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.

 

[Dannone]

The way ASA has us doing it by dialing in the lowest hard altitude and following the snowflake really bothers me because you are setting in a lower altitude then you are cleared to. Works great until you get distracted and try to catch up. There is nothing to stop you from descending below the min altitude except the snowflake. People will bust altitudes with this method without a doubt!!

 

[777forever]

The way ASA has us doing it by dialing in the lowest hard altitude and following the snowflake really bothers me because you are setting in a lower altitude then you are cleared to. Works great until you get distracted and try to catch up. There is nothing to stop you from descending below the min altitude except the snowflake. People will bust altitudes with this method without a doubt!!

If you follow the snowflake you will not bust an altitude. As far as getting distracted, that's why we get CRM drilled into us every recurrent

 

[Dannone]

I love when people like 777 say that they cannot get distracted, won't be a month until you are covering your a$$ with an asap. I have seen people forget to descend on a mandatory altitude I can't count how many times. So let's say you do, even though I know you are a super pilot and begin to descend at a higher rate to catch up. Throw in a single chime, no big deal and you start to address it. You are now descending faster than you should be to catch the snow flake and you forget for like 60 seconds to adjust. OOPS!!! You went below a min alt. You have to be kidding me to think because you took a crm class you can't seriously F UP!! I prefer to know that I can and will so I don't set the lower alt until I cross the fix that allows it.

 

[CRJ puppy]

May be proprietary, but as mentioned, doesn't have to have a collins set up to have it.

Which is EXACTLY what I said...

 

[imacdog]

Right but if you have several consecutive constraints, aren't you doing a lot of "diving and driving" to make the next constraint? In otherwords, in an A320 for instance, you get a "descend via" clearance and you dial in the lowest alt on the arrival and the VNAV and A/P fly the aircraft to make each constraint. I would imagine in the RJ, you would be doing a lot of tweaking with the VS wheel making sure to hit at or below, at or above etc.

Sometimes you have to put the sammich down and do some of that pilot stuff.

 

[mtsupilot376]

Sometimes you have to put the sammich down and do some of that pilot stuff.

Win!

 

[airplane wizard]

If you follow the snowflake you will not bust an altitude. As far as getting distracted, that's why we get CRM drilled into us every recurrent

What is the snowflake?

 

[say again]

If you follow the snowflake you will not bust an altitude. As far as getting distracted, that's why we get CRM drilled into us every recurrent

Seriously?!?! You'll be one to bust an altitude thinking it will never happen to you.

 

[Flyer1015]

What is the snowflake?

Like a VDEV dot.

 

[Always deferred]

Here’s the official definition of Advisory VNAV from AC 90-107

a. Advisory Vertical Guidance. Vertical path deviation guidance indication that is
generated by any means, but is only an aid provided by some manufacturers to help pilots meet
altitude restrictions. Advisory vertical guidance is an optional capability implemented at the
manufacturer’s discretion; not a requirement for positioning and navigation equipment.

NOTE: It is the pilot’s responsibility to use the barometric altimeter to
ensure compliance with altitude restrictions, particularly during approach
operations. Advisory vertical guidance is not approved vertical guidance like
that found on approaches with lateral navigation (LNAV)/vertical navigation
(VNAV), LPV or instrument landing system (ILS) lines of minima.