it would be the heaviest/most dense thing there, and gravity would bring it to the bottom of the chamber.

Of course technically as soon as anything is put in the vacuum, it's no longer a vacuum.
Click to expand...

Except for Dark Matter.
 
JOhnH said:
Are you sure about that? Or are you thinking about gravity instead of a vacuum?
Click to expand...

Helium floats because it's lighter than an equivalent volume of air. If there's no air then what is it lighter than? Of course a Mylar or rubber ballon isn't going to be able to hold it's cookies in a vacuum anyway so the point is moot.
 
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