§91.175 Landing Under IFR - IN PLAIN ENGLISH

FAR says vasi. Is that meant as VASI? I mean...I fly in and out of airports with a PAPI all the time. I realize it isnt usually the first thing you see (i.e. rabbits), but this has caused me to believe a vasi is used as a generic term (including PAPI). If they actually capitalized the letters, then it would be more specific towards the actual approach light system. Does any of this make sense? I mean, PAPI counts, yes?
 
Mr_Creepy said:
I wish I could get it to load my Yahoo calendar. It won't load anything but today's page.

John, I don't think that anybody has ever had any success doing that. Have you been introduced to the incredibly geeky Treo forums?:)
 
mtsu_av8er said:
Not in my OPSEPCS . . . :)

Nor in mine.

I know a guy who got busted for landing with less than the required visibility, so obviously the flight visibility argument doesn't work.
 
johns13b said:
FAR says vasi. Is that meant as VASI? I mean...I fly in and out of airports with a PAPI all the time. I realize it isnt usually the first thing you see (i.e. rabbits), but this has caused me to believe a vasi is used as a generic term (including PAPI). If they actually capitalized the letters, then it would be more specific towards the actual approach light system. Does any of this make sense? I mean, PAPI counts, yes?

WTF? Calm down - need some Ritalin? :insane:

VASI is an incredibly generic term. PAPI is a type of VASI.
 
johns13b said:
FAR says vasi. Is that meant as VASI? I mean...I fly in and out of airports with a PAPI all the time. I realize it isnt usually the first thing you see (i.e. rabbits), but this has caused me to believe a vasi is used as a generic term (including PAPI). If they actually capitalized the letters, then it would be more specific towards the actual approach light system. Does any of this make sense? I mean, PAPI counts, yes?

One flight instructor actually told me that PAPI's don't count for the 91.175 reg. Only VASIs count. Weird huh? Anyone care to elaborate?
 
mtsu_av8er said:
Not in my OPSEPCS . . . :)
Lloyd, your opspecs refer to INITIATING the approach (RVR is controlling.) For 91.175 (continuing flight below DH or MDA) it is flight visibility.
 
JaceTheAce said:
One flight instructor actually told me that PAPI's don't count for the 91.175 reg. Only VASIs count. Weird huh? Anyone care to elaborate?
That's true. Reason unknown.

Folks I don't know if you know this but I am an Aviation Safety Counselor and one of my "areas of expertise" is regulatory enforcement. I have been in a few hearings on this reg before.
 
"VASI is an incredibly generic term. PAPI is a type of VASI."

MTSU-
While I agree with you 100% in a practical day-to-day sense, I think if you go to the AIM you will see that VASI is not generic ( not even understanding the breadth of the 'incredibly' adjective) and PAPI "while similar to" is not a TYPE of PAPI. If you accept the organization of the AIM, then PAPI is PAPI and VASI is VASI :)

I love the AIM, its my personal bible, but let me add something from a practical sense.. comgn from 2 years of 135 freight: if you reach DA and its white fog and the ONLY thing you see is the PAPI... you better not be thinking about whether it's on the FAA list or not. Ya ought to be wondering why THATS the only thing you see. I mean.. it's 1000' down the runway (usually...) and off to one side. no ALS? no concrete? centerline lights? nothing but PAPI or VASI... if that happened I might really be questioning if I was really looking at what I thought I was looking at... i am imagining a windscreen filled with ALL paste white and nothing but 1 tiny white and 1 tiny red.. no thanks :) sh@@.. that could be a car backing up at the FBO with a backup tail light inop !!!
 
Mr_Creepy said:
As long as you have your argument ready the judge has to take your word. I suggest something along the lines of:

"Your honor, I was at one end of the rabbit and I could see the terminating bars at the other end. As this graphic depiction can show, that's 3000 feet! I had a half mile so I was legal to proceed."


I've been five hundred AGL with clear skies and a full view of the runway. Eight feet above the runway I settled into a 1/16th mile visibility layer in fog. The slant range view from decision height is much different from the forward prevailing visibility on the ground. Obviously, this ground fog scenario is extreme and rare...but it highlights that vis may change below DH.

The only gotchya in this situation is...at anytime the flight vis goes below the prescribed vis...you must execute a missed approach. So if the flight vis is good at 200' and is good at 100' but goes to nil at 50'...you must execute the missed approach.

Could an Inspector in a vehicle near the touchdown zone testify that the flight visibility was below mins? I guess a judge would have to decide. I could see how this scenario might go against the pilot.
 
bluelake said:
MTSU- While I agree with you 100% in a practical day-to-day sense, I think if you go to the AIM you will see that VASI is not generic ( not even understanding the breadth of the 'incredibly' adjective) and PAPI "while similar to" is not a TYPE of PAPI. If you accept the organization of the AIM, then PAPI is PAPI and VASI is VASI :)

You know, I went back and read that - you're absolutely correct. I stand corrected!
 
B767Driver said:
I've been five hundred AGL with clear skies and a full view of the runway. Eight feet above the runway I settled into a 1/16th mile visibility layer in fog. The slant range view from decision height is much different from the forward prevailing visibility on the ground. Obviously, this ground fog scenario is extreme and rare...but it highlights that vis may change below DH.

The only gotchya in this situation is...at anytime the flight vis goes below the prescribed vis...you must execute a missed approach. So if the flight vis is good at 200' and is good at 100' but goes to nil at 50'...you must execute the missed approach.

Could an Inspector in a vehicle near the touchdown zone testify that the flight visibility was below mins? I guess a judge would have to decide. I could see how this scenario might go against the pilot.
Had a few of those approaches myself. Did the miss on all but one. The one scared me spitless!

From now on, I go missed in the ground fog situation.
 
91.175....easy to understand.

"....except a military aqircraft of the United States...."

Easily interperted for me, sounds plain english enough. lol
 
MikeD said:
91.175....easy to understand.

"....except a military aqircraft of the United States...."

Easily interperted for me, sounds plain english enough. lol

LOL . . . sure makes life easy, huh?
 
Back
Top