I-10 Rating



Fly from Santa Barbara (KSBA) to Santa Maria (KSMX), shoot the LOC/DME BC-A approach, execute the missed approach, hold, then divert to KSBP for the VOR-A approach, circling to the active runway.

Learning objectives

  • reinforce the use of Standard Instrument Departures (SIDs)
  • introduce back course approaches
  • introduce the missed approach segment including holding procedures
  • introduce a diversion to another destination
  • reinforce full non-precision approaches with circling

Flying the Rating

To successfully complete this rating you must accomplish the following tasks:

  • Fly from KSBA to KSBP via the LOC/DME BC-A approach at KSMX
  • Inform ATC on initial contact at KSBA that you are performing the I-10 Rating
  • Execute LOC/DME BC-A approach from RZS, advising controller of intention to go missed
  • Execute missed approach procedure utilizing the most appropriate hold entry and at least one complete lap of the hold
  • Inform controller of intention to divert to KSBP via MQO
  • Once enroute to KSBP, request full VOR-A approach with a full stop landing

Rating Description

File a flight plan from KSBA to KSMX, via FLOUT5.RZS, with an alternate destination of KSBP. File an altitude that is appropriate for the direction of flight, and above the MEA (Minimum Enroute Altitude) listed on the RZS transition of the SID.

Pick up the IFR clearance and depart from Santa Barbara (KSBA). Prior to reaching RZS, request the LOC/DME BC-A into KSMX (Localizer DME Backcourse Alpha into Santa Maria) and advise the controller of intention to execute the missed and divert to the filed alternate, KSBP. Upon reaching RZS, fly the approach into KSMX to minimums and then execute the missed approach as published, flying the hold at Guadalupe VOR.

A parallel or teardrop entry will be used (pilot’s choice) to become established in the hold, and then fly one complete lap of the hold. Whilst in the hold, negotiate an IFR clearance to San Luis Obispo (KSBP) via Morro Bay VOR (MQO).

Request the VOR-A full approach into KSBP. The approach controller will specify the circling runway in the approach clearance. Perform a full stop landing on the runway specified by the controller. Note the circling restrictions published on the chart, negating the option of circling north of the field.

Information is provided below regarding the back course approach and the hold. The VOR-A into KSBP is similar in nature to the non-precision approach in the I-7 rating. Be sure to depart MQO to the west to execute the course reversal (procedure turn).


Back Course Approach and Hold

Open or print the KSMX LOC/DME BC-A (Santa Maria Localizer DME Backcourse Alpha) approach plate.This non-precision approach is based on a navigation aid, I-SMX, which is the localizer normally used for the KSMX ILS RWY 12 approach. Whilst the front course of I-SMX (running from the station to the northwest) services the ILS approach, the back course of the localizer (running from the station to the southeast) services the LOC/DME BC-A approach.

Reverse Sensing. What the….

Unlike VORs, localizers only transmit a single radial. This is why technically possible to fly an ILS or LOC approach without setting the OBS on your NAV receiver (although it is considered good practice to do so to aid in visualization and situational awareness). For this reason, though, when flying the backcourse approach, you will experiencing reverse sensing when interpreting the Course Deviation Indicator (CDI), or the ‘needle’ on your VOR receiver.

This is the same experience that can be had by tracking towards a VOR with the needle centered and the TO/FROM flag indicating FROM. When dealing with a VOR, you can adjust the OBS to alleviate the reverse sensing issue. With a back course localizer approach, however, you must deal with it. If you are using an autopilot to maintain lateral control on the back course of the localizer, you must TELL the autopilot that you are using the back course by using the cunningly named “BC” button. If one is not available, do not attempt to have the autopilot track the localizer back course, unless you are a fan of seeing your autopilot become depressed, or worse, angry.

When flying the front course, if the needle is to the left, then the localizer is on your left, and you need to make a left turn to recapture. You fly ‘to’ the needle. On the back course, the opposite is true. If the needle is offset to the left, you need to turn RIGHT to recapture. You fly ‘away’ from the needle.

A reasonable way to practice reverse sensing is to takeoff under VFR, find a nearby VOR, become established either to or from the VOR, using the appropriate OBS setting, and then either turn the airplane 180 degrees, or spin the OBS 180 degrees. You will then experience reverse sensing and can practice holding the course and making reversed corrections.

If you are lucky enough to be flying an airplane equipped with an HSI. Try setting the HSI to the front course heading, this will cancel the reverse sensing.

Flying the Approach from RZS

With the plate in hand, let’s fly the approach from San Marcus (RZS). Set your NAV1 radio to the I-SMX localizer with the OBS set to 300. Set your NAV2 to RZS, with GLJ in the standby freq, we’ll need it to set up for the missed. Departing RZS, the NAV2 OBS should be set to 286, to track the RZS R-286 outbound. Maintain at or above 6000, as published to 14 DME (MADOO), then at or above 4600 until KOAKS.

KOAKS is located at the intersection of the I-SMX back course, and the RZS R-286, at RZS 29 DME. Approching KOAKS, the needle on the NAV1 should swing from a right deflection to being centered (even though we were on the RIGHT side of the back course, we were on the LEFT side, relative to the heading of the front course, which is all I-SMX is good for telling us about, as discussed above.)

At KOAKS, we join the back-course and proceed on the 300 course, using the NAV1 needle to remain on track. Descend to cross CAMCO at or above 3000 and PATER at or above 1700. After PATER, we can descend to the Minimum Descent Altitude (MDA), which is likely to be 1100 MSL, unless you’re flying an SR-71 (Category D), in which case….good for you.

Once established on the localizer, and when time permits, drop RZS from the NAV2 and bring GLJ to life, it’ll be needed for the missed. Set the NAV2 OBS to 300.

You may receive a glideslope indication during this approach. Treat this as you would your spouse, mother-in-law, or low oil light in a rental vehicle….ignore it. It’s a really great thing to follow on the ILS RWY 12, but not so good for this approach. It says it right there on the vertical profile on the plate, too.

Reaching I-SMX 0.5 DME, we execute the missed approach.


The final approach course is suspiciously well-aligned with runway 30, isn’t it? This is not surprising since the front side signal is used for a PRECISION approach to the same piece of asphalt, runway 12. A fair question, then, is why this is a circling approach without any straight-in minimums. The descent gradient of this approach exceeds the maximum stipulated for straight in approaches, so this is a circling approach only, hence the Alpha designation. The VOR-A into KSMO is another example of such an approach.

Does it mean that you must physically circle the aircraft even if you plan to land on runway 30? No. If you can safely land the airplane with a straight-in approach, then do so.

Flying the Missed

Reaching the missed approach point, execute the missed approach, by climbing to 2000ft and proceeding direct Guadalupe (GLJ). Reaching GLJ, enter the hold as published. Given the direction from which we are arriving, a parallel entry would be the appropriate method. Depart GLJ outbound on the holding course for for 1 minute then start a right turn. During this time, spin the NAV2 OBS to the inbound heading for the hold, 120.

Continue the right turn to set up a 30 degree intercept to the holding course, 150 will work here. Continue on that heading until the NAV2 needle centers, and turn left to join the holding course, 120. Once this happens, you are established in the published hold at GLJ. Passing over the station, make a left 180 degree turn, proceed north for one minute, make another 180 degree turn and join the holding course with the centered CDI (indicating you are on the desired radial). Your inbound leg should take 1 minute. You’ve just flown a full lap of the hold.

Required Material

  • KSBA airport diagram
  • Current FLOUD SID chart
  • KSMX LOC/DME BC-A approach chart
  • KSBP VOR-A approach chart
  • KSBP airport diagram