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This definition also agrees with ICAO and the European Aviation Safety Agency (EASA), which has been a leader in using CDFA approaches for years. They even highlight this in their approach procedures when applicable. When reviewing the approach procedures for the VOR Rwy 36C Approach at EHAM/AMS (Am- sterdam, Netherlands), you will see published DME al- titudes for each mile on final approach and published “CDFA” minimums.
The advantages of CDFA include stabilized approach criteria, standardized procedures, improved situational awareness, reduced workload, improved fuel efficiency, reduced noise level, and safety. It also reduces the prob- ability of infringement on obstacles, something even the least risk-averse pilot would agree is a good thing to avoid. Precision approaches provide vertical guidance and have a significantly better safety record, while non-precision approaches were originally designed without vertical guidance and sacrifice some of this safety margin. Flying a CDFA approach emulates some of the benefits of a preci- sion approach and will provide a more stabilized descent.
The best part is that CDFA only requires what is neces- sary to fly the non-precision approach. Any FAR Part 91 operator may also adopt CDFA without any FAA approval process. Part 135 operators do not require FAA Operations Specifications for CDFA approval, but the procedure should be added to their manuals and training program.
Now, you may be thinking, how do I conduct a CDFA approach?
When flying a localizer, LDA, or back-course (LOC, LDA, or BC) approach, the pilots need to determine the vertical descent rate required for the approach from the table on the approach chart (Jeppesen Charts). (If you use U.S. Government Charts, you must determine the descent rate from the published Climb/Descent Table. You will then need to use Vertical Speed (VS) to descend. This sounds confusing if you have never done it, but I promise it is easy when you see how it works.
Let’s look at an example.
To conduct an approach with a 3-degree glide path and an approach speed of 134 knots, look at the descent rate table and choose the next higher approach speed of 140 knots. Then observe that your target VS will be a descent rate of 743 fpm. You should be fully configured as you cross the Final Approach Fix (FAF). At the FAF, start your descent using VS. This should put you close to a 3-degree glide path, approximating an ILS Glide Slope. As you break out of the weather and see the runway or PAPI, you should make any necessary adjustments visu- ally to your descent rate.
How you enter this in your avionics package might vary. If we considered the Rockwell Collins Proline 21, a pilot would select the lateral mode to “APPR mode” for navigation transfer from FMS to the localizer, then select NAV mode to prohibit capturing any glide slope. You would select “BC” for a Back-Course approach. For the
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