Full power with brakes on
I've flown many times but I took two flights recently that were unusual in terms of the take off.
Both flights were with Islandsflug on a 737-400.
Our take off started with the usual spooling up of the engines then full power so that you were pushed into the seat. However, brakes were still on and remained on for approx 5 secs. Then the brakes came off and it felt like we had been flung down the rwy on a catapult.
I enjoyed it as it was different but it seemed to bother a number of the passengers. One guy behind me turned to his wife and said "that will be the handbrake off then!"
What are the reasons why this would happen?
1st take off was at EGNT (so runway length not a problem) and the return at Zakynthos.
Many thanks.