Ask Captain Lim

Hi Capt Lim,

Every time I fly on the Boeing 777-200ER, there is a noise (TIK TIK, TIK, TIK) 5 minutes before it lands (like a very old bus :) Further, the end of the wings move up and down a lot. I didn't notice that in the A340-200.Sometimes the Boeing 777 fly very quietly and some very noisily. Why? Do the total weight play part in that.

Kind regards,

Sonique.

Hi Sonique,

The noise from the airplane can come from many sources. They could come from the vibrations and the whirring sounds during the retraction of the landing gears. Then there is the slamming sounds from the loose articles in the galley caused by the movement of the modules during take off or the reduction of power after airborne to comply with the noise abatement procedures in certain airports. The air-conditioning noise may change to cater for the cooling or heating needs.

The Tik, Tik, Tik sound seems to come from the operation of the landing flaps five minutes prior to landing. All these noise are normal and are nothing to worry about. Any abnormal noise would be picked up by the Flight Attendants and they would in turn notify the Captain. If you sat near to the engines, the noise level is usually higher than elsewhere.

The little flexing of the wings is normal. For your information, during a trial in the development stages of the Boeing 747, the wings were stressed and bent as much as 22 feet before it gave way! You observed the wing tip flex a lot because it is more obvious on the Boeing 777 as it has no winglets as compared to an A340.

The total weight of the airplane does not play any major part in the noise of the airplane, except during take off, more power are required and that may contribute to the noise level.