NADP

[dr_anthony]

Guys, interesting to now, how you are use NADP1 and NADP2 ICAO procedure. 

And question to Jan, how it use in real life? Not uderstand clearly, because 733 FMC haven't CUTBACK feature like NG. Thanks.

[Eddie]

NADP1 is just 800 thrust reduction/3000 acceleration. NADP2 generally requires FLCH with the IXEG bundled software version, in my experience.

[Litjan]

Hmm, not sure I understand the question correctly.

You just set the thrust reduction altitude to 1000 AAL for the NADP 2 and also initiate acceleration from V2+10 to 250kts at that altitude. This results in a flightpath that is a little closer ot the ground at first, but ultimately achieves a clean aircraft (saves fuel) and steeper overall climbout angle (less noise further from airport). It is the preferred method for airlines.

For NADP 1 you leave the TRA at 1500 AAL, but wait with the acceleration until you reach 3000 AAL. This yields a steeper initial climbout (less noise closer to airport) but results in overall more fuel used (longer flight with higher drag).

To determine the point of when you start acceleration is done by choosing when to exit the TO/GA pitch mode. Simply delay pushing VNAV or FL CHG until you are high enough. This point can not be coded into the FMS like it is done for Airbus FMGC or (I assume) NG FMC versions.

Jan

 

[dr_anthony]

Thanks a lot. I confused, becouse in some situation R-TO trust is closely to CLB 1 or 2 trust (88 RTO and 87 CLB for example). Its the reason why reduce of engine noise not look sufficiently big instead of CUTBACK feature of NG FMC, which "cuts" trust" to near of 75 %.

[Litjan]

Yes, sometimes you will not notice a reduction in thrust from R-TO to CLB-1 or CLB-2... In the economically ideal case there would even be an increase in N1 from R-TO to CLB. It is more economical to climb to altitude with full climb thrust (faster in thinner air -> more TAS, less specific fuel consumption). But the manufacturer wants the thrust to always DECREASE at the thrust reduction altitude, for fear of confusing the pilots when thrust suddently increases...

Jan