The pilot had to strangle the parrot to stop the radar interference.
strangle the parrot
idiomTo switch off the transponder, for example, because it is interfering with the radar system.
Origin
disputed originFrom parrot (“(aviation, slang) transponder”). “Parrot” was the British codename for the identification friend or foe system on World War II aircraft which used transponders.
After the air traffic controller noticed the signal error, he ordered the pilot to strangle the parrot immediately.
To prevent the faulty transponder from cluttering the display with false echoes, the flight crew proceeded to strangle the parrot during the final approach.