The following is a proposed rule change to standardize the regulations governing the 

dimensions of carry-on baggage for flights in the United States. Currently, carry-on baggage is 

regulated by each individual FAA certificate holder. This has led to great disparity regarding the 

maximal size for carry-on baggage. For example, the following table lists the maximum carry-on 

baggage dimensions for the twelve (12) major passenger carriers (as classified by the U.S. 

Department of Transportation):

Airline Max Length (in.) Max Height (in.) Max Depth (in.) Source

Alaska Airlines 24 17 10 Here

Allegiant Air 22 14 9 Here

American Airlines 22 14 9 Here

Delta Air Lines 22 14 9 Here

Frontier Airlines 24 16 10 Here

Hawaiian Airlines 22 14 9 Here

JetBlue 22 14 9 Here

Southwest Airlines 24 16 10 Here

Sprit Airlines 22 18 10 Here

United Airlines 22 14 9 Here

US Airways 22 14 9 Here

Virgin America 24 16 10 Here

This confusion is further aggravated by the International Air Transport Association’s 

recent suggestion that optimal carry-on bags should be no larger than 21.5 inches by 13.5 inches 

by 7.5 inches, significantly smaller than the limits enforced by all 12 airlines listed above. This 

will only encourage some airlines to further cut gate-checking costs by reducing their carry-on 

limits, increasing the diversity of carry-on regulations and decreasing standardization.

The current situation has an economic downside as well. Diversity of requirements hurts 

the luggage industry since it is impossible to manufacture carry-on bags that are guaranteed to 

meet size restrictions. Diversity also hurts the airline industry since carry-on bags that are too 

large are often allowed through ticketing and security before needing to be gate-checked upon 

boarding. This increases the labor cost of the luggage stowing process and the time cost to the 

boarding process, reducing the profitability of the airline industry. Most importantly, diversity 

hurts consumers because they are unable to purchase carry-on bags that are guaranteed on all 

flights, leading to a need to purchase more luggage, and they are often unable to accurately 

determine if their items needed for a trip will fit into their carry-on, leading to a need to pay to 

check bags more frequently than necessary.

The economic benefits of standardization are well established as well as long known. The 

adoption of the Constitution in 1787, the federal enforcement of the standard gauge for railroads 

in 1863, and the establishment of the Federal Communications Commission in 1934 to regulate 

radio and television broadcasts are just a few of the many actions undertaken for the sake of 

standardization that led to sustainable economic growth in specific economic sectors. This 

proposed rule change will similarly lead to economic growth in the luggage industry and the 

airline industry, as well as encouraging growth in consumer travel.
In addition to the economic advantages, the advantages to airline passengers ought not to 

be overlooked. Airline passengers will no longer suffer the stress of having their carry-on 

luggage denied access to the overhead compartments due to the multiplicity of perplexing 

regulations. Removing stress from passengers’ experiences will lessen tensions between 

passengers and airline carriers, leading to fewer disagreements and fewer customer service 

clashes. This gain in travel efficiency aligns with the FAA’s goal of a creating “the safest, most 

efficient aerospace system in the world” (see http://www.faa.gov/about/).

The proposed maximal dimensions below are a compromise. They incorporate the modal 

length and height maxima of 22 inches and 14 inches, respectively, while incorporating a 

maximal depth of 10 inches, which is found in the restrictions of every airline that has more 

generous maxima than the mode.

This proposed rule change is to amend Title 14 §121.589(a) to read as follows (the 

emendations are demarcated in italics):

Carry-on baggage.

(a) No certificate holder may allow the boarding of carry-on baggage on an 

airplane unless each passenger's baggage has been scanned to control the size and 

amount carried on board in accordance with an approved carry-on baggage 

program in its operations specifications, provided that this program does not 

prescribe greater restrictions on the dimensions of carry-on baggage than those 

in subsection (i), (ii), and (iii) below. In addition, no passenger may board an 

airplane if his/her carry-on baggage exceeds the baggage allowance prescribed 

below:

(i) a maximum of twenty-two (22) inches in length;

(ii) a maximum of fourteen (14) inches in height;

(iii) a maximum of ten (10) inches in depth.