Originally Posted by
RVDT
Hi VF,
5 minutes in a 6 above 7000' would have you convinced not to ever get in one again!
We had the 2nd one in service.
Where to start? I had a lot of time on the tools and cut my teeth on 5's from early C18 ships through to D's. The 6 is something else entirely.
In the first year we changed -
1/ Undercarriage - wasn't up to the arrival speed at the ground in auto above a DA of about 3500' from fast depleting memory.
2/ OR clutch housing due to improvement. You cant take the engine out of a 6 like a 5. The little inbuilt hook for the block and tackle is not an option. Serious crane special tool needed.
3/ Changed all the TOT and Q gauge arrangement as the original supplier went out of business. Was a serious upgrade and Boeing actually did it for us.
4/ In the beginning, the MRH bearings had a 300 hour life.
5/ Swashplate link changed as the offset was out of whack originally.
6/ Notar fan shroud - they are now improved but used to go rotten due to holding water in the bottom part of the abradable coating. Fix was to add drain holes and paint them.
7/ Extensive EMI testing of the FADEC.
8/ Fuel system has a few pitfalls - you can incorrectly install the main pick up and motive fuel lines as the connections are the same size. It has consequences. The baffle arrangement and check valves in the tank need attention.
Ours had the motive fuel line installed incorrectly and it was holding the baffle down which was interesting. The motive fuel pumps fuel aft of the baffle. If the baffle isn't working you end up feeling like an EC135 pilot with low fuel light yet plenty on the gauge. It is a LOW FUEL situation. Understanding of the system helps - slow down and it will run back through the check valves to where it can be picked up. I was 20 miles offshore at the time!!
Flying characteristics -
In the beginning, they had a cap on the end of the thruster can and the wake separation point would swap from side to side and you would constantly be out of balance. As you corrected the out of balance it would pop out the other
way. Thet removed the cap and threw it away in the end.
6 of the old blades with the original profile dont make for an efficient rotor - too much parasite drag as the A of A is not ideal.
Auto's like a brick and you really need better than average skills. Youtube is your friend. Take aim between your toes and you need about 80 knots. The autorotative driving area is blanketed by the cab.
And the old Notar Catch 22 - you need to lead with right pedal in the pitch pull on touch down as the "anti-torque" uses Coanda from the rotor downwash just when you don't actually need or want it. If you are not aware of the phenomena it will turn left on you and as the Nr is rapidly decaying you will possibly touch down travelling sideways. Not pretty.
There is quite a bit of feedback through the collective. Especially up high. You felt like you were hanging on by your fingernails and had to really concentrate to get any performance out of it.
We gave it away in the end and I think it is still flying. Was glad to see the end of it and moved on - nothing to see here. After we sold it the AD came out on the tail boom attachments and yes one of them was cracked!
The only upside was that the C47 is a fairly good engine (everything a C30 isn't) and the MGB is a good option for a retro by a D/E operator. That would be about the only value in one. There is a reason that they dont sell.
To me it was an exercise in how not to build a helicopter. If it was the only one you had flown and did not know any better it is possibly better than walking but hey.............still a tur&.
On another point, as you are possibly one of the elite really high altitude operators out there get yourself in a BK117-D2 (H145) for a look see. Now that is a high altitude rocket ship. Certified to T/O and Land up to 20K!
Rant over!
G'day RVDT...awesome info & rant Mate, many thanks. I didn't wanna operate above 6,000' for landings
But also didn't realise the extent of the flying lemon she is
Thank You....cheers