I just changed CI from 40 to 100 and mye crz speed is noe at 330 insted of 301 , afte 1 hours flight at fl250 relaxing with my cup off thea i uddenly was at 345 and managed to overspeed at broke the plane.......Why did i pass 330? and is 330 to close to dangerous....... What should be max crz speed ............

Could have been a sudden windshift...

When you get to your cruise level hit Alt Hold Button and set cruise speed to mach .78 If it was a short flight I could see why you were at FL250 but if not then you were a little low for cruise. And yes if you use a CI of 100 it is going to fly 330 like that and on descent as well which is too fast! Try using 40 or less for your CI.

Thx gents, maybee try get my CI about 70-80 so I get my speed on crz to about 310, and yes maybee my crz was a ittle to low for that flight, I was doing EDDH - ENGM who is about 404nm and should maybee be atleast FL300+ .....

400 miles? I'd probably be in the upper 30's FL in most cases.With that high a CI and 330 knots for IAS, the usual mach speedwould probably be about .80 or so.. Which is not too awful out of linereally, unless winds shifts are a problem.At high altitude the IAS will drop on back. I've had many cases where wind shifts would bump me overspeed.Sometimes several in a row if the "real weather" changes arereally coming at you due to passing many airports, etc..It would have to be a real short trip for me not to get high enoughto go to a mach speed, vs the IAS. I rarely cruise in the 20's.Like I say, only a real short hop would I do that. In most cases with 400 miles, I would be shooting for FL370-380+,depending on the direction. I usually run the usual recommendationsthe FMC spits out for econ crz.But I tend to like to go high. Many of my flights I'll hit TOC, and 40miles later hit TOD.. :/ Say from Houston to Dallas, etc which isabout 245 miles. Even that distance, I'll shoot for say FL300, andquite often bump even higher. Each flight will be a bit differentdue to winds, temps, etc..Check out Flight aware for that route.. The altitudes used eachday will vary a good bit for the real world.Almost all the long hauls end up near 40k.. IE: FL370-390 east,FL380-400 west are really common with the long haul Southwestflights. Some of the ones running east will jump on up to 410in some cases, but 390 is probably a bit more common.Maybe my thirst for altitude stems from sim driving Learjetsfor quite a while.. :/ I'm almost always above 40k in thoseunless a shorty hop.

When you get to your cruise level hit Alt Hold Button and set cruise speed to mach .78

Why would you do that if you're already on VNAV?

http://forum.avsim.net/topic/350389-my-weather-config-for-pmdg-planes-part-ii/page__hl__weather+settings__fromsearch__1 Check the above Tutorial if you having the radical FSX Wind Shift issues.

Why would you do that if you're already on VNAV?

His cost index is too high. Thats why the plane overspeeded and crashed when he hit the radical windshift.

Why would you do that if you're already on VNAV?

exactly...

afte 1 hours flight at fl250 relaxing with my cup off thea

FL250 for cruise? I imagine that the CRZ page suggests a much higher altitude as the optimum. Next time you are "cruising" at FL250, try plugging in a step altitude in the high 30's on the CRZ page and see what the projected fuel saving is. I bet you'll start climbing

http://forum.avsim.net/topic/350389-my-weather-config-for-pmdg-planes-part-ii/page__hl__weather+settings__fromsearch__1 Check the above Tutorial if you having the radical FSX Wind Shift issues. His cost index is too high. Thats why the plane overspeeded and crashed when he hit the radical windshift.

My point is you shouldnt have to press alt hold and manually set speed.. thats what VNAV does.

...His cost index is too high. Thats why the plane overspeeded and crashed when he hit the radical windshift.

The cost index is what it is. If the pilot didn't monitor the conditions and allowed a sustained overspeed situation to develop, don't try to blame the cost index, or the dispatcher that assigned it, or anybody else other then the pilot who didn't do his job.

If you're overcooking it, just change the cost index. VNAV will reduce the thrust immediately. Or if you're late for tea, do the opposite :)

If you're overcooking it, just change the cost index. VNAV will reduce the thrust immediately. Or if you're late for tea, do the opposite :)

Thats probably the best advice here. I just didnt think he would listen to me if I told him Cost Index by most airlines today is 40 or less in the NGX and its not like the bigger jets that use 70 or 80.

Thx Gnets for replyes, Im on CI 70 and doing FL250-280 and at Crz speed 310 doing good since im on short trips like 3-500 nm.NB: If im above FL300 I see that my max speed reduces to just above 300kts , If im at 250kts or lower I can make 340kts at max.........therefore I like FL250 ;) Whats the Normal crx or FL for 737 at 3-500nm trips?

Keep in mind that the speed indicated on the speed tape is indicated airspeed. For a given constant true airspeed (TAS), IAS will reduce as you climb and the air gets thinner. So beware of using the speed tape to judge how fast you are going relative to the ground... The GS readout is king here.The reason that your maximum IAS reduces as you climb above FL250 is that Mmo becomes limiting above this altitude. The TAS corresponding to Vmo does reduce a little as you climb and the air becomes colder, but the effect is not strong. Essentially, your maximum TAS changes only a few percent. The dominant effect is that the IAS corresponding to this TAS reduces with altitude.Bottom line: Don't be afraid to climb if you want to go fast. The optimal FL computed by the FMC is a good guide on how high to climb.---Martin Boehme

Thx Gnets for replyes, Im on CI 70 and doing FL250-280 and at Crz speed 310 doing good since im on short trips like 3-500 nm.NB: If im above FL300 I see that my max speed reduces to just above 300kts , If im at 250kts or lower I can make 340kts at max.........therefore I like FL250 ;) Whats the Normal crx or FL for 737 at 3-500nm trips?

You're flying too low. Normal cruise altitudes for those trips are anywhere from FL360-FL410.