WS posted record net earnings of $140.7 million in Q1, compared with the net earnings of $89.3 million reported in the 1^st quarter of 2014 – a 57.6% jump.

"We started 2015 with a record quarter as we achieved our best ever quarterly net earnings and earnings per share, exceeded our 12% ROIC target for the 11^th consecutive quarter by achieving an all-time high of 15.8%, and saw our operating margin expand by 5.6 percentage points to 18.2%," said WestJet President & CEO Gregg Saretsky.

"WestJetters are at the core of our success, and I am very excited to celebrate that success with a record profit share pay out later this month," Saretzky added.

WS achieved an on-time performance rate of 78% in the 1^st quarter, a year-over-year improvement of 10.1 percentage points. Based on the trailing 12 months, the airline achieved a return on invested capital of 15.8%, compared with the 14.3% reported in the previous quarter.

WS carried 4.914 million pax during the quarter. Capacity was up 4.7% while traffic increased 2.8%. Load factor was 81.6%, down 1.5 points from 83.1% in Q1 2014.

The airline has also just released its April traffic and capacity report. WS carried a record 1.7 million pax during the month, filling 80.2% of seats, down 2.1 points from last April. On-time performance was an impressive 91.2%, up 8.5 percentage points from April 2014.