Hi, thank you for reporting that @monkie, this issue should be fixed in the next patch .
@Kang So the logic for Dash-60 appearing and disappearing is based on several condtitions. Generally after you started up your jet and disconnected external power and air, the Crew Chief will start the spool down of the GPU (Ground Power Unit) and after it spools down, it will be removed. It should appear at any time you request the Crew Chief to connect external power or air (provided you are stationary). Currently this logic is not working properly in some cases, but as I wrote, it will be corrected in the upcoming hotfix .