IFR Fix: Seeing, but not believing

January 28, 2013

It wasn’t supposed to be a difficult approach.

Now, as you near decision height, you yearn for a glimpse of the threshold, runway markings, or the haloed gleam of a lighting system.

What will appear first, if anything?

It would be mighty helpful to know exactly what’s down there. The uncertainty will serve as a reminder to focus more study on the more obscurely presented details of published instrument approach procedures—including the presentations of approach lighting systems and associated components.

Reviewing that material later, you notice the small box on the approach plate, designating the approach lighting system for this ILS or LOC RWY 33 approach as MALSR (medium intensity approach lighting system with runway alignment indicator lights). It has the same configuration as the higher-intensity SSALR, and they are designated as simplified short approach lighting systems.

The small information box on the approach plate contains “A5” in a circle for the MALSR, also providing a tiny illustration of the lighting system’s layout.

There’s more to review about that information box before your next venture down an unfamiliar airport’s instrument approach. The dot atop the circle containing A5 informs the pilot that sequenced flashing lights are installed—potentially one of the most helpful means of spotting the “runway environment” near minimums.

The circle contains white characters on a black background but you recall that in other cases those tones are reversed. Why?

The “negative symbology” signifies, importantly, pilot-controlled lighting.

If your prior exposure to low approach scenarios consists mainly of hearing the hangar heroes hold forth on how they completed tough approaches after making visual contact with some portion of the runway environment, one hard fact is clear now: You can’t land on an environment.

Regulations require that at least one of one several itemized components be “distinctly visible and identifiable” to the pilot (and note the caveat about using approach lights as a reference).

If you find yourself overcontrolling to keep that component distinctively visible, go missed. Your aircraft isn’t “continuously in a position from which a descent to a landing on the intended runway can be made at a normal rate of descent using normal maneuvers.”

It isn’t enough to just see something down there. It has to take you down to a normal landing.

Dan Namowitz

Dan Namowitz | Aviation Writer

Dan Namowitz is an aviation writer and flight instructor. He has been a pilot since 1985 and an instructor since 1990.

Topics IFR, Technique