[cynicalheretic]

$this->bbcode_second_pass_quote('davep', '')$this->bbcode_second_pass_quote('cynicalheretic', '')$this->bbcode_second_pass_quote('davep', 'E')rr, maybe the control isn't quite as omnipresent as you'd like to think (given that the evidence against ciggies has been so overwhelming for so long).

[Chicken_Little]

The take-off speed of a normally loaded Boeing 747 is 180 mph.

A normally laden Boeing 747 is placed on a conveyor belt which moves in the opposite direction to the aircraft. The pilot then attempts to take off.

The conveyor belt is tuned such that it matches the speed of the aircraft whatever ground speed the aircraft attains. There is no wind. Atmospheric conditions are normal.

Can the Boeing 747 take off?

[Zardoz]

$this->bbcode_second_pass_quote('Chicken_Little', 'T')he take-off speed of a normally loaded Boeing 747 is 180 mph.

A normally laden Boeing 747 is placed on a conveyor belt which moves in the opposite direction to the aircraft. The pilot then attempts to take off.

The conveyor belt is tuned such that it matches the speed of the aircraft whatever ground speed the aircraft attains.

Can the Boeing 747 take off?

[davep]

Yes, if it can double its takeoff speed (or if there is a large headwind).

Actually, I've just read the question properly. Therefore doubling takeoff speed wouldn't help. However, the belt can basically be ignored if he's got decent tyres, as the thrust is from the engines, not the wheels. So yes, unless his tyres explode first.

[Chicken_Little]

$this->bbcode_second_pass_quote('Zardoz', '')$this->bbcode_second_pass_quote('Chicken_Little', 'T')he take-off speed of a normally loaded Boeing 747 is 180 mph.

A normally laden Boeing 747 is placed on a conveyor belt which moves in the opposite direction to the aircraft. The pilot then attempts to take off.

The conveyor belt is tuned such that it matches the speed of the aircraft whatever ground speed the aircraft attains.

Can the Boeing 747 take off?

[Chicken_Little]

$this->bbcode_second_pass_quote('davep', 'Y')es, if it can double its takeoff speed (or if there is a large headwind).

Actually, I've just read the question properly. Therefore doubling takeoff speed wouldn't help. However, the belt can basically be ignored if he's got decent tyres, as the thrust is from the engines, not the wheels. So yes, unless his tyres explode first.

[davep]

For me, if the wheels are in constant contact with the conveyor and the tyres can handle 360mph (i.e. twice normal takeoff speed) then (if the friction of the conveyor is considered equivalent to a runway), yes, it can take off.

[davep]

$this->bbcode_second_pass_quote('Chicken_Little', '')$this->bbcode_second_pass_quote('davep', 'Y')es, if it can double its takeoff speed (or if there is a large headwind).

Actually, I've just read the question properly. Therefore doubling takeoff speed wouldn't help. However, the belt can basically be ignored if he's got decent tyres, as the thrust is from the engines, not the wheels. So yes, unless his tyres explode first.

[Chicken_Little]

$this->bbcode_second_pass_quote('davep', 'F')or me, if the wheels are in constant contact with the conveyor and the tyres can handle 360mph (i.e. twice normal takeoff speed) then (if the friction of the conveyor is considered equivalent to a runway), yes, it can take off.

[davep]

$this->bbcode_second_pass_quote('Chicken_Little', '')$this->bbcode_second_pass_quote('davep', 'F')or me, if the wheels are in constant contact with the conveyor and the tyres can handle 360mph (i.e. twice normal takeoff speed) then (if the friction of the conveyor is considered equivalent to a runway), yes, it can take off.

[Chicken_Little]

$this->bbcode_second_pass_quote('davep', '')$this->bbcode_second_pass_quote('Chicken_Little', '')$this->bbcode_second_pass_quote('davep', 'F')or me, if the wheels are in constant contact with the conveyor and the tyres can handle 360mph (i.e. twice normal takeoff speed) then (if the friction of the conveyor is considered equivalent to a runway), yes, it can take off.

[davep]

for clarification:

$this->bbcode_second_pass_quote('Chicken_Little', 'T')he conveyor belt is tuned such that it matches the speed of the aircraft whatever ground speed the aircraft attains.

[davep]

$this->bbcode_second_pass_quote('Chicken_Little', '')$this->bbcode_second_pass_quote('davep', '')$this->bbcode_second_pass_quote('Chicken_Little', '')$this->bbcode_second_pass_quote('davep', 'F')or me, if the wheels are in constant contact with the conveyor and the tyres can handle 360mph (i.e. twice normal takeoff speed) then (if the friction of the conveyor is considered equivalent to a runway), yes, it can take off.

[Chicken_Little]

$this->bbcode_second_pass_quote('davep', '')$this->bbcode_second_pass_quote('Chicken_Little', '')$this->bbcode_second_pass_quote('davep', '')$this->bbcode_second_pass_quote('Chicken_Little', '')$this->bbcode_second_pass_quote('davep', 'F')or me, if the wheels are in constant contact with the conveyor and the tyres can handle 360mph (i.e. twice normal takeoff speed) then (if the friction of the conveyor is considered equivalent to a runway), yes, it can take off.

[davep]

$this->bbcode_second_pass_quote('Chicken_Little', 'b')ut the surrounding air is not moving (no wind) and neither is the plane relative to the surrounding air.

[Chicken_Little]

$this->bbcode_second_pass_quote('davep', '')$this->bbcode_second_pass_quote('Chicken_Little', 'b')ut the surrounding air is not moving (no wind) and neither is the plane relative to the surrounding air.

[davep]

$this->bbcode_second_pass_quote('Chicken_Little', 't')he plane is stationary relative to the ground. it remains in exactly the same position no matter what notional ground speed it attains.

[Chicken_Little]

$this->bbcode_second_pass_quote('davep', '')$this->bbcode_second_pass_quote('Chicken_Little', 't')he plane is stationary relative to the ground. it remains in exactly the same position no matter what notional ground speed it attains.

[davep]

OK, I'll type this slowly...

The plane starts moving, so does the conveyor. The plane hits 5mph. So does the conveyor. The plane is still doing 5mph relative to the ground, only its wheels are turning as if it were doing 10mph.

Now it accelerates to 180mph (relative to the ground). Its wheels are spinning as if it were doing 360mph, however it is doing 180 and takes off.

Your conveyor in no way stops the plane from taking off. As soon as the plane accelerates, the conveyor starts. Therefore, the fact that the conveyor belt is moving means that the plane is moving <b> relative to the ground, not just the conveyor</b> So, the plane will attain 180mph, only its wheels will be turning twice as fast, capiche?

The only situation where the plane is still is if the conveyor is is still, i.e. there is no thrust.

[Chicken_Little]

$this->bbcode_second_pass_quote('davep', 'O')K, I'll type this slowly...

The plane starts moving, so does the conveyor. The plane hits 5mph. So does the conveyor. The plane is still doing 5mph relative to the ground, only its wheels are turning as if it were doing 10mph.

Now it accelerates to 180mph (relative to the ground). Its wheels are spinning as if it were doing 360mph, however it is doing 180 and takes off.

Your conveyor in no way stops the plane from taking off. As soon as the plane accelerates, the conveyor starts. Therefore, the fact that the conveyor belt is moving means that the plane is moving <b> relative to the ground, not just the conveyor</b> So, the plane will attain 180mph, only its wheels will be turning twice as fast, capiche?

The only situation where the plane is still is if the conveyor is is still, i.e. there is no thrust.