Here's why he's wrong. He's a former mechanic, not an engineer.
These planes have a higher clearance than commercial planes. These engines are eight feet above the ground. The same engines on a 757 are 29 inches off the ground.
If they were prancing around a 757 with engines on, yes, very likely someone would have been sucked in. But this is a C-17. The engines would have to overcome the full force of gravity to lift a fully-grown man completely off of the ground. This doesn't happen in reality.
The reason is because the range of danger is 20 feet LATERALLY. The range of danger increases ABOVE the engine, and decreases BELOW it.
So, with a 757, a human body's mass is largely at the same level as the engine. For the C-17 it is ALL several feel below the engine. So the ability of the engine to pull in a whole person is diminished by the force of gravity. Yes, the engine CAN do it, but only from probably within a foot or so.
As for the heat, again the ground clearance matters. Also, hot air is less dense than cold air so it expands rapidly and rises into the atmosphere. It works the same way as a hair dryer. Put it on full blast and stick your hand one inch away. It will burn your hand. Move it one foot away, nice and cozy.
The noise level argument is nonsense also. It makes the assumption that all four engines are under throttle at all times. That's not how planes taxi. They give it a little thrust to get the plane rolling then back off to conserve fuel. Once the plane is rolling, the amount of thrust needed to keep it moving is less.
The noise level would only be an issue when the plane needed to ACCELERATE, not maintain speed.
Also, this is military. If they were given orders to take off, they are going to take off. Especially in a hostile environment.
This guy is trying to throw out his mechanic and employment credentials like he's some authority, but he's not. His premises fail to consider basic things like the force of gravity.
Here's why he's wrong. He's a former mechanic, not an engineer.
These planes have a higher clearance than commercial planes. These engines are eight feet above the ground. The same engines on a 757 are 29 inches off the ground.
If they were prancing around a 757 with engines on, yes, very likely someone would have been sucked in. But this is a C-17. The engines would have to overcome the full force of gravity to lift a fully-grown man completely off of the ground. This doesn't happen in reality.
The reason is because the range of danger is 20 feet LATERALLY. The range of danger increases ABOVE the engine, and decreases BELOW it.
So, with a 757, a human body's mass is largely at the same level as the engine. For the C-17 it is ALL several feel below the engine. So the ability of the engine to pull in a whole person is diminished by the force of gravity. Yes, the engine CAN do it, but only from probably within a foot or so.
As for the heat, again the ground clearance matters. Also, hot air is less dense than cold air so it expands rapidly and rises into the atmosphere. It works the same way as a hair dryer. Put it on full blast and stick your hand one inch away. It will burn your hand. Move it one foot away, nice and cozy.
The noise level argument is nonsense also. It makes the assumption that all four engines are under throttle at all times. That's not how planes taxi. They give it a little thrust to get the plane rolling then back off to conserve fuel. Once the plane is rolling, the amount of thrust needed to keep it moving is less.
The noise level would only be an issue when the plane needed to ACCELERATE, not maintain speed.
Also, this is military. If they were given orders to take off, they are going to take off. Especially in a hostile environment.
This guy is trying to throw out his mechanic and employment credentials like he's some authority, but he's not. His premises fail to consider basic things like the force of gravity.