Pertaining to the EgyptAir explosion theory

It was reported from multiple reliable sources today that window on the A320 were ‘open to the sky’ according to broadcast ACARS satellite data.
However, while the spreading of smoke alerts was reportedly way to fast to be a cabin fire, or electrical fire, it was also said to be way to slow for an explosion …
Back to Times Square NYC:

A street vendor spotted smoke coming from the SUV and alerted police, who quickly cleared the area. The bomb attempt set off an intense investigation that culminated two days later with investigators plucking Shahzad off a Dubai-bound plane at a New York airport.
Prosecutors had introduced a dramatic video of an FBI-staged explosion they said demonstrated how deadly Shahzad’s bomb could have been.
The FBI bomb – an identical vehicle fitted with 250 pounds of ammonium nitrate and diesel fuel, three 25-pound propane tanks and two five-gallon gasoline canisters – blew up with a force that ripped the vehicle in half. The explosion caused a giant fireball that overturned and shredded four other cars parked nearby in an open field, obliterated about a dozen dummies posed as pedestrians and shot fiery debris hundreds of feet in all directions.

This was also the case for the shoe bomber who needed a lit source to explode his bomb.
And I believe the crotch bomber who bothered the president during his holiday in HI, also tried to ignite his crotch.
The worry is that ISIS (or whoever) did NOT have an inside man to place a conventional explosive on the aircraft, the worry is that they have something we cannot yet detect in baggage or carry on.