PTS to ACS

[drunkenbeagle]

A bigger hangup for most applicants is that once they get to DA and get the runway in sight, they actually need to continue following the GS to the runway below the DA while in visual conditions!

I know you are supposed to stay on the GS until the runway threshold. At the same time, I usually would prefer to be adding flaps then and not be praying that the brakes won't fail once the runway is in sight. So, anyway, instructors might be to blame here too.

 

[Roger Roger]

Although I agree with you in concept, as an examiner, it was really hard (at least in my state) to find an ILS or LPV that had a DA less than 300 HAT. We would have to travel two hours just to get to an airport that had an ILS, whereas my hometown airport had an LPV of 323 feet.

I mean, that’s kinda what you get living in the middle of nowhere in the mountains. Same same for us up here. You just deal.

Also, as a rule of thumb, it was very rare for someone to unsat a checkride in the last couple of hundred feet. Usually, Instrument unsats were due to procedural problems or knowledge gaps, not stick and rudder skills in the last couple of hundred feet. If they did poorly in the last couple of hundred feet, they were usually unsat long before that point.

A bigger hangup for most applicants is that once they get to DA and get the runway in sight, they actually need to continue following the GS to the runway below the DA while in visual conditions!

If that’s a common issue then I think that makes the low DA even more important, as making that transition at 200’ vs 500’ is a different level of difficulty.

 

[drunkenbeagle]

Is it a bust to go below GS/GP below DA?

In the training world, I think we end up going missed 99% percent of the time on an ILS, so how to actually land doesn't actually happen very often. @DPApilot was kind enough to point this error out to me not too long ago. Which either I forgot or never knew. It definitely wasn't something my CFI-I ever said back in the day - I'm pretty sure we never did a landing an ILS.

 

[Roger Roger]

I don’t know man, you were able to dig deeper into the old lore than I am. That sounds reasonable. The point being, shouldn’t an LPV damn damn near just as sensitive as on ILS close to DA but more consistently? Maybe? I really don’t know… I don’t think I’ve ever done an LPV. I have done a few RNAV/RNP approaches with some pretty tight tolerances and I can’t see them being easier or harder to fly at the end than an ILS

An LPV is going to be the same as an ILS for sensitivity, but since both scale angularly if you’re flying either one to a 500’ DA vs 200’ DA that last 300’ is going to be more challenging. Also, getting configured and stable while transitioning to the papi after a breakout at 200’ vs 500’ is a pretty different skill set.

 

[drunkenbeagle]

Also, getting configured and stable while transitioning to the papi after a breakout at 200’ vs 500’ is a pretty different skill set.

Per @Fly_Unity, shouldn't you still be on the GP after 500 breaking out anyway? Especially if the PAPI isn't coincident? In my plane, I'm doubt the antique Narco GS receiver was ever tested or certified to be usable below DH though.

 

[Fly_Unity]

Per @Fly_Unity, shouldn't you still be on the GP after 500 breaking out anyway? Especially if the PAPI isn't coincident? In my plane, I'm doubt the antique Narco GS receiver was ever tested or certified to be usable below DH though.

You would want to transition visually to the PAPI once visual. Common error though is once the foggles come off, chop the power and nearly hit the approach lights!

 

[Fly_Unity]

Actually there seems to be continuous debates which one to follow (GS or PAPI) when they do not conicide. Seems like the heavies prefer GS, and smaller planes prefer PAPIs. But regardless, I need to see a stabilized approach.

Maybe someone with better technical knowledge can explain which one to use!

 

[poser765]

An LPV is going to be the same as an ILS for sensitivity, but since both scale angularly if you’re flying either one to a 500’ DA vs 200’ DA that last 300’ is going to be more challenging. Also, getting configured and stable while transitioning to the papi after a breakout at 200’ vs 500’ is a pretty different skill set.

I thought LPVs had DAs much lower than 500. Again I could be totally wrong, I honestly have no idea.

Also it’s seems to me like a breakout at 500 HAT would be more challenging to fly to the ground than 200. 300 extra feet get unstable while mentally transitioning from approach mode to land the airplane mode.

 

[SteveC]

Actually there seems to be continuous debates which one to follow (GS or PAPI) when they do not conicide. Seems like the heavies prefer GS, and smaller planes prefer PAPIs. But regardless, I need to see a stabilized approach.

Maybe someone with better technical knowledge can explain which one to use!

Do you have any guidance on what constitutes a stabilized approach, or what your response is supposed to be? (Going back to my question if going below GS/GP/PAPI is a bust-able offense.)

 

[drunkenbeagle]

Maybe someone with better technical knowledge can explain which one to use!

Very honest here - I don't know the answer to this one, so looking forward to seeing what is authoritative. The PTS/ACS aren't very clear to me on this (that's probably me)

 

[Fly_Unity]

Do you have any guidance on what constitutes a stabilized approach, or what your response is supposed to be? (Going back to my question if going below GS/GP/PAPI is a bust-able offense.)

Here is my guidance:
Instrument ACS: "Maintain a stabilized visual flight path from the DA/DH to the runway aiming point where a normal landing landing may be accomplished within the touchdown zone".

91.129: Each pilot operating an airplane approaching to land on a runway served by a visual approach slope indicator must maintain an altitude at or above the glide path until a lower altitude is necessary for a safe landing.

AIM 1-1-14 (2)..(5): ".... The glidepath may not be suitable for navigation below the lowest authorized DH and any reference to glidepath indications below that height must be supplemented by visual references to the runway environment."
"make every effort to remain on the indicated glidepath. Caution - Avoid flying below the glidepath to assure obstacle/terrain clearance is maintained"

There is also language on what the FAA considers the TCH (threshold crossing height of usually around 50 feet) to be stabilized. I heard of FAA examiners say if you are below TCH, you are unstabilized on an instrument aoproach because if you are below TCH, you are not guaranteed to clear obstacles.


So to answer your question, there is no clear cut reg saying if you dip below glidepath that you are out of standards, we are taught in DPE school that dipping below glidepath "could" constitute an unstabilized approach and if you do on my checkride, the above will be mentioned on my debrief.

In DPE school during practice checkrides, we had FAA guys on the simulator intentionally dip below GS as soon as runway is in sight, and we would simulate fail them. But its a clear case of unstabilized. If its just a matter of adjusting your aiming point so that you have more unsable runway available, then I personally would not unsat anyone for that. But I can not speak for other examiners.

 

[Roger Roger]

The way those read to me is that in a case where both are not in agreement, the VASI/PAPI takes precedence once visual.

 

[Roger Roger]

You would want to transition visually to the PAPI once visual. Common error though is once the foggles come off, chop the power and nearly hit the approach lights!

I mean if you’re flying your approach at 100 knots clean in a 172 chopping the power at 200 is probably about what you need to get the rest of the flaps out and land in the TDZ

 

[Fly_Unity]

I mean if you’re flying your approach at 100 knots clean in a 172 chopping the power at 200 is probably about what you need to get the rest of the flaps out and land in the TDZ

Many flight schools now are teaching full flaps at the FAF in a 172 and fly at 65 knots all the way down.. drives me nuts, but I do not grade technique....

 

[Minuteman]

I’m coming from the perspective of a graybeard who has not flown in a long time, but I get confused every time y’all talk about a “glideslope”/GS.

It was drilled into my head that a glideslope is a term specific to an ILS, and any RNAV vertical guidance is a “glidepath”. Has the terminology changed?

 

[drunkenbeagle]

Many flight schools now are teaching full flaps at the FAF in a 172 and fly at 65 knots all the way down.. drives me nuts, but I do not grade technique....

You would never get cleared or stay on the localizer for long here. Last ILS flew, ATC was asking for better forward speed (we were already 135kts) more than once, or they would be vectoring us around. This was just inside the FAF.

In training aircraft, the practicalities of actually getting cleared for these procedures, which are busy, means not doing them configured to land most of the time. In the real world, it doesn't matter - any airport with an ILS around here most likely has a ~10,000' runway, and there is plenty of time to slow down over the runway. You also landing a pretty long ways down. The ACS doesn't reflect this reality at all (to me anyway).

 

[ahw01]

Many flight schools now are teaching full flaps at the FAF in a 172 and fly at 65 knots all the way down.. drives me nuts, but I do not grade technique....

My checkride was rental power until the FAF which the school definitely didn't train but was ok

 

[MidlifeFlyer]

Many flight schools now are teaching full flaps at the FAF in a 172 and fly at 65 knots all the way down.. drives me nuts, but I do not grade technique....

I was behind a Cherokee like that several years ago. First and only time ATC ever asked me to slow down in a 172 while in an instrument approach. Always wonder where they would actually be able to go IFR once they get the rating.

Heck, my CFII couldn’t get me to use any flaps until breaking out/minimums.

 

[Minuteman]

Always wonder where they would actually be able to go IFR once they get the rating.

45 degrees to the left or right.

For spacing.

 

[MikeD]

In the training world, I think we end up going missed 99% percent of the time on an ILS, so how to actually land doesn't actually happen very often. @DPApilot was kind enough to point this error out to me not too long ago. Which either I forgot or never knew. It definitely wasn't something my CFI-I ever said back in the day - I'm pretty sure we never did a landing an ILS.

That’s weird. We would usually alternate between a missed approach, then a touch and go on the next one, another missed, maybe a full stop/taxi back on another. Mainly so the pilots could practice the landing portion and maintaining a stable glidepath or a controlled adjustment post-DA.

Here is my guidance:
Instrument ACS: "Maintain a stabilized visual flight path from the DA/DH to the runway aiming point where a normal landing landing may be accomplished within the touchdown zone".

91.129: Each pilot operating an airplane approaching to land on a runway served by a visual approach slope indicator must maintain an altitude at or above the glide path until a lower altitude is necessary for a safe landing.

AIM 1-1-14 (2)..(5): ".... The glidepath may not be suitable for navigation below the lowest authorized DH and any reference to glidepath indications below that height must be supplemented by visual references to the runway environment."
"make every effort to remain on the indicated glidepath. Caution - Avoid flying below the glidepath to assure obstacle/terrain clearance is maintained"

There is also language on what the FAA considers the TCH (threshold crossing height of usually around 50 feet) to be stabilized. I heard of FAA examiners say if you are below TCH, you are unstabilized on an instrument aoproach because if you are below TCH, you are not guaranteed to clear obstacles.


So to answer your question, there is no clear cut reg saying if you dip below glidepath that you are out of standards, we are taught in DPE school that dipping below glidepath "could" constitute an unstabilized approach and if you do on my checkride, the above will be mentioned on my debrief.

In DPE school during practice checkrides, we had FAA guys on the simulator intentionally dip below GS as soon as runway is in sight, and we would simulate fail them. But its a clear case of unstabilized. If its just a matter of adjusting your aiming point so that you have more unsable runway available, then I personally would not unsat anyone for that. But I can not speak for other examiners.

You’ll see this in fighter jets as a norm. Usually at breakout to a visual landing, an aimpoint shift is visually made towards the overrun for touchdown to have more runway available, which dips you below the glidepath and places you on a red over red on the VASI or all red PAPI at very end game. It’s also used in order to be on the ground if doing a short field arrestment so as to not overfly the approach end arresting gear when following the GS..