Crossing restrictions are rigid. These are fixed altitudes where aircraft are expected to be as hand off from one controller to another takes place, for one.

 

Until you meet the required altitude you will be given vectors within to descend and when you meet the required altitude you will be allowed to progress to the next waypoint.

Ron is right... if you you accept and miss a crossing restriction, you are probably going to end up on a vector.  In real life, you'll also be asked to make a "courtesy call" to the controlling facility when you get on the ground.

Ron is right... if you you accept and miss a crossing restriction, you are probably going to end up on a vector.  

 

In 21 years of listening to the air band radio and after many flights in cockpit, never heard or seen anything like that, go figure if ATC tells you to go back to the opposite direction of your descent path... (at least in Europe). In my opinion it should be removed from RC, it's only an unrealistic attempt to do something "realistic", becoming very boring and completely screwing up your VNAV descent...

http://flightaware.com/resources/airport/KMSP/STAR/EAU+CLAIRE+NINE

 

is a real world STAR into KMSP, Minneapolis. note the jet crossing restriction at checkpoint TWINZ. Note the bar above and below 11,000 feet which stands for "at". Also note it is 41 nm from KMSP as denoted by the DME to on airport VOR.

 

In some jurisdictions in the U.S. Constant Descent Approaches were being tested. While some airport ATC management allowed them, many stated it made life difficult for hand-offs and also it allowed conflicts of horizontal nav paths to be resolved by expected vertical separation especially between arrivals and departures.

 

One of the now retired ATC controllers in Australia stated they do allow CDAs except in extreme high traffic areas because down there traffic is less compared to the heavy corridors in the U.S.

Ok, Ron, but that restriction is part of that STAR and all STARs have their restrictions, which are included in the FMC programmed route. In RC, ANY flight I do I have the same ATC restriction of 12/13000 feet at the same distance from the arrival airport, even if the STAR has completely different restrictions. It could be wise then to remove that restriction and leave only the restrictions included in the STAR. This of course leaving untouched the heading and altitude vectors given by the controllers during the descent and approach phase...

Controllers supercede FMC data or if on their "scopes" echo it. Note that the TWINZ notation states "expect".

 

Not wanting to get into details, RC5 did take a different approach to SIDs (tested) and STARs but in its state did require some effort pre-flight  from the user.

 

In the evolution of RC4 it had to be much simpler.

 

Most altitude restrictions on terminal procedures state at or above (10000) or at or below (bar on top of digits).

In RC, ANY flight I do I have the same ATC restriction of 12/13000 feet at the same distance from the arrival airport, even if the STAR has completely different restrictions.

I'll agree that the 11/12000' crossing restriction is repetitive (and feels a little "canned"); but I can assure you that receiving crossing restrictions that are different from the published STAR are very commonplace. It's the most efficient way to ensure vertical separation with other traffic in the enroute environment - if you accept the descent and you're not at that altitude when you should be, the controller has to turn/vector you to avoid the conflict. In the real world, you can choose not to accept the restriction for performance reasons - but you have to do it when the restriction is given (RC simulates that if memory serves)... you will then most likely receive a vector right then and there. Since RC has no real separation function, I like to think that the restrictions are given to avoid another controller's airspace (which is a also a valid reason in the real world).

completely screwing up your VNAV descent...

I can't comment on other places in the world; but I can tell you that in the U.S., your chances of having a continuous, uninterrupted vnav descent into any airport with even a little bit of traffic is slim to none.

I agree that there are many restrictions in real life, and there is the problem! In RC you have only that canned and repetitive restriction of the 12/13000 ft. It would be much better to have some more and more random restrictions, so that you don't know when you will get them in each flight...

 

 

It would be much better to have some more and more random restrictions, so that you don't know when you will get them in each flight...

 

I totally agree.

Just to be clear, disregarding the crossing restriction problem, RC does provide enroute separation from ai by issuing deviations for traffic to the user and ai in many circumstances. It provides separation on final from ai by slowing ai behind you and should force them to go around if they get too close.

 

 

RC does provide enroute separation from ai by issuing deviations for traffic to the user and ai in many circumstances.

 

Hmm... I knew about the slowing on final; but was not aware of any enroute separation.  I gotta say that if it is attempting to do it... it doesn't do a very good job (based on the number of RAs I commonly experience while cruising).  I get traffic calls all the time from RC; but have never received an enroute turn or altitude change to avoid a conflict.