Shares in regional carrier Flybe have plunged by as much as 19% after a profit warning saw it become the latest airline to hit turbulence.
Flybe said it had incurred higher than expected costs in the first half of its financial year after a review of aircraft maintenance.
It said this reflected a drive to improve the reliability of its aircraft, particularly the Bombardier Q400 turboprop.
The company, Europe’s largest regional airline, now expects adjusted profit before tax for the period to be in the range of £5m to £10m, against market expectations of £15m.
It compares with a profit of £15.9m in the same period last year.
The fall also includes a previously disclosed £6m in IT costs related to the development of a new digital platform.
Shares opened nearly a fifth lower and though they slightly recovered shortly afterwards they were still 15% down.
Chief executive Christine Ourmieres-Widener, who took over the running of the airline in January, said: “While half year profits are lower than expected, I am confident that we are still on a clear sustainable path to profitability.
“Our sustainable business improvement plan is delivering benefits with the fleet size now reducing and consequently both yield and load factors are increasing.”
Interim results will be published on 9 November.
Earlier this year, the Exeter-based company set out plans to slow expansion as it contends with increasing competition and slowing growth in consumer demand.
It reported a pre-tax loss of £19.9m for the year to 31 March, down from a £2.7m profit the year before.
Airlines across Europe are facing tough conditions in what is seen as over-capacity in the market.
The UK’s fifth biggest airline, Monarch, went into administration earlier this month, while elsewhere Alitalia and Air Berlin have gone under.