hello everybody...I'll be very happy if anyone can help my questions~~In the real flight with 767 or other aircraft, do we need to maintain a specific pitch during cruise in order to decrease the pressure of the wings..for example i've seen many cockpit videos which they always have 2.5 degrees of pitch up during cruise whatever they got a long flight or a short flight, and also i know during flight, aircraft will try to put COG in the rear of aircraft by adjusting the fuel placement during flight. And by my own experience in 767PIC, take off with MTOW and cruise at FL370 with M.80, the pitch will be around 3 degrees or even more, so in the case should i cruise at lower altitude at first then climb to higher altitude when i'm lighter? And also if i take off with less fuel and cruise at FL370 with M.80, the pitch will be less then 2.5 degrees. Does these pitch degrees does matter or not really?Can anyone tell me anything i should know about this questions? Thank you!!

You don't pitch up to "relieve pressure on the wings". You pitch up to whatever attitude you need to maintain constant altitude. This angle would be affected by things such as gross weight, airspeed, altitude, etc. However, you don't really need to worry about a specific attitude: if you're climbing, your nose is too high, if you are descending, your nose is too low (assuming speed is where you want it).Perhaps I misread your question?Lee Hetherington (KBOS)

As Lee stated, you dont pitch up to relieve pressure from the wings, but you pitch up to maintain altitude. This is because angle of attack is not the same as pitch. To achieve 0 degrees AOA, you need to pitch up. This is how wings/aircraft are designed. The faster you go, the smaller the difference between AOA and pitch will become.Now to the second part: you dont decide the cruise altitude on what pitch attitude you would have at that level, but rather if you have enough performance to get up there. Also, stall speed decreases as you burn off fuel, and this then allows for greater margins of operation. As you get higher, the margin between max mach and stall speed get smaller, as your airspeed decreases. This is one limiting factor. To determine what your maximum and optimum cruise altitudes are, you have to consult the FMS VNAV 2/3 page. You, however, have to input all the correct weights for the FMS to provide these calculations.Refer to the FMS manual for more information.Regards,Mark

Normally cruise pitch attitudes are anything from 1.5 degrees at high speed/low weight, to 3.5 degrees at low speed/high weight.Your altitude selection should be based on the optimum altitude in the VNAV CRZ page, which takes into account weight/temperature/wind etc.

Thank you guys for these clear explanation~So basically what altitude should we cruise is base on the FMC's calculation, and in real flight we also request for higher cruise altitude base on our VNAV CRZ page...am i right?As in the flight planner of FS2002, what cruise altitude should i decide? or should i decide it base on something.

Well the FMS is only used as a reference. Flight crews dont plan their flights checking the FMS. Professional flight planners have all the data required to calculate these things, and those plans are also filed with ATC. Now, if lets say the weather changes as your flight progresses, and if 2000 ft above your level the winds are much better, then you consult the FMS if the climb is possible, and if it is worth the extra fuel used up during the climb. (This calculation is not available in PIC, as winds are not modelled in the FMS). If your (real) FMS says the climb is worth the cost, you then ask ATC if they can clear you for that level.As for the FS2002 flight planner, well, I dont know. I never really used it. Are step climbs modelled? (I doubt that!) I guess you could file your highest climb level, unless ATC will annoy you why you are not flying at that level.Good luck,Regards,Mark

Mark, you're idea is right but the way you say it isn't. If your AOA is zero, you have zero lift! If you have zero lift you will descend at a rate which is related to your aircraft mass (gravity).A positive AOA is required to maintain equal lift to mass (the lift vector must be precisely the opposite and equal of the mass vector for level flight).Iz

Cheers~~ and by now i'm going to do some step climb myself~~