Hi Captain Lim,
I was flying with United Airlines from New York to London last March and before we even got off the runway I noticed my seat (the actual seat part of the chair) was loose and almost off the hinges. I should have recognized this as an omen?
After about an hour into our flight the plane suddenly went crazy. It started jolting from side to side and dropped rapidly. It gave me, and I am sure other passenger, that roller-coaster stomach feeling. Then the lights flickered inside the aircraft and this went on for about an hour. The plane seemed like it was going to fall out of the sky! The turbulence was so bad and rocky that the duty free cart sailed down the aisle and you could hear things crashing from cabin crew*s department. The pilot began to talk to us and then his line was cut off.
Eventually the alarms on board started ringing like crazy and people were basically either waiting to be killed or they were bargaining with God. This ended after an hour and things were steady, and then it happened again. And going into Heathrow, we seemed to be off our flight path as the plane circled around the South of England a few times before landing, and it was scary times - planes were flying past us and underneath us and above us, etc.
I was wondering if a plane could just fall out of the sky?
Also, this might put my random flying panic attacks at ease (I*ve noticed this a lot with Easy Jet) why do the engines sound like they are suddenly going a lot quieter than they previously were as we climb, and why do they make a clicking noise?
Planes just don't drop off the sky because of turbulence! In order to fall off, the wings of the plane must "stall". A "stall" is an aerodynamic term to mean that the wings of the plane are not moving fast enough through the air to produce lift needed to keep it in the air. For example, if the stalling speed of a Boeing 777 is 150 knots (172 mph) (the stall speed is lower at lighter weights and with flaps), at a particular weight, it will stall if the pilot allows the plane to drop below 150 knots.
Normally, during the cruise, the speed is around 300 knots or more on the air speed indicator. When encountering turbulence, the pilot will reduce the speed to around 280 knots or Mach 0.82 (82 % speed of sound). Some fearful flyers think the sudden reduction of power as a sign of engine failure. No, it's not - it's merely a power-reduction reaction - just like you stepping on the brakes when you are about to drive over bumps on the road!
Manufacturers of modern planes have made it almost impossible to stall a wing through many protections; one example - a stall warning known as the stick shaker. The control wheel will "shake like crazy" when approaching the stall. So it is impossible for the pilot not to react - by the recovery technique of moving the control forward and then increasing the speed through power application once out of the stall.
In fact, when the fly-by-wire Airbus A320 was first introduced, it was touted as "uncrashable", but it could, outside the normal control law!
Anyway, it is not easy to stall a plane; and even if it did, with sufficient height, most planes are designed such that, with a forward CG (center of gravity) it would recover by itself and glide safely down when the nose drops as it stalls. Remember, paper planes that you may have used to throw as a kid? Same principle - a plane will glide when the nose drops.
During the take off and climb, the engine sound suddenly going a little quieter all because of the compliance to nose abatement procedures in some airports (As discussed in past FAQ). I am not sure about the "clicking noise" you are referring to. There are many sounds in the airplanes caused by the retraction of landing gears, screw jacks of the flaps, hydraulic pumps, etc. that I have also written earlier in my site.
Hope my explanation would reduce your panic attacks in your future flights!