Skip to main content

Questions tagged [papi]

Papi is the short for "Precision approach path indicator". It's a visual aid providing guidance information to help a pilot acquire and maintain the correct approach.

Filter by
Sorted by
Tagged with
41 votes
4 answers
37k views

How do PAPI lights work?

Usually, there are four lights at the sides of runways which show airplanes' altitude status: four red lights: too low two red, two white: appropriate altitude four white lights: too high. If two ...
Super Hornet's user avatar
30 votes
2 answers
104k views

What's the functional difference between PAPI and VASI?

PAPI and VASI seem to be very similar in the the information they provide - i.e. are you on the glide slope or off it. Is there a functional difference between the two? If there is a difference, and ...
Jeff B's user avatar
  • 1,755
15 votes
5 answers
5k views

Can we always trust the PAPI lights?

I have a question about the PAPI system. One of the first things student pilots learn during their ground school is the PAPI. You get two whites and two reds on a visual approach, you're on the 3 ...
lemonincider's user avatar
  • 7,565
11 votes
4 answers
5k views

Why would a PAPI and ILS glide slope for the same runway not coincide?

Some pilots are reporting the glide slope on our PAPI is not coinciding with the glide slope on our ILS even though FAA did a flight check of our PAPI's. Are there any reasons why a PAPI and ILS would ...
Almighty 's user avatar
11 votes
2 answers
4k views

How to decide on which side of the runway the approach path indicator (VASI, PAPI) are placed?

This answer provides pictures and drawing of implementation of both PAPI and VASI. In all pictures I found, I cannot figure if there is a rule to put those lights on the right, on the left, or on both ...
Manu H's user avatar
  • 16.5k
9 votes
2 answers
10k views

What determines the positioning of PAPI lights from the runway threshold?

Why are PAPI lights installed 300m from the threshold? What are the conditions that define the position of the PAPI lights from threshold?
mrinal anurag's user avatar
8 votes
2 answers
4k views

How to know if an airport has PAPI lights?

Is there any way to identify whether an airport has PAPI lights (2-light or 4 light system, doesn't matter)? I am working on some map generation and using aerial images to identify PAPI lights for ...
ha9u63a7's user avatar
  • 663
7 votes
1 answer
3k views

What is the horizontal and vertical fields of view for a VASI and a PAPI approach system as you come in to land?

As you come in for landing, at what angles should the VASI or PAPI lights be visible on the approach in the Horizontal and vertical planes. {E.G. 30 degrees horizontal and 20 degrees vertical}
J. Fourie's user avatar
6 votes
5 answers
674 views

Do different planes (category) aim differently in the 'final stages before flaring'?

(youtube.com) Do different planes (categories A through D) aim differently in the final stages before flaring? I'm asking about precision runways. The reasons I ask: An ILS' glide slope is not ...
user avatar
5 votes
3 answers
3k views

Does a pilot follow the PAPI lights in the same way in all categories of aircraft?

Since there are different dimensions of aircraft in various approach categories, I wonder what changes pilots in different aircraft have to make when following the PAPI lights. I know that 3° (for ...
Andrea Ghilardi's user avatar
3 votes
3 answers
1k views

Why is an approach that relies on both LOC and PAPI not considered a precision approach?

I am an aviation layman. I am reading about PAPI lighting system and it seems like it provides vertical guidance, just like the glideslope component of an ILS. Coupled with a LOC, both vertical and ...
Tyler Lungrin's user avatar
3 votes
1 answer
3k views

What is the average deviation from the PAPI glide slope at the threshold?

If one approaches with three red and one white light what will be the average deviation from the standard threshold height of 50 feet?
Art Buenaventura's user avatar
3 votes
1 answer
2k views

Are there limitations on taking off or landing if airport lighting such as the VGSI (PAPI) is out of service?

There are many types of airport lighting that aid pilot to land safely such as ALS, VGSI or runway lights. And some instrument approach procedures state that their weather minimums must be raised in ...
Min's user avatar
  • 661
1 vote
1 answer
5k views

What is MEHT (minimum eye height over the threshold)?

What is MEHT (minimum eye height over the threshold)? I can't find the definition and how to use it.
pilot162's user avatar
  • 2,205
0 votes
0 answers
108 views

Perpendicular Distance between PAPI and Aiming point

We are in the middle of a new runway construction. The airport requested the aiming point to follow the PAPI. Should they be aligned head to head, or there can be some meters difference?
Shirley Azer's user avatar
-1 votes
1 answer
140 views

Why aren't the left and right papi lights written "in-line" in the lighting icons section of the Jeppesen chart?

Why aren't the left and right papi lights written "in-line" in the lighting icons section of the Jeppesen chart? Although there is REIL on other charts, it is written in line. Could this be ...
pilot162's user avatar
  • 2,205