FMS flight levels - how to enter them

[sgwestrip 0]

I know how to enter absolute flight levels for any particular waypoint but I cannot find out what the format is to add, say, '6000 feet or below' or '6000 feet and above' or how to add speed restrictions.

 

Thanks,

Stephen Westrip

[hopskip 253]

How do you expect an aircraft without an auto-throttle system to actually meet a speed restriction? This isn't some jet. If you want to fly at 240 knots, then you have to get your hand, and move the throttle levers toward the rear of the aircraft until the speed starts reducing. To avoid ending up at 160 knots, you will have to monitor the airspeed indicator, and when near 240 knots you will need to use your hand and push the throttle levers toward the nose of the aircraft. Careful slight adjustments of the throttle levers using your hand will be required to keep the speed in the 235-245 range.

[sgwestrip 0]

How do you expect an aircraft without an auto-throttle system to actually meet a speed restriction? This isn't some jet. If you want to fly at 240 knots, then you have to get your hand, and move the throttle levers toward the rear of the aircraft until the speed starts reducing. To avoid ending up at 160 knots, you will have to monitor the airspeed indicator, and when near 240 knots you will need to use your hand and push the throttle levers toward the nose of the aircraft. Careful slight adjustments of the throttle levers using your hand will be required to keep the speed in the 235-245 range.

I take it you have no idea about the flight levels then?

[Chrjs 61]

There is no way to enter these values in the "FMC". YOu can only enter "full" levels/altitudes. You as the Captain has to make sure that the restrictions are met.

[sgwestrip 0]

There is no way to enter these values in the "FMC". YOu can only enter "full" levels/altitudes. You as the Captain has to make sure that the restrictions are met.

That is strange. If you set up VNAV for a waypoint that is near your destination you quite often see the flight level with an up or down arrow next to it. From what you have just said the conclusion is that the FMS can use altitude restrictions (above and below) but you cannot manually enter them. Very strange!!

[Jetstream96 20]

To enter 6000' or above, type /6000A and put it into the desired waypoint. 6000' or below is "6000B". The speed restriction is similar. You can enter "220" (means exactly 220 knots), 220B, or 220A.

[Chrjs 61]

To enter 6000' or above, type /6000A and put it into the desired waypoint. 6000' or below is "6000B". The speed restriction is similar. You can enter "220" (means exactly 220 knots), 220B, or 220A.

Are you sure we are talking about the same aircraft? This is neither an Airbus nor Boeing. There is no AT so no use in entering speeds in the FMC...

[sgwestrip 0]

No "/" on the Q400 FMS and A's and B's not allowed either when entering an FL, only numbers.

[pete_auau 1,154]

suggest to post this on the q400 forum, where hopefully you will get  an answer

[hopskip 253]

I think the answer may be "Hard altitudes only, & the FMS VNAV will guide the aircraft on a single, angle of descent to that hard altitude.

 

We already know for a fact that the FMC cannot control the engine thrust, and I haven't seen any reference to "At or Below" type altitudes. Lots of these complicated VNAV functions require that the autopilot have full control over the engine thrust, and most, if not all Turboprop aircraft do not.

[Kiwi Spitfire 1]

You can manually enter altitude contraints in the Universal FMS by pressing the ALT CONST right LSK, you will get a page with options for the specific type of constraint you want. Particularly useful if you are creating pilot-defined SID's/STAR's enroute segment etc.

 

However I am not sure this is present in the Q400's particular model of Universal FMS, (or if pilot defined stuff has been modelled). Different models of Universal FMS have slightly different techniques to manually enter altitude contraints, but I assure you it is possible. Saying that, it is not generally advisable to re-program published altitude constraints automatically entered by a specific STAR etc, that is when you start building your own instead.

 

Most altitude constraints you see automatically entered in the FPL are by virtue of the approach you have previously selected. If there is a star in front of the altitude then it has specifically been placed there by the FMS as a hard altitude.

 

But as suggested in posts above, altitude restrictions in the FPL are largely for information only in the UN1, as they play a different role in the Boeing or Airbus with their advanced VNAV capabilities over the Q400.