No OP so I can't comment on his source, but I heard the exact same statement from a maintenance engineer who works on Boeing aircrafts for over 30 years (https:

No OP so I can't comment on his source, but I heard the exact same statement from a maintenance engineer who works on Boeing aircrafts for over 30 years (https://www.linkedin.com/in/joselitosousa https://www.linkedin.com/in/joselitosousa). He also owns a youtube channel on which he discuss mainly aviation (pt/br) (https://www.youtube.com/avioesemusicas https://www.youtube.com/avioesemusicas)