Patience, my friend, is requirement number one for profiling!
Think of the props or rotor heads as profiles in themselves and it gets a lot easier. I always work in the same scale and I am slowly building up a catalogue of wheels, tyres, weapons, props, jet tubes and rotors as individual renders and I can just grab these and put them in whatever subject I am currently working on. A classic example is the props on the light aircraft I have done recently are all one render used over and over again.
As much as like to help you out by drawing stuff for you, when would I get my stuff done?
I've bolted some seats in the back now and added the soundproofing. I can't imagine this had much effect considering how often they flew with the doors open...
That looks really nice Grubby! But could I interest you in a little reflected light?
I know it isn't for everyone but I think it makes that curve around the underside look much more 3D