Air cargo shipments fell 2.1% in March, the Air Transport Association said Monday.
Domestic shipments plunged 3.5% compared with a year ago to 1.07 billion revenue ton-miles, while international shipments dipped 0.9% to 1.24 billion RTMs, the group said in its monthly report.
A revenue ton-mile is the revenue generated by carrying one ton of freight one mile.
Air cargo shipments always have a trucking component, since air carriers use trucks for local and regional ground transportation.