I don’t think a B777 will stall 45,000. Sure, you can stall it deliberately.
Service ceiling is defined as the maximum altitude at which and aircraft can maintain a climb of fifty feet per minute.
The chief pilot in my company is a brilliant man. He has thousands of hours in the 757, 767 and 777 with a major airline before being forced to retire due to age. I checked him out in a certain corporate jet. Out company acquired another jet of that make it model, but it had some very minor differences, one of them being service ceiling. The jet I checked him on had a ceiling of FL450. This other aircraft had a ceiling of FL410.
I didn’t make him do a complete new check out in the new aircraft, but I did discuss the difference of service ceilings. He came back from his first trip in the new aircraft and declared that the new airplane was a real dog at FL430. I reminded him that it’s ceiling was FL410. That’s the only mistake I’ve ever seen him make. Again, he is a wonderful pilot.
Wow. And you are an instructor no less?
You got the 50 feet climb performance required to establish the service ceiling. But my friend many many other factors involved. Like weight and temperature. We have on average a plus 15 to 20 ISA here in the mid latitudes. Full of fuel, high temperatures. A sudden and dramatic drop after reaching 45,000 feet. Come on, you are better than that
Sounds like he made a series of mistakes including CHECKING the FMC or performance charts BEFORE he attempted to climb. Sounds like he just did his thing. And that my friend is dangerous