Hi there.This is last error message i got on FMC, with bells and whistles...Cannot set VNAV at all. What does this means? And what should i do in that case. I set my CRZ ALT at FL280 and once i'm at that altitude cannot engage VNAVThanks for helpingLuigi ;-)

Could mean that the aircraft does not have enought time at criuse level to have a TOC and TOD. A copy of your flight plan and aircraft weight would help..Best Wishes,[h4]Randy J. Smith[/h4]http://www.rawbw.com/~bdoolin/shinault/Animation1.gifCaution! Not a real pilot, but do play one on TV ;-)AMD 64 3200+ | ASUS KV8 DELUXE | GFORCE 5700 ULTRA @535/1000 | Maxtor 6Y080M0 SATA 80 GIG | 512 DDR 400 | Windows Xp Pro | Windows Xp Pro 64 |

OK Randy.FL280 is the altitude that FSBuild planner set for LIML - EHAM flight. Should i lower CRZ FL once message received?ThanksLuigi ;-)

Vnav descent is automaticlly initiated at T/D if a lower MCP altitude has been set. The PATH DECSENT profile terminates at the altitude restriction on the LEGS page.This is important.A PATH DESCENT can only be computed if a mandatory "at" altitude restriction is set. For example, set 150/3000 on the LEGS page abeam the final approach fix. The FMC will provide a slowdown profile for the approach. In this case, the airplane will be at 150 knots and at 3000 feet at the final approach fix.During descent you may have help the deceleration with SPEED BRAKES, flaps on schedule, and gear at the approprate times.The DESCENT page, line 1R is very helpful in montioring altitude and speed restrictions because it displays the next waypoint constraint from the LEGS page.Below 10,000 feet, in VNAV PATH descent, TARGET SPEED must be kept within a + 10 knots or VNAV will disconnect.Floyd

Milan to Schiphol, how far is that? You don't need very far to reach FL280. Can you try increasing your climb rate from the clb page and see if that fixes it? When are you getting the message? Best Wishes,[h4]Randy J. Smith[/h4]http://www.rawbw.com/~bdoolin/shinault/Animation1.gifCaution! Not a real pilot, but do play one on TV ;-)AMD 64 3200+ | ASUS KV8 DELUXE | GFORCE 5700 ULTRA @535/1000 | Maxtor 6Y080M0 SATA 80 GIG | 512 DDR 400 | Windows Xp Pro | Windows Xp Pro 64 |

If i let FSBuild auto generate route it set CRZ to FL 280.Is there a way to know which will be most suitable CRZ level for a specific flightplan?Thanks a lot for helpingLuigi ;-)Flightplanhttp://forums.avsim.net/user_files/90869.jpgAC loadinghttp://forums.avsim.net/user_files/90870.jpg

Yes, very simple.Always plan to fly at or near optimum altitude. Remember on shorter trips optimum altitude may not be achievable since T/D point occurs proir to completing the climb to optimum Altitude.The FMC can help you calculate a CRUISE altiude:-Put the route into the FMC. -Add any waypoint altitude and airspeed containts.-If you want to use VNAV DESCENT down to the final approach fix then put a speed and altitude restriction there to help the slowdown profile.-On the PERF INIT page, insert all data except a TRIP/CRZ ALT.-Now look at the TRIP/CRZ ALT. The FMC should offer the Maximum altitude under TRIP. -Round it down to the next lower altitude or even lower to give a longer CRISE segment. -If you insert an altitude any higher than this you will get a FMC message "Unable CRZ Altitude". Insert a lower altitude.-This will asure there is a CRUISE segment no matter how short between T/C and T/D. Floyd

Hi Floyd,very clear. One question though: can i do this also if i usually load a FSBuild plan instead of planning in FMC?Thanks for helpingLuigi ;-)

Hello Luigi,you should try not to load ready flightplans, but to type them into the FMC instead. The savings from loading the f/p is minimal (about 1-2 minutes at all), but if you do it by yourself you always know what