Yes and no. It is often just dead equipment. But sometimes it could still be turned on but there is no purpose for it anymore. The P-3 has been used for a -lot-

Yes and no. It is often just dead equipment. But sometimes it could still be turned on but there is no purpose for it anymore. The P-3 has been used for a -lot- of things over the years. Beyond that it is just heavy old versions of things that could easily have been lighter and required far less power. Using a 60 year old design for a replaceable part is an expensive luxury only the military can afford. If we had modernized the avionics and the main load center on that plane it probably would have save 10-15k lbs without even changing the engines or airframe.