In a bid to find cost savings, bosses at one carrier in the 1970s stumbled upon a revolutionary idea that would alter the way most future commercial jet aircraft would take to the sky
During the 1970s, Gatwick-based Laker Airways pioneered a number of cost-saving techniques to lessen its engines’ wear and tear and reduce fuel consumption, while extending the specified range of its aircraft.
Chief amongst the measures was the “reduced thrust take-off” technique, which it had developed for its BAC One-Eleven fleet that were powered by two Rolls-Royce Spey engines.
Later dubbed Flex temp, the method maximises the use of the runway by lowering the required thrust setting to better match the available runway length. Laker Airways was the first airline to introduce this procedure and pioneered its use and eventual adoption by other carriers.
The benefits for the carrier were significant. Not only did it increase the engines’ time between overall, but it also led to a reduction in costs and prolonged the life of the powerplants.
It’s reported that Rolls-Royce remarked that the Spey engines Laker Airways sent to them for overhaul were the best-maintained of any BAC One-Eleven operator.
Flex temp is now used by all airlines as a way of increasing efficiency and reducing operational costs. Nowadays, the flight management computer will calculate and preselect the required thrust setting for departures based upon data inputted by pilots.
This need for manual input has been the cause of several incidents when the flex temp was incorrectly calculated leading to the insufficient application of power for take-off.
Emirates Flight 407 is a prime example of this. On March 20, 2009, the Airbus A340-500 – which was conducting a service between Melbourne and Dubai – failed to lift off properly at the Australian facility and hit several structures at the end of the runway before becoming airborne and climbing enough to return to the airport safely.
Upon review, the first officer discovered he had understated the aircraft’s weight by 100 tonnes which meant an incorrect flex temp was applied, which had resulted in a lower than necessary engine thrust and consequently insufficient acceleration to achieve lift-off.
Other cost-saving innovations
Laker Airways also pioneered high-speed climbs which would allow its aircraft to achieve optimal cruising altitude as quickly as possible after take-off. Through coordinating with other aircrews and air traffic control, Laker pilots would encourage others around them to climb as quickly as possible.
This helped the carrier’s BAC One-Elevens climb faster without using too much power, in turn helping them reduce fuel consumption during the most fuel-exhaustive phase of flight.
Another cost-saving technique the airline introduced were weight-saving measures that allowed it to increase the range of its aircraft. Limits on baggage were lowered below the industry standard at the time and the airline carried fewer passengers than the One-Eleven’s capacity.
By limiting the free baggage allowance and restricting passenger numbers, the firm was able to use the weight saved to carry more fuel, allowing it to increase its range and be more competitive against larger, longer-range aircraft operated by its rivals.
These innovations pioneered by Laker in the 1970s have mostly found their way into the low-cost airlines we know and love today. However, the revolutionary flex temp take-off technique is now not just confined to budget operators but can be found across the entire airline industry.