Avasi ????

[walkthasky]

What is an AVASI ??? I know it stands for Abbreviated Vasi, but what is it ??

Thanks!

 

[avbug]

Avasi:

1. The act of blocking an uppercut in Fredlundvania, in May

2. "A Vasi" pronounced by someone from Brooklyn.

3. A well known and recognized brand of Itallian suit, made only with natural silk fibres, and a trademark line of pastel colors.

4. isavA spelled backward.

5. Avasi stands for abbreviated VASI, also known as VASI-2, or the 2 Box VASI. It is a type of economy approach lighting aid. "Economy approach lighting aids" includes a medium intensity approach lighting system (MALS) that may include a sequence flasher (SF); a runway end identifier lights system (REILS): and an abbreviated visual approach slope indicator (AVASI).

The 2 box VASI, or VASI-2 (AVASI) is the typical VASI you find at most smaller airfields. It's just two transmitting boxes, with a multi-path indication of high, low, and on-glidepath. The abbreviated visual approach sope indicator is the most common kind.

There are three basic configurations of VASI that are described below. These are left side of runway, both sides of runway, and the walker 4 bar configuration. Each configuration has several variations on the theme, and different limitations as follows:

1. Left Side of Runway:

VASI-2 consists of two light boxes. This system provides descent information under daytime conditions to a distance of 3 miles.

SAVASI-2 consists of two light boxes with a single lamp in each box as. This system is designed for nonjet, utility airports, and provides descent information under daytime conditions to a distance of 1.5 miles.

VASI-4 consists of four light boxes installed. This system provides descent information under daytime conditions to a distance of 4 miles.

2. Both Sides of Runway.

VASI-12 consists of 12 light boxes installed. This system provides descent information under daytime conditions to a distance of 5 miles.

VASI-8 consists of eight light boxes installed. This system is basically the 12-box system with the outer four boxes removed and provides descent information under daytime conditions to a distance of 5 miles.

3. Walker 3-Bar System.

Walker 3-Bar VASI-6 is a 3-bar system installed. Each bar consists of two light boxes aligned on the left side of the runway. The system provides descent information under daytime conditions to a distance of 3 miles.

Walker 3-Bar VASI-16 consists of 16 light boxes installed. The system is basically a VASI-12 with the addition of a 2-box light bar on each side of the runway which provides an additional visual glidepath at a higher angle. The lower path is designed for large aircraft. This system provides descent information under daytime conditions to a distance of 5 miles.

 

[501261]

Couple of years ago they had an AVASI at DVT, ended up being one of those tri-color single lens units. It was real hard to see and I guess its been replaced with a PAPI.

 

[dlhind]

Read the Jeppesen introduction section, it has all of the symbolog and a wealth of information. AVASI means that it's different than the standard 3 degree glideslope.

 

[avbug]

Dlhind,

AVASI has nothing to do with glidepath, and does not denote something other than a three degree glide path. It denotes exactly what was explained above in my previous post. Nothing more.

You used the Jeppesen legend in the introduction section as your source, and misread the explaination. It's easy to do. It states that VASI/AVASI/Non-std angles are show to be less than...

What that paragraph is telling you is that nonstandard angles are shown. In other words, the presence of an AVASI has nothing to do with a non-standard angle, but the jepp charts print the actual glide path angle when it's nonstandard. The wording of that paragraph note is intended to state that non-standard angles for VASI/AVASI are provided. You'll be shown the specific angle, with it printed next to the VASI symbol or in the proceedural notes.

Above that paragraph is a note for VASI's labled (non-std), which simply means that the chart is annotated to show that the VASI is non-standard. The presence of an AVASI does not indicate automatically that the glide path is non-standard. Rather, the words "non-std" will be placed on the chart to indicate a non-standard glide path.