The autopilot was flying the aircraft. The Co-pilot managed to get the faulty indicator light out of its holder. The Flight Engineer examined it. Unfortunately the Co-pilot then replaced the light indicator in the wrong way and it got jammed.
Captain: See if you can get that light out (the wheel down indicator light) Co-pilot: Alright Captain: Now push the switches just a ... forward. Captain: Okay. Captain: You got it sideways, then. Someone: Naw, I don't think it'll fit. Captain: You gotta turn it one quarter turn to the left.
The co-pilots seat in a similar aircraft. The red arrow points to the wheel lowering switch (the one with a white wheel on it). Below the switch are three black squares which are the wheel indicator lights ( if lit they would be green.) (Photo copyright Justin Cederholm)