Navy CH-46 Sea Knight Crew duties?

Question

2 questions.

1. According to one helipcopter site, in addition to the two pilots, crew chief and a mechanic were listed as crew. What were the crew chiefs and mechanic's duties? Specifically, I'm wondering why a mechanic was necessary on every flight.

2. with two rotors, is there an additional or independent flight controller for the rear rotor, or is it just synced to the main rotor for control? Thanks in advance.

Answer 1

Someone else can answer this better but your second question caught my eye and I have something to comment about.  The rear rotor is synched w/ the front one.  There was an accident many yrs ago that killed about 15 soldiers when the thing fell out of the sky.  An investigation showed that the front and rear rotor collided because they came out of synch.  The root cause was a bearing failure that allowed the rotors to collide, which normally intertwine with each other with each rotation.  At some point, the military started using crushed walnut shell media to clean out the bearings (walnut shell sand is used in many cleaning operations elsewhere).  The problem was that if all the shell media was not removed, it could block the oil ports that lubricated the bearing.  This was the cause of that catastrophic accident, the oil port became blocked by the walnut shell cleaning media, which prevented oil from entering, which in turn allowed the bearing to seize, which ultimately slowed down/stopped the front rotor blades.  Once out of synch, the rear ones collided w/ the front and the helicopter turned into a falling heap of non-flying metal.

When the investigation concluded, the military stopped using walnut shell media to clean critical parts like that and went back to using standard solvents.

Answer 2

Fas.org has two different crews listed for normal and combat missions.The crew of pilots, crew chief, and 1st mechanic is stated as non combat crew. While I can't find specific duties for the mechanic, I assume it would be monitoring systems and assessing maintenance needs, as the mechanic isn't critical enough to be included on combat missions. The combat crew is listed as two pilots, two door gunners, and the crew chief. While the first four are somewhat self-explanatory, the crew chief has a few jobs like handling chocks and tiedowns, operating doors, maintaining cargo and passenger safety, and supervising loading. Basically, he's in charge of everything aft of the cockpit.  As for your second question, the above answer is correct. The rotors are synced. They're connected by a drive shaft between them, which holds ther synchronization and allows both rotors to be turned by one set of engines in case of a failure.

EDIT:  There's something to add about the crew. Boeing and the Navy both list this helicopter as manning a crew of three. Though they aren't specific, this likely refers to pilots and crew chief. Gunners and other crew aren't necessarily permanent crew. I think the mechanic being stated as crew is likely an operational standard to increase maintenance efficacy, but isn't absolutely necessary for the aircraft's operation. The whole question seems to come down to what a particular source considers "crew" to be. Considering the length of my answer, I hope I've covered everything. Thanks for the great question!