If I get on a plane with my 500 lb parakeet Buster on my shoulder...

… you would almost certainly be assigned the seat next to mine. :eek:

Technically no, but even with a regular-sized bird in a regular-sized plane, the effect will be so slight that it would probably be impossible to measure it. As the weight of the plane increases compared to the weight of the bird, the effect on the plane becomes smaller and smaller.

Think about what weight is. The weight of an object measures how strongly it is pulled downward by the Earth’s gravitational field. The idea of the weight of the Earth makes no sense. Sometimes you see measurements for “the weight of the Earth,” but that is really just the mass of the Earth multiplied by the Earth’s** gravitational constant to put it in terms that people used to imperial units understand. The imperial unit for mass is slugs, which are never used for some reason, while the unit for force (or weight) is pounds. In metric mass is measured by kilograms while force is measured in Newtons. Anyway, the mass of a given amount of matter does not change.

**the word “Earth” has lost all meaning to me

Another thing about breaking through the floor of the plane: 52,500 lb (the weight of the people assuming ~150 lb each) is the amount of force “crashing down” on the the floor when the people are just standing there. The force of the people landing will be greater than this. How much greater depends on the length of time between first contacting the floor and coming to a halt (this is the length of the impulse). If they land stiff legged and upright, the impulse will be very short and the force will be huge. If they bend their knees and “absorb” the impact, what they are really doing is increasing the length of the impulse so that the amount of force is much less (but it lasts for longer).

I don’t know how much weight an airplane deck can hold or how much pressure will puncture it.

What if the parakeet was flying around the cabin while the passengers simutaneously jumped in an airplane which was on a treadmill as it fell through a hole that went all the way through the earth?

…and the pilot was Monty Hall

I was doing a search for giant parakeet vs stingray…

Does Buster the Parakeet wear diapers? If not and he defecated, would his weight diminish while the weight of the airplane increased? How would the speed be affected and would the passengers expire from noxious fumes?

Years ago I saw an episode of Newton’s Apple (kid’s science show) that demonstrated this quite well.

The question was phrased If a truck full of parakeets hit a bump and they all flew off their perches would the truck suddenly get lighter? It was explained by showing a remote control model helicopter sitting on a digital scale and then starting it and having it hover over the scale (i.e. the reading on the scale stayed essentially the same).

So actually, as the birds accelerated up to a hover it would actually get heavier briefly.

Ouch, my brain hurts…

Not much left to say here except that Buster is an entirely appropriate name for a bird of such magnitude.