FLIR vs Approach Minimas

[divinehover]

Hi All

I was wondering if the same Viz/RVR/Cloudbase limits apply to aircraft (Gulfstream ect) equipped with Infra Red vision as convention types. If you can see through the cloud one must assume the Viz/RVR/Cloudbase is of no importance.

DH

[Zeffy]

14 CFR 91.175 (l) (http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=f03846ec13d24656a600bae9a51ad6b7&rgn=div8&view=text&node=14:2.0.1.3.10.2.6.42&idno=14) provides for descent below a straight-in MDA/DA down to 100' HAT based solely on the IR image in the HUD.


(l) Approach to straight-in landing operations below DH, or MDA using an enhanced flight vision system (EFVS). For straight-in instrument approach procedures other than Category II or Category III, no pilot operating under this section or §§121.651, 125.381, and 135.225 of this chapter may operate an aircraft at any airport below the authorized MDA or continue an approach below the authorized DH and land 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 of this chapter, the descent rate will allow touchdown to occur within the touchdown zone of the runway of intended landing;
(2) The pilot determines that the enhanced flight visibility observed by use of a certified enhanced flight vision system is not less than the visibility prescribed in the standard instrument approach procedure being used;
(3) The following visual references for the intended runway are distinctly visible and identifiable to the pilot using the enhanced flight vision system:
(i) The approach light system (if installed); or
(ii) The following visual references in both paragraphs (l)(3)(ii)(A) and (B) of this section:
(A) The runway threshold, identified by at least one of the following:
( 1 ) The beginning of the runway landing surface;
( 2 ) The threshold lights; or
( 3 ) The runway end identifier lights.
(B) The touchdown zone, identified by at least one of the following:
( 1 ) The runway touchdown zone landing surface;
( 2 ) The touchdown zone lights;
( 3 ) The touchdown zone markings; or
( 4 ) The runway lights.
(4) 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 the following to be distinctly visible and identifiable to the pilot without reliance on the enhanced flight vision system to continue to a landing:
(i) The lights or markings of the threshold; or
(ii) The lights or markings of the touchdown zone;
(5) The pilot(s) is qualified to use an EFVS as follows—
(i) For parts 119 and 125 certificate holders, the applicable training, testing and qualification provisions of parts 121, 125, and 135 of this chapter;
(ii) For foreign persons, in accordance with the requirements of the civil aviation authority of the State of the operator; or
(iii) For persons conducting any other operation, in accordance with the applicable currency and proficiency requirements of part 61 of this chapter;
(6) For parts 119 and 125 certificate holders, and part 129 operations specifications holders, their operations specifications authorize use of EFVS; and
(7) The aircraft is equipped with, and the pilot uses, an enhanced flight vision system, the display of which is suitable for maneuvering the aircraft and has either an FAA type design approval or, for a foreign-registered aircraft, the EFVS complies with all of the EFVS requirements of this chapter.
(m) For purposes of this section, “enhanced flight vision system” (EFVS) is an installed airborne system comprised of the following features and characteristics:
(1) An electronic means to provide a display of the forward external scene topography (the 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, such as a forward-looking infrared, millimeter wave radiometry, millimeter wave radar, and low-light level image intensifying;
(2) The EFVS sensor imagery and aircraft flight symbology ( i.e., at least airspeed, vertical speed, aircraft attitude, heading, altitude, command guidance as appropriate for the approach to be flown, path deviation indications, and flight path vector, and flight path angle reference cue) are presented on a head-up display, or an equivalent display, so that they are clearly visible to the pilot flying in his or her normal position and line of vision and looking forward along the flight path, to include:
(i) The displayed EFVS imagery, attitude symbology, flight path vector, and flight path angle reference cue, and other cues, which are referenced to this imagery and external scene topography, must be presented so that they are aligned with and scaled to the external view; and
(ii) The flight path angle reference cue must be displayed with the pitch scale, selectable by the pilot to the desired descent angle for the approach, and suitable for monitoring the vertical flight path of the aircraft on approaches without vertical guidance; and
(iii) The displayed imagery and aircraft flight symbology do not adversely obscure the pilot's outside view or field of view through the cockpit window;
(3) The EFVS includes the display element, sensors, computers and power supplies, indications, and controls. It may receive inputs from an airborne navigation system or flight guidance system; and
(4) The display characteristics and dynamics are suitable for manual control of the aircraft.
[Doc. No. 18334, 54 FR 34294, Aug. 18, 1989, as amended by Amdt. 91–267, 66 FR 21066, Apr. 27, 2001; Amdt. 91–281, 69 FR 1640, Jan. 9, 2004; Amdt. 91–296, 72 FR 31678, June 7, 2007; Amdt. 91–306, 74 FR 20205, May 1, 2009]

[muduckace]

Basically it brings you down to 100ft DH, but who's to say you are not visual at 100ft (naked eye). I have been told that dual FLIR equipped aircraft and approved A/P can bring you down to CAT IIIC.

[kijangnim]

Greetings
FLIR is mostly used where procedures requires a Ceiling, and in that case enables you to fly down to 100ft by which point you should visual (in fact the EVS will be automatically switched off.
CAT IIIB CATIIIC relies only on instruments (meaning Guidance), unlike CAT I or NPAs relies on visual clues.
So EVS FLIR will not be used for that purpose, however on the ground to taxy yes:ok:

[muduckace]

CAT IIIB CATIIIC relies only on instruments (meaning Guidance),

Yes in reference to the ILS but I have never known any operator to certify an aircraft cat IIIb w/o a minimum of 2 autopilots, sure the flight director will continue with rollout but what is the point if you have been met RVR minimums at 200-300 feet.

I have not heard of FLIR shutting down at 100 ft agl, I suppose it may be specific to the aircraft you are operating. I work with single EFVS systems, great to get you off the ground in foggy weather and enhance safety in the muck.

There is talk about CAT IIIC certification for the aircraft as our flir computer has a second output if we continue with the instalation in the F/O's position as well. To correct myself it would bring RVR down to 0.

Commercially it is still a system that is under continuous development and federal approval.

[kijangnim]

FLIR Failure is why commercial plnes we have a big issue, sure it is still in development but intended to be used down to 100 feet AGL only (just like for NPA, the AP will trip -50 feet below min to be sure that you are not going to continue....)
and/or for low vis taxy, great tool for runway incursions...
But CAT IIIC....
BTW it is not a competition, just providing what I was once involved with :ok:

[Denti]

just like for NPA, the AP will trip -50 feet below min to be sure that you are not going to continue....)

Depends on the plane i guess? AFAIK it is not a requirement and on "my" type the AP doesn't trip, you have to actively switch it off. Sadly no EVS yet although boeing announced it 7 years ago, seems there is no market for CAT IIIb plus EVS.