Patna, March 27: Flying in winter is a pain because of frequent flight delays. The summer is no better, at least for Patnaites. Fewer seats will be available in planes taking off from the city airport as the temperature soars.

The airlines will cut the seating capacity of their aircraft operating from the city in summer months for load penalty factor. Under this norm, the operators have to reduce the weight of planes by leaving some seats vacant for smooth take-off when the temperature is high.

“The aircraft engine has to create a certain minimum thrust while taking off. As the air becomes thinner during summer, the flight captains prefer to reduce the aircraft load for a safe take-off from a short runway so that the necessary engine thrust is available. With reduced weight, the engine requires less thrust. That is why full load flights do not operate during the summer months, especially in the day when the temperature is higher,” said a source in the aviation industry.

The load penalty factor plays a major role at Patna airport because of its short runway. Against the total runway length of 2,286m (7,500 feet), only 1,954m (6409 feet) remains available at the time of take-off because of location constraint of the airport.

Over 12 passengers booked on Jet Airways’ Patna-Mumbai flight (S2 721) today had a taste of trouble the load penalty factor can lead to. They were not allowed to board the plane despite having boarding cards when fight captain Tina Updhayaya told the airline officials that she would not be able to take-off with full load flight as the temperature was high.

The airline faced the same problem with its Delhi flight. Over 20 passengers were not allowed to board the plane because of load penalty factor.

The Jet officials had a tough time explaining the technical reasons to the passengers offloaded. They could pacify the disgruntled fliers only after making arrangements to send them to Mumbai by different flights.

“We had issued the boarding pass presuming that the flight would operate full load. When the flight captain expressed inability to take-off with full load flight we denied access to the passengers whose boarding passes were issued last,” said a Jet official.

He said steps would be taken to reduce the number of available seats in the flights operating during the day hours. “The number of available seats in our Mumbai flight is likely to be brought down from 144 to around 115,” said the official.

Air India (AI) is also planning to reduce the number of available seats in its Patna-Delhi afternoon flight from 145 to 100. Private operator Kingfisher has imposed load penalty on its Delhi flight. Only 140 seats are booked in its 180-seater Airbus-320 aircraft.