Supposedly, a witness said the initial explosion was caused by one of the bombs (sticky taped) on the ceiling falling down. (pinch of salt territory here, granted)
I'm positive that russian military helicopters had been circling the scene
for the entire time the crisis lasted, however. I remember a BBC reporter mentioning it. So the scramble time is a non-issue.
Personaly, I kind of doubt it was a planned assault because it was such an almighty botch job. Apparently the Russian commandos and the Alpha squad (Spetznaz IIRC) had no idea what the others entry plan was..... hence why there was a 10-hour long shootout.
EDIT;
http://news.bbc.co.uk/1/hi/world/europe/3627406.stmInteresting conflict of stories;
"Marat Khamayev, 15 , also spoke to Kommersant
"Initially we were escorted to the toilet together, then they stopped doing that, and only took the little kids. All the time the explosives were hanging above us - they used adhesive tape to fix it there.
"Before the assault the bandits started arguing with each other about something. I've spent a long time in Chechnya, I know the Chechen language, and they weren't speaking Chechen - they were just speaking a strange language like Arabic, and also Ingush.
"One of the gunmen was reading the Koran constantly, and I counted exactly 23 gunmen altogether. The leader was on the roof the whole time with a sniper's rifle. We realised that, because the others went to him for advice.
"The older pupils were forced to carry desks to barricade the windows. When the assault started one of the bandits shouted 'I'll save you'. Everybody ran towards him and then he blew himself up, killing many people.
"The whole time they never let anybody sleep - if somebody dozed off they would shake him awake again, saying 'no sleeping!' The explosion took place under the roof - there was no external explosion... When the assault came I pulled two girls out with me." "
NB: 'there was no external explosion'.... sounds like an odd turn of phrase for a 15-year old. but it could be due to translation.
"Diana Gadzhinova, 14-year-old girl hostage, speaking to Izvestiya newspaper
"It took us all by surprise. We were told there would be talks and we were ordered to lie face down [in the gym]... Then there was an explosion in the yard. Then there was shooting... [My sister and I] stayed where we were, lying on the floor. But suddenly there was another explosion above us and part of the ceiling fell in. People were screaming, there was panic.
"I looked up and saw some children lying on the floor covered in blood and not moving. There was a dead lady lying beside me. Torn-off arms and legs were lying everywhere. There were bombs hanging on the rope they'd strung up between the basketball hoops, across the gym. And now these bombs began going off, one after the other, coming closer and closer to us. Anyone who could get up ran screaming to the windows and the back entrance corridor. Alina and I were near a window [both sisters managed to escape unscathed]." "
EDIT2: RE the second one, the editor of Izvestiya was apprently
forced out by the KreminNB: If this was a deliberate and planned storming, it will go down as the worst in history - 40% of hostages injured, 40% killed.