Need Any Info On Bell 47 Cam Box

[hyke_48]

hey, im an aircraft maitnence student and im looking for some info on the bell 47 cam box, any help would be greatly appreciated

[vortex]

I've spent a bit of time staring at them...what would you like to know?

[hyke_48]

any info you can think of would be greatly appriciated, mainly what they do and how it works

[Cambox]

any info you can think of would be greatly appriciated, mainly what they do and how it works

<{POST_SNAPBACK}>

 

 

Basically an interface between collective and throttle. Used on Bell 47 series, mounted on LHS of the center frame............. Lots of wear......

[vortex]

The cambox is described in the Bell 47 M & O manual as "Throttle Controls" The carburetor throttle is manually controlled through the collective stick, which is geared to a torque tube operating inside the collective tube. Rotation of the collective stick grip is transmitted through a push-pull tube, throttle cam box, and an enclosed cable to move the carb. throttle arm. The throttle is synchronized, by cam box action, so that movement of the control stick to increase or decrease main rotor pitch also changes throttle setting to provide more or less power as required.

In effect it is a governor that was manufactured in a time when man was just happy to fly vertically. It requires almost continuous inputs during changes in collective settings and makes a 47 challenging to fly for someone that has never tried to correlate throttle and collective together.

The cam box is mounted in different locations on all the models of 47...the inefficient effect is universal between models.

FYI...fly the 47 well and when you jump in a 204/205 with a governor in manual mode, its no big deal.

[cap]

**** I'm getting old. Never thought I'd see the day that folks were talking about a manual throttle like it was a crank-start on a Model T. Manual throttle is all you had one time on anything in the helicopter world and that's where the word "co-ordination" was born in helciopter flying. It was usually "tied-in" on many occasions with a now-arcahic word known as "milk".

[vortex]

Ah yes "milk"...often used in conjunction with its almost forgotten friend "pump". :shock: Droop is usually not far away too.

Hey Cap, I see you're from "The Peg", are you the same guy (mid-nineties, 1995 I think) I was on a 204 in northern PQ with, then we traded for a 205 and went on to Cape Breton?

[Skids Up]

It was usually "tied-in" on many occasions with a now-arcahic word know as "milk"

"milk"...often used in conjunction with its almost forgotten friend "pump"

 

Quite often in conjunction with "Oh S...!" and a tightening and loosening of the seat cushion anchor at times....