Kritchlow
Final Approach
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Kritchlow
Which post are you referring to?
That's why I like quoting.
Timing an ILS Approach or Not?
- Thread starter FreqFlyrJr
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That's why I like quoting.
denverpilot
Tied Down
Who says you're getting any correct "deflections" at all, if you GS isn't working well enough to fly an ILS? You sure that LOC receiver is working properly, too?
I'm still going with, "If I'm flying an ILS and there's a reason to go missed, I'm going missed, and troubleshooting at a much higher and more reasonable altitude for such things. If the silly LOC is working and the GS isn't, I may have even better options on board than a LOC approach, or I might not, but I'm not making that decision to flip approaches to something I wasn't flying down low with an OBS head doing oddball things.
Doesn't really matter if it's needles or glass, either... one of the number one things heard in any glass setup is "WTF is that thing doing, now?" even when folks have trained pretty well on the buttonology.
If [insert whatever system or portion of system used for whatever approach you're flying] is not working right, a miss and deal with it aloft is still the best option. IMHO.
MAKG1
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I can find you a couple of exceptions.
Even so, the San Bernardino Mountains are not something you'll climb over in a spam can. You'll just crash a little higher up the slope.
And it seems to me you're advising to continue the descent to find the MAP....
I don't consider the "cleared for the ILS as opposed to the associated "or LOC" to be that big a deal, practically speaking. ATC doesn't really care unless you set off alarms when you dive below the glideslope and that's easily remedied by telling them you lost GS and are continuing LOC only. Which of course you have plenty of time to do since changing horses in mid-stream is so easy-peasy
The initial post:
The threshold lights is one of the ten "required markings/lights" in 91.175. By the way (l) only applies when you are using an EVFS. The normal instrument approach is covered by (c)(3). But either way, the threshold lights are as good as seeing the runway itself.
I don't consider the "cleared for the ILS as opposed to the associated "or LOC" to be that big a deal, practically speaking. ATC doesn't really care unless you set off alarms when you dive below the glideslope and that's easily remedied by telling them you lost GS and are continuing LOC only. Which of course you have plenty of time to do since changing horses in mid-stream is so easy-peasy
Frankly, I've never been convinced of the "change the ILS to LOC" idea. This has been hashed out before. Frankly, it only makes sense if this happens while you are above the LOC MDA. If I'm below that and the GS crumps, I'm going missed immediately. You're now in the land of the unknowns.
Absolutely. No argument from me. My comment was only addressed to the concern expressed that making the switch would cause problems with ATC because you were technically only cleared for the ILS.
MauleSkinner
Touchdown! Greaser!
Try reading the post I replied to for context.
Pretty much every checkride I ever took. That's why I prefer a sweep second hand on the clock....easier to fake the timing.
I just went to a digital clock and I agree 100%!
As far as the original question, I agree with everybody else here. I am wondering why two CFI's would have a disagreement on this. Also, like just about everyone else, I was taught to start the timer at the FAF, but if it is windy at all, pitching up and down to stay on the glideslope makes it pretty difficult to stay at the charted speed. I would prefer to stay on the ILS and go missed if the GS craps out. Far safer, I think.
Harold Rutila
Pre-takeoff checklist
Is this a trick question? Flyingron already said this, but I'll say it again: If you see the threshold lights, you can descend below the DA and execute a landing. See 14 CFR Part 91.175(c)(3).
If the other CFII is actually quoting 91.175(l), tell him he needs to get back to the academy.
How on earth does ATC know or care? EIther you're cleared the approach or not. If it's a field that has IFR radar separation they're looking at your horizontal position. If not, they're holding the next plane until you land or miss.
AWACSEng
Cleared for Takeoff
That's a tough way to find out the EVS boresight isn't calibrated properly and the EVS runway threshold is not where the actual runway threshold is. I guess you can try anything once, though.
Yup. We agree. That's what I said.
aterpster
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aterpster
Contrary to another post you are correct. If the title on the chart includes both procedures, you are cleared for either one. But, if the ILS and LOC are on separate charts (separate titles) such as the example given at KSNS, then clearance for one doesn't include the other. Having said that, I doubt most NCT controllers working KSNS would actually care if they cleared someone for the ILS and the pilot, instead, flew the LOC procedure. It's the same airspace.
If there is a case where a mandatory altitude applies on one, but not the other, then I could see an issue.
Yes, if they are both on the same chart, it's pretty much the same thing as being cleared for the RNAV GPS, which also has different minima and descent profiles depending on the equipment used.
MAKG1
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The KSNS ILS has an additional IAF and procedure turn that the LOC/DME doesn't have.
aterpster
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aterpster
Indeed they are separate procedures when on separate charts. But, arriving via the 22 mile NoPT DME arc, I doubt they would care whether you were going to fly the ILS or the LOC DME. If in doubt, though, clarify.
MAKG1
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It seems a bit odd, but I actually do like to use that PT for the ILS, as the DME arc alternative puts me close to terrain on both sides of the valley (and the IAF puts me a bit closer to the worst bird strike I can imagine than I would like -- see the VFR chart). It means that if I'm outbound or at any point on the PT, and the GS flags, the only way to "revert to LOC" is to ask for VTF.
I actually don't like VTF on either of those approaches, as I've had NorCal "forget" about me while headed toward the localizer, more than once. With the terrain around there, blowing through the LOC is not a good thing.
ARFlyer
En-Route
I don't consider the "cleared for the ILS as opposed to the associated "or LOC" to be that big a deal, practically speaking. ATC doesn't really care unless you set off alarms when you dive below the glideslope and that's easily remedied by telling them you lost GS and are continuing LOC only. Which of course you have plenty of time to do since changing horses in mid-stream is so easy-peasy
Yeah I wasn't clear on that. I also don't think it's smart to be doing a ILS to LOC past the MDA of the LOC.
GA I can see you might have time to switch. However, 121 I'm going missed. The procedure change from an ILS to a LOC is enough to get you in trouble very very quickly. I have to be set up in a very particular way according to our POH. Honestly I can't wait for contentious decent authorization!
aterpster
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aterpster
If the GS flags outbound to the procedure turn, how do you know it isn't because your GS antenna is pointed away from the GS transmitter? And, that it will resolve itself rolling out of the procedure turn inbound?
MAKG1
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Because when you turn and intercept the loc inbound and you have a GS indicator you know you are good to go. And if it's not there, go missed or ask for help.
I sometimes wonder how you ever get in the air.
I sometimes wonder how you ever get in the air.
MAKG1
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Sometimes I wonder how you get out of it.
IF I lose GS on that approach, it's really lost. I fly that approach from time to time, and GS never flags during the PT.
And if you learn to read, you'll see my solution. Comprehension is a really good idea. The point I make is that converting it to a LOC approach doesn't work. Get it?
Burn.
I guess some folks have a psychological need to proclaim everything they do to super dangerous. That way they can be a mini hero and simultaneously self affirm that they are better than everyone else because only they can do it safely.
I guess some folks have a psychological need to proclaim everything they do to super dangerous. That way they can be a mini hero and simultaneously self affirm that they are better than everyone else because only they can do it safely.
aterpster
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aterpster
It doesn't become a safety issue unless you try to switch gears to the LOC profile. I don't advocate that. If you know with certainty that it is a GS failure while outbound then request vectors to the LOC DME or, perhaps, divert to KMRY.
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Kayoh@190
I guess it depends on what you're used to getting from the equipment you're flying. The #1 LOC and GS on my model airplane is constantly unreliable until I'm inbound and within about five miles of the FAF. Most of the time it's not this way, but it happens enough that anything flagged outside about couple miles from the FAF doesn't concern me. The #2 is always significantly better, however.
GCA319
Cleared for Takeoff
I'm only smart enough to brief one approach at a time. Unless I were in an emergency situation and needed to get on the ground, I'm not going to switch to a LOC approach on a whim after briefing and setting up for the ILS. If I lost my GS, I'd go missed, advise ATC of what was going on and what my intentions were (i.e be re-vectored or get re-set up for the LOC only if need be). Now granted, if I'm outside the FAF when it happens and not too busy, I may quickly rebrief the LOC only and start the time at the FAF..it just depends on circumstances.
aterpster
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aterpster
This discussion of the ILS at KSNS, jogs my memory about the topography of the area. It was a long time ago, and I was doing an obstacle clearance analysis of the KMRY LOC 28L approach. At the time, I did a bit of a review of the SNS ILS because of the localizer's proximity to generally the same terrain. I don't have that much confidence in a localizer that far out, and that close to significant terrain. Although ILS ground transmitters have improved over the years, it is nonetheless very old technology that relies on the airport area to be a ground plane antenna of sorts. Not so with RNAV, and especially SBAS (WAAS) enhancement. This particular ILS and associated terrain early in the approach makes a strong case for LPV vs. the ILS.
Clip4
Touchdown! Greaser!
When i learned to fly inst in a plane without DME or RNAV, there was good reason to time a ILS approach. If you lost the GS, it was the only way to determine the MAP.
The MAP on the ILS is where the DA is encountered while the GS is centered. Absent the GS signal, there's no way to determine it PERIOD. Your timing only tells you where the "or LOC" MAP is (which is only useful if you are not below the MDA).
dtuuri
Final Approach
I agree with Clip4. If you lose your GS, you go to plan B, which doesn't include being below the MDA any longer than it takes to get back up to it (assuming LOC minima are on the plate).
dtuuri
dtuuri
Nope, if I'm below the MDA, I am 100% going missed, not just climbing back up the MDA. I'm not sure I'm even going to continue the approach if the GS crumps above the MDA.
dtuuri
Final Approach
I didn't say differently, just that "plan B" is to reference the stop watch to find the MAP. Clip4 didn't have RNAV or DME. Turning too early could be trouble, so that's why the backup timing. I'm not opposed to making a LOC approach out of it either, though I wouldn't argue against somebody who doesn't feel capable. Milling around in the soup has its own set of possible risks: icing, thunderstorms, fuel starvation, worsening fog, etc.
dtuuri
dtuuri
Sluggo63
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Meh. We have EVS on all our aircraft except the Airbuses. It's a neat toy, but practically, I have found that they are of minimal use when you really want it working... in thick, wet cloud. In wet clouds, the EVS blanks out due to the lack of temperature differential that's sensed. All you get is a washed out screen. But, I will say, the EVS shines in dry particulate. Flying an approach into somewhere with industrial haze/smog (LA, Mumbai, Guangzhou) you can cut through all that mess and see the runway beautifully. Maybe we just have a first generation system, but there's no way I would trust our EVS to land with without outside reference.
Sluggo63
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SWA and JB hand fly their Cat III approaches using a HUD to touchdown. No EVS. Just HUD.
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jsstevens
Wow. That's dramatic.
denverpilot
Tied Down
Damn that's cool.
Sluggo63
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Yeah. It's a neat toy, but like I said above, I wouldn't trust it to do a CAT III using it as "natural vision."
Some interesting things in the EVS photo. Obviously, you're seeing heat, not light, so it's weird to the the heat from the engines reflected in the pavement. That's how warm it gets the ground as they sit there. Also, how hot the main tires get. Those glow pretty good even after a little bit of taxi time. On the horizontal stab, you can see where the exhaust is heating the portion behind the engines. Can't really see it here, but from the side, you'd see the AC packs glowing also. Lastly, if you look at the taxiway centerline lights, just ahead and to the left of each light is the IR signature of the light. That's due to the position of the camera in relation to the eye position. Things don't quite line up correctly, especially up close. You can also see the taxiway stripe, since the paint absorbs heat at a different rate than the pavement around it.