The change in the interior configuration of United’s Boeing 757 aircraft showed how sensitive and adaptive aviation has always been. It all started when people started noticing that some seats on United Airlines’ Boeing 757 planes were banned from being used on any flight or route.
On the United Airlines 757-200, configured for domestic flights, seats 24B, 24E, 27E, 30B, 37B and 40B are not available, while on international flights, seats 29B, 32E and 36B are not. On the largest model, the 757-300, the unused seats are 16B, 19E, 27B, 30E, 36B and 39E, according to the portal. Live and let’s fly.
What these closed seats have in common is that they are middle seats and are located in the back half of the plane. This shutdown will only last until mid-April, when winter is over in the United States. This has an explanation.
In the United States, the government, through the Federal Aviation Administration, sets the average weight of each passenger, as it is used in the flight calculations of any aircraft. The last changes were in 2019 and before that in the 1990s, with a more recent change, the passenger weight was taken from 65kg to 81kg. In the winter, because they wore more clothes, the weight of the woman increased from 68 kg to 83 kg.
The same applies to male travelers, whose weight has increased from 84 kg to 90 kg in summer, and from 86 kg to 92 kg in winter. These changes take into account that the American population is generally fatter, following data from the CDC (the US Centers for Disease Control and Prevention), and also bearing in mind that passengers are carrying more carry-on baggage, with the expansion of low-cost companies charging Fee for everything, including baggage.
Why 757?
With that, at least in theory, the plane takes off up to 1.8 tons heavier, in the case of a full Boeing 757. This will not be a problem at first, because the final weight calculation always takes the actual number of passengers on board, which is a variable.
It turns out that the situation in the 757 is a little more complicated, because the plane has the design Where is the fuselage section behind the wing and the main landing gear relatively Longer than other aircraft. This generates a tendency to touch the tail to the ground during take-off or landing, the so-called Tail blow, precisely because it is longer. To avoid this it is necessary that the aircraft be well balanced.
In the case of United, it takes more seats excellent forward, such as the Polaris Executive and Premium Economy, which take up more space, and provide more comfort for passengers. Therefore, the front part of the aircraft is less dense and lighter.
However, as passengers gain more weight, United will likely see that during the winter, aircraft can become more easily unbalanced, as the economy is heavier, with the aircraft’s center of gravity tilting back, facilitating tail stroke.
One solution that was found was to reduce the number of seats in economy class, to prevent passengers from sitting in them by making them unusable with red stickers and to reinforce them with crews so that no one would occupy them during the entire flight. Removing the seats might also be an option, but since the winter itself isn’t that long, it’s not worth it bothering to park the plane, take out only 6 seats, fly with it, and then redo the process to put the seats back in.
United, in turn, did not mention the reasons, but emphasized that the change was due to Aircraft weighing and balancing according to FAA rules.. Interestingly, Delta has several different configurations on the 757-200 and -300, many of them similar to United, but they haven’t adopted any seat locks.
