SIDs and STARs useless?

[Guest]

Hello,

 

I have been flying PMDG aircrafts for 3 months now and I have noticed something strange with my SIDs and STARs.

In my flightplan I do mention which SID and STAR I am using but every time the controller (vatsim) gives me a specific heading while I have a perfect departure or approach in my FMC.

This gives me a feeling that SIDs and STARs are actually useless.

Am I doing something wrong or do more people experience this?

 

Best regards,

 

Collin Meerman

[icemarkom 59]

This is to a large extent working as intended. SID and STAR stand for *standard* instrument departure, and *standard* terminal arrival. The key word there being: *standard*. These work perfectly well for controlling the traffic flow and control in the real world, since there are multiple controllers that you interact in a space of a 50-100 nautical miles that SID/STAR often cover. For example of where I fly in Northern California, taking off from San Jose International, going to Las Vegas, you would speak to at least 4 controllers before you reach 1000ft of altitude. By the time you are done with the SID, you are likely to interact with at least 3-4 more (3x NorCal, 1xCenter). Handing off "some weird" procedure between this many controllers, and maintaining steady uninterrupted flow of aircraft is simply not scalable.

 

However, on VATSIM, flying the same route, you may interact with 2 controllers (for example Oakland Center, Los Angeles Center). Those two are handling usually less than a 20 aircraft each. In those circumstances, and to not make the experience *utterly boring* for everyone, controllers usually vector aircraft a little more.

 

So, having that in mind, when you are given the initial clearance, you can always say something along the lines of: "Nxxxx would like to practice flying the filed SID, if able". Or even better put "SID/STAR strongly preferred" in your flight plan.

 

Myself, I usually put "No SID. No STAR" when flying on VATSIM, because the only reason I fly online is because I enjoy the interaction. Otherwise, I may as well fly offline.

[downscc 1,327]

I always fly off line with an ATC in my head... I like to mimic real world flights like today I just finished AA1200 a B738 KSMF-KDFW and according to the ground track on Flightaware they are landing visual today at DFW so the STAR is used until about 30nm from airport then a vector for a 3-5 nm final, and that is how I flew it.  When it is busy the traffic will pretty much follow the STAR all the way to the approach.  All departures at DFW are on the SIDs to reduce controller workload and they have implemented all RNAV procedures so the aircraft pretty much all follow the same tracks and separation is made easier.

[skelsey 765]

Actually (in the UK at least) in real life it is VERY rare to fly the full SID. You will almost always get put on a heading very soon after departure.

 

This is because there is a lot of interaction between the SID routes from each airport and the arrival streams, and the easiest and quickest way to climb the outbounds is usually to put them on a radar heading and sort the situation out tactically.

 

Arrivals are more likely to go all the way to the IAF on the STAR but even then if it's quiet you might be vectored early to give you a shortcut.

 

Even enroute it's not uncommon for aircraft to be put on headings for streaming and separation.

 

In a nutshell -- the controllers are doing what controllers do, both in real life and on VATSIM -- separating the traffic and helping to provide an efficient flight.

 

The SIDs and STARs are standard routes and in theory if there was a mass comms blackout they should keep everything separated if everybody adheres to them, but they are not necessarily the most efficient way of getting everybody in and out.

[scandinavian13 5,192]

Am I doing something wrong or do more people experience this?

 

Might also be that so many people screw the SID or STAR up that they just vector instead. Have a look at the Kennedy, and Newark SIDs (the SIDs named specifically that, and not the others with different names at those airports). If people don't read the chart (which they rarely do), they won't fly it properly, so it defeats the whole purpose. As such the VATSIM controller will usually vector those. There are a few out of LGA as well.

[manoliar 2]

As in real life, you have the right to ask for an SID or a STAR and not accept vectors. If traffic flow permits  the controller has no reason to deny that. But If he has a lot of traffic he may delay your departure or arrival (hold). 

 

You may also try smaller airports with no radar environment in the real life. If the Vatsim controllers want to simulate this accurately they must not give you vectors. 

 

In real life usually the pilot preferes vectors to expedite his arrival or departure. Less time means less fuel, less operating hours for the aircraft (lower maintenance cost) and for the crew and  more money.

[racingmars 6]

As in real life, you have the right to ask for an SID or a STAR and not accept vectors. If traffic flow permits  the controller has no reason to deny that. But If he has a lot of traffic he may delay your departure or arrival (hold). 

 

I guess it's true pilots can ask for a SID or STAR, but in reality the SID/STAR is for ATC's benefit, not the pilot's benefit. If you're given vectors in lieu of flying the full SID/STAR, unless you have a flight safety reason not to comply, the pilot's job is to fly as per the ATC instructions. If you want to fly a full SID/STAR for training purposes, for example, then I agree that if workload and traffic permits ATC will probably try to accommodate the request. But the only reference I can find on the topic in the AIM is 5-1-8 b.6, which states that ATC may issue a SID or STAR as appropriate, with a note saying that pilots can file flight plans indicating that they do *not* want to accept a SID or STAR. But not the other way around—there's no reason for a pilot to "force" a SID or STAR if ATC doesn't need it for traffic management.

 

In short, it would be okay for a pilot to not accept a SID or STAR, but I think it would be highly unusual for a pilot to not accept vectors.

[manoliar 2]

Matthew

I agree with you that it is "highly unusual for a pilot to not accept vectors". That is what I also said.

I also agree with you that the most common reason to decline vectors and ask for SID/STAR is for training purposes.

I also agree that you can file No SID/STAR/DP but nowhere says that you can decline vectors.(except for PRM  ASR and PAR approaches which is not the case of our discussion)

But..

The only rule that overcomes all others is the general rule of safety.(of course not in Vatsim :smile: )

As a pilot you have the responsibility to request an amendment to a clearance if it is unacceptable from a safety perspective. (This is good to be done ahead of time.)

You can imagine a lot of scenarios that from a safety perspective you will ask for an SID and not vectors. If you explain it to the controller I am sure that he will understand. He will also think that if he refuses to do so and you have an accident he will also be in troubles.

This can also be simulated in Vatsim.

 

Emmanuel Argiropoulos

LGMT

[scandinavian13 5,192]

 

 

but in reality the SID/STAR is for ATC's benefit, not the pilot's benefit

 

That's not entirely true. Sure, it alleviates the controller from having to provide additional instructions and essentially navigate the aircraft for the crew, but in the end, it lightens the load on the pilots as well. We all have a certain amount of selective hearing that we gain over time as pilots, but even then, knowing that you're going to get an instruction (or several) in a particular moment does get a little taxing as you have to listen more carefully, and your mind is also trying to be prepared to react quickly to said instruction. That's also not mentioning the mental unease of not being on your plan, and/or wondering if this long vector you're on means if they've forgotten about you.

 

From the actual work side, though, it's much easier on the pilot to be on the SID/STAR. There are fewer instructions coming at you - both vertical and lateral instructions - which also usually means that you can LNAV/VNAV it right down the SID/STAR. That means fewer things to worry about fussing with on the MCP, or fewer hand adjustments if flying by hand. Even the SIDs that are really only there to cut down on radio work make life easier for both sides. Charted vectored SIDs are an example of this.

[CajunRon 8]

I've got a related question (though it may not apply to VATSIM...I use ProATC).   ProATC always gives me a shortcut in the STAR/Final Approach and it doesn't have the capability for me to ask for the full approach.   The problem I often encounter is that the FMC is following the VNAV profile of the full STAR/Final Approach.  So when I comply with the vectoring shortcut, I find myself sometimes thousands of feet above the FMC profile and have to work like hell (early gear down, full spoilers almost to the runway, vertical speed control mode) to try to get the 737 down and slow.   Is this real life?

[downscc 1,327]

No, controllers know how many feet per mile you descend at and will not vector you into a situation where you have to drop out of the sky.., normally. Third party ATC simulators are better than the default in the simulator but they are a long ways from realistic.  The 777 has a nice off path descent feature in the FMC but the NGX doesn't with the software version included in the product.  You can copy the runway fix from the legs page into a fix page and see roughly how many miles to touchdown, rough rule of thumb is 3 nm for every 1000 ft.  This is about a 3-deg slope which is about as fast a descent rate as you want..., I like to plan on 4nm per 1000 below FL280 where you are flying a speed instead of a mach.  Most STARS allow about 250ft/nm which is 4nm per 1000 ft..

[skelsey 765]

 

 

Is this real life?

 

Depends where you fly in to... there are some parts of the world where ATC just loves to keep you high (Italy, for example, is notorious for it), either because of airspace restrictions, terrain, other traffic flows or various other reasons. In other places you might get offered a big shortcut if you can make the profile work (Heathrow, for example, will occasionally offer a very direct routing perhaps from some way prior to the holding fix if it's quiet and the result is usually a high speed descent with lots of speedbrake), but it will be on the basis of mutual agreement. In the UK you will be given your track miles to touchdown at the start of vectoring to final approach so you can judge your rate of descent (ideally to achieve a continuous descent from that point, i.e. avoiding level flight all the way up to glideslope capture and beyond).

 

Generally speaking though, as Dan says, most controllers have a reasonable idea of aircraft performance and will know more or less what is and isn't typically achievable -- bear in mind that they'll generally be working the same sector very regularly if not every day and they will know the points where pilots usually want to start down, how fast they can descend and the normal vectoring profile will have been constructed with typical performance capabilities in mind.

[phrgflyer 50]

Make sure you read the actual SID/STAR plate, a lot of them say expect radar vectors to .......

[Steve Dra 7,574]

I've very recently (after a 16-year break) started to fly on VATSIM again.  One thing I immediately noticed was how lazy I had gotten flying all by myself (well, AI traffic only counts a little bit).

One route I like to fly for its time/distance and scenery is KLAX-KLAS.  No need to even export a route out of Simbrief, 99% of the time its LOOP8-DAG-KEPEC looking at live flights on flightaware, with the occasional Hotlz SID.

Anyway...on my 1st few flights the VATSIM traffic was pretty light...so light in fact I thought I had the hang of it.  In my 16-year break I was not even using ATC of any type, so I thought a vector was a graphic type (vector vs raster, I'm a painter, you get the idea, hehe).

Sooooo....just when I'm thinking this is a cakewalk...I'm feeling so confident after my relatively easy trip to KLAS, I was gonna fuel up my mighty FedEx 777F and return to KLAX.

 

Well i missed the memo where a VA planned an impromptu  fly-in to said airport, and I happened to be arriving roughly at the same time.

Long story short, for the 1st time in 16 years (yes....I know that is a timeframe away from VATSIM longer than some here have been on this earth, LOL), I get "FedEx123, left to XXX descend to FLxxx, HOLD at XXX".  I'm like...Huh?  do what? hold what?

Here I was cruising along on MY terms, enjoying the scenery, expecting to fly the STAR with maybe a vector or two, then enjoy an uneventful landing on 25L, left off the active and back to the FedEx ramp.

How dare those evil controllers make me be a pilot when I was just happy to press a few buttons I've pressed so many times I could do it in my sleep!

Long story short, as you can imagine, the stress level in the cockpit went up a few hundred notches, being caught totally off guard is never  comfortable, even in the virtual world.

"Complacency kills" is the defacto motto for our passion (aviation), although in this scenario I'm happy to report that even though my racetrack pattern in the hold was nothing to be proud of, I eventually made it back to the FedEx ramp with my 777F in tact, landing on 24R and having the ground controller talk in some coded language I only assumed was English, hehe.  I had to break out the airport map for understanding (like I said...when I flew offline...I ALWAYS assigned myself  25L for some reason, hmmm)

 

In the end, I actually like being vectored, and I agree with others here that it adds to the immersion, especially when the vectoring is due to real issues (within the VATSIM world) like traffic, sigmets, emergencies, etc.  

When I feel I'm being vectored because the controller is needing something to do, I remember that they are their helping us pilots with the immersion factor, so I'm courteous and return the favor. :smile:

  

 

 

[signmanbob 592]

I also believe that the big advantage of SIDs and STARs are if you loose communications with ATC, you have your route set with the procedures.  It doesn't necessarily mean that ATC is going to make you fly it as it is printed.  They may even try to give you short cuts to get you where you're going quicker if it is possible.

This is why it is so funny when people are really trying to fly the full procedure with VNAV decent.  I don't believe that is ever done.  Once below 10,000 ft., pilots will use the vertical speed wheel for decent to ATC instructions.