R66 Turbine Lag

[cherminator]

I've recently started flying a Robinson R66 and I've really noticed a lag when pulling power compared to the EC130 I used to fly. It takes like three seconds before anything happens when pulling some power and it's taking some getting used to.

 

I'm a private pilot without a lot of experience flying different types of helicopters but I don't recall the 130 having this issue. Does anyone know why there is such a difference in the two machines?

[Wally]

Twenty years since I flew an Allison/Rolls-Royce 250 with pneumatic fuel controls, which are slower than some other, newer fuel controls. Is everything FADEC now by cracky?

 

On the pneumatics, there is/was an 'anticipator' (pilot phraseololgy, maybe?) on either the actual fuel control or governor (yes- two separate units, linkages) that "quick and dirty roughly" adjusts fuel delivered for 'big' power changes. Poor rigging woud slow engine power change response. I pretended that it made me a smoother pilot...

Three seconds sounds like a lot, but to be honest, I couldn't say how long it took for everything to get back to nominal settings, just slower than an Ariel.

 

The big trap with the pneumatics was long, low power descents- like autorotations with ACTUAL rotor tach splits. The N2 drops away letting the NR autorotate, and the demand for fuel drops to an idle, allowing the N1 to spool down almost to an idle. It takes time to get the N1 back into the range of delivering useable power, if you forget that your power recovery won't involve enough power to fly away as the NR droops. An aggressive descending, turning final also allows the split and droop.

 

If you're