Sunday, July 16, 2006

Pilot Nav SIDs & the G1000

About 6 years ago, the FAA decided it would be simpler if all instrument departure procedures (other than simple obstacle departure procedures described textually) were referred to simply as DPs. This change in terminology was short lived because of the confusion it created, especially among foreign pilots and operators who were still using the term SID (Standard Instrument Departure) for all graphically depicted instrument departure procedures. So the FAA relented and now refers to all graphically depicted instrument departure procedures as SIDs. Last I checked, several questions in the FAA knowledge test question bank still seem to adhere to the old naming convention. The more things change, the more they stay the same.

Another interesting thing is that the NACO web site lists SIDs as DPs.


In a previous installment, I talked about flying a vectored SID with the G1000. Now it's time to consider a pilot nav SIDs, which are designed to allow the pilot to fly a departure on his or her own navigation with minimal input from ATC.

The only pilot nav SID that I've flown regularly is the Salad One Departure out of Oakland.

Here's a G1000 flight plan from Oakland to Reno, Nevada that uses the Salad One departure. Note that once you have entered your departure and destination airports, the flight plan page on the MFD defines some soft keys along the bottom that allow you to quickly load and select a DP (Garmin doesn't call them SIDs either!), STAR, or instrument approach procedure.



Flying a pilot nav SID is pretty simple. Climb to 400 feet above ground level before making any turns, then fly the headings depicted and intercept the specified course or airway. Here's what the G1000 displays after you've turned to the 092˚ heading and intercepted the Oakland 060˚ radial. The G1000 does what you would expect: It activates the first leg of the SID for you.



Something I recommend to my instrument students is to tune the VORs that define the underlying airways or course for the SID. In the case of an RNAV SID, there may not be any VORs involved. But in this case, there are several VORs that can be set up. In my example, the #1 nav is tuned to Oakland (116.8) and the #2 is tuned to Scaggs Island (112.1) to allow the identification of SALAD intersection. I always recommend being able to identify the first intersection or waypoint on an airway or SID, just in case. In my example, the back-up frequencies are set to allow you to identify the next waypoint, ALTAM, using VORs.



Oh, and you did a RAIM check before departing, right?

11 comments:

Ron said...

If you select a DP/SID or STAR on the G1000 by using the PROC key rather than the soft keys, notice that it says:

SELECT DEPARTURE
SELECT ARRIVAL

rather than calling it a DP, SID, or STAR. It's almost as if the user interface people at Garmin knew the FAA would be changing its mind...

The RAIM check is interesting, I have not been having my students do that. Not that I have a problem with it, it's just an oversight on my part. When to do a RAIM prediction is an interesting question, because we use it basically all the time for, if nothing else, backups, cross checking, and overall situational awareness. So at what point would a RAIM prediction be *required*? I don't see this addressed anywhere, unless it's in one of the 3 bazillion pages of G1000 documentation on the Garmin site.

John said...

Ron,

I tend to be pretty critical of the user interface people at Garmin. I'm not sure there are any, quite frankly, or if there are, they're are very cloistered group with little contact with the outside world.
;-)

Regarding RAIM, the AIM advises in several places that a RAIM prediction check should be done. I like pilots to get into the habit of performing a RAIM prediction because many pilots seem to assume GPS is fool proof and are unaware of its limitations.

Scott said...

I've been using the Garmin 430/530 since it was first introduced. I've done tons of SIDs and STARs during this time with these units. However, as I began to teach in the G1000 I noticed something a bit different with SIDs that I have not resolved.

I departed out of BJC (in Denver)headed westbound and was assigned the Rockies-5 SID with Kremmling transition. No problem. With my flight plan loaded in the G1000, select the DP and done. Ah, but wait a minute. No magenta line from DEN to ZIMMR. The route starts at ZIMMR. How come? Did I do something wrong?

See http://chesavtraining.com/images/rockies-5-sid.gif for an image of the G1000 as we departed. The route started at ZIMMR. By the time I took the pic we had been given Direct ZIMMR, hence the magenta line on this image.

Why isn't there a line drawn from DEN to ZIMMR? I have seen this with other SIDs on the G1000.

See http://www.naco.faa.gov/d-tpp/0703/05612ROCKIES.PDF and http://www.naco.faa.gov/d-tpp/0703/05612ROCKIES_C.PDF for the SID.

John said...

Scott,

The SID you mentioned is not a pilot nav SID. Note the first line of the instructions on the second page: "Fly assigned heading and altitude for radar vectors to assigned transition."

I believe you'd see this same representation of this SID in the Garmin 430/530, but I'd have to fire up my simulator to be certain.

Michael said...

Hi..
I am new to the G1000. Your blog is an excellent resource. When you say use the VOR's as backup to ID intersections are you using the DME reading from the bearing pointers. How do you tell when you actually arrive at the intersection since you have no CDI on the NAV 2??

John said...

Michael,

Glad you find my blog useful and I hope you'll consider making a donation to support my efforts!

The G1000 lets you display bearing pointers simultaneously with the HSI representation, so you don't need a second CDI.

Press the PFD softkey and you'll see that you can use the BRG1 softkey scroll through Off, Nav1 or GPS1. BRG2 can be either Off, Nav2 or GPS2.

With a bearing pointer displayed, a GPS-derived distance is also shown, and you can certainly use that to determine when you've arrived at the intersection. Or you can look at the tail of the bearing pointer, which shows which radial you are on. With your Nav radios set up properly, when the tail of the bearing pointer matches the cross-radial for the intersection, you've arrived.

Many pilots either never learn or forget how to determine the position relative to an intersection using a cross-radial or they are unfamiliar with using bearing pointers since, prior to the introduction of the G1000, RMI style indications were rarely found on inexpensive GA aircraft.

Many pilots also don't bother to read their chart and determine which Nav frequencies to set, preferring instead to just follow the GPS' magenta line.

If you set your NAV radios and bearing pointers to back-up your GPS position, you'll stay in practice at referring to your IFR charts and relating the bearing pointers to your position relative to an intersection. Then if your GPS should fail, you won't be left struggling to remember how to use the Nav receivers.

Michael said...

Excellent information John. I never thought to consider that the bearing pointers are nothing more than a dual set of RMI's. As you said, I have not had any experience with that type of instrument, except maybe on FAA written examinations!

Thanks for following up my question and good luck with the blog. I enjoy reading it and I will be making a donation shortly.

Best,

Michael

merit said...

Does anybody know if you can load and have the G1000 fly victor airways in your IFR flight plan? If so, how?

I understand you can load specific waypoints but not sure about putting in airways.

John said...

Merit,

Yes, you can if your G1000 has the appropriate S/W revision. If it does, you can find a description of loading airways here.

Christopher said...

Hello,
I am an Instrument Student and new to the G1000. Just wondering if it is possible to display both NAV1 and NAV2 on the HIS? Thanks for your help, and great web site!!

John said...

Christopher,

The HSI can only display one nav source at a time - GPS, NAV1 or NAV2. You select the nav source for the HSI using the CDI softkey.

However, depending on the model of G1000 you are using and the software revision, you can display bearing pointers underneath the HSI. Bearing pointer #1 can be set to either NAV1 or GPS1. Bearing pointer #2 can be set to either NAV2 or GPS2. The bearing pointer basically acts like an RMP, pointing to the station (or if set to GPS to the current waypoint).

You access the Bearing pointers by pressing the PFD softkey, then the appropriate bearing pointer softkey to scroll through the available choices.

Hope that helps,

John