justwork wrote: It is my understanding that Q400 operators, if they choose, will be able to taxi on one engine very soon. Meaning there will be an AOM revision approving this. Not only will the operator still need to stay within the restrictions outlined in the AOM but being responsible they will also have to amend their SOP's and implement some sort of training to do this. You can't just say one day that you can do single engine taxi with no SOP revision and expect to save money, the bent metal will quickly negate years of savings. At some airports this will save significant amounts of fuel while at others it will save virtually none.
Now I have no knowledge oh how this will all go down but I would imagine that taxing with the #1 engine running and the #2 shut down is what will be standard. The #1 hydraulic system powers a PTU to drive the #2 hydraulics. This makes a lot more sense to me than running the #2 engine and having a standby pump powering your #1 hydraulics which is what your brakes are on.
Fuel is a huge cost, and this cost will continue to go up. If you can find a way to decrease your fuel consumption by a few % points, you're going to save millions.
ninja, I can tell you that the landing checks in the 100/200/300 include setting both SPU's to "ON" and they don't come off till you are parked at the gate, then they get switched off, and the last engine comes into feather (and you lose the AC power).ninjacrumb wrote:linecrew, I find that unlikely.
For the Dash 8'ers out there, I'm sure most are aware of FARPIN and LOSER. That is an acronym for hydraulic systems powered by an engine.
Unless the #2 SPU was activated taxiing with #1 shut down means you have no "Normal" brakes (the N in FARPIN). Guess the SPU could be turned on, I think Bombardier would say WTF though.
And I hope you mean #1 SPU was activated taxiing in with the number #1 shut down.. If you shutdown engine #1 and don't turn on the #1 SPU you have no hydraulics on the left side including the AntiSkid / Normal Brakes. I think you are confusing where the #1 SPU / #2 SPU is powered electrically from with the system that the pump itself powers.
