Quick cruising speed question!

[gravanom]

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. :confused:

[212man]

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.

[gravanom]

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?

[212man]

Either that or you were doing 600 kts at 150 ft!

[gravanom]

Well I bloody wish I was!

though perhaps in something FW!

(edited for post pub spelling)

[NickLappos]

gravanom,

Your numbers are correct. At a very light condition, the aircraft will cruise above Vne, so keep the speed down, or the Feds will pull you over!

At 7000 lbs, it will cruise above 170 KTAS.