MD-11 FMS wind entry format?

[strider 0]

Once again, I'm going to guess that PMDG was faithful in it's reproduction of the real world MD-11 FMS. If so, why in the world would MD require a pilot to do geometry calculations just to figure out what the wind component is, before entering it into the FMS? If the runway or flight leg has a crosswind it becomes very difficult to figure out what to put in the FMS. I can't see pilots having to do math calculations, for every leg of the flight? And I don't see how only being able to enter head or tail wind can allow the FMS to account for a crosswind? Still buried in manuals and very confused on this point. Victor Buck

[michal 44]

I can't see pilots having to do math calculations, for every leg of the flight? And I don't see how only being able to enter head or tail wind can allow the FMS to account for a crosswind?

Victor, pilots do NOT have to enter any winds for the autopilot to keep them on a programmed course (in climb/cruise or approach), no wind at all. This is a common property of all modern autopilots, even ones in a Cessna 172, many such aircraft are not even equipped with FMS where you could enter winds.If there is an FMS and you can enter winds - they are for trip planning only or perhaps for more accurate computation of PROF/VNAV descents. It is not mandatory to enter any winds. Normally pilots would get such information (tail/head) from their dispatch center, often such data can be directly up-loaded into their FMS via a ground link. You are right on this point - pilots do not have to engage in any complicated math in the cockpit.

[strider 0]

Victor, pilots do NOT have to enter any winds for the autopilot to keep them on a programmed course, no wind at all. This is a common property of all autopilots, even ones in a Cessna 172, many aircraft are not even equipped with FMS where you could enter winds.If there is an FMS and you can enter winds - they are for trip planning only or perhaps for computation of PROF descents. It is not mandatory to enter any winds. Normally pilots would get such information (tail/head) from their dispatch center. You are right no this point - pilots do not have to engage in any complicated math in the cockpit.

True, Michal...the AP will maintain course regardless of any FMS entries. I was under the impression that runway wind, however, was important for more than simple flight planning? Will this not affect the V speeds? I'm no pilot so I may be talking out of turn. I guess my main point is...why would MD not allow a simple entry format like Boeing does...wind direction/speed?Victor Buck

[Check_Airman 3]

The program has a bug. The FMC will only accept wind entry if the FL is included. In the actual plane, once the first entry has been made (eg. FL390/250/35), there's no need to include the FL for subsequent waypoints (eg 270/50 will suffice).

[Guest krullenbol]

Yes, pilots do have to make windcomponent caculations for crosswind limiations and performance calculations.Floris

[michal 44]

True, Michal...the AP will maintain course regardless of any FMS entries. I was under the impression that runway wind, however, was important for more than simple flight planning? Will this not affect the V speeds?

I don't think that wind corrected V-ref speeds are calculated by any FMS (company policy may also play a part here). These adjustment are usually made by pilots - these are simple calculations. Takeoff/landing perf. calculations as far as I know are also done outside of FMC.

[trisager 2]

And I don't see how only being able to enter head or tail wind can allow the FMS to account for a crosswind?

The winds that you enter for waypoints are specified using both direction and magnitude. So the FMS does have the information available.Tom

[strider 0]

The winds that you enter for waypoints are specified using both direction and magnitude. So the FMS does have the information available.Tom

HMmm...I just reread the FMS manual and the wind entry for individual waypoints does not apparently allow compass direction, Tom. Only speed and either head or tailwind? Perhaps it's elsewhere in the manual but I see no way to enter a wind direction...other than head or tail. Only the "Climb forecast" page appears to accept wind compass direction? Victor Buck

[Guest bkhopp]

HMmm...I just reread the FMS manual and the wind entry for individual waypoints does not apparently allow compass direction, Tom. Only speed and either head or tailwind? Perhaps it's elsewhere in the manual but I see no way to enter a wind direction...other than head or tail. Only the "Climb forecast" page appears to accept wind compass direction? Victor Buck

Yes, I am wondering about this too. Every time I try to enter winds for the waypoints I get NOT ALLOWED. This happens both on the ground and in the air. Any help on waypoint wind entry would be appreciated.Thanks,Benjamin Hopp

[trisager 2]

Yes, I am wondering about this too. Every time I try to enter winds for the waypoints I get NOT ALLOWED. This happens both on the ground and in the air. Any help on waypoint wind entry would be appreciated.Thanks,Benjamin Hopp

Not at the sim right now, but if I remeber right you do a right-side LSK next to one of the enroute waypoints (may have to be after TOC). It might be a further selection, or a page 2 after that. I'm sure I've done this. Also, as someone mentioned above, you may have to enter the flight level also.I'll get the exaxt steps later if you cannot find it from my vague directions :)Tom

[downscc 1,327]

To enter enroute wind go to F-PLN page 2, press RSK (right side key) next to fix to enter winds.This brings up a page for wind entry... enter FL/DIR/VELNote that the FMS calculates wind from that point forward to the TOD providing the HD or TL values.