There were additional verses - presumably made up waiting for the planes to return

the RFF is dead
The hydraulics show three red
Coming in on a wing an a prayer


RFF is 'recognition friend or foe' - a signal sent out by our planes which was supposed to stop friendly fire accidents,

When the undercarriage went down, pushed by hydraulic rams, there were three lights to show that they were fully down - three green lights good - three red lights - God help us all.