I Misread the PAPI Lights Today

[Matt45609]

So today, while I was on final to land, I misread the PAPI lights at my local airport. It was a bright, sunny day with relatively clear conditions and with no apparent mist or fog in the air. On final, I glanced at the PAPI’s and could have sworn I saw 4 whites, when in reality, they were 4 reds.. soon after realising, (judging my actual height above the ground compared to where I would usually expect to be) I climbed higher and then was able to clearly see the difference when the others began changing to white.

The PAPI’s at my local airport have never been overly vibrant, except at night. The white, for example, is more of a yellow color, which is what I thought I was seeing when in fact they were all a mild red.. I’m not sure if the conditions or anything else played a part in this.

As you can imagine, this has concerned me a little as it’s the first time I’ve thought to descend in a situation where I should have climbed.

I’m wondering if anyone has ever experienced anything similar to this before? I’m trying to figure out whether this is a normal occurrence or if I should be worried. Any advice would be helpful!

[Sea Plane Driver]

It was a bright, sunny day with relatively clear conditions and with no apparent mist or fog in the air

I assume you are new to this sport?
On a bright and sunny day there should be no reason to use, or to follow PAPI's unless you had an emergency needing all the
help you can get. (Engine failure, smoke in the cockpit, flight control problems, health problems, etc)
If you see the runway, then go for a visual approach, life is good.
​​​​​​​

[Mach E Avelli]

I assume you are new to this sport?
On a bright and sunny day there should be no reason to use, or to follow PAPI's unless you had an emergency needing all the
help you can get. (Engine failure, smoke in the cockpit, flight control problems, health problems, etc)
If you see the runway, then go for a visual approach, life is good.
.

Disagree with some of the above. If you've got it, flaunt it. Flying the PAPI (when available) is simply good airmanship. Practising visual approaches with no glideslope guidance is also good airmanship. Do both. It's also good practice to compare altimeter readings with distance to the threshold, particularly at night, aiming for approx 300ft above touchdown per mile to run to touchdown.
As for misreading the PAPI colors. If you pass the color test on your medical with no problems, suspect that bright sunlight with perhaps some other atmospheric 'filters' (smoke? haze?, condensation?) coupled with an old and fairly dim system may have conspired against you.
The important thing is that you corrected the error.

[BraceBrace]

I assume you are new to this sport?
...
If you see the runway, then go for a visual approach, life is good.


It's not a sport when you hit too low. There is a sad fire fighting vid in Greece this week that shows what happens when you get too close to the trees. A gentle reminder it is something to avoid, and a gentle reminder you might be as confident as you are, sometimes **** just happens and it's only in hindsight you think "what happened? (if you're lucky)"

PAPI's are designed for visual approaches, the letter "P" only signifies they are more "P" than the "V" lighting system (they were never designed for instrument approaches). So use them.

And yes colo(u)r confusion happens. Sometimes the colors seem to blend in a bizar way for unknown reasons.

[El Grifo]

"PAPI's are designed for visual approaches, the letter "P" only signifies they are more "P" than the "V" lighting system (they were never designed for instrument approaches). So use them"

Can you help me with "V" lighting BraceBrace.
I always understood PAPI's but "V" is new to me.
Google is not helping !

El Grifo

[BraceBrace]

https://en.wikipedia.org/wiki/Visual_approach_slope_indicator

PAPI was designed to be more precise close the runway compare to the old VASI system, hence it was named "precision". I referred to them to indicate even though a PAPI is designated "precision", it is stil a "visual" approach system.

[El Grifo]

Ah VASI !!
Got you now.
Thanks for that BraceBrace
El G.

[Capn Bloggs]

And yes colo(u)r confusion happens. Sometimes the colors seem to blend in a bizar way for unknown reasons.
Because they are cheap-charlie and not maintained; tick the regulator's box though. Give me a T Vasis any day.

​​​​​​​This is one of the applications where LED lighting would be great: white whites and Red reds.

[mustafagander]

I still wonder why the Australian invented T VASIS was killed off.
Super simple - the lights on the leg of the T, aligned with the runway centre line, pointed to where you were going to touch down. If it pointed downfield you were set up to land long and vice-versa. There were 3 lights on each side of the wing bar. It also had reds for extreme low approach but otherwise all white so no problem with mist, haze smoke etc.
It allowed for long bodied aircraft by allowing a constant "2 dots fly down" to be flown for the B747 etc.

[EXDAC]

Flying the PAPI (when available) is simply good airmanship.

I would suggest that it would depend on what you are flying. I hate dragged in approaches and I'm always well above a PAPI or VASI glidepath except when flying an instrument approach procedure (ILS or LPV)

[India Four Two]

I agree with EXDAC. For a visual approach in a light aircraft, there is no reason to be following the PAPI/VASI. My approaches are typically 6º or steeper.

[Piper.Classique]

If it's a visual approach then you could consider just MK1 eyeball of the runway perspective. PAPI are set up for quite a shallow approach compared to real world light aircraft flying. They do permit some "slackness" of judgement compared to a glide approach where you do actually need to "ahem" round out and hold off.
But if you want to use them as preparation for flying airline type stuff fair enough. Just don't have an engine failure on long final in a draggy single.
​​​​​

[Bogner]

Just to add, if it was a sunny day could sunglasses have played a part? I've noticed in the past that some sunnies can make it harder to distinguish between certain colours.

Thanks for bringing up the subject! 👍

[Contact Approach]

Is this a joke?

[Matt45609]

Is this a joke?

Why would I joke about this? I’m admitting a genuine mistake and hoping to hear advice from the community, it would be quite a silly and elaborate joke to make.

[EXDAC]

Fairly recently I gave a newly licensed pilot his first flight review. He is color blind, He can see changes in the PAPAI/VASI colors but cannot distinguish all red from all white. We discussed how he could safely use the PAPI/VASI. There seemed to be two options.

1. Plan a steep approach and descend to intercept the PAPI/VASI from above
2. Approach the airport at or above traffic pattern altitude and do not descend until intercepting PAPI/VASI from below.

We both agreed that always flying a steeper approach than PAPI/VASI would be safer than depending on it.

Almost all my approaches to my base airport are type 1 and I pass though the PAPI/VASI inside the airport fence and land short of the PAPI/VASI aim point. My hangar taxiway is just past the 1,000 ft marker. There are no visual aids at the short dirt strips I like to visit.

[Sue Vêtements]

Old perspex in the windshield?

[Mach E Avelli]

Is this a joke?
The only ‘joke’ here is the joker with nothing to contribute. The OP sounds relatively inexperienced, recognised hazard, managed risk, admits error, seeks feedback, gets feedback. More pilots like that should be encouraged, as should those who provide good advice.

[Check Airman]

With some installations, I can definitely see this happening. Sounds like you’re (relatively) new, and haven’t seen all the imperfections the world has to offer.

Good job catching the error, and even better job for coming here to talk about it. We can always learn.

What happened to you is one of the reasons airlines always back up a visual approach with an instrument approach. That would have helped you to catch the error a bit sooner.

An instrument rating is a worthwhile investment, even if you’re a fair weather guy.

Perhaps a NASA report is warranted. Since you say that the lights are pretty dim, maybe it’ll be the kick the airport needs to fix the problem.

[Uplinker]

Well done Matt45609 for telling us about this.

One of the most important contributions to aviation safety is pilots reporting problems, errors and mistakes, so that pilots can learn from others, and the whole process becomes generally safer.

You had a potentially dangerous situation, but spotted it, corrected it, and learned a valuable lesson. Very well done :ok:

Please ignore the smart-arses and armchair-pilots here on Pprune, and thank you for bringing this up.

I would file an official safety report, and hopefully, the airfield will check their PAPI lenses.

[FlexibleResponse]

Hi Matt,

An interesting discussion on the subject of VASI/PAPI anomalies from 2014:

https://www.pprune.org/pacific-general-aviation-questions/547990-papi-vasis-erroneous-light-indications.html

I love your probing mind which will greatly assist your long term survival in aviation.