Providing line maintenance, base maintenance and 24/7 technical support from its facilities located at Liège & Brussels Airports

In August 2022, ASL Aviation Holdings and Sabena technics announced an agreement whereby ASL assumed full ownership of X-air services, which has been renamed to ASL Maintenance. The Liège and Brussels based maintenance organisation had been jointly owned on a fifty-fifty basis by ASL and Sabena technics since the acquisition of TNT Airways by ASL in 2016.

ASL Airlines Belgium is X-air’s largest customer, and ASL Aviation Holdings’ other European airlines in Ireland and France also use the MRO’s facilities for light and heavy maintenance checks on B737-400 Classic and B737-800BCF next-generation aircraft. X-air also provides some maintenance services for ASL Belgium’s fleet of B747-400 freighter aircraft.

X-air services is a Belgian certified Part 145 MRO with 200 specialised staff providing line maintenance, light maintenance, base maintenance services and technical services at its two strategic hubs located at Liège and Brussels airports

X-air services’ 2000m² hangar space facility at Liège Airport offers line maintenance and logistics support up to A-checks:

  • Daily/Weekly transit
  • Aircraft mods, SB’s, AD’s and NDT
  • Scheduled/Unscheduled maintenance
  • Engine, APU and landing gear replacement
  • 24/7 AOG rescue
  • A/C logistics including sourcing and PBH management


At Brussels airport, its 6000m² hangar space operates two heavy maintenance lines providing:

  • A-checks / C-checks / D-checks
  • Landing gear and engine replacements
  • Aircraft weighing
  • Structural corrosion and fatigue inspection programs
  • Minor and major modifications embodiment
  • Minor and major structural repairs
  • Dent and buckle inspections and assessment


In addition, X-air services offers engine boroscope inspections for ALF-502/507, CFM56-3, RB211 and PW2000 models.

Aircraft Types Maintained

Boeing 737-300QC

Boeing 737-400 Passenger

Boeing 737-700 Passenger

Boeing 737-800 Passenger