> Hi Ian, We cross paths quite a bit, don't we!LOL... We do indeed, Rich... The other twenty forums were a bit slow today (PPRuNe, Bluecoat, Aerowinx, ...)... and I thought I'd better give a real-world aviation expert like yourself a proper response ;-)Cheers.Ian.

V/S mode would the apporprate mode if you wanted to cut the V/S to a set target or to lower the ROC/ROD as you approach the target altitude. I use this technique in the real aircraft to smooth the transition both for passenger comfort and to avoid TCAS TA/RA events that might occur due to crossing traffic above/below our level-off altitude. Sometimes it's easier to add or reduce thrust to quickly effect a vertical speed change. This of course assumes you're flying an aircraft without AT's or with the AT's disengaged.However, the speed on elevator autoflight mode (MSP SPD or VNAV) provides protection in the event of performance problems such as engine failure. The observed behavior in LVL CHG mode during a climb would mimic actual aircraft performance in V/S following an engine failure. It's for the reason the V/S mode is frowned on as climb mode for most aircraft (B737 Low Speed Protection Reversion notwithstanding). I just bought a set of rudder pedals and I'm having a lot of fun with V1 cuts and other engine failures.Take care and again great product!Rich BollWichita Kansas

Rich,Response to first paragraph : YEAP ! (i.e. yeap to 1000-to-go, TCAS TA/RA events etc)Response to second paragraph : That's why I mentioned the word "problem". If for any reason AT is disengaged the FD should still guide the pilot...I might also give you an explanation regarding this behaviour that you see. In level change mode there exists a primary controller using speed deviation as an argument. However, I have implemented a number of "secondary" pitch controllers. One of them uses N1 deviation as an argument. Why you might ask ? Consider this scenario : an NG transitioning from ALT HOLD at, say 4000' and 250 KIAS, to a LVLCHG mode. This might be due to a specific departure procedure, initial ATC clearance etc. This is a very very difficult case. In the worse event of a lightly loaded (overpowered) 737-600 using max climb if no such controller exists the aircraft will bust the MCP target by more than 15 knots while the engine is still spooling up (from about 45% to 90% N1). Unless the aircraft pulls more than 0.5g's to pitch up quickly (unacceptable). This secondary controller will therefore use the aircraft performance library and command a "lead" pitch-up in anticipation of considerable thrust increase. Modulating throttle lever movement is also helpful and impemented (Ian was kind enough in sending a few numbers for "degrees-throttle-movement"/second). The pitch "lead" effect magnitude also depends on altitude and target IAS. This little trick reduces target speed overshoots to about 5-7 knots at most under all conditions. The opposite happens for descend (i.e. thrust reduction) cases. Now the problem is that this naturally should only happen if AT is engaged. A victim of one's own complexity. Many thanks for the kind words.Best Regards,VangelisPS. Hope you do try the stall and overspeed protection reversions in this one.===================================== E. M. Vaos Precision Manual Development Group www.precisionmanuals.com=====================================

It is amazing, how prompt you guys from PMDG react! That is what I call really good support!Excellent job!Wolfgang

Vangelis,Thanks for the insight into the coding process. I can imagine the difficulties in making all of the components work together. If it's help, the LVL CHG modes in the real aircraft can be rather abrupt if one is not smooth with power changes. So I do understand the problem.I will try the stall and overspeed protection modes. Thanks again! Take care.Rich Boll