First line sector of command assesment training from Manchester to Heathrow in a B737. Twenty nine minute sector. Just before descent a duct overheat light came on. The QRH said 'Retard the throttle and observe the light go out . . . Trouble was the light stayed on! So, Pan Pan Pan and a single engined approach (with one engine in idle) to RW 27R at Heathrow. The rest of the day spent sorting out the paperwork followed by an 'early' stack.
!!!! happens and the detail could not have been scripted better for an early introduction to the hassle of command.