Question for RJ drivers without VNAV

[Flyin2low]

The "banana bar" is a Collins proprietary feature.

That's funny because the Honeywell FMS had one too?

 

[Flyin2low]

Putting the lowest altitude in and flying the snowflake works but you have to be paying attention (4eyeballs) and adjust VSI to hit the constraints along the arrival, even leveling off for a short time when the flake disappears and then continue the descent when it reappears. Seriously cuts into USAToday time...

That's the only way to do it. I have been told that VPA 2.4-2.2 works to set up a continuous descent on the Freedom or Truups arrivals. Maneuver between the snowflake and bananna and have a lot of Pilot Deviation reports ready to file.

 

[Oakum_Boy]

2.2 is more realistic. Saves the dive and drive nonsense, but requires math to figure the optimized angle. Too bad the angle isn't published on the charts

 

[CRJ puppy]

That's funny because the Honeywell FMS had one too?

Not all Honeywell FMS's have it. It is dependent upon whether that particular operator wanted that feature, which in turn increases the price so that Honeywell can pay Collins the appropriate licensing fees...

 

[Flyer1015]

I am going to address you first part prior to your edit. You must not really understand true VNAV. I would never want an airplane to start down on its own because it reached TOD. I would though if I were CLEARED to descend VIA. if you trucking along at FL340 and have been cleared to descend at pilots discretion or VIA XYZ arrival in an airbus and set in your lowest alt the bus will maintain your cruising alt. Now in a boeing or any other plane with a coupled auto pilot and a true VNAV you set in your bottom alt WHEN CLEARED!!!! and the airplane will start down at the TOD.

You are correct you would get in a lot of trouble if we had airplanes with out clearance starting down to a lower alt with out pilots input. Come on man!

Thanks for the clarification. I have 0 time in a Boeing and don't know how their VNAV logic is.

 

[rjacobs]

In the ERJ the FMS has all the above/below altitudes loaded(which we obviously cross check with the chart). If you have the descent function setup at an appropriate angle for your wind conditions you just follow the VPI(pink glide slope) at the appropriate descent rate for your GS(which the FMS will give you a target, although its usually only a good target at TOD, then it fluctuates, but isnt accurate). You can also get into a maintenance page and see how high or low you are on the vertical path. I have made it a habit to set the bottom of each "window" into the altitude selector just to assure I dont bust the bottom and as long as I am on or under the VPI I will clear the top. Seems to work out ok, but you do end up, at least every time I have done them, shallowing at some point to like 1000fpm so you dont hit your final hard altitude like 20 miles early. Its not that hard, but you do have to pay attention.

 

[higney85]

When cleared "via", plug the bottom altitude, make sure the FMS has the correct altitudes programmed, and decend at the most restrictive rate when hitting "DIR INTC".

Works good, lasts long time.

 

[dojetdriver]

The "banana bar" is a Collins proprietary feature.

May be proprietary, but as mentioned, doesn't have to have a collins set up to have it. The Dornier (both prop and jet) was designed/buit BEFORE the ERJ. Yet came with a more advanced PRIMUS avionics and but the same FMS. And the Dornier (both prop and jet) had the "banana bar" with the Honeywell FMS. The perf init page on the FMS that can ACTUALLY be programmed with various climb/descent profiles that the VNAV can be coupled to and follow. As opposed to the VNAV advisory of the ERJ. Flying these style arrivals in the that airplane required way less management. Simply set the LOWEST alt of the arrival and the VNAV won't violate ANY constraint between the TOD and that alt.

That's funny because the Honeywell FMS had one too?

See above.

 

[777forever]

XJT is starting an autopilot coupled VNAV test program with some our CRJ 900s, should be an interesting program

Sent from my HTC One X+ using Tapatalk 2

 

[Always deferred]

That's the only way to do it. I have been told that VPA 2.4-2.2 works to set up a continuous descent on the Freedom or Truups arrivals. Maneuver between the snowflake and bananna and have a lot of Pilot Deviation reports ready to file.

If you feel these arrival procedures present increased risk of PD, please file ASAP reports.