An MoD spokesman said the incident was now a police matter and "our involvement is over".
He said Typhoon jets can be scrambled after the pilot or crew of a passenger aircraft sends out an emergency signal.
"The purpose of going up is to investigate what the situation is," he said. "Often when a Quick Reaction Alert aircraft is launched the details are not known, but it is known that a signal has been sent. Part of the purpose of sending a Typhoon up is to have a look and see what they can see."
The very same plane on the very same flight - from Lahore to Manchester - had been diverted to Stansted on September 7 2011 due to a bomb scare.
More top news
The Number 91 was travelling from Trafalgar Square to Tottenham in north London when it came to an unexpected halt.
It didn't take long for the converted flower shop to be snapped up. 220,000 people looked at the advert on Zoopla.
Glen Hazel, who was an 11-year-old schoolboy, has a clear memory of the events of 1966.