have done some recent aerobatics practice. Airliners aren't built to pull very many Gs before parts start falling off. An airliner is clean aerodynamically and picks up speed in a hurry when the nose is pushed down sharply. It'd be easy to exceed Vne (never exceed airspeed) under those conditions. If a pilot's last aerobatics experience happened 20 years ago in an F-4, well, he'd better brush up on his technique.

It's possible to do an impressive aerobatics display without pulling more than 3 Gs. Bob Hoover did that for years in a Shrike Commander, a twin engined private plane not built for aerobatics. I saw his act several times. He's the master of smooth flying and considered by many to be one of the best pilots who ever lived. Bob started doing his act in the 1970s when he worked for Rockwell. The act was so impressive that Shrike sales skyrocketed and Rockwell took back his plane. When sales dropped, they gave him a new plane.

Back in the 1970s, I saw a DC-8 freighter make a high speed pass at the Oshkosh airshow. The pilot then pulled up sharply and rolled the plane to about a 60 degree bank angle. It appeared that he was going to do a slow roll but the feds were on the airport. I've heard some airline pilots say that they have rolled their planes when no one else is on board. They were probably inspired by Boeing test pilot "Tex" Hill who rolled the 707 prototype near Seattle back in the 1950s in front of thousands of people. Boeing was pissed but people were impressed at the plane's strength.