EasyJet posted a 5.3 percent rise in third-quarter sales and its new chief executive pledged to make the carrier more efficient and repair its fractured relationship with a key shareholder.

Former Guardian Media boss Carolyn McCall, who replaced Andy Harrison as easyJet’s Chief Executive earlier this month, said she was reviewing the business, with crewing shortages and punctuality at London’s Gatwick airport — where it is the largest carrier — two of the main challenges facing her.

“We need to get Gatwick performing well for us because it affects the whole network,” McCall told reporters on Wednesday.

“There are crew shortages in certain places and we need to get to the bottom of why.”

Recent data from the UK’s Civil Aviation Authority shows easyJet’s punctuality performance at London airports has deteriorated year-on-year.

EasyJet’s founder and largest shareholder Stelios Haji-Ioannou, who stepped down from the board in May, has threatened to remove the low-cost airline’s right to the easy brand name if it doesn’t improve its punctuality.

“We’re somewhat concerned by the operational problems experienced by the airline, which may not be completely one-off, and given the uncertainty created by the ongoing dispute with its largest shareholder, we’re cautious,” said Arbuthnot analyst Gerald Khoo, who holds a ‘neutral’ rating on the stock.

It said its load factor — a measure of how well it fills its planes — increased by 1.4 points to 86.1 percent.