Aser said “Well... you won't find the "Orbit function" in a 767 FMS...
Now seriously I'd like to hear why they find it a pain, it isn't so bad.”
Just a few thoughts
The 139 makes a very fine ‘heli-liner’ (although the ergonomics don’t suit me – but that’s a whole other thread). The FMS data base is mind blowing to the average rotary pilot like me, all that data on runways, sids, transitions, airways, stars and approaches. Just amazing!
But does it make a good offshore multi sector shuttle aircraft? Which is how I am being asked to operate it. Well as it stands I’m not so sure.
I can only compare it with my experiences operating the S76 A+ and C models in the environment in which I currently operate.
Leaving single engine performance to one side, let’s just consider the 139’s HW Primus Epic FMS against Rnav 2 for say a four hour 20 sector oil/gas field shuttle.
I guess data input for both systems is as good as each other. Putting together a routing and therefore using either system for navigation is just fine.
But that is just part of the game for me as an offshore pilot. As important is the ability and reliability of each system to compute fuel figures around the route.
This is especially relevant when operating for one customer in the SNS who can only offer fuel on one platform while shuttling between four different gas fields with sectors varying from 2nm up to 115nm.
For many years S76 pilots have been working and trusting Rnav 2 backed up with gross error checks to offer payloads way down route to the nearest 10 lbs. And, it works well.
Now consider the FMS in the 139. With all the computing power of NASA on board the FMS can’t work to closer than the nearest 0.1 of a metric tonne! How useful is that? Great I guess if you are sitting at the pointy end of a 767. But 0.1 of a tonne (220lbs) is the weight of a man and his bags. Surly we can do better than that?
Also Rnav can accept that the helicopter may finish where it started (along a route), and so can compute groundspeeds in both (all) directions and therefore accurate fuel burns too. And, while I know I can programme a 139 flight plan to start and finish at the same place I get the feeling the machine is looking down its nose at me thinking what kind of an airline pilot are you? It strikes me that the 139 fuel management just isn’t accurate enough in either current ff/gs or pilot spd/ff. Well not for my purposes anyway.
Now I admit that I don’t have many hours under my belt on the 139, and I am happy to learn from those that know it better, but it really annoys me that with such amazing computers on board that I have to rely on my wiz wheel to work out my bingo figures and reserves. Its either that or I offer the customer c**p payloads.
I just hope that while we’re busy worrying about fuel figures that we don’t gently drift down towards the water (cos we don’t have the fourth axis of the auto pilot and we’re not allowed (limitation) to couple the other three axis’s below 1000ft offshore), missing our tiny DH “MIN” box on the PFD and the ladies 150ft call (the only real warning we have) before hitting the water.
So, I for one might choose Rnav over FMS i.e. old technology over new in this context.
Detach me to Bergen (or any strange, busy place) for a month an I’ll take FMS every time.
Now, how we got from the development of the S92 to me shuttling in a AB139, I’m not sure.
But in an attempt to move closer to this thread I’d love to have even a simple AVAD on my expensive new Italian toy. Or possibly EGPWS.
…Mornington Crescent!
So I guess we now get back to Nick’s other point. Here is an aircraft that has staggering performance for which someone pays handsomely, buy very little to help stop us flying it into the water on a inky night.
Long live CRM and SOPs!
Red