WestJet almost puts one in the drink

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C.W.E.
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Re: WestJet almost puts one in the drink

#151 Post by C.W.E. » Wed Jun 06, 2018 8:13 pm

Height judgement over water in reduced visibility is a bit tricky in my experience, but that's just me.
It is not just you, it can be very tricky.
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Re: WestJet almost puts one in the drink

#152 Post by Dry Guy » Wed Jun 06, 2018 8:34 pm

confusedalot wrote:
Wed Jun 06, 2018 7:48 pm
Too lazy to read the whole thread but I get the gist.

I confirm to anybody out there that the FMC, if properly set up, will get you to the threshold of the runway at the proper altitude and the proper position. It's been doing that since 1988 from my first experiences with the equipment and well before that, even before gps became popular. IRS, DME/DME, VOR/VOR, VOR/DME, and all of those sort of rnav combinations get you to your target.

Most pilots keep an eye on their magic even if they are visual. Yet, we as humans, do in fact get distracted. They fell into the trap, and that is not a condemnation or judgement. Shit happens as they say. Those two will never fall into that trap again.

Height judgement over water in reduced visibility is a bit tricky in my experience, but that's just me.
From what I've read above it sounds like Westjet's policy is to turn off the flight directors if continuing past the MAP. I'm not sure if that is only for this approach or for all approaches. The MAP for this approach was at 2 miles before the runway so they would just have raw data to go on from then which is easier to ignore than a flight director showing you way below your previous glidepath.
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Re: WestJet almost puts one in the drink

#153 Post by pelmet » Wed Jun 06, 2018 9:51 pm

Dry Guy wrote:
Wed Jun 06, 2018 7:20 pm
The poster a few above you said the FMC would not take you to the airport. I guess there is no waypoint there? So following your FD's to continue the approach apparently would not work.
If you re-read my post, you will see that I was very, very, very careful with my words. I made contingencies for various aircraft and technological set-ups as to what would be the best thing to do to remain on a proper path to the runway in conditions conducive to a visual segment becoming destabilized.

"Depending on how the FMC is configured, on some Boeings, the path of some non-precision approaches in the FMC will take you to 50 feet above the runway in a proper position to land with command bars. If familiar with the FMC waypoints, you can tell this by looking at the waypoints in the FMC. Then you can just follow command bars while having your marginal but legal required visual references which in reality, provide little depth perception and quite possibly, misleading cues."

"If for some reason, you won't be using the flight director cues from the FMC generated path, you might consider using the VS function to give you similar flight director guidance or the more accurate Flight Path Angle if it is installed. A simple push of the appropriate button at the desired, stable descent rate give a continuation of what you already have. But even without this stuff, you can do just like in the good old days......if you know you are on the proper descent angle, just maintain the same rate of descent which can be maintain by maintaining the same pitch once the autopilot has been disconnected."

It is correct that in some cases, the FD's will not take you to the desired location. It is important to be aware of this. Many years ago, a Air France ran a 747 off the runway in Tahiti following an unstabilized approach after trying to follow command bars on an early software FMC which levelled the aircraft instead of continuing the descent.

https://www.google.com/search?q=air+fra ... SUBRvre6lM:
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Re: WestJet almost puts one in the drink

#154 Post by DropTanks » Thu Jun 07, 2018 4:45 am

CL-Skadoo! wrote:
Thu Apr 27, 2017 4:05 am
pdw wrote:
'97 Tercel wrote: Thrust vector?
I guess it could
Low level funnel gunnel?
Now THAT was a great movie reference! One of my favorites.
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Re: WestJet almost puts one in the drink

#155 Post by CCR » Thu Jun 07, 2018 6:30 am

If the FD is not turned off, it commands the missed approach turn and climb.
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Re: WestJet almost puts one in the drink

#156 Post by J31 » Thu Jun 07, 2018 3:24 pm

CCR wrote:
Thu Jun 07, 2018 6:30 am
If the FD is not turned off, it commands the missed approach turn and climb.
FINALLY someone who understands the ST Maarten RNAV Rwy 10 approach and what the Boeing 737 Classic/NG/Max flight director does at MAPON. MAPON is the missed approach point 2 miles from the runway.

That is why it is a visual maneuver with no lateral or vertical electronic guidance the last 2 miles to the runway.
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Re: WestJet almost puts one in the drink

#157 Post by Donald » Thu Jun 07, 2018 5:57 pm

You guys are missing the point.

The PM did not call out the sink rate deviation. (Although the CVR is missing, so who really knows).

This is a failure of situational awareness, and failure of the PM. Just like SFO.
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Re: WestJet almost puts one in the drink

#158 Post by pelmet » Thu Jun 07, 2018 10:13 pm

J31 wrote:
Thu Jun 07, 2018 3:24 pm
CCR wrote:
Thu Jun 07, 2018 6:30 am
If the FD is not turned off, it commands the missed approach turn and climb.
FINALLY someone who understands the ST Maarten RNAV Rwy 10 approach and what the Boeing 737 Classic/NG/Max flight director does at MAPON. MAPON is the missed approach point 2 miles from the runway.

That is why it is a visual maneuver with no lateral or vertical electronic guidance the last 2 miles to the runway.
Meaning one can fly the old fashioned way when the outside visual is as it was in figure 3 of the report. By maintaining pitch, power, and attitude while things become clearer although on some Boeing's, you can just select V/S and the command bars will display in such a way so as to maintain the rate of descent at the time of VS selection. FPA could do the same. All the while having the murky visual references but little depth perception.
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Re: WestJet almost puts one in the drink

#159 Post by Eric Janson » Sat Jun 09, 2018 12:04 am

J31 wrote:
Thu Jun 07, 2018 3:24 pm
CCR wrote:
Thu Jun 07, 2018 6:30 am
If the FD is not turned off, it commands the missed approach turn and climb.
FINALLY someone who understands the ST Maarten RNAV Rwy 10 approach and what the Boeing 737 Classic/NG/Max flight director does at MAPON. MAPON is the missed approach point 2 miles from the runway.

That is why it is a visual maneuver with no lateral or vertical electronic guidance the last 2 miles to the runway.
It seems to me that pushing HDG would be a smart move at MAPON - if I remember correctly the vertical mode will go to V/S. Leave the automatics until the aircraft is closer to the runway and then disconnect. Certainly lowers the workload and would have prevented what happened imho.
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Re: WestJet almost puts one in the drink

#160 Post by photofly » Sat Jun 09, 2018 6:29 am

If there is little or no depth perception, how can you have to the “required visual reference necessary to continue the approach to land”?

For reference:

“required visual reference, in respect of an aircraft on an approach to a runway, means that portion of the approach area of the runway or those visual aids that, when viewed by the pilot of the aircraft, enable the pilot to make an assessment of the aircraft position and rate of change of position, in order to continue the approach and complete a landing; (référence visuelle requise)”

I guess what I’m asking is, if you need the command bars to continue the approach past the MAP (and can’t complete it safely without them) even if you have a visual reference, how are you meeting the intent of having a missed approach point?
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Re: WestJet almost puts one in the drink

#161 Post by pelmet » Sat Jun 09, 2018 10:13 am

photofly wrote:
Sat Jun 09, 2018 6:29 am
If there is little or no depth perception, how can you have to the “required visual reference necessary to continue the approach to land”?

For reference:

“required visual reference, in respect of an aircraft on an approach to a runway, means that portion of the approach area of the runway or those visual aids that, when viewed by the pilot of the aircraft, enable the pilot to make an assessment of the aircraft position and rate of change of position, in order to continue the approach and complete a landing; (référence visuelle requise)”

I guess what I’m asking is, if you need the command bars to continue the approach past the MAP (and can’t complete it safely without them) even if you have a visual reference, how are you meeting the intent of having a missed approach point?
This is where the ideal world collides with the real world. One need only ask themeselves doing an approach on a clear dark night up north where the only lights are the runway lights. Have you really got depth perception? Yet you have the required visual references and it is actually good VFR.

There is logic in the way the CARS are written on the subject but if one relies on following the CAR's exclusively to the letter of the law, they will be cancelling flights when it is perfectly reasonable to go flying and go flying when the flight should be cancelled.

That is the reality of being a pilot and the reason that good judgement is required to be a safe pilot.
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Re: WestJet almost puts one in the drink

#162 Post by photofly » Sat Jun 09, 2018 10:57 am

pelmet wrote:
Sat Jun 09, 2018 10:13 am
if one relies on following the CAR's exclusively to the letter of the law...
I guess I missed the class on deciding which CARs are optional. On this topic, perhaps approach minimums should be considered advisory?
pelmet wrote:
Sat Jun 09, 2018 10:13 am
One need only ask themeselves doing an approach on a clear dark night up north where the only lights are the runway lights.
Do you need command bars to fly in those circumstances? What I’m reading in this thread is that at Sint Maaaarten, you do. If the visual references are so poor that you can only follow the FD then why not just leave the autopilot on and have done with it.
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Re: WestJet almost puts one in the drink

#163 Post by digits_ » Sat Jun 09, 2018 2:17 pm

photofly wrote:
Sat Jun 09, 2018 6:29 am
If there is little or no depth perception, how can you have to the “required visual reference necessary to continue the approach to land”?

For reference:

“required visual reference, in respect of an aircraft on an approach to a runway, means that portion of the approach area of the runway or those visual aids that, when viewed by the pilot of the aircraft, enable the pilot to make an assessment of the aircraft position and rate of change of position, in order to continue the approach and complete a landing; (référence visuelle requise)”

I guess what I’m asking is, if you need the command bars to continue the approach past the MAP (and can’t complete it safely without them) even if you have a visual reference, how are you meeting the intent of having a missed approach point?
That might be true, but isn't that the case with any ifr approach to minima? If you see one runway light at minima during an RNAV approach, can you really claim you have assessed all the necessary parameters in less than a second to allow you to continue? Yet it is common practice to continue the approach at that point. Same with an ILS at night where one approach light pops up. You're visual, but you don't have enough info to land the plane, you are counting on all those other lights to appear in the next 10 seconds before you touch down.
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Re: WestJet almost puts one in the drink

#164 Post by photofly » Sat Jun 09, 2018 2:30 pm

digits_ wrote:
Sat Jun 09, 2018 2:17 pm
... Same with an ILS at night where one approach light pops up. You're visual, but you don't have enough info to land the plane, you are counting on all those other lights to appear in the next 10 seconds before you touch down.
Are you still flying the plane using the command bars on the FD during those 10 seconds? Or the ILS guidance?

This ... seems to be cheating horribly (I just realized it was your comment:)
Push the VS button(or FPA if you are lucky enough to have it) and stay partially inside while maintaining the same descent rate using the flight director bars.
If the guidance is considered to be good enough for that to be ok, why are the minimums there at all?

Someone else wrote "Most pilots keep an eye on their magic even if they are visual." That seems reasonable. But when the magic says one thing, and your eyes say something else, which do you trust? I thought the whole point of continuing past minimums was that you had to have enough to trust your eyes, and not the magic.
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Re: WestJet almost puts one in the drink

#165 Post by digits_ » Sat Jun 09, 2018 5:17 pm

photofly wrote:
Sat Jun 09, 2018 2:30 pm

Are you still flying the plane using the command bars on the FD during those 10 seconds? Or the ILS guidance?
A mix of both. On the RNAV example, with higher minima, you'd be using the guidance more initially.

Basically like this:
photofly wrote:
Sat Jun 09, 2018 2:30 pm

Someone else wrote "Most pilots keep an eye on their magic even if they are visual." That seems reasonable. But when the magic says one thing, and your eyes say something else, which do you trust? I thought the whole point of continuing past minimums was that you had to have enough to trust your eyes, and not the magic.
A big difference at that stage would probably result in a go-around. If anything, you'd be either confused or unstable, neither of those options have a high chance of turning into a succesful landing.
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Re: WestJet almost puts one in the drink

#166 Post by pelmet » Sat Jun 09, 2018 6:36 pm

photofly wrote:
Sat Jun 09, 2018 10:57 am
pelmet wrote:
Sat Jun 09, 2018 10:13 am
if one relies on following the CAR's exclusively to the letter of the law...
I guess I missed the class on deciding which CARs are optional. On this topic, perhaps approach minimums should be considered advisory?
Of course, you will always win the argument of whether or not the CAR's are optional. There is even a CAR(and FAR) about reckless operation of an aircraft in which one can be guilty of reckless operation for many of the things we do on a regular basis. For example, considering an engine failure in a single engine aircraft point of view.....you chose to takeoff on the closer but much shorter runway instead of the much longer but much further away runway and therefore were reckless in case you lost your engine at a critical moment. Or you chose to fly at a lower altitude than you could have over the city and therefore couldn't have made that nice field for an emergency landing that you could if you had chosen to fly 5000 feet higher). In other words, you are always breaking the CAR's

As I said, there is a real world out there and one can have a black and white interpretation on all kinds of regulations from required visual reference to personal fatigue management to VFR requirements. I remember one particular type of operation I flew in the past where i was convinced that if one were to interpret the CAR's literally, no flight would ever have been legal.

This sort of a discussion came up in a thread I had recently where one of the strobe lights on a C172 has burned out which makes a flight illegal even in the daytime. I am quite confident that given such a situation, you Photofly, would choose the option to take your C172 back to home base, regardless of how you might respond on this forum about it and regardless of the non-optional CAR's.

The reality of the airline world(the safest mode of air transportation) is that thousands of approaches are flown to minimums each year by our carriers. Using an ILS as an example, when they get a few lights in view at minimums, one can argue that they should go around because there is initially, little depth perception at the DH due to fog, rain on windshield, or snowfall situations. But the reality is...the pilots usually continue for landing and they continue safely because they use their on-board equipment in the appropriate manner for a little bit longer until things become much clearer and depth perception is acquired. Something that I suggest was not appropriately done in Saint Martin.

As a final note....check out this video of a King Air flight to ILS minimums. Perhaps any IFR airline pilot can answer if they would go around based on the picture seen at 3:31 which is when minimums are announced. I would continue and so would most others but is it legal? I don't see depth perception here, therefore it is not legal. But this is the real world and few are going to do a missed approach in this situation. That being said, you would be a fool suddenly just fly visually at this point but there is nothing particularly unsafe about continuing if done properly.

https://www.youtube.com/watch?v=oxUsvw6gHhc
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Re: WestJet almost puts one in the drink

#167 Post by Eric Janson » Thu Jun 14, 2018 8:28 pm

photofly wrote:
Sat Jun 09, 2018 6:29 am
If there is little or no depth perception, how can you have to the “required visual reference necessary to continue the approach to land”?

For reference:

“required visual reference, in respect of an aircraft on an approach to a runway, means that portion of the approach area of the runway or those visual aids that, when viewed by the pilot of the aircraft, enable the pilot to make an assessment of the aircraft position and rate of change of position, in order to continue the approach and complete a landing; (référence visuelle requise)”

I guess what I’m asking is, if you need the command bars to continue the approach past the MAP (and can’t complete it safely without them) even if you have a visual reference, how are you meeting the intent of having a missed approach point?
It's not a depth perception issue.

Approaches are designed so that at minimums you have the required references to continue to a safe landing.

That means you have to be able to determine your horizontal and vertical position relative to the runway.

For the horizontal position there's the runway lights/Approach lights/Localiser.

For the vertical part there's the PAPI/VASI/GS.

On a non precision approach you will be flying the segment from the MDA to the runway VFR in IFR conditions. This is one of the reasons accident rates are much higher on non precision approaches.

Continuing an approach past/below MDA without having the runway/lights in sight is not acceptable.

Lower visibility results in the horizon being closer which makes the horizon line lower when looking outside. This creates the illusion of the aircraft pitch being high with an instinctive nose down input being the result. In this incident this is exactly what happened but the report doesn't discuss optical illusions.

By using the Flight Directors (with the appropriate modes) you can create an extra crosscheck that things are not getting out of hand - this certainly would have helped here imho.

You can also create an extended runway centreline on the moving map display which can be extremely useful if you are flying an approach that is offset. I think this would also have helped here - but the report doesn't discuss this.

No issue with the King Air video posted earlier - that's what an ILS to minimums looks like.
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Re: WestJet almost puts one in the drink

#168 Post by digits_ » Thu Jun 14, 2018 9:30 pm

Eric Janson wrote:
Thu Jun 14, 2018 8:28 pm


It's not a depth perception issue.
[....]

That means you have to be able to determine [..] vertical position relative to the runway.
Isn't that exactly what depth perception is?

Question: ILS to minima, at minima you can see only the first flashing light of the rabbit (not sure what the official name is). Can you continue the approach?
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Re: WestJet almost puts one in the drink

#169 Post by wrightflyer » Fri Jun 15, 2018 4:23 am

digits_ wrote:
Thu Jun 14, 2018 9:30 pm

Question: ILS to minima, at minima you can see only the first flashing light of the rabbit (not sure what the official name is). Can you continue the approach?
Everyone will have a different answer. In the video provided the ceiling is not 200' (the vis is closer to 1/4 SM), for if it were at the 3:31' mark of the video you should have seen all of the runway lights right up to the green threshold bars.

ALSF2 lighting (on the runway flown in the video) is 2400' long, which is 1/2 SM. From 1/2 SM on a 3 deg glidepath you are 200' AGL. Vis on that approach as indicated in the video is 1/4 SM.

If you are familiar with the lighting system installed on the runway(published on your handy approach plate) then you have to assess if the required visual reference to land exists. Makes this decision very subjective and individual. As everyone will see something different from that video.
KSHV plate.pdf
(59.17 KiB) Downloaded 16 times
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Re: WestJet almost puts one in the drink

#170 Post by photofly » Fri Jun 15, 2018 4:54 am

Eric Janson wrote:
Thu Jun 14, 2018 8:28 pm
Lower visibility results in the horizon being closer which makes the horizon line lower when looking outside.
I don’t follow this. If anything, I would expect the opposite to be true - a distant horizon is depressed because of earth curvature. Can you explain in more detail?
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Re: WestJet almost puts one in the drink

#171 Post by mbav8r » Fri Jun 15, 2018 1:47 pm

Photofly, my interpretation of that is under lower visibility, once you are visual you would be looking down for your horizon because you cannot see the horizon further out, giving the illusion you are higher.
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Re: WestJet almost puts one in the drink

#172 Post by upnatem » Sat Jun 16, 2018 7:10 am

Somebody is working on it.....


Sensor Fusion Method for Horizon Detection From an Aircraft in Low Visibility Conditions

Abstract:
The approach and landing of an aircraft under low visibility has been a subject of great interest in recent years. Although much advanced equipment has been designed and used on airplanes to improve the safety threshold in manipulating it, low visibility has remained the potential threat of causing controlled flight into terrain and runway intrusion. Besides, low visibility is also the main cause for flight delay, which reduces the efficiency of transportation systems. Clear landmarks on the ground will significantly improve pilots' spatial awareness under low visibility conditions, and among all landmarks, horizon position is the key one to count on for successfully controlling an aircraft during landing. The purpose of this paper is to design a horizon detection method based on a multisensor fusion strategy suitable for poor visibility conditions. With the fusion approach, pilots are able to recover/reconstruct the horizon under low visibility conditions. Analysis of experimental results and comparisons with reported methods are furnished at the end of this paper.
Published in: IEEE Transactions on Instrumentation and Measurement ( Volume: 63, Issue: 3, March 2014 )


https://ieeexplore.ieee.org/document/6689328/
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Re: WestJet almost puts one in the drink

#173 Post by J31 » Sat Jun 16, 2018 8:18 am

Eric Janson wrote:
Sat Jun 09, 2018 12:04 am
It seems to me that pushing HDG would be a smart move at MAPON - if I remember correctly the vertical mode will go to V/S. Leave the automatics until the aircraft is closer to the runway and then disconnect. Certainly lowers the workload and would have prevented what happened imho.
Boeing 737 Classic, NG, and MAX: Selecting HDG will only command the flight director to heading mode. VNAV will stay in the missed approach mode and command a climb. Selecting V/S will give you the vertical speed at the point the selection is made. And yes you could leave the autopilot on.

On the TNCM RNAV Rwy 10 you could select HDG and V/S just prior to the missed approach point of MAPON and it would give flight director guidance. The problem however the guidance will only be heading and vertical speed at the point selected. It initially may be better than no flight director but may or may not align you with the runway or on the vertical profile to the runway threshold. The trap then is the flight director may be commanding a different profile as you maneuver to land on the runway.

There is no RNAV coding on the TNCM RNAV Rwy 10 from missed approach point MAPON to the runway. It is Boeing's recommendation and Westjets SOP to disengage the auto pilot and cycle the flight directors. This removes the flight director from view and will arm the FD for a missed approach inside MAPON.

This is to explain how the TNCM RNAV Rwy 10 approach approach works with the Boeing 737 and Westjets SOP.

I am not dismissing that things went very wrong. This crew misidentified a hotel in heavy rain as the runway. They did not monitor their vertical profile and got VERY low while hand flying with no electronic guidance.

This is a very challenging scenario looking at what you believe is the runway and managing the vertical profile over featureless ocean.
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Re: WestJet almost puts one in the drink

#174 Post by Eric Janson » Sat Jun 16, 2018 6:23 pm

@digits_

It has nothing to do with depth perception. It's about being able to see if you are high, low or on the correct profile.

@photofly

Just look at a photograph with objects at different distances. As you reduce the visibility so that only the closer objects are visible you will see that the horizon line moves down as it moves closer to you.

You can do the same sitting in a car with a sheet of paper to simulate a reduction in visibility with the bottom edge representing the horizon. As you block out distant objects the paper moves down the windshield.

@J31

Thanks for the explanation.

I've only flown the 737-300. No GPS.

Company policy was LVL CHG on descent below 10000' and we flew non precision approaches in basic modes - this was pre RNAV. FDs off at Pilots discretion. At MDA we could just continue in basic modes if desired.

Pushing a TOGA button would cause the FDs to 'Pop up' and then you could select the appropriate lateral mode as required.

This worked very well - we flew a lot of non precision approaches.

I know that companies want approaches flown the same way every time - and it works 99.9% of the time. This incident is the 0.1% where the SOP contributed to the incident imho.

Sometimes the highest level of automation isn't the most appropriate. I've watched people try to save a situation by pushing buttons when disconnecting and flying manually was the better option. I'm noticing a real reluctance to turn anything 'off' in the younger generation.
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Re: WestJet almost puts one in the drink

#175 Post by digits_ » Sat Jun 16, 2018 6:28 pm

Eric Janson wrote:
Sat Jun 16, 2018 6:23 pm
@digits_

It has nothing to do with depth perception. It's about being able to see if you are high, low or on the correct profile.
We're into semantics now, but is that not the exact definition of depth perception? What do you understand as depth perception?
depth per·cep·tion
noun: depth perception; plural noun: depth perceptions

the ability to perceive the relative distance of objects in one's visual field.
You want to know your relative altitude above the ground in relation to your distance to the field etc, no?
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