Sign in to follow this  
Guest LSangiovanni LIML

How do i Fill these two entries in FMC?

Recommended Posts

Hi friends,can anyone please tell me how do i fill CostIndex and Reserve data; supposing for example that my flight needs 14000 lbs of fuel and i want to load 5000 more lbs?Thanks in advanceLuigi ;-)

Share this post


Link to post
Help AVSIM continue to serve you!
Please donate today!

Cost Index is probably one of the most advanced things there is.A "very" simple explanation: It is a trade off ratio between speed vs economy.A value of 0 means maximum speed, who cares about fuel economy.A value of 100 (or 1000 not sure on the NG) means set speed to BEST fuel economy values.They will adjust your N1 rates accordingly (not sure if this is modelled).Reserves is simply the amount of extra fuel you want to be holding for emegency measures, ETOPS operation, holds, etc. It is used for fuel predictions, it does not imply that setting it gives you that much extra fuel onboard. It just tells the FMC how much of the actual fuel loaded should be considered not used for your flight plan.Ray

Share this post


Link to post

Hi RayGood "short" explanation! As I know the max economy value is 100 I think...BTW:COST INDEX IS NOT SIMULATED YET!If you select either 0 or 100 it will give you the same N1 settings and the same fuel flow!Fly safeMartin---------------------Martin Paulimartin@paulifamily.chhttp://www.period.com/airlines/swissair.jpg!!!FOREVER!!!

Share this post


Link to post

I think that might be backwards. At least on a 767, higher cost indices yield higher speeds, and lower indices better economy.Lee Hetherington (KBED)

Share this post


Link to post

I thought also 100 is higher speeds ;-)Andr

Share this post


Link to post

You might have me there, I can't remember which way was better or worse ;)Ray

Share this post


Link to post

Ray,thanks a lot for the clear explanation.Think i need one more little help: during DF734 days i remember that filling most of FMC pages i could have V1-Vr-V2 automatically filled; now i tried in 737NG but probably i miss something and those three data do not show at all :-(Am i wrong or those speed should auto fill once te other data are inserted?Thanks in advanceLuigi ;-)

Share this post


Link to post

The "Cheat" is to simply press the LSK to the right of each V field. In real life the pilot fill these in manually(?).

Share this post


Link to post

>The "Cheat" is to simply press the LSK to the right of each V>field. In real life the pilot fill these in manually(?).Yes, i remember also in DF734 it worked once Flaps, OAT, etc. set ....but now on NG737 it doesn't work :-(Do i miss anything? Can you please help?take careLuigi ;-)

Share this post


Link to post

Well, assuming that you have entered all the requierd parts such as the route, weights, flap settings etc (there should be no entry fields with square boxes left), the only thing that comes to mind is that you may be overweight. If you load the default plane it is too heavy. If you change the fuel load in FS you should see a overweight warning if this is the case. If so, reduce the fuel load and see what happens. I

Share this post


Link to post

Yes, you had it backwards.:-)The cost index represents a relationship between fuel-related costs and time-related costs. A cost index of zero means that fuel-related costs are the only costs that matter. If cost index were implemented in the PMDG 737NG FMC, a cost index of zero would give you maximum range cruise speed. As you increase the cost index, the speeds would increase, since you are telling the FMC that time-related costs are of relative greater importance.Don S.

Share this post


Link to post

SAS,it's your name? ;-) now i can remember the day before yesterday this trick worked also on my FMC; so it's urely my fault. Now i'm ging for some investigation....thanksLuigi ;-)

Share this post


Link to post

"In real life the pilot fill these in manually(?)."It depends on the FMC options chosen by the airline, Tord ;-)On some NG's, the recommended (calculated) value appears in small font to the left of the (empty) V Speed slots. If you push the (right hand side) line select key (as you do in PMDG), it puts the small values into the right places (in large font).Hope this helps.Cheers.Ian.

Share this post


Link to post

Tord,on my last flight DTTA Tunis to LFPG all went just fine and V1-Vr-V2 were there. I really do not know what i missed last time.One more question: can you please explain how can i center the small plane in MFD-PLAN page? It seems it can only keep departure apt in its center and the small white plane, fortunately, flies away.......Thanks Luigi ;-)

Share this post


Link to post

Sir- The PLAN mode is only used to review your Route segment that you cannot see in MAP mode, you can see if there are any problems prior to departure. You do not use it while flying, insted use the MAP mode. In the PLAN mode the aircraft icon will move according to the aircraft's current position, if you wnat to view it in PLAN mode do this.While flying set the efis to PLAN mode, expand the range. Then bring up the LEGS page on the FMC. You will see a CENTER PROMPT that cycles through the waypoints on the PLAN map. [h4]Best Wishes,Randy J. Smithhttp://img.villagephotos.com/p/2003-8/196432/winglets_lg.jpg [h3] AMD XP 2200 |MUNCHKIN 512 DDR RAM |ECS[/b ][i] K7S5A MB[/i] |GF2 MX 32 MEG and still runs GOOD!|WIN XP PRO |MITSUBISHI DIAMOND PLUS 91 19"[/h3]

Share this post


Link to post

If you can't get your Vspeeds to appear when you click on the buttons beside them, you are generally either overweight or have flaps set wrong for takeoff or you have derated TO thrust to the point that the plane can not take off.Here are the 3 key pages that make or break you:Perf Init:http://forums.avsim.net/user_files/34126.jpgGW (Gross Weight of the aircraft)This is automatically filled in for you by clicking on the LSK, but your aircraft could be exceeding takeoff weight because you have too much fuel and cargo onboard. You can override this and key in your own weight.N1 Limit:http://forums.avsim.net/user_files/34127.jpgHere you have two things that can stop you. Your (T)ake(o)ff power setting may be derated which means not enough power to get airborne or your OAT (Outside Air Temperature) may be too high meaning not enough lift (we all remember hot air = less lift then cold air right?)Takeoff Ref:http://forums.avsim.net/user_files/34125.jpgHere you set your Flaps, wrong flaps combined with above means there is no possible Vspeeds so clicking on the V1/Vr/V2 buttons will not produce anything.In the interests of education, I suggest you play with these key pages and adjust values for hot days, cold days, overweight, various flaps, etc and you will see that your Vspeeds will change accordingly.Ray

Share this post


Link to post

As soon as i needed!Thanks a lot Randy!Take careLuigi ;-)

Share this post


Link to post

Ray,thanks alot for the clear explanation.Should get those values every time now...Luigi ;-)

Share this post


Link to post

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this