Southwest Airlines was forced to cancel 9400 flights between mid-February and March 31, including 2800 due to the grounding of the Boeing 787 MAX. The airline told investors this week that the cancellations meant it’s first-quarter year-on-year capacity growth had been slashed from the 3.5 to 5 percent range to about 1 percent. But it wasn't all just about the MAX. The airline said about 3800 cancelations were due to weather and another 2800 resulted from to unscheduled maintenance disruptions arising from contract negotiations with the Aircraft Mechanics Fraternal Association. READ: stunned British Airways passengers land in the wrong country. Southwest is the biggest MAX operator in the US and as of  March 13 had 41 remaining MAX deliveries scheduled in 2019,  with 221 firm orders, 115 options, and 3 additional MAX deliveries beyond 2019. The company said it had complied immediately with the March 13  US Federal Aviation Administration order to ground all 737 MAX aircraft and taken all 34 of its 737 MAX 8s out of operation. It was in the process temporarily relocating its aircraft to a third-party facility and implementing an enhanced storage program as it reduced its published flight schedule through to April 20. Pictures have emerged of Southwest MAX planes massed the famous aircraft "boneyard" at Victorville in California. One plane diverted to Orlando, Florida, on its way to the storage facility this week due to an engine issue unrelated to the problems that have prompted the MAX fleet to be grounded More cancellations are on the way and Southwest said it was evaluating future schedule reductions. “Due to the current uncertainty regarding the duration of the MAX groundings and any requirements for reinstatement of the aircraft into service, it is difficult for the company to forecast the impact of the MAX groundings beyond first quarter 2019,’’ it said. “The company is proactively managing cancellations, minimizing operational disruptions, accommodating Customers, and minimizing the impact on its on-time performance. “Despite the ongoing effects of the MAX groundings, the company's current operational performance is solid.” The airline estimated a combination of softer passenger demand due to the US government shutdown, greater than expected winter weather disruption, softness in leisure travel and the MAX grounding would cost it $US150m in lost revenues in the first quarter.