Transitioning from the star to the approach

General Discussion Pilot Talk
1

I have a question regarding transitioning from a STAR to an ILS approach when flying on VATSIM. I came across this issue a couple of times in the past so I need some direction on how to manage it moving forward.

In a flight to KBOS, my flight plan had the OOSHN 5 ARRIVAL and KBOS Center asked me to descend via this STAR. My flight plan had runway 4R per the ATIS. KBOS Approach confirmed the runway. The last waypoint on the STAR is JOBEE, which has an ALT CNSTR of 6000A. When the A/C’s position was on the downwind leg just prior to the abeam point of runway 4R FAF MILTT, the controller cleared me to 3000’ and then just past the abeam point with MILTT, the approach controller asked me to turn right to 300 and then to 010 to intercept the localizer for landing on runway 4R. The A/C’s altitude at the time I was asked to turn was somewhere around 4000’-5000’. On the approach plate the FAF MILTT has an altitude of 1700’, which means the A/C would have had to descend about 3000’ during the turn to be at the appropriate altitude for capturing the G/S. Here is the question.

Does the controller have any responsibility for making sure the A/C is at an appropriate altitude when providing vectors for capturing the G/S or is this exclusively the responsibility of the flight crew, i.e., accept the vectors or tell ATC “not doable” ? I would think that when abbreviating a STAR, the controller making sure that the A/C’s altitude is appropriate for this change is a key consideration but then again maybe not.

If it is the flight crew’s responsibility, what is the appropriate communication to ATC to tell them “not doable” ?

Thanks

2

The ATCO should have picked up the fact that you were way too high for these kinds of vectors. On the other hand the ATCO probably expected you to cross JOBEE at 6000ft, because on the charts that I have this waypoint has a constraint of “AT 6000ft”, same as the point prior to it, GGABE (AT 6000ft).

No matter who made a mistake here, if you are not able to follow an instruction or if you are unable to achieve a profile, you can always report “unable to…”.

3

Exactly right, the A/C’s rate of descent was to comply with the 6000’ constraint of the STAR’s last two way waypoints and then all of a sudden vectors to the FAF with a 1700’ G/S capture altitude, which left me wondering. As I hinted in my OP, the VATSIM approach controllers seem to favor aggressive vectors to final, which in the past have led to “slam dunks” on a couple occasions so I think they should be a little more conservative and/or be more aware of the situation. Thanks for the “unable to…”, will do the next time.

4

In your first post you wrote, that the constraint was shown as “6000ft or ABOVE” and that’s what your FMC/VNAV was doing. Had it been “AT 6000ft”, your situation wouldn’t have evolved like this. That’s why it is imperative to always check your FMC waypoints against the charts, including constraints.

EDIT: if you get into such a situation again, consider configuring the plane already, this will help you greatly in achieving the required descent rate without increasing your forward speed.

5

It’s possible the approach controller was being too aggressive, but probably only a little bit too aggressive from what I’m reading. I say probably only a little too aggressive because, assuming you were maybe 3 miles beyond the abeam point, at about 4500 feet (assuming the average of 4000 to 5000 as you described) and 5 miles offset from the final approach course, I’d expect you to eat up another 3 or 4 miles away from the airport in the turn, which would put you 6-7 miles away at the farthest point of the turn at roughly 3300 feet or less, continuing your descent, which, as you complete the turn to intercept and then intercept, should put you at roughly 2000 feet and 1-2 miles from MILTT at your intercept point. That, of course, assumes you were at roughly 190 knots on the downwind and slowing to intercept at about 170 knots, and winds were not too crazy at the time. All rules of thumb with lots of assumptions. Maybe a tiny bit aggressive to assume where you started your turn, at a reasonable speed and a descending, slowing turn, and a healthy dose of perfection? Yep, could be… :slight_smile:

If it’s really busy, controllers can be a little aggressive. I know I’ve been aggressive to try to fit people in. When everyone’s at the top of their game, it works out quite impressively. But (and maybe more on VATSIM than IRL) sometimes it doesn’t work out impressively, and the approach controller will have to clean up his mess. Side note: When it’s busy, I am one of those aggressive ones – I’ve even said, “Do you like Oreos?” (then when hearing a Yes reply) “Great, you’re now the filling I’m putting in between 2 cookies, you’re 8 miles from MILTT, turn right heading 010, maintain 2000 'til established, cleared ILS 4R Approach!”) – most times it works out, occasionally I have to apologize and clean up the mess.

It’s also possible that the controller was a newer Boston Approach controller and needs a bit more seasoning to make everything work out perfectly. In my experience, they are generally excellent in Boston, but like with most things in life, sometimes you get the lesser experienced controller, the stressed-and-just-trying-to-make-it-work controller, or the student (or just certified with a shiny new “license to learn” controller.

Another side note: This happens all day long in real life, too. :slight_smile:

In most or all facilities on VATSIM, you can offer constructive feedback via their facility feedback form. Typically what happens is facility leadership will review the submitted feedback, discuss the situation with the controller to try to get a clear picture from both pilot and controller perspectives, and discuss opportunities for improvement. Boston’s feedback form is at Feedback - Boston Virtual ARTCC

I’ve given more slam dunks than I’d like to admit (and always apologize to the pilot when handing them off to the tower or vectoring them around again), and I’ve gotten plenty, too. VATSIM and IRL.

Likely (and hopefully) all that resulted was the controller’s knee and legs spasming rapidly while he was saying an impressive multitude of “please please please please let this work out!” in a row, followed by a muttered “aw, crap” when it didn’t, and he learned from the experience and will do better next time.

What can you do? Well, make sure you’re on speed and target, and if you don’t feel like it’s going to work / result in a stabilized approach, you can tell the controller “unable” or “I don’t feel like this is going to work, can you please vector me around for another try.” It’s factual, isn’t indicting, and will (hopefully) result in a better-set stage next time around.

Wishing you even better experiences going forward!

6

Thanks a lot for your comments, I really enjoyed your mixing facts and humor. I am hoping that the OP did not come across as I if I think of myself as the second coming of Charles Lindbergh. It’s just that I attempted to follow the instructions as closely as possible, which resulted in a very ugly landing and when I looked back at what had transpired, I did not think my flying was the only factor in the less than stellar results. By the way, I think very highly of the Boston ARTCC. In general they do a good job and this airspace has high controller availabilty so I tend to favor it. Here is a general ATC question that has been on my mind for some time.

It seems that Approach controllers seem to favor cutting as short as possible the transition from STAR to the runway. This of course saves time and fuel but it also adds complexity and risk. The A/C (airliners not Cessnas) has to descend faster while it concurrently reduces speed. This requires serious due diligence on the part of the controller and highly skilled flying by the flight crew. Excluding the time and fuel factors, why is this abbreviated approach favored ?
Thanks again for your comments

7

Don’t worry, your question was perceived as normal!

I think a contributing factor to your situation was the incorrect coding of JOBEE, it should have been 6000 and not 6000A. Had it been 6000, you would have crossed that point at 6000ft, ready for a shortcut.

8

Controllers are required to have you established at 2 miles outside the approach gate which is typically the FAF at glide slope intercept altitude. As a retired controller, at minimum an air carrier likes to be established, cleared and configured nlo later than 10 mile final.

We all know how crazy it gets when we are out of profile. High and tight approaches just aren’t acceptable with modern airliners.

Back in the day of the 727, DC9 and B737 you could do that with those types. They descend like a rock. Good times.