Budget airlines are cracking down harder than ever on carry-on sizes, forcing travelers to master the art of strategic underpacking or face expensive checked bag fees at the gate.
A recent report from a Flair Airlines passenger reveals just how strict these policies have become—and offers a glimpse into what it takes to pass increasingly stringent bag checks.
The Flair Airlines Test
The traveler successfully fit an Osprey Daylite 26+6 backpack into Flair Airlines' notoriously strict carry-on sizer, but only after strategic underpacking and some tense moments at check-in.
"I had to remove the Amazon Paperwhite reader and other stuff from the front pocket, as otherwise it was hard to push into the sizer," they report. Even an underpacked bag required adjustment to squeeze through the measurement device.
The packing list that made it through: a medium-size packing cube with four socks, four pairs of underwear, and two t-shirts, plus one larger fleece jacket, small toiletries, and a small water bottle. This is bare-bones travel that leaves zero room for excess.
The Budget Airline Arms Race
Ultra-low-cost carriers like Flair, Spirit, Ryanair, and Frontier have built their business models around unbundling services. The advertised ticket price looks attractive, but airlines expect to recoup revenue through ancillary fees—especially checked baggage charges.
To maximize these fees, airlines are getting increasingly aggressive about enforcing carry-on limits. Gate agents now routinely use sizing devices, and bags that previously would have been allowed are being flagged for paid check-in.
The New Reality: Pack for the Sizer, Not the Plane
Experienced budget travelers emphasize that your bag needs to fit the sizer, not just the plane's overhead bin. This is a crucial distinction.
Many backpacks that are marketed as will fit in overhead compartments but won't squeeze into the airline's metal testing frame, especially if packed full. Airlines have no incentive to be lenient—every bag they can force you to check generates $50-80 in revenue.
