Birds On A Plane., riddle

In a "perfect world" if the maximum takeoff weight (MTO) of an airplane [in this case, the MTO is maximum weight the aircraft could be for it to be possible to lift off the ground] is 20,000kg and the plane is loaded, and weighs 19,995kg. Then 10kg of live birds is added making the total weight 20,005kg (exceeding MTO)

Assuming this situation, if the birds were to fly within the cabin of the aircraft while on its takeoff role, would the airplane be able to take off?

And does is make a difference if the cabin is pressurized or not?

I have me own ideas but I really do not have any solid evidence to suggest either way, ideas?:


Brandon

Hi Kearney,
I've seen this one on mythbusters (not the be source of scientific info , I know), but what they claim is that the lift that keeps the birds flying actually adds their weight to the plane, hence it would exceed MTO.
Peace,
Ron

Yes, that's what I saw, too. Essentially, the force transmitted by the birds to the air is transmitted to the plane by the air. Pretty much for the same reasons that when a plane takes off, all the air isn't pushed to the back of the plane by its acceleration leaving you high and dry in the first row!

Interesting, do you know how the Mythbusters figured it out? What type of model was used to represent this situation?

Brandon

They actually got a truck, some birds, some accurate scales and zapped the birds or something to get them all in the air.

Ah, another great example of how well we treat our lab animals nowadays.

- Gehn

Well, since certain forum members here were unavailablle, that's the best they could do.

Hi NoCleverName, kearney_b, Ron,Gehn and All,

Consider that the birds were flying "outside of the plane" then does anyone think that their actions would add to the weight at take off of the plane... of course not. There are several stages in this operation. If the plane was "pressurized" with the birds inside and was traveling at several hundred kph on take off then the birds are "dead weight". If the plane was a "Sopwith Camel" and the birds were tethered on strings by really little harnesses then they could be encouraged to partially lift the plane or at least assist it into the air if take off velocity was far less than the speed of the birds in air. Shades of Cyrano de Bergerac.... He he he!

... Click to enlarge...
You just got to think "outside of the box" or in this case the pressurized cabin of a plane. Certainly beats the inflight movie "Snakes on a Plane"... eh?

Cheers

This post has been edited by Good Elf on Dec 27 2007, 03:10 AM

Actually the air in a plane is pushed to the back on acceleration.
The pressure difference is small but it does exist.
Simple way to see his in action is to get a helium balloon in your car with the windows up.
Upon acceleration the balloon will actually be pushed forward by the flow of air.
Apply the brakes and the balloon will go towards the back of the car.
Odd, but true!

Bruce

Did I not say all the air is not pushed back?

If there were birds it would Bird Flu within the plane from the noses of the passengers.

So a immediate rerouting of the plane to get rid of the sparrows.

A sky marshal can only do so much.

no, the plane wont be able to take off, because of newtons third law of motion, the lift that the birds use( which is a force) is pushing the plane down,

for every action their is a exact and opposite reaction!!

just like a person under a helicopter on takeoff, if the helicopter took off, he would feel the weight of the helicopter pushing down on him!!!!


einstienear

using the helium balloon theory to help you wont do you much help in concrete hard evidence!!!

why?

well, the reason the balloon flings back due to acceleration is because the air molecules move around it freely!!!!

its like water, you can put your hand in it and wave it around.......if your theory was correct....the every time you walk around the house, the air pressurization becomes directly proportionate to the momentum and speed that you happen to "make" as you trot around this house of yours!!! (well the "directly proportionate" is irrelevant)!!

The bird needs to provide its own lift and acceleration - and I don´t know of any bird that can accelerate to over 100 knots in about 20 seconds - so the bird will collapse exhausted to the floor of the aircraft which will then be overweight.

Not a theory..just a fact that I have verified myself.

And I said the balloon moves forward within the cab of the car upon acceleration.

Bruce