All instrument rated pilots are familiar with the term “chop it and drop it.” If the runway environment comes into sight just as the missed approach point is reached, the pilot can cut the power, enter a slip and drop it like it’s hot – or so the theory goes. Although widely practiced and propagated by many a CFI, is it really safe? Furthermore, is it even legal?
Take a look at 14 CFR 91.175: Takeoff and landing under IFR – Operation below DH or MDA:
(c) Operation below DA/ DH or MDA. Except as provided in paragraph (l) of this section, where a DA/DH or MDA is applicable, no pilot may operate an aircraft, except a military aircraft of the United States, below the authorized MDA or continue an approach below the authorized DA/DH unless—
(1) The aircraft is 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, and for operations conducted under part 121 or part 135 unless that descent rate will allow touchdown to occur within the touchdown zone of the runway of intended landing;
(2) The flight visibility is not less than the visibility prescribed in the standard instrument approach being used; and
(3) Except for a Category II or Category III approach where any necessary visual reference requirements are specified by the Administrator, at least one of the following visual references for the intended runway is distinctly visible and identifiable to the pilot…
“Normal maneuvers” are just what you might think: any maneuver one would perform during a stabilized approach and landing. This includes normal heading and altitude bracketing, minor airspeed adjustments and ordinary descent rates (no more than 1,000 feet per minute in most airplanes). If you wouldn’t do it in a run-of-the-mill visual approach, then you shouldn’t do it on an instrument approach. With these standards, the old “chop it and drop it” just doesn’t cut it. The prudent pilot ought to realize when landing with a normal rate of descent using normal maneuvers cannot be accomplished. A missed approach is the appropriate response.