Can Planes Stop in Mid-Air?

When coming back from airport, I often see people staring at a 747 above us and stating "Look. That plane stopped moving. It's probably waiting to land." And when I tell them it's still flying, they say "What are you saying? You blind/crazy?"

Humans tend to believe what they see in front of their eyes, without thinking. It is because of this human tendency, sequels of movies like Paranormal Activity is being released. Believing a 747 can stop in mid-air is like Paranormal activity to me.

Anyway, Commercial aircraft cannot "stop" in mid-air. It's a fact. They are not designed to stop in mid-air. Allow me to explain this phenomena in two parts.

Part 1, Why planes cannot stop in mid-air :

The answer to this question can be explained by any average google search: "How Planes Fly?"

It's basics. It's all about four forces and an aerofoil shape.

It's old school. 

Anyway what I need you to understand from this is that, the aircraft will fall down from sky if any one of those four forces disappear ( Lift, Thrust, Weight or Drag).

Let's assume that the plane do stop in mid-air. If that is to happen, then the engines are to be switched off. Just like that of car - if the engine is stopped, the car stops. Same thing happens with aircraft. If the engine is stopped - aircraft stop producing thrust - and no lift is generated. If that happens the pilot will say nothing but " mayday mayday - Get me outta here!"

Part 2: OK,so if the plane is not moving; then why does it look like - "stopped in mid-air"?

Well actually you are staring at the aircraft for around 3 seconds max. You look once, "it ain't moving"; you look the second time within 2 seconds "nope, not moving at all" and you leave it at that. You probably must be in a vehicle when this happens.

The fact is, aircraft is moving. Since it is coming to land, the speed is considerably reduced which in turn effects its ground speed. The head wind speed is reduced from the total airspeed causing the ground speed to be less than that of the real value. It like the hour hand of a clock.

 There are plenty of literature written on this subject, feel free to read those.

Before concluding, keep in mind that there are aircraft that do stop in the air. Those are military aircraft specially designed to hover. The F-35 JSF is one of these aircraft that can hover or "stop in mid-air".

I recommend you to check Lockheed Martin YouTube channel  (http://www.youtube.com/user/LockheedMartinVideos) - they have plenty of videos on F-35s.

Live Happy - Chan