原來又唔係喎 都係縮上去
見有人解釋係咁
"They have a pneumatic override to operate in an emergency mode where the door is opened by a co2 charge. They also have a manual lift bar incase of total power failure where one person holds the door arming lever up in the manual override position while two ABP's lift the door from the bottom. This is also on the DC10." https://www.airliners.net/forum/viewtopic.php?t=744429