What is the passenger size range of a 121 aircraft?
Part 121 covers "common carnage" operations- basically airlines. The section primarily lays out the rules for operators, not aircraft. Part 121 operators have flown everything from Cessna 401's to Boeing 747's.. The lower limit is mainly an economic decision - there would be little point in going through the cost of following the 121 rules for a plane of limited capacity. There is no upper limit in the 121 regs.
The plane is much bigger than the passengers.
There is not an " average passenger size" for aircraft used in Part 121 operations. For regularly scheduled passenger service, a turbojet aircraft of any size must be operated under Part 121, and any propeller driven aircraft having 10 passenger seats or more must be operated under Part 121 if the operator flies between any two points more than 4 times per week. All of this is governed by Part 119 of the FAR's.
I'm trying to find the average passenger size . How nice that you WANT this number The information is collected. for those that NEED it many commercial sites will sell the information to you. I just want to know the size range of this classification of aircraft. Make up your mind. Do you want the range of sizes allowed or the AVERAGE size. The range is from the smallest plane the carrier wants to use up to the largest manufactured. Cross border flights can be very short from one small place to another with small planes of a few passengers to the huge jets flying halfway around the world. https://registry.faa.gov/aircraftemail/aircraftemail.aspx