When the skies are cleared of all air traffic for 3-4 days (as it was post 911 and would be if aircraft started to fall out of the skies) due to the hand baggage restrictions, I will concede you have a point.
The 9/11 aircraft did not explode in middair, to refresh your memory, they were flown into buildings killing many thousands, a completely different situation, that's why the US locked down the airspace.
You are making an illogical point and I am not going to waste anymore bandwith arguing with you.
BTW, Heathrow is now closed to incoming flights for your info.