Quick cruising speed question!
Thread Starter
Joined: Feb 2002
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From: East Sussex
Quick cruising speed question!
Having been working offshore for the last 12 years and travelled in all sorts of helicopters I was recently in a S76C+(+?) in the GoM and the PFD seemed to be saying we were cruising at 150+ kts!
Having usually cruised along at a leisurely 120 kts in Bell 412's etc I was a surprised/impressed and wondered if TAS or groundspeed was being displayed? (we were ~600ft AGL).
Good to get there quicker.....but is getting to a rig faster a good thing.
Having usually cruised along at a leisurely 120 kts in Bell 412's etc I was a surprised/impressed and wondered if TAS or groundspeed was being displayed? (we were ~600ft AGL).
Good to get there quicker.....but is getting to a rig faster a good thing.
Last edited by gravanom; 29th November 2004 at 07:05.
Joined: Oct 1999
Aviation Qualifications: ATPL
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From: Den Haag
Hopefully not too much above 150 kts as the Vne is 155!
This is quite a normal speed for a/c such as the 76 and Dauphin, though when at max weight they tend to fly nearer 140 kts.
It would be IAS, not TAS; you would not normally have a TAS indication other than on one of the FMS/GPS pages (though if the wind is displayed on the ND you can get a pretty good idea from the ground speed).
What is more impressive with the EC-155 is that you can maintain max cruise power at all altitudes and not become Vne limited, whereas the 76 has quite a penalty as you climb. Consequently you can see IAS' of 140 kts at FL80-100, giving higher TAS than sea level but with a 20% reduction in fuel consumption.
This is quite a normal speed for a/c such as the 76 and Dauphin, though when at max weight they tend to fly nearer 140 kts.
It would be IAS, not TAS; you would not normally have a TAS indication other than on one of the FMS/GPS pages (though if the wind is displayed on the ND you can get a pretty good idea from the ground speed).
What is more impressive with the EC-155 is that you can maintain max cruise power at all altitudes and not become Vne limited, whereas the 76 has quite a penalty as you climb. Consequently you can see IAS' of 140 kts at FL80-100, giving higher TAS than sea level but with a 20% reduction in fuel consumption.
Thread Starter
Joined: Feb 2002
Posts: 19
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From: East Sussex
Cheers - IAS it is (somewhat expired PPL I'm afraid!) and it was definitely in the 150 to 153 kt range though with a light load, only 6 pax and very little cargo/baggage.
Assuming of course that I was reading it correctly - left hand side of the PFD?
Assuming of course that I was reading it correctly - left hand side of the PFD?
