Weaning Your Baby Onto Solids. The term 'to wean' comes from an ancient phrase that means 'to accustom to'. So weaning refers to the period during which an infant gradually becomes accustomed to food other than milk (breast or formula). Up until 6 months of age, breast or formula milk alone is nutritionally adequate.
Occasional airplane vibration during flight is not unusual. There are many causes of airplane vibration, including landing gear extension and retraction, extension of speed brakes, free play in movable surfaces, and systems malfunctions.
Two of the biggest sources of noise are the sounds from the engine running while in flight and the sounds of the wind rushing around the aircraft as it moves through the air. Much as in a car, the aircraft engine produces sound as more power is demanded by the operator. Cars, however, are usually much quieter due to the exhaust equipment. Weight and cost restrictions do not allow for the average general aviation aircraft to obtain a sound level that is comparable to that of an automobile.