Yeah, but I think you can step THERE just not above it. But I don't know. Lol
All of the fillet radius where the wing root meets the center nacelle is super critical, as is the side window itself. if you damage the fillet radius, or don't have the side window rolled all the way up, it causes a massive airflow disruption, and severe buffeting, even at take off. It is actually the fillet radius, from the leading edge back, at the center wing where the wing root meets the center nacelle, that is the cause for the relatively low critical Mach of 0.67, and the compressibility problem. Most do not know, but Hap Arnold convinced NACA to allow Lockheed to test it in the wind tunnel, and help develop a fix. They did introduce a slightly improved fillet radius. However, NACA developed an entirely new fillet radius, and a leading edge modification that worked with the airfoil and the center nacelle, it increased the critical Mach to nearly 0.75 without the dive flaps. However, as was the case with the 1875HP engines and the 13'6" Hamilton Standard hydrostatic high activity paddle props that were on the P-38K, the War Production Board denied Lockheed a short production interruption to introduce the new wing improvement.
I had a friend who said that he actually took off once with both side windows down. He said it nearly shook him out of the plane even before he raised the flaps and gear. It may have been Ken Lloyd, as he was a Pacific theater pilot.
