ILS vs LPV

[gsxrpilot]

1 minute ago, flyboy0681 said:

So what I'm hearing is that flagrantly busting the minimums is an unenforceable action since the pilot could always claim that he had all of the required elements in sight.

If there's an accident there might be some repercussions based on "reported" conditions. But if the pilot lands safely, no, there's no violation if the Part 91 pilot says there was no violation.

This is the case with lots of things in aviation. 

[Jerry 5TJ]

15 minutes ago, flyboy0681 said:

So why have a DA at all for Part 91?

Perhaps you might say there’s no strictly applied requirement for non-commercial Part 91 operations to abide by the DA and RVR limits.  

But the limits must be established.  

The DA / RVR figures are driven in the design of the approach by many variables.  For the airport: local obstacles, runway width and length, slope, and terrain gradient are considered.   For the aircraft: approach speed, control response, autopilot and auto throttle capability, enhanced vision are factors.  For the navigation sources: reliability, availability, accuracy and integrity are critical.  For the flight crew training, currency and workloads all apply.  

 

[flyboy0681]

2 minutes ago, gsxrpilot said:

If there's an accident there might be some repercussions based on "reported" conditions. But if the pilot lands safely, no, there's no violation if the Part 91 pilot says there was no violation.

This is the case with lots of things in aviation. 

Most interesting. During our training the text says "must" when reaching the DA or DH and the environment is not in sight, but I guess if there isn't an FAA rep sitting beside you, anything goes.

[midlifeflyer]

 

3 minutes ago, flyboy0681 said:

So what I'm hearing is that flagrantly busting the minimums is an unenforceable action since the pilot could always claim that he had all of the required elements in sight.

Pilots have been busted for this type of violation - although it sounds like you are assuming there was a violation. . But here's an enforcement reality here. Just a YouTube video with questionable accuracy and a pilot who insists he did follow the rules is not enough.

It would take witnesses on the ground, not some guys in the tower with no view  of landing conditions. Maybe expert witnesses to prove that the RVR equipment was working perfectly, that with 1,000 RVR reported on that day at that airport, the visibility could not be more than 1/4 SM. Maybe even some guy who happened to be at the approach end waiting for takeoff to say what he or she saw for visibility. 

Not exactly a big budget item for the FAA without an exceptionally good reason.

 

[flyboy0681]

1 minute ago, midlifeflyer said:

 

Pilots have been busted for this type of violation - although it sounds like you are assuming there was a violation. . But here's an enforcement reality here. Just a YouTube video with questionable accuracy and a pilot who insists he did follow the rules is not enough.

It would take witnesses on the ground, not some guys in the tower with no view  of landing conditions. Maybe expert witnesses to prove that the RVR equipment was working perfectly, that with 1,000 RVR reported on that day at that airport, the visibility could not be more than 1/4 SM. Maybe even some guy who happened to be at the approach end waiting for takeoff to say what he or she saw for visibility. 

Not exactly a big budget item for the FAA without an exceptionally good reason.

 

Sounds like the whole thing is a judgement call.

[Jerry 5TJ]

1 minute ago, flyboy0681 said:

Sounds like the whole thing is a judgement call.

It’s a statistical call. 

Abide by the rules / guidelines exactly for a high probability of success.   

Cut away DA / RVR protection margins and you lower the probability of success.   

[midlifeflyer]

Just now, flyboy0681 said:

Most interesting. During our training the text says "must" when reaching the DA or DH and the environment is not in sight, but I guess if there isn't an FAA rep sitting beside you, anything goes.

The text says when reaching DA the pilot must have one of the elements of the environment in sight. Jerry says he saw the approach lights at that point.

The text says if the only thing you have is the approach lights, you may go 100' below DA, so long as you have the 1/2 mile visibility. Jerry insists he did.

The text says if you have at least the red terminating bars or red side bars in sight when you get to 100' below DA, and that 1/2 mile visibility, you may land. That's what Jerry said he did. 

[gsxrpilot]

1 minute ago, flyboy0681 said:

Most interesting. During our training the text says "must" when reaching the DA or DH and the environment is not in sight, but I guess if there isn't an FAA rep sitting beside you, anything goes.

Again, you're assuming the pilot violated the regs here. If he says he had the environment in sight upon reaching the DA or DH, then he did, as far as any of us can say. He was the only one there to say. 

I landed an ILS approach into KOKC on a day when a lot of the commercial operators were holding. They are bound by the reported RVR, I wasn't. I just had to see the environment at the DA. The tower volunteered that they had the lights turned up all the way to help me. I had the environment in sight at the DH and landed easily. Of course no one else was in the cockpit with me to verify. But even so, the regs don't say both pilots have to have the environment in sight.

[midlifeflyer]

5 minutes ago, flyboy0681 said:

Sounds like the whole thing is a judgement call.

That it is.

[gsxrpilot]

Just now, midlifeflyer said:

The text says when reaching DA the pilot must have one of the elements of the environment in sight. Jerry says he saw the approach lights at that point.

The text says if the only thing you have is the approach lights, you may go 100' below DA, so long as you have the 1/2 mile visibility. Jerry insists he did.

The text says if you have at least the red terminating bars or red side bars in sight when you get to 100' below DA, and that 1/2 mile visibility, you may land. That's what Jerry said he did. 

Exactly, so no violation as all the regs were followed.

[midlifeflyer]

Sigh. I can't believe I'm defending Jerry

[gsxrpilot]

1 minute ago, midlifeflyer said:

Sigh. I can't believe I'm defending Jerry

Hahahah... Yeah I wouldn't ride with him either... but there's no grounds for a violation.

[midlifeflyer]

4 minutes ago, gsxrpilot said:

Exactly, so no violation as all the regs were followed.

...at least he says they were followed and there's apparently no incentive to prove he didn't.

[flyboy0681]

5 minutes ago, midlifeflyer said:

The text says when reaching DA the pilot must have one of the elements of the environment in sight. Jerry says he saw the approach lights at that point.

The text says if the only thing you have is the approach lights, you may go 100' below DA, so long as you have the 1/2 mile visibility. Jerry insists he did.

The text says if you have at least the red terminating bars or red side bars in sight when you get to 100' below DA, and that 1/2 mile visibility, you may land. That's what Jerry said he did. 

Our assumption on this whole argument was that he did not see anything at DA and that he proceeded in hopes of eventually seeing something. I guess if you go low enough you will eventually see something.

[kpaul]

12 hours ago, carusoam said:

NVG... night vision goggles...

-a-

Yes.  Headache producing tubes of pain and agony. Here is a picture (not mine) on the flight deck of a C-130.  Somewhere, I have pictures taken through the NVGs while flying Herks all over IRAQ.

[Marauder]

Sigh. I can't believe I'm defending Jerry

 

I can’t believe you are too!

 

On his LPV approach to Auburn, he does a cut away shot using the front camera. That camera view indicated to me that it was able to “see” pretty well on that approach and although viewing angles comes into play, suggests the RVR on the Oakland ILS approach was pretty close to what was reported. Even his taxi on the runway confirms the low visibility. His removal of the video may be related to the “hey dummy” comments he received but in previous videos where he clearly busted the terrain clearance requirements, those videos came down pretty quick as well.

 

I do find it funny that he points out the “almighty checklist” on every flight. I remember someone pointing out his clock showing no time had elapsed from when he supposedly started the checklist and since then he points out the checklist usage.

 

I wouldn’t ride with him.

 

 

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[Marauder]

 
Pilots have been busted for this type of violation - although it sounds like you are assuming there was a violation. . But here's an enforcement reality here. Just a YouTube video with questionable accuracy and a pilot who insists he did follow the rules is not enough.
It would take witnesses on the ground, not some guys in the tower with no view  of landing conditions. Maybe expert witnesses to prove that the RVR equipment was working perfectly, that with 1,000 RVR reported on that day at that airport, the visibility could not be more than 1/4 SM. Maybe even some guy who happened to be at the approach end waiting for takeoff to say what he or she saw for visibility. 
Not exactly a big budget item for the FAA without an exceptionally good reason.
 

Where I have heard pilots getting violated on an approach is canceling IFR when they can’t meet the VFR cloud clearance requirements.


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[midlifeflyer]

3 hours ago, Marauder said:

 

Where I have heard pilots getting violated on an approach is canceling IFR when they can’t meet the VFR cloud clearance requirements.


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Here's one. Eerie similarity to Jerry. Makes interesting reading since the NTSB decided there was no proof of a visibility violation but found the pilot (who caused a problem) careless and reckless. Kind of make one understand why the FAA would hesitant unless there's something more. FAA v Pisarek.

There are others. In one (not in the public database) there was a violation found. Among other things, the evidence was the plot landed 2800 feet short. The ALJ used it as circumstantial evidence supporting a finding that the pilot did not have the required visibility.

Edited December 25, 2018 by midlifeflyer

[midlifeflyer]

Jerry put the video back up. With some edits telling us what he saw along the way. The relevant portion begins about 28 minutes in. (Of course, "approach lights in sight" doesn't necessarily mean there is no violation. 

https://youtu.be/kCER9yUXIZE 

Edited December 25, 2018 by midlifeflyer

[Jerry 5TJ]

ILS GUIDANCE BELOW DH 

Some of this thread’s discussion is about guidance accuracy below the decision height.  A recent 777 runway excursion due to ILS signal obstruction illustrates the problem.  

Munich ILS Signal Blockage

The approach loaded by the crew was a Cat III ILS and they flew it as a fully automatic landing.  So this particular ILS ground equipment was surveyed to the tight Cat III standards.  

However, the weather was good enough for standard ILS (Category I) and this the controllers were not maintaining Cat III separation.  The 777 crew did not tell the controller of their choice to use a Cat IIII and auto land.  Another aircraft on the ground or just departing affected the ILS localizer signals momentarily when the 777 was about 50’ AGL.  

[Bob - S50]

6 hours ago, Jerry 5TJ said:

ILS GUIDANCE BELOW DH 

Some of this thread’s discussion is about guidance accuracy below the decision height.  A recent 777 runway excursion due to ILS signal obstruction illustrates the problem.  

Munich ILS Signal Blockage

The approach loaded by the crew was a Cat III ILS and they flew it as a fully automatic landing.  So this particular ILS ground equipment was surveyed to the tight Cat III standards.  

However, the weather was good enough for standard ILS (Category I) and this the controllers were not maintaining Cat III separation.  The 777 crew did not tell the controller of their choice to use a Cat IIII and auto land.  Another aircraft on the ground or just departing affected the ILS localizer signals momentarily when the 777 was about 50’ AGL.  

And there are fewer points of failure for the LPV. 

LPV: multiple GPS satellites (or jamming), or GPS receiver

ILS: LOC transmitter, GS transmitter, LOC receiver, GS receiver

Lose any single point of failure for either system and you lose the approach as planned.

[bradp]

Here’s a good question. 

My very first wet ticket ILS approach was into CHO one night when a fog bank rolled over the field.    

Had flight visibility all the way down the runway above the fog bank (could see the red bars / Reils through he fog).  Available reported weather didn’t have the fog conditions yet. Last maybe 10 feet of the flare went into the soup and flight visibility went down to maybe 1/4-1/8 of a mile if that.  I recall being able to see a few sets of lights in my peripheral vision (200x?).  Was a bit surprised in my discovery of unexpected below minimums. In the round out and flare I thought the safer thing to do was land, which I did.  

Tower asked me the visibility and I sheepishly said something stupid like it’s right at minimums for the last 10 feet not wanting to get in trouble.  Tower called my bluff and the grumpy dude chuckles and says yeah right goodnight and something like good luck with your taxi...

 Did I pull a “technical jerry” on that one ...? 

[Marauder]

Here’s a good question. 
My very first wet ticket ILS approach was into CHO one night when a fog bank rolled over the field.    
Had flight visibility all the way down the runway above the fog bank (could see the red bars / Reils through he fog).  Available reported weather didn’t have the fog conditions yet. Last maybe 10 feet of the flare went into the soup and flight visibility went down to maybe 1/4-1/8 of a mile if that.  I recall being able to see a few sets of lights in my peripheral vision (200x?).  Was a bit surprised in my discovery of unexpected below minimums. In the round out and flare I thought the safer thing to do was land, which I did.  
Tower asked me the visibility and I sheepishly said something stupid like it’s right at minimums for the last 10 feet not wanting to get in trouble.  Tower called my bluff and the grumpy dude chuckles and says yeah right goodnight and something like good luck with your taxi...
 Did I pull a “technical jerry” on that one ...? 

I think you’d need to work at it a bit to be a Jerry. Flight conditions during the identification of the landing runway are the key to completing the approach legally. I would have just told them that the visibility was deteriorating after you identified the runway.


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[jaylw314]

11 hours ago, Bob - S50 said:

And there are fewer points of failure for the LPV. 

LPV: multiple GPS satellites (or jamming), or GPS receiver

ILS: LOC transmitter, GS transmitter, LOC receiver, GS receiver

Lose any single point of failure for either system and you lose the approach as planned.

Both systems can degrade--ILS to a LOC only if you lose GS, LPV to LNAV only if you lose precision.

LPV has a slight advantage there in that if some LOC approaches do not have timed MAP and depend on a second input, such as DME or a second VOR.  If you don't happen to have the hardware to do the LOC approach, you're out of luck, whereas if you go from LPV to LNAV, you won't lose the waypoints.  Granted, that's realistically not much of a difference

[jaylw314]

3 hours ago, bradp said:

Here’s a good question. 

My very first wet ticket ILS approach was into CHO one night when a fog bank rolled over the field.    

Had flight visibility all the way down the runway above the fog bank (could see the red bars / Reils through he fog).  Available reported weather didn’t have the fog conditions yet. Last maybe 10 feet of the flare went into the soup and flight visibility went down to maybe 1/4-1/8 of a mile if that.  I recall being able to see a few sets of lights in my peripheral vision (200x?).  Was a bit surprised in my discovery of unexpected below minimums. In the round out and flare I thought the safer thing to do was land, which I did.  

Tower asked me the visibility and I sheepishly said something stupid like it’s right at minimums for the last 10 feet not wanting to get in trouble.  Tower called my bluff and the grumpy dude chuckles and says yeah right goodnight and something like good luck with your taxi...

 Did I pull a “technical jerry” on that one ...? 

Well technically, yes, anytime you lose the flight visibility requirement below DA on an ILS, I think you're supposed to immediately do the missed approach.  The problem is, the AIM points out that the published missed approach only guarantees terrain clearance if executed from above DA or MDA, then it gets kind of vague on what you're supposed to do.

So if they wanted to give you a hard time, they probably could have since you couldn't really make the argument it was unsafe to execute the published missed from that altitude, since there was clear air above the fog.  If there were any obstacles or terrain near the airport (especially at night), it still would have been worth trying to make that argument, though.