Several previously undisclosed features that Boeing added for the 737 Max 10 will be retrofitted in United Airlines’ fleet of 737-900 and 737-900ER aircraft, an employer letter to United’s pilots says.
The internal letter from Howard Attarian, United’s senior vice-president for flight operations, was sent to pilots at the Chicago-based carrier on 20 June, shortly United announced a decision to convert orders for 100 737 Max 9 aircraft to the 737 Max 10.
Boeing has disclosed the 737 Max 10 would feature a 1.7m (5.3ft) stretch of the fuselage to accommodate 10 more passengers and a modified landing gear that extends up to 23cm on take-off to prevent tail strike.
But Attarian’s letter lists several more features that Boeing has added to the aircraft to “improve the aircraft and better address some of the operational issues we see in the 737-900/ER variants”.
Boeing declines to comment on the contents of the letter.
The upgrades include an “improved flap design” that enables more approaches and landing at Flaps 40, the slowest-speed setting for the 737.
Boeing also adjusted the maximum landing weight centre of gravity grid in a way that will avoid “tail tip” events. Some airlines use special tail stands to prevent a 737-900 with a heavy rear cargo load from tipping the nose up at the gate.
Boeing also improved the body contour of the 737 Max 10 to reduce the risk of tail strikes, Attarian writes.
Finally, Boeing will certificate autoland capability for the 737 Max 10 with alternate flap settings for approach and landing, Attarian says, adding that this should improve performance during enroute icing conditions.
“The hard work has really paid off in an airplane that is truly a step change improvement relative to the 900/ER,” Attarian writes.
Some of the upgrades, he adds, will be retrofitted to United’s 737-900/900ER fleet “in the coming months”. The 737 Max 10, meanwhile, is scheduled to enter service in 2020.
Additional reporting by Edward Russell.