For the sixth time this week, mechanical or technical issues have disrupted flight schedules with two flights out of Canberra yesterday cancelled due to mechanical or electrical failures.

Passengers on a Dash-8 aircraft scheduled to leave the nation’s capital for Sydney at 12.05pm were told by the pilot that a “battery in the electrical system was not performing as it should”.

A Qantas A380 which was forced to land in Perth after experiencing mid-air difficulties / Picture: Channel Nine Source: Supplied

The passengers remained on the aircraft — flight QF 1474 — while the flight was checked. They were then told to disembark and milled around on the tarmac for some minutes before they were told the flight had been cancelled.

They were then told they would be placed on a replacement aircraft. That flight was due to leave about 1.15pm. Earlier in the day, a Boeing 717 due to leave Canberra at 6.25am did not get off the ground. Passengers booked on the flight were placed on other services.

Source: DailyTelegraph

Passengers disembark from the fifth Qantas flight hit with technical problems / Picture: Supplied Source: Supplied

A Qantas spokeswoman said it was a case of putting “safety before schedule”.

It follows four “turnarounds” in the past two days including another Boeing 717 that left Hobart for Melbourne last night. Twenty minutes into the flight a cockpit warning light came on indicating a minor systems issue. The captain made the decision to go back to Hobart.

After checks on the ground, the aircraft was allowed to take off again about 90 minutes later. It came after three turnarounds in a day on Monday, ­involving two A380s and a Boeing 737.

Unions have suggested the issues are linked to cost-cutting, in particular the decision to consolidate heavy maintenance to one facility in Brisbane.

CEO Alan Joyce yesterday apologised to passengers for the disruption but reassured travellers Qantas ­remained one of the most reliable airlines in the world.

The problems have almost overshadowed Mr Joyce’s announcement of a forecast underlying profit in the range of $300 to $350 million for the first half of the financial year. The outlook has buoyed Qantas’ shares which climbed more than 10 per cent this week.