Middle Eastern carrier Etihad Airways is ordering 40 A350-900s and 10 -1000s, plus 36 A320neo-family twinjets.
The airline is taking the regional version of the A350, and is also taking a single additional A330-200 freighter.
Etihad says the single-aisle deal includes 26 A321neos and 10 A320neos. The A321neos will be fitted with CFM International Leap-1A powerplants.
All A350s are available only with the Rolls-Royce Trent XWB engine.
Etihad chief James Hogan says the aircraft will start arriving in 2018. The deal also includes options on another 30 aircraft, taking the total potentially to 117 jets.
Hogan says the structure of the order allows the carrier to move aircraft between its equity alliance partners.
Etihad values the agreement at $26.9 billion.