Shortly after delivery, the aircraft started to have strange technical issues and failures. Sometimes, the aircraft would turn its external lights on by itself and then back off when someone tried to intervene.[4] Occasionally, the lights of the emergency exits would turn on one by one from front to back "like a Mexican wave", not all at the same time, which according to the cabin crew meant that Deli Mike "was in a good mood". The aircraft also made "small jokes" to passengers and crew. On one occasion, the aircraft started sounding the master caution alarm in the cockpit, causing one of the inexperienced cabin crew members to panic. Frequent problems with the aircraft included the reading light of a completely different passenger turning on when the button is pressed, and the same issue also exists with the button used to call a crew member. One popular story among technical staff states that a senior employee fixed the faulty flight instruments of the aircraft simply by patting its door and saying "what happened to you big man?" Basically, the A340 had a soul.