American Airlines Airbus A319 taxiing at a US airport.

United Airlines Boeing 737-900ER N17403 taxiing at Chicago O'Hare International Airport with distinctive split scimitar winglets in the Evo Blue livery.

United Airlines Boeing 737-800 (N26226) prepares for departure at Denver International Airport under clear blue skies.

Taxiing in the early morning or golden hour, this Southwest Airlines Boeing 737-800 wears the vibrant 'Heart' livery with split scimitar winglets in front of a Frontier Airlines hangar.

United Airlines Boeing 737-900ER awaits departure at gate A14, showing the modern globe livery and signature split scimitar winglets.

Delta Air Lines Airbus A321-211 (N375DN) taxiing on the ramp with iconic sharklet winglets in view.

United Airlines Boeing 737-800 (N27213) taxiing at San Francisco International, sporting the globe livery with blended winglets.