Chart Wise: Training and Technique

A new GPS procedure demands some study.

The RNAV GPS Z approach to Runway 3 at Santa Monica is so new (April 2017), many pilots might not yet even be aware of its existence. (Two additional approaches to SMO were commissioned at the same time.) This new approach comes with a handful of restrictions, many of which are significant enough to demand a pilot closely scrutinize the approach plate before the first attempt. Expect speed, climb, approach minimums and time-of-day restrictions, just for starters. It’s also an LP, not an LPV, approach, which translates into a more traditional non-precision-approach procedure. It’s worth noting the prevailing winds are coming from the west, putting the airplane in a tailwind at the completion of the approach.

1) Note, the WAAS Channel 77839 is seldom used because most GPS units tune this automatically.

2) This approach is not authorized at night.

3) The missed approach holds the aircraft to 175 knots maximum until 5,000 feet.

4) The missed approach uses nonstandard 5 nm legs that are becoming more common in GPS-only approaches.

5) Approach minimums vary widely here, depending on whether the aircraft can make the required climb gradient of the missed-approach procedure (see Note 1).

6) Although the aircraft approaches SMO from across the water, this is not a straight-in approach. The final approach course is offset 30 degrees from the runway heading, which means the pilot must remember to look for the runway out the left window at minimums.

7) The approach puts the aircraft at a relatively low altitude over the water. Should the engine fail in a single, the airplane might not be able to glide to terra firma.

8) Notice that the required missed-approach climb is stated as 290 feet per nautical mile and not in feet per minute. This requires converting feet per nautical mile into a climb rate using the conversion chart in the instrument-approach supplement.

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