Shares of Delta Air Lines (DAL - Get Report) rose on Tuesday after the company announced it was boosting its second-quarter revenue and earnings guidance amid a broad increase in ticket sales and what total load factor -- the number of full airplanes it has in the skies.

Shares of Delta gained 1.5% to $58.63 after the company said it was lifting its second-quarter per-share earnings guidance to between $2.25 and $2.35, up from $2.05 to $2.35 a share it had guided to in April.

The company also lifted its revenue guidance, indicating it now expects total revenue to have come in 8% to 8.5% higher at the end of the second quarter vs. earlier guidance of between 6% to 8%.

#FirstDayofSummer so...

— Delta (@Delta) June 21, 2019

Revenue per available seat mile, or RASM -- a key metric used in the airline industry to measure profitability -- is now expected to rise by 3.5% vs. previous projections of 1% to 1.5%.

Separately, Delta said its total June load factor rose to 90.4% from 88.5%, as domestic load factor improved to 90.9% from 88% and international load factor rose to 89.5% from 89.4%. Total traffic increased 6.2% to 22.77 billion revenue passenger miles, while capacity rose 4% to 25.19 billion available seat miles.

The Atlanta-based carrier said it flew a record 18.9 million customers in June, including a single-day record of 697,745 customers on June 21st. The company has largely skirted economic fallout that its competitors have experienced resulting from the grounding of Boeing's (BA - Get Report) 737 MAX jets.