Israel carried out its operation against Hezbollah on Tuesday by hiding explosive material within a new batch of Taiwanese-made pagers imported into Lebanon, according to American and other officials briefed on the operation.
The pagers, which Hezbollah had ordered from Gold Apollo in Taiwan, had been tampered with before they reached Lebanon, according to some of the officials. Most were the company’s AP924 model, though three other Gold Apollo models were also included in the shipment.
The explosive material, as little as one to two ounces, was implanted next to the battery in each pager, two of the officials said. A switch was also embedded that could be triggered remotely to detonate the explosives.
I assume they use the cell phone network these days, so any in flight probably weren’t able to receive the signal. On board but not at elevation is a pretty small window, so the number could be as small as zero.
That’s not an actual limitation of cell signal, it’s entirely regulatory.
https://en.m.wikipedia.org/wiki/Mobile_phones_on_aircraft
Cell phones get a surprising amount of viable service on flights. If you don’t turn your cell radio off you can absolutely get text messages.