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How to fly the RIIVR1 without FMS

Describes the RIIVR1 'profile', and how to use VOR's to fly the arrival into KLAX



Preface

This document was originally written to describe the RIIVR1 arrival into KLAX.  Since then, the RIIVR2 has been released, which does NOT have runway-specific transitions. The concepts introduced are still relevant, however, the RIIVR2 now terminates at the RIIVR intersection.  The ILS approaches into KLAX have been revised such that the procedure can be commenced from RIIVR (which is now an IAF).  In other words, the STAR has been shortened, while the instrument approach has been extended to meet the shortened STAR.

Introduction

"I don't have that arrival in my FMC."  Do you need an FMC to fly the wonder that is LAX's RIVVR1 arrival? Absolutely not.  All you need is a VOR (preferably two of them) and DME. Open or print the RIVVR1 chart (available in the Required Materials below) and let's go through it.

The majority of this tutorial assumes you are arriving from Hector (HEC) and will be flying the 25L transition. As the chart says, expect your actual runway assignment on initial contact with the SoCal Approach controller.  The last section, Another Day, Another Runway covers the 24R transition.

You fit the profile!


The RIVVR and SEAVU STARs for LAX, and the TYSSN, KEPEC, GRNPA, and SUNST STARs for Las Vegas are all PROFILE STARS.  This means they contain specific altitude restrictions at various points during the arrival. This should NOT be confused with STARs that contain EXPECTED crossing altitudes, such as the SADDE6 arrival into LAX, which says "expect to cross SYMON at 12,000."

What is the significance of a PROFILE STAR versus, say, the SADDE6?  It's simple - on a PROFILE STAR, ATC can use the phraseology "DESCEND VIA..." to remove any previous altitude restriction, and have you comply with the altitude restrictions associated with the STAR.

Let's review the relevant restrictions for the HEC transition, for RWY 25L and start putting this all together.  Looking southwest from HEC along the arrival track, we see some '17,000' references. Are those the restrictions the controller wants us to follow?  Nope.  Those are MEAs (Minimum Enroute Altitude), more relevant to lost communications procedures that guarantee terrain/obstacle separation as well as reception of the signal from the required navaids.

Moving along, notice the 'FL210, 17000' and '290K' reference at GRAMM.  THOSE are the puppies we're after. The horizontal line ABOVE FL210 means "at or below FL210".  The line BELOW 17,000 means "at or above 17,000". Put them together, and you actually get a pretty simple restriction, we need to cross GRAMM between 17,000 and FL210.  The '290K' is a speed reference, 290KIAS.  This speed restriction sets up predictable spacing for the controllers working the often-congested SoCal airspace.

 riivr_snippet.PNG


Looking ahead, we need to be:
  • at or above 14,000 at HABSO
  • between 12,000 and 14,000 at RIIVR
  • at or above 10,000 at KRAIN
  • between 9000 and 9700 at TAROC
  • at or above 8000 at DYMMO
  • at or above 7000 at FUELR

When to fly the profile

So, we know what the profile looks like. The question is, when can we start down?  Let's rewind now, and assume we're northeast of HEC, coming out of Vegas, at FL240.  ATC then says, "cross GRAMM at and maintain FL180."  Fantastic, down we go. Should we fly the profile as published?  Absolutely not.  You should do exactly what was said, which was to cross GRAMM at FL180 and stay there.

How do you know when you can descend? "Descend and maintain" is pretty darn clear, particularly the "MAINTAIN" part.  No profile for you!  Well, not yet.

For reasons that are beyond the scope of this document, the enroute controller has a Letter of Agreement with the muppets in the TRACON (Socal Approach) that says "And yay, thou shalt ensure that esteemed pilots cross GRAMM, son of GRAMM, at the lowest of the Usable Levels of Flight."  Essentially, CTR will park you at FL180 or FL190 (depending on the barometric pressure) to cross GRAMM, and then send you to Socal Approach.

Once handed to Socal Approach, you're most likely going to hear, "SIR, _WHY_ are you turning RIGHT on the LOOP4 departure?"  But, that's for someone else.  YOU are going to be issued the instruction, "descend via the RIIVR1 arrival, runway 25L."  This is where the choirs sing, the clouds part, and that guy on the LOOP4 utters a sentence beginning with one of the following phrases, "My FMC...", "My GPS...", or "My autopilot..."

In any case, we've been given the all clear!  "DESCEND VIA" cancels the "maintain FL180" we previously received and we are now expected to descend, on our own, to meet the published restrictions. Have at it!

But, But, I don't have an FMC

Stop blubbering, you'll be ok.  This section will deal with the LATERAL (the left and right wobbly bit) portion of the STAR, since we covered the VERTICAL portion above.

We need to have our plane fly over HEC, DYPSO, GRAMM, RUSTT, HABSO, RIIVR, KRAIN, TAROC, DYMMO, FUELR and then the remainder of the ILS 25L approach.  Each of those points can be identified by a VOR, a radial, and a distance from said VOR. My gosh, it's almost as though people were flying airplanes before GPS existed.

This text assumes you understand the basic tenets of VOR navigation. If not, then it's time to fire up MSFS, a Cessna 172 and use the tutorials, or do some additional reading.

From HEC, proceed southwest along the 203 radial.  Passing 4 DME, you will pass the least interesting fix on this STAR...DYPSO. Continuing along the radial, 48 miles later, we hit GRAMM. This is identified by PDZ 24 DME (note the '24' in the box, oriented with the PDZ R-046 radial).

Speaking of the PDZ 046 radial, it's going to come in awfully handy to get from GRAMM to RUSTT. Your NAV1 should be tuned to HEC with OBS set to 203. NAV2 should be tuned to PDZ, with OBS set to 226 (allowing us to track the 046 radial inbound).

Passing GRAMM, we turn right to join the PDZ 046 radial inbound, with a ground track of 226. We no longer need the HEC VOR, so tune your NAV1 VOR to LAX, we're going to need that shortly. We're still inbound from GRAMM to RUSTT (a short, 8 mile leg). Set NAV1 OBS to 248. Reaching PDZ 16 DME (and when the the NAV1 needle centers), we're at RUSTT and should proceed towards HABSO by turning right to that 248 track using our NAV1.

From here on in, we're using DME from LAX to identify each of the fixes beyond HABSO, passing RIIVR, KRAIN, TAROC, etc.  Some point along the way, move your NAV1 settings over NAV2, and set your NAV1 to the 25L localizer frequency, unless you're comfortable flying the ILS approach using the NAV2 radio.

It looks/sounds like a lot of work, but really, there are just two right turns, that's it.  We're going to fly a ground track of 203, 226, and 248, using radial intersections and DME to know when to execute each turn.

So, next time you fire up a plane, and it doesn't have the RIIVR1 in the database, don't be shy about whipping out the chart, tuning some VORs, and getting it done. The first few times you try this, feel free to advise ATC you're trying it with unfamiliar equipment, and that you'd appreciate some latitude.  If you get completely disoriented and uncomfortable, say "sorry Approach, unable the RIIVR1, request vectors."   We'll take care of you, and will respect you even more for a) giving it a try, and b) letting us know that you need some help, and c) the third item in this list, because all truly great lists usually have a third, crucial item.

All dressed up, nowhere to go?

We've reached FUELR. Is ATC going to vector us? Panic not, fair pilot. A glance at the ILS RWY 25L approach chart (you DO have that chart open when you fly this approach, right?) shows that FUELR is an IAF (Initial Approach Fix).  Isn't it crafty of the airspace designers to have a STAR that terminates in an IAF for an approach? It's uncanny! It looks nothing like a can!!

This is precisely why you will hear ATC say, almost without fail, "after FUELR, cleared ILS rwy 25L approach."  Does this mean you stay at 7k after FUELR? Only if you are planning on continuing to Hawaii.  You are now established on a segment of the approach, have received a clearance for the approach, and can therefore fly the chart as published.  The number of people who remain at 7000 after FUELR is astronomical.  Controllers can actually hear the screams of passengers as the pilot shoves the control column through the panel in an effort to make the glide slope intercept at 3,500 at HUNDA. 

"Why did you leave me at 7000??" the pilot will often ask. "I didn't, you were cleared for the approach," ATC will reply, and then casually order the death of your family pet.  So, please, read the charts, ask questions if you need help, but don't stay at 7k.  Do it for Sparkles.

Another day, another runway

By and large, you'll be assigned 25L when flying this arrival. If you have a preference for the north complex at LAX (24L/R), if your airline's gate is on the north side, or for sequencing purposes, you may be assigned the north complex. This will always be rwy 24R, as 24L is used as a departing runway.

So, if you are assigned 24R when you check in with SoCal Approach for the first time, how does that change your ground track and descent profile? Looking at the chart, nothing changes until you reach RIIVR.  For rwy 24R, you then fly a heading (with no wind correction) of 258, for approximately 6 miles, and join the 24R localizer.  Cross SKOLL at or above 10,000, DECOR between 9000 and 9800, BREEA at or above 8000, and PALAC at or above 7000, using DME to identify each fix.

What happens after PALAC?  You'll hear "after PALAC, cleared ILS rwy 24R approach."  PALAC is the IAF for that approach, so you can descend as published on the chart. Those crafty airspace elves have done it again!

That said, the localizer in MSFS is only receivable within approximately 31 miles of the transmitter. For this reason, aircraft without GPS using MSFS are advised to request 25L. If ATC particularly needs you to be on 24R, you should advise that due to equipment limitations, you're unable the 24R transition, but could accept vectors for the ILS 24R.  If that occurs, the moment you receive the first vector, you're no longer flying the RIVVR1 arrival, and should comply with whatever instructions ATC provides.



Required Materials
RIIVR2 Arrival
KLAX STAR

Related Materials
KLAX ILS rwy 25L chart