FAA Instrument Flight Instructor (FII)IFR Procedures and ApproachesHard
A pilot flying an ILS approach reaches decision height and has the approach light system in sight, but cannot distinctly identify the red terminating bars or red side row bars. According to 14 CFR 91.175, what is the pilot required to do?
- ADescend no lower than 100 feet above the touchdown zone elevation unless further required visual references become distinctly visible
- BContinue descent to touchdown since the approach lights are visible
- CImmediately execute a missed approach regardless of further visual contact
- DDescend to 50 feet above touchdown zone elevation and level off there
Show answer & explanationAnswer & explanation
Correct answer: A. Descend no lower than 100 feet above the touchdown zone elevation unless further required visual references become distinctly visible
Under 91.175(c)(3), sighting the approach light system alone allows descent to no lower than 100 feet above the touchdown zone elevation; further descent below that point requires distinct visibility of the red terminating bars or red side row bars (or other qualifying visual references such as the runway itself).
Why the other options are wrong
- B. Approach lights alone only permit descent to 100 feet above TDZE, not to touchdown.
- C. A missed approach is not automatically required merely because red bars aren't yet visible; the pilot may level at 100 feet above TDZE and continue if other references appear.
- D. There is no such regulatory stopping point at 50 feet.
91.175 Visual Reference Requirements Below DH/MDA
Regulation specifying the minimum visual references required to descend below DH or MDA, with an additional 100-foot AGL floor when only the approach light system (without red bars) is in sight.
- Approach lights alone: descend no lower than 100 feet above TDZE
- Red terminating bars or red side row bars distinctly visible: may continue below 100 feet
- Other qualifying references (runway, threshold markings, PAPI/VASI, etc.) also permit continued descent
- Flight visibility must also be at or above the published minimum
Memory trick: 'Lights alone stop you at 100 — red bars let you go lower'