So basically there is no need to see the rabbit or ALS system at or prior to the normal 250/200 foot minimum on an ILS. Instead you can continue to 100 above TDZE without any visual ques, then at that point you still need the visibility, airport environment and in a normal position to land to continue? SO in the end, at 100 above TDZE you need the same requirements as a traditional ILS?

 

You haven't used EVS apparently. At 200', in this example, you do have visual cues, they are just based on the IR image from EVS in HUD. In the right conditions, Delhi at 3am comes to mind, you'll have a perfect EVS IR image of the airfield lighting. You're are using that as the visual cues. At 100', the pilot has to transition to the normal vision.

GF

 

GF is spot on. I should have used different wording other than "reduced minimums". The mins are not reduced, rather you are using the IR image on the HUD to give you the visual cues to descend from DA to 100' above TDZE. At 100' the pilot must be able to see runway environment with normal vision.

GVCPT

* Sorry for the redundant post. I guess GF and I were typing a reply at the same time and it looks like he can type faster than me.

 

The trick is that the right seater who does not have a HUD most of the time can not see anything, but is generally the guy who is supposed to say land or go around. CRM becomes a little tricky when the left seater says continue to 100' but the right seater has nothing.

 

Not sure about Part 91 but I can speak from the 121 side.

On my aircraft, the 777, the EFVS allows...

Take-off:

Low Visibility Take-off's down to 300 RVR (normally 500 RVR) on approved runways. This will be charted usually with a "ball note" for operators with approved HUD installation. What's unique is that the EVS/FLIR is NOT required, LVTO is based on HUD guidance only. This is available at any international location that has the ball note on the Jepp (Our Jepps are custom tailored).

Landing:

All DOMESTIC CAT 1 approaches (precision and non-precision) have minimums of 1000 RVR.

The "Approach Ban" is removed (domestic only). This allows me to BEGIN an approach that is "below minimums" down to 1,000 RVR (i.e. RNAV/RNP).
It effectively turns all CAT 1 ILS's or non-precision approaches into a CAT II approach down to 1,000 RVR.

If the pilot see's what we call "EFIS Lights", (synthetically generated via the FLIR image), during the approach, he may continue down to 100'. No later than 100' he MUST see the required items via the "naked eye" (natural vision), to continue to a landing. Here's the biggie...the things you must see naturally by 100' are FAR MORE restrictive if you used the EVS to get to 100'. You MUST see:
1. TDZ Lights or
2. TDZ markings (paint) or
3. Threshold Lights or
4. Threshold Markings (paint)

That's it! Notice runway lights, centerline lights, REILS, VASI, PAPI, etc. DO NOT qualify. It's very busy at 100' at 150 knots and tempting to continue when you see anything not in 1 through 4 above.

Again, this is how my airline uses it. Low visibility take-offs world-wide, Approach Ban and 1,000 RVR on CAT I's Domestically. For me, it's probably going to be a CAT IIIb "NO SEE TO LAND" auto land monitored through the HUD at my destinations.

Cheers!

 

Jabba,

Can't speak for GLF products but on Bombardier's EVS, the co-pilot has a video display of the EVS image the pilot sees in the HUD.

GF

 

After reaching out to Gulfstream, the answer in a nutshell is:

-The allowance for continuing beyond the DA/MDA to 100 feet above TDZE using enhanced vision to identify the approach lights is restricted to within the U.S.
-FAR 91.175 details the specifics and AC 90-106 provides more guidance
-EASA and ICAO do not yet have similar allowances for Part 91 operations
-EASA and ICAO are working on something along the lines of 91.175 that will potentially provide similar allowances but may require an LOA from the country of registry

So, the answer to my original question is that you may not continue beyond the DA/MDA using enhanced vision in any region other than the United States