Green & White VASIS??
Thread Starter
Joined: Oct 2002
Posts: 108
Likes: 0
From: Canada
Green & White VASIS??
Has anyone here ever seen a VASIS light system which uses green and white lights, instead of red and white? Apparently that's what they have at La Cieba, Honduras. My question is, which colour is "bad"??
Can anyone help?
Thanks,
SG
Can anyone help?
Thanks,
SG
Joined: May 2003
Posts: 198
Likes: 1
From: france
hello safety guy,
it could be a tri-color visual approach slope indicator: (TRCV)
quote jepp in introduction chapter:"tcrv is normally a single light unit located on the left side of the runway".
amber: above glide path
green: on glide path
red: below glide path
caution note added: "when the aircraft descends from green to red, the pilot may see a dark amber color during the transition from green to red".
another possibility is the "pulsating visual approach slope indicator
PLASI) but only with white & red lights, also located normally on left side of rwy.
pulsating white: abv glide path
steady white: on glide path
steady red: slightly below glide path
pulsating red: below glide path
caution note this time: "when viewing the pulsating visual approach slope indicators in the pulsating white or pulsating red sectors, it is possible to mistake this lighting aid for another aircraft or ground vehicle. pilots should exercise caution when using this system".
last remark: vasi/papi are certified only from about 4nm out cfr obstacles & if non-std coverage a caution note is usually added.
vasi is normally ok till 200ft agl.
papi is ok till 100ft agl.
and, yes, growing grass can obscure correct viewing of colors, as can hazy wx conditions(prisma effect).
the system can be off or on maintenance or even worse, not installed at all, see paris orly where no vasi/papi system exist on the main landing rwy's.
and safety guy, cfr some funny comments of some previous posts: don't worry, quote the bible as jesus was saying on mount golgotha: "forgive them, my lord, they do not know what they are doing".
it could be a tri-color visual approach slope indicator: (TRCV)
quote jepp in introduction chapter:"tcrv is normally a single light unit located on the left side of the runway".
amber: above glide path
green: on glide path
red: below glide path
caution note added: "when the aircraft descends from green to red, the pilot may see a dark amber color during the transition from green to red".
another possibility is the "pulsating visual approach slope indicator
PLASI) but only with white & red lights, also located normally on left side of rwy.pulsating white: abv glide path
steady white: on glide path
steady red: slightly below glide path
pulsating red: below glide path
caution note this time: "when viewing the pulsating visual approach slope indicators in the pulsating white or pulsating red sectors, it is possible to mistake this lighting aid for another aircraft or ground vehicle. pilots should exercise caution when using this system".
last remark: vasi/papi are certified only from about 4nm out cfr obstacles & if non-std coverage a caution note is usually added.
vasi is normally ok till 200ft agl.
papi is ok till 100ft agl.
and, yes, growing grass can obscure correct viewing of colors, as can hazy wx conditions(prisma effect).
the system can be off or on maintenance or even worse, not installed at all, see paris orly where no vasi/papi system exist on the main landing rwy's.
and safety guy, cfr some funny comments of some previous posts: don't worry, quote the bible as jesus was saying on mount golgotha: "forgive them, my lord, they do not know what they are doing".
Thread Starter
Joined: Oct 2002
Posts: 108
Likes: 0
From: Canada
Wow, thanks for the detailed response, blackmail! I wondered about the TRCV, but it was the white light that threw me off.
As for the humourous resposes, I know that they "know not what they do". I just assumed that a Tech Log forum would only be frequented by knowledge freaks and techno geeks, not winged comedians. Wrong again!
As for the humourous resposes, I know that they "know not what they do". I just assumed that a Tech Log forum would only be frequented by knowledge freaks and techno geeks, not winged comedians. Wrong again!
Joined: Nov 2004
Posts: 244
Likes: 0
From: Earth
Did a trip to Roatan, Honduras, last Sept. and the rwy was equipped with the usual red/white papi.....Also went to La Ceiba about a year ago, and the rwy at that time also had the usual red/white papi.....but it may have changed since....
Joined: Aug 2000
Posts: 324
Likes: 1
From: Hindhead, UK
Overheard a conversation to ATC in the mid-west (USA) recently - the upshot was that a few months back an aircraft had left the runway and rearranged the PAPIs - unfortunately when they replaced them they managed to install one of them upside down!
Really helpful!
T'bug
Really helpful!
T'bug
