ILS or LPV?

bcool

bcool

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Bud
Given the choice and equipment availability, which do you fly?

In my (limited) experience the default at airports seems to be the ILS. If you want to fly the RNAV approach, do you ask for it immediately when contacting approach, or do you wait until they tell you to expect the ILS?
 
Either, depends on my mood. If it's not on ATIS, I ask for what I want. If it's on the ATIS, I just use that. Flying to Teterboro on my IR cross country in IMC ATIS said ILS, I got to the final controller and asked for the RNAV, was told it was not available, made for an anxious few minutes resetting everything and rebriefing.
 
bcool said:
Given the choice and equipment availability, which do you fly?

In my (limited) experience the default at airports seems to be the ILS. If you want to fly the RNAV approach, do you ask for it immediately when contacting approach, or do you wait until they tell you to expect the ILS?
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Given the choice, I would prefer the LPV. You don't have to worry about the signal going haywire if a fuel truck drives in front of the glideslope antenna.

PaulS said:
Either, depends on my mood. If it's not on ATIS, I ask for what I want. If it's on the ATIS, I just use that. Flying to Teterboro on my IR cross country in IMC ATIS said ILS, I got to the final controller and asked for the RNAV, was told it was not available, made for an anxious few minutes resetting everything and rebriefing.
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Don't ever expect to get anything besides what is on the ATIS if you are going to TEB. Just the way it is.
 
I'm curious...why would they deny the RNAV? Due to traffic routing?
 
Assuming equivalent minimums, LPV. Once loaded I just find it simpler. No need to switch CDIs from GPS to LPV when intercepting, and then back again for the missed.

For a nontowered destination just ask for it when Approach asks you which approach you want. For a towered airport where the default is the ILS (most which have one), ask for it when Approach first informs you to "expect the ILS." If ATC doesn't say that but the ILS is advertised on ATIS, I'd make the request as part of my confirmation that I "have Golf."
 
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To my knowledge the FAA doesn't publish performance information on the signal stability of any particular Category I ILS. But, they indeed vary. Some are as good as a Category II ILS. Others have stability issues that make coupled approaches unacceptable. Some have the glideslope go haywire below DA. LPV doesn't have any of these issues. In the early days of LPV design criteria limited them more than Category I ILS. But, that is no longer the case. As the S-L-O-W revision process reaches an airport where the LPV DA is higher than the ILS DA, they will be harmonized.

I'd take LPV over ILS anytime. Like Mark says, just to avoid the switching from a 21st Century system to a 20th Century system.
 
bcool said:
Given the choice and equipment availability, which do you fly?

In my (limited) experience the default at airports seems to be the ILS. If you want to fly the RNAV approach, do you ask for it immediately when contacting approach, or do you wait until they tell you to expect the ILS?
Click to expand...

Make the request on initial check in. Yo, approach, it's me at 5000 with Bravo, request whatever approach. Yo, dude expect that. Two transmissions. As opposed to Yo, approach, it's me at 5000 with Bravo. Yo, dude, expect the ILS Approach. Yo, approach, iwanna do the RNAV. Yo, dude, expect that. Four transmisionns
 
Really doesn’t matter to me. I just fly what’s advertised on the ATIS.
 
midlifeflyer said:
I'm wondering whether any one has ever been given the published missed at LGA (or most Class C and B airports), except in training. :D
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It's not the published miss at LGA, is is the published miss off of TEB. Chances are you won't do that, but they still have to protect the airspace in the event of lost comms.
 
MauleSkinner said:
Not nearly as real as the number of pilots who can’t fly ANY approach without the help of automation.
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Not really sure how that happens, I did my IR check ride just over a year ago in a Cirrus with Perspective (g1000) and a GFC 700 autopilot. I had to fly the most of the ride under the hood by hand. The last approach, non precision, was flown coupled because if the airplane has it you have to prove you know how to use it for the check ride.
 
Groundpounder said:
It's not the published miss at LGA, is is the published miss off of TEB. Chances are you won't do that, but they still have to protect the airspace in the event of lost comms.
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That raises an interesting question. How much of that do they actively protect and for what period of time? I know that alternate missed instructions tend to be because of airspace use.

The NYC area with its multiple major airports use a very small amount of space would be a good example. Assuming everyone is giving alternate missed instructions is it necessary to keep traffic out of the published missed for each airport before there is a lost comm situation?
 
PaulS said:
Not really sure how that happens,
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Pilots who are maintaining currency by flying 6 coupled approaches, sometimes the exact approach into their home base they have memorized anyway. Legally current but a lot of skills, not just hand-flying, degrade
 
PaulS said:
Not really sure how that happens, I did my IR check ride just over a year ago in a Cirrus with Perspective (g1000) and a GFC 700 autopilot. I had to fly the most of the ride under the hood by hand. The last approach, non precision, was flown coupled because if the airplane has it you have to prove you know how to use it for the check ride.
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It happens because pilots do all of their day to day flying using the automation, and the skills to do them without automation atrophy.
 
PaulS said:
Not really sure how that happens, I did my IR check ride just over a year ago in a Cirrus with Perspective (g1000) and a GFC 700 autopilot. I had to fly the most of the ride under the hood by hand. The last approach, non precision, was flown coupled because if the airplane has it you have to prove you know how to use it for the check ride.
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Delta has a much more conservative policy than Endeavor. We have to use the autopilot and FD for every ILS if weather is below 4000 RVR or 3/4. The autopilot is also required for every non precision approach in IMC. At Endeavor the only time we had to use the AP for an approach was for a CATII approach. I can see getting complacent with these restrictions.
 
jordane93 said:
Delta has a much more conservative policy than Endeavor. We have to use the autopilot and FD for every ILS if weather is below 4000 RVR or 3/4. The autopilot is also required for every non precision approach in IMC. At Endeavor the only time we had to use the AP for an approach was for a CATII approach. I can see getting complacent with these restrictions.
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Yes, I had a corporate pilot instructor who told me that they are required to use the autopilot flying including approaches, he said that they figure the autopilot is better at flying the airplane than the pilot, he was half kidding. I asked him how he stays proficient, he said they spend a lot of time in the simulator during checkouts.
 
midlifeflyer said:
That raises an interesting question. How much of that do they actively protect and for what period of time? I know that alternate missed instructions tend to be because of airspace use.

The NYC area with its multiple major airports use a very small amount of space would be a good example. Assuming everyone is giving alternate missed instructions is it necessary to keep traffic out of the published missed for each airport before there is a lost comm situation?
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They just use approaches that won't go into protected airspace, i.e. the ILS 6 into TEB vs the RNAV.

There is also a configuration where TEB cannot depart any aircraft if LGA is doing the ILS to 13. They try to avoid that whenever possible, but sometimes they don't have a choice.
 
The LPV is a bit simpler in terms of managing the GPS/NAV/COM boxes and a legacy autopilot, but at busy airports it seems like the ILS is what gets assigned. You can always ask for the LPV approach if the minimums are adequate.
 
MauleSkinner said:
It happens because pilots do all of their day to day flying using the automation, and the skills to do them without automation atrophy.
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My instrument instructor used to joke that the kid who just just passed his IFR ticket in a clapped out 172 with no autopilot is better at ACTUALLY flying approaches than the airlines jockeys. Truth to that. I learned on a 172 with DME/VORs, and after years of being out of currency and then getting current in a sweet plane equipped with a GTN750 and autopilot(even a crap KAP140), i was SHOCKED about how easy it is. No more calculating teardrop hold entries, just follow the magenta line. I still haven’t flown with an AP that can fly an approach, but at least the KAP140 can offer enroute automation, when it’s working.
 
midlifeflyer said:
Assuming equivalent minimums, LPV. Once loaded I just find it simpler. No need to switch CDIs from GPS to LPV when intercepting, and then back again for the missed.
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There's also the need to capture the ILS glideslope from underneath (not that it's a big deal but it is something you have to remember to do).
 
Geosync said:
My instrument instructor used to joke that the kid who just just passed his IFR ticket in a clapped out 172 with no autopilot is better at ACTUALLY flying approaches than the airlines jockeys. Truth to that. I learned on a 172 with DME/VORs, and after years of being out of currency and then getting current in a sweet plane equipped with a GTN750 and autopilot(even a crap KAP140), i was SHOCKED about how easy it is. No more calculating teardrop hold entries, just follow the magenta line. I still haven’t flown with an AP that can fly an approach, but at least the KAP140 can offer enroute automation, when it’s working.
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You had DME?? DME is just a crutch.:D
 
asicer said:
There's also the need to capture the ILS glideslope from underneath (not that it's a big deal but it is something you have to remember to do).
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Please go on... Where is this "need" in writing?
 
asicer said:
There's also the need to capture the ILS glideslope from underneath (not that it's a big deal but it is something you have to remember to do).
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You shouldn't have to remember to. While false glidesllope exists, on a normal approach it should not be a factor.
 
i don't do ILS unless it is the only option. So far since 2008, I have not had a need to do an actual ILS. I often need to request the RNAV. Usually the RNAV is the same FAC path and in most cases the same LPV minimum. At the major airports, you are going to be vectored to final anyway. I do teach and practice ILS, but they are much more work and easier to screw up. With LPV, no need to tune and identify the localizer, switch the CDI to VLOC and the guidance is smoother.
 
KSCessnaDriver said:
Please go on... Where is this "need" in writing?
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Instrument Flying Handbook chapter 9 and AIM 1-1-9. However, as Mark notes below, it is implicit in the procedure so I was not entirely correct in that you need to remember it.

midlifeflyer said:
While false glidesllope exists, on a normal approach it should not be a factor.
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Would you see the false glideslope if you are outbound on the localizer prior to a procedure turn? My instrument flying has mostly been on GPS/NAVCOMs so I switch to VLOC when turning inbound and have only very recently started flying a plane with a dedicated backup NAV/GS/CDI.
 
asicer said:
Instrument Flying Handbook chapter 9 and AIM 1-1-9. However, as Mark notes below, it is implicit in the procedure so I was not entirely correct in that you need to remember it.
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I don’t see a need to do it there, nor do I see anything that notes it is “implicit in the procedure”.
 
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asicer said:
Would you see the false glideslope if you are outbound on the localizer prior to a procedure turn? My instrument flying has mostly been on GPS/NAVCOMs so I switch to VLOC when turning inbound and have only very recently started flying a plane with a dedicated backup NAV/GS/CDI.
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Even if I did, I wouldn't care. As the AIM says about the back course, disregard. It doesn't matter. You are flying an altitude at that point, not a vertical path..

But here's the thing. My answer about not worrying was being practical. Someone taught me this the past year or two (I think it was here). The false glideslope exists at multiples of the true glideslope. So on your typical 3° glideslope, we are talking at 6, 9, 12 degrees. IOW, double, triple and quadruple the (AGL) altitude difference . Even without heavy math (not my forte, so I will probably screw this up), let's take one at random. Say the ILS at TOP (Topeka, KS). Glideslope intercept is 2,300 msl or about 1400' above the TDZE. So your first false glideslope indication right over the intercept will be at 1,400 feet above crossing altitude, 3700 msl o that approach. I can't imagine being even 1,000' high crossing the PFAF, but if you back it up further away, the altitude differential increases.
 
midlifeflyer said:
Even if I did, I wouldn't care. As the AIM says about the back course, disregard. It doesn't matter. You are flying an altitude at that point, not a vertical path..

But here's the thing. My answer about not worrying was being practical. Someone taught me this the past year or two (I think it was here). The false glideslope exists at multiples of the true glideslope. So on your typical 3° glideslope, we are talking at 6, 9, 12 degrees. IOW, double, triple and quadruple the (AGL) altitude difference . Even without heavy math (not my forte, so I will probably screw this up), let's take one at random. Say the ILS at TOP (Topeka, KS). Glideslope intercept is 2,300 msl or about 1400' above the TDZE. So your first false glideslope indication right over the intercept will be at 1,400 feet above crossing altitude, 3700 msl o that approach. I can't imagine being even 1,000' high crossing the PFAF, but if you back it up further away, the altitude differential increases.
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I would also hope that most pilots would figure out something was wrong when they needed 1000 or 1500 fpm descent to maintain the glide slope instead of their normal 500 or 800.
 
midlifeflyer said:
Even if I did, I wouldn't care. As the AIM says about the back course, disregard. It doesn't matter. You are flying an altitude at that point, not a vertical path..

But here's the thing. My answer about not worrying was being practical. Someone taught me this the past year or two (I think it was here). The false glideslope exists at multiples of the true glideslope. So on your typical 3° glideslope, we are talking at 6, 9, 12 degrees. IOW, double, triple and quadruple the (AGL) altitude difference . Even without heavy math (not my forte, so I will probably screw this up), let's take one at random. Say the ILS at TOP (Topeka, KS). Glideslope intercept is 2,300 msl or about 1400' above the TDZE. So your first false glideslope indication right over the intercept will be at 1,400 feet above crossing altitude, 3700 msl o that approach. I can't imagine being even 1,000' high crossing the PFAF, but if you back it up further away, the altitude differential increases.
Click to expand...

In addition, every other false glideslope is "reversed". So the first false glideslope at 6 degrees, is "backwards" - meaning if you're below it, you will get a "fly down" indication and vice versa. The 9 degree false glideslope is normal. The 12 degree glideslope is back to normal. But, these are getting really really high above the published altitude - and the signal is progressively weaker. So if you're seeing these, you've already clearly messed up the approach and should go missed. I've seen some of these, but only when intentionally not flying the approach - like tracking the localizer for practice in level flight.
 
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