Hello guys,
Few days ago, I travelled as a passenger from Chengdu to Lhasa on an A319.
Was quite interesting to see things from the cabin in a different airline: Sichuan Airlines.
One thing really puzzled me: During engines start, I noticed PTU was running for few seconds then stopped as normal. But then just when the aircraft started to taxi out, PTU kept running all the time until take off power was applied?! And both engines were running for taxi. Is there any failure which require an operational procedure to run the PTU during taxi out?
Today I flew again on A319 from Lhasa to Chengdu and they did not run the PTU during taxi.
Fun fact also, I noticed PTU runned for 2 seconds during gear up and gear down transition. Never noticed that before. Probably because of the temporary drop of pressure of the green system.
Bonus question: Lhasa airport is at 11700 feet. Do you know if the crew applied a specific procedure?
And A319 is normally operating to airport up to 9200 feet maximum.To operate higher do they have more powerful engines?
Thank you.