Killeen Regional Airport at Robert Gray Army Airfield GRK / KGRK

Envoy Air, the American Airlines Group regional subsidiary operating American Eagle flights between GRK and Dallas/Fort Worth, self-handles ramp, baggage, and customer-service functions at its GRK station; no third-party ground handling contractor was found for this airport. Confirmed via an active Envoy Air 'Airport Agent - Ramp and Customer Service' job listing for the Killeen, TX (GRK) station.

The City of Killeen's Flightline Services/Airport Operations division (the municipal airport authority operating GRK and sister field Skylark/ILE) is the on-field fuel seller, offering AvFuel-branded full-service Jet A during staffed hours with after-hours call-out, plus 24-hour self-service Jet A and 100LL from the north apron. Line service agents are NATA certified, with fuel storage/delivery maintained to AvFuel Corporation and ATA-103 standards; this office is the operator behind an older, now-superseded 'Corporate Aviation' FBO listing still seen in some third-party directories at the same field address. · Full service ~0400-2100 daily per FBO listings; self-service 24 hours; Airport Operations Center staffed 24/7 for after-hours call-out

CSI Aviation, a FAR Part 135 air charter/air ambulance operator, leases a hangar at GRK (expanded in 2021-2022 to a 21,900 sq ft, six-door facility with capacity for up to five aircraft) as its regional maintenance base for King Air 200/300 and Beechcraft 1900D turboprops, alongside crew and administrative offices.