The chaotic opening of Heathrow’s Terminal 5 last month led to British Airways’ worst April since the start of the Iraq war. Yesterday the airline said that passenger numbers had fallen by 7.9 per cent, or 221,000 people, to 2.5 million after the problematic opening of the £4.3 billion terminal.

The British flag carrier was forced to cancel more than 430 flights and lost about 20,000 pieces of luggage as it moved into its new home at T5. The negative publicity and cancelled flights are thought to have contributed substantially to the fall in passenger numbers during the month.

This particularly affected BA’s UK and European operations, which were the first to move into T5. Short-haul passenger numbers fell 8.5 per cent last month and BA’s aircraft were operating at only 70 per cent of capacity.

Worldwide, the carrier’s aircraft were 71.6 per cent full during the month, the lowest April load factor since the Iraq war began in March 2003. Load factors are seasonal and typically in April traffic rises before the summer. The decline in passenger numbers last month was worst in the economy cabins, with an8.8 per cent fall compared with last year. Premium passenger numbers rebounded by 3.4 per cent after a 5 per cent fall in the previous month.

Of particular concern to BA will be the sudden drop in transatlantic travel, which is where the carrier makes the bulk of its money. Passenger numbers to and from the Americas fell 7.9 per cent and the load factor fell to 72.2 per cent, from 78.5 per cent in the same month last year.

Nick van den Brul, aviation analyst for Exane BNP Paribas, said: “T5 has clearly been a big problem and it will have an impact on profits. April is usually a good month, when things start to pick up after the winter, but this has not happened.”

Analysts are concerned that BA’s passenger numbers are falling just as costs rise and the economy slows. Oil prices have hit record levels and this has caused a number of airlines to go into bankruptcy.

BA put up its fuel surcharge last week to cover these increased costs, but it risks losing passengers, particularly as the economies of Britain and the United States slow.

Doug McVitie, managing director of Arran Aerospace, an aviation consult-ancy, said: “The combination of higher fares, higher costs and falling passenger numbers is very bad news and the more bad news there is, the more people will be put off the airline.”

BA’s share price fell 9¾p to 239p yesterday and is trading at less than half the level of a year ago.

The company said: “Market conditions are broadly unchanged with long-haul, nonpremium traffic showing significant weakness. In April some impact was felt, particularly on transfer traffic, from the move to T5 and the operational problems in the early part of the month.”

Ryanair, the low-cost carrier, has also suffered from weaker demand as a result of tighter household budgets.

Its traffic figures for April show that it is not increasing passenger numbers by enough to cope with the capacity it is adding. Passenger numbers rose by 15 per cent to 4.7 million, compared with the same month last year, but load factors dropped to 79 per cent from 83 per cent.

Further indications of weakness in the airline sector is expected today when easyJet, another budget airline, reports its first-half figures. Analysts expect a loss of about £50 million compared with a £17 million loss in the same half last year.

Times Recommends

• Millions enter fuel poverty as energy costs soar
• High street sales stage surprise July upturn
• Persimmon says housing market will not worsen