EFVS Operations

FAR 91.176 EFVS Operations

FAR 91.176 explains how pilots may use an Enhanced Flight Vision System (EFVS) to descend below DA/DH or MDA on straight-in IFR approaches.

In Plain English

FAR 91.176 governs how pilots may use an Enhanced Flight Vision System (EFVS) to continue an instrument approach below the published DA/DH or MDA under IFR. It matters because EFVS lets you legally descend toward the runway when natural visibility alone wouldn't reveal the required visual references.

Key points:

  • Equipment: The aircraft must have an operable, airworthy EFVS that displays sensor imagery (infrared, millimeter wave, or image intensification) plus flight symbology (airspeed, altitude, attitude, heading, flight path vector, etc.) on a head-up display or equivalent.
  • No circling minimums — straight-in approaches only, and the approach must have a DA/DH for paragraph (a) operations to touchdown.
  • Down to 100 ft above TDZE: The pilot must see the approach lights, or both the runway threshold and the touchdown zone, using EFVS, and visibility (as seen via EFVS) must equal or exceed that prescribed for the approach.
  • Below 100 ft above TDZE: Under paragraph (a), EFVS may continue to be used to touchdown; under paragraph (b) (down to 100 ft only), the runway threshold or touchdown zone references must be visible without reliance on EFVS.
  • Authorization: Part 121/125/129/135 and subpart K operators need OpSpecs, MSpecs, or a Letter of Authorization; pilots must meet § 61.66 training and currency.
Regulation Text
14 CFR § 91.176
§ 91.176 Straight-in landing operations below DA/DH or MDA using an enhanced flight vision system (EFVS) under IFR. (a)Unless otherwise authorized by the Administrator to use an MDA as a DA/DH with vertical navigation on an instrument approach procedure, or unless paragraph (d) of this section applies, no person may conduct an EFVS operation in an aircraft, except a military aircraft of the United States, at any airport below the authorized DA/DH to touchdown and rollout unless the minimums used for the particular approach procedure being flown include a DA or DH, and the following requirements are met: (1)(i) The aircraft must be equipped with an operable EFVS that meets the applicable airworthiness requirements. The EFVS must: (A) Have an electronic means to provide a display of the forward external scene topography (the applicable natural or manmade features of a place or region especially in a way to show their relative positions and elevation) through the use of imaging sensors, including but not limited to forward-looking infrared, millimeter wave radiometry, millimeter wave radar, or low-light level image intensification. (B) Present EFVS sensor imagery, aircraft flight information, and flight symbology on a head up display, or an equivalent display, so that the imagery, information and symbology are clearly visible to the pilot flying in his or her normal position with the line of vision looking forward along the flight path. Aircraft flight information and flight symbology must consist of at least airspeed, vertical speed, aircraft attitude, heading, altitude, height above ground level such as that provided by a radio altimeter or other device capable of providing equivalent performance, command guidance as appropriate for the approach to be flown, path deviation indications, flight path vector, and flight path angle reference cue. Additionally, for aircraft other than rotorcraft, the EFVS must display flare prompt or flare guidance. (C) Present the displayed EFVS sensor imagery, attitude symbology, flight path vector, and flight path angle reference cue, and other cues, which are referenced to the EFVS sensor imagery and external scene topography, so that they are aligned with, and scaled to, the external view. (D) Display the flight path angle reference cue with a pitch scale. The flight path angle reference cue must be selectable by the pilot to the desired descent angle for the approach and be sufficient to monitor the vertical flight path of the aircraft. (E) Display the EFVS sensor imagery, aircraft flight information, and flight symbology such that they do not adversely obscure the pilot's outside view or field of view through the cockpit window. (F) Have display characteristics, dynamics, and cues that are suitable for manual control of the aircraft to touchdown in the touchdown zone of the runway of intended landing and during rollout. (ii) When a minimum flightcrew of more than one pilot is required, the aircraft must be equipped with a display that provides the pilot monitoring with EFVS sensor imagery. Any symbology displayed may not adversely obscure the sensor imagery of the runway environment. (2)(i) The pilot conducting the EFVS operation may not use circling minimums. (ii) Each required pilot flightcrew member must have adequate knowledge of, and familiarity with, the aircraft, the EFVS, and the procedures to be used. (iii) The aircraft must be equipped with, and the pilot flying must use, an operable EFVS that meets the equipment requirements of paragraph (a)(1) of this section. (iv) When a minimum flightcrew of more than one pilot is required, the pilot monitoring must use the display specified in paragraph (a)(1)(ii) to monitor and assess the safe conduct of the approach, landing, and rollout. (v) The aircraft must continuously be 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. (vi) The descent rate must allow touchdown to occur within the touchdown zone of the runway of intended landing. (vii) Each required pilot flightcrew member must meet the following requirements— (A) A person exercising the privileges of a pilot certificate issued under this chapter, any person serving as a required pilot flightcrew member of a U.S.-registered aircraft, or any person serving as a required pilot flightcrew member for a part 121, 125, or 135 operator, must be qualified in accordance with part 61 and, as applicable, the training, testing, and qualification provisions of subpart K of this part, part 121, 125, or 135 of this chapter that apply to the operation; or (B) Each person acting as a required pilot flightcrew member for a foreign air carrier subject to part 129, or any person serving as a required pilot flightcrew member of a foreign registered aircraft, must be qualified in accordance with the training requirements of the civil aviation authority of the State of the operator for the EFVS operation to be conducted. (viii) A person conducting operations under this part must conduct the operation in accordance with a letter of authorization for the use of EFVS unless the operation is conducted in an aircraft that has been issued an experimental certificate under § 21.191 of this chapter for the purpose of research and development or showing compliance with regulations, or the operation is being conducted by a person otherwise authorized to conduct EFVS operations under paragraphs (a)(2)(ix) through (xii) of this section. A person applying to the FAA for a letter of authorization must submit an application in a form and manner prescribed by the Administrator. (ix) A person conducting operations under subpart K of this part must conduct the operation in accordance with management specifications authorizing the use of EFVS. (x) A person conducting operations under part 121, 129, or 135 of this chapter must conduct the operation in accordance with operations specifications authorizing the use of EFVS. (xi) A person conducting operations under part 125 of this chapter must conduct the operation in accordance with operations specifications authorizing the use of EFVS or, for a holder of a part 125 letter of deviation authority, a letter of authorization for the use of EFVS. (xii) A person conducting an EFVS operation during an authorized Category II or Category III operation must conduct the operation in accordance with operations specifications, management specifications, or a letter of authorization authorizing EFVS operations during authorized Category II or Category III operations. (3)No pilot operating under this section or §§ 121.651, 125.381, or 135.225 of this chapter may continue an approach below the authorized DA/DH and land unless: (i) The pilot determines that the enhanced flight visibility observed by use of an EFVS is not less than the visibility prescribed in the instrument approach procedure being used. (ii) From the authorized DA/DH to 100 feet above the touchdown zone elevation of the runway of intended landing, any approach light system or both the runway threshold and the touchdown zone are distinctly visible and identifiable to the pilot using an EFVS. (A) The pilot must identify the runway threshold using at least one of the following visual references— () The beginning of the runway landing surface; () The threshold lights; or () The runway end identifier lights. (B) The pilot must identify the touchdown zone using at least one of the following visual references— () The runway touchdown zone landing surface; () The touchdown zone lights; () The touchdown zone markings; or () The runway lights. (iii) At 100 feet above the touchdown zone elevation of the runway of intended landing and below that altitude, the enhanced flight visibility using EFVS must be sufficient for one of the following visual references to be distinctly visible and identifiable to the pilot— (A) The runway threshold; (B) The lights or markings of the threshold; (C) The runway touchdown zone landing surface; or (D) The lights or markings of the touchdown zone. (4)The Administrator may prescribe additional equipment, operational, and visibility and visual reference requirements to account for specific equipment characteristics, operational procedures, or approach characteristics. These requirements will be specified in an operator's operations specifications, management specifications, or letter of authorization authorizing the use of EFVS. (b)Except as specified in paragraph (d) of this section, no person may conduct an EFVS operation in an aircraft, except a military aircraft of the United States, at any airport below the authorized DA/DH or MDA to 100 feet above the touchdown zone elevation unless the following requirements are met: (1)(i) The aircraft must be equipped with an operable EFVS that meets the applicable airworthiness requirements. (ii) The EFVS must meet the requirements of paragraph (a)(1)(i)(A) through (F) of this section, but need not present flare prompt, flare guidance, or height above ground level. (2)(i) The pilot conducting the EFVS operation may not use circling minimums. (ii) Each required pilot flightcrew member must have adequate knowledge of, and familiarity with, the aircraft, the EFVS, and the procedures to be used. (iii) The aircraft must be equipped with, and the pilot flying must use, an operable EFVS that meets the equipment requirements of paragraph (b)(1) of this section. (iv) The aircraft must continuously be 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. (v) For operations conducted under part 121 or part 135 of this chapter, the descent rate must allow touchdown to occur within the touchdown zone of the runway of intended landing. (vi) Each required pilot flightcrew member must meet the following requirements— (A) A person exercising the privileges of a pilot certificate issued under this chapter, any person serving as a required pilot flightcrew member of a U.S.-registered aircraft, or any person serving as a required pilot flightcrew member for a part 121, 125, or 135 operator, must be qualified in accordance with part 61 and, as applicable, the training, testing, and qualification provisions of subpart K of this part, part 121, 125, or 135 of this chapter that apply to the operation; or (B) Each person acting as a required pilot flightcrew member for a foreign air carrier subject to part 129, or any person serving as a required pilot flightcrew member of a foreign registered aircraft, must be qualified in accordance with the training requirements of the civil aviation authority of the State of the operator for the EFVS operation to be conducted. (vii) A person conducting operations under subpart K of this part must conduct the operation in accordance with management specifications authorizing the use of EFVS. (viii) A person conducting operations under part 121, 129, or 135 of this chapter must conduct the operation in accordance with operations specifications authorizing the use of EFVS. (ix) A person conducting operations under part 125 of this chapter must conduct the operation in accordance with operations specifications authorizing the use of EFVS or, for a holder of a part 125 letter of deviation authority, a letter of authorization for the use of EFVS. (x) A person conducting an EFVS operation during an authorized Category II or Category III operation must conduct the operation in accordance with operations specifications, management specifications, or a letter of authorization authorizing EFVS operations during authorized Category II or Category III operations. (3)No pilot operating under this section or § 121.651, § 125.381, or § 135.225 of this chapter may continue an approach below the authorized MDA or continue an approach below the authorized DA/DH and land unless: (i) The pilot determines that the enhanced flight visibility observed by use of an EFVS is not less than the visibility prescribed in the instrument approach procedure being used. (ii) From the authorized MDA or DA/DH to 100 feet above the touchdown zone elevation of the runway of intended landing, any approach light system or both the runway threshold and the touchdown zone are distinctly visible and identifiable to the pilot using an EFVS. (A) The pilot must identify the runway threshold using at least one of the following visual references- () The beginning of the runway landing surface; () The threshold lights; or () The runway end identifier lights. (B) The pilot must identify the touchdown zone using at least one of the following visual references— () The runway touchdown zone landing surface; () The touchdown zone lights; () The touchdown zone markings; or () The runway lights. (iii) At 100 feet above the touchdown zone elevation of the runway of intended landing and below that altitude, the flight visibility must be sufficient for one of the following visual references to be distinctly visible and identifiable to the pilot without reliance on the EFVS— (A) The runway threshold; (B) The lights or markings of the threshold; (C) The runway touchdown zone landing surface; or (D) The lights or markings of the touchdown zone. (4) Compliance Date. Beginning on March 13, 2018, a person conducting an EFVS operation to 100 feet above the touchdown zone elevation must comply with the requirements of paragraph (b) of this section. (c)A public aircraft operator, other than the U.S. military, may conduct an EFVS operation under paragraph (a) or (b) of this section only if: (1) The aircraft meets all of the civil certification and airworthiness requirements of paragraph (a)(1) or (b)(1) of this section, as applicable to the EFVS operation to be conducted; and (2) The pilot flightcrew member, or any other person who manipulates the controls of an aircraft during an EFVS operation, meets the training, recent flight experience and refresher training requirements of § 61.66 of this chapter applicable to EFVS operations. (d)The requirement to use an EFVS that meets the applicable airworthiness requirements specified in paragraphs (a)(1)(i), (a)(2)(iii), (b)(1)(i), and (b)(2)(iii) of this section does not apply to operations conducted in an aircraft issued an experimental certificate under § 21.191 of this chapter for the purpose of research and development or showing compliance with regulations, provided the Administrator has determined that the operations can be conducted safely in accordance with operating limitations issued for that purpose. [Docket FAA-2013-0485, Amdt. 91-345, 81 FR 90172, Dec. 13, 2016; 82 FR 2193, Jan. 9, 2017]
Oral Exam Questions a DPE Might Ask
Q1What is an EFVS, and what does FAR 91.176 allow you to do with one?
An EFVS is an Enhanced Flight Vision System using imaging sensors (infrared, millimeter wave, or image intensification) displayed on a HUD or equivalent. Per FAR 91.176, it allows a properly equipped and authorized pilot to descend below DA/DH (paragraph a, to touchdown and rollout) or below DA/DH or MDA to 100 ft above TDZE (paragraph b) on a straight-in IFR approach when the EFVS provides the required enhanced flight visibility.
Q2Can you use EFVS to fly to circling minimums?
No. FAR 91.176(a)(2)(i) and (b)(2)(i) explicitly prohibit the use of circling minimums during an EFVS operation — only straight-in approaches with a published DA/DH (or MDA under paragraph b) qualify.
Q3Under FAR 91.176(b), what visual references must you see at 100 feet above the touchdown zone elevation, and is EFVS still acceptable there?
Per FAR 91.176(b)(3)(iii), at and below 100 ft above TDZE the pilot must distinctly see the runway threshold, threshold lights or markings, the touchdown zone landing surface, or the touchdown zone lights or markings — and these must be visible using natural flight visibility **without reliance on the EFVS**.
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FAR 91.176 — EFVS Straight-In Landings Below DA/DH or MDA