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Cpt_Kirk

Cpt_Kirk

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Display name:
Ted Striker
Scenario:

Rain showers are moving off the field. Field is IFR because of rain on AWOS equipment. You are VMC on a straight in RNAV approach. You have the entire runway and field environment in sight 5 miles out. Tower reports visibility as 2 miles and increasing. AWOS reports 1/4 mile because of rain and location on field.

Approach mins are 1 mile and 500 feet. Which vis report takes precedence? Is it legal to land? Can't find in FAR/AIM. Only looked for a few mins.
 
Cpt_Kirk said:
Scenario:

Rain showers are moving off the field. Field is IFR because of rain on AWOS equipment. You are VMC on a straight in RNAV approach. You have the entire runway and field environment in sight 5 miles out. Tower reports visibility as 2 miles and increasing. AWOS reports 1/4 mile because of rain and location on field.

Approach mins are 1 mile and 500 feet. Which vis report takes precedence? Is it legal to land? Can't find in FAR/AIM. Only looked for a few mins.
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I believe that in the absence of RVR, airborne visibility is senior.
 
AWOS reports ground visibility. Approach mins are flight visibility as specified.
 
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You are good. Landing mins are flight vis. You can state your vis on the air to get it on record should there ever be a discrepancy.
 
Kritchlow said:
You are good. Landing mins are flight vis. You can state your vis on the air to get it on record should there ever be a discrepancy.
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And don't cancel IFR until you are on the ground.
 
Also, snap a picture in case some jackwad at the FAA wants to bust you - as they have done to others in the past.
 
Good opportunity to use ground references to help measure distances such as runway markings, approach lighting configurations, etc.
 
Your good to land,stay on the IFR clearance,report to tower actual conditions.
 
EdFred said:
Also, snap a picture in case some jackwad at the FAA wants to bust you - as they have done to others in the past.
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It also doesn't hurt to state to the tower clearing the runway, "I found my landing limits to exist."
 
There's no such thing as a ceiling minimum by the way, just a MDA or DA. Ceiling minimum only applies to VFRs in the airspace formerly known as control zones.
 
EdFred said:
Also, snap a picture in case some jackwad at the FAA wants to bust you - as they have done to others in the past.
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No need for a picture. Unless the FAA has someone in the cockpit with you to rebut your testimony as to the flight visibility as viewed from the cockpit, they have no case for a violation of 91.175(c)(2). See Administrator v. Pisarek. However, they still might get you for 91.13 careless/reckless -- as they did Mr. Pisarek. That said, unless something bad happens (as it did with Mr. Pisarek, who wrecked his Aztec by landing with one main wheel in the snow and the other on the plowed runway at night with 1/16 mile ground vis), the FSDO is most unlikely to ever hear about it, no less do anything about it.
 
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flyingron said:
There's no such thing as a ceiling minimum by the way, just a MDA or DA. Ceiling minimum only applies to VFRs in the airspace formerly known as control zones.
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...and currently known as "within the lateral boundaries of controlled airspace designated to the surface for an airport." See 91.155(c).
 
also 91.175 h(1) -

(h) Comparable values of RVR and ground visibility.
(1) Except for Category II or Category III minimums, if RVR minimums for takeoff or landing are prescribed in an instrument approach procedure, but RVR is not reported for the runway of intended operation, the RVR minimum shall be converted to ground visibility in accordance with the table in paragraph (h)(2) of this section and shall be the visibility minimum for takeoff or landing on that runway.

So if RVR is prescribed in the IAP but wasn't reported at the airport, you have to convert and abide by it. There is the possibility someone might say the AWOS said 1/4 mile/RVR 1600 and the approach required more so you weren't legal to land. I'd counter that the AWOS doesn't report runway conditions, but FAA officials don't take their legal direction from me.
 
If you were VFR, would an SVFR approach be allowed in this case?
 
flyingron said:
There's no such thing as a ceiling minimum by the way, just a MDA or DA. Ceiling minimum only applies to VFRs in the airspace formerly known as control zones.
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For civilian operations, correct.
 
Bill Jennings said:
If you were VFR, would an SVFR approach be allowed in this case?
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SVFR requires reported 1 mile ground vis when visibility is reported. If the AWOS is reporting 1/4 mile, the tower must override it and make an observation of 1 mile or better before they can issue the SVFR clearance.
 
Ron Levy said:
No need for a picture. Unless the FAA has someone in the cockpit with you to rebut your testimony as to the flight visibility as viewed from the cockpit, they have no case for a violation of 91.175(c)(2). See Administrator v. Pisarek. However, they still might get you for 91.13 careless/reckless -- as they did Mr. Pisarek. That said, unless something bad happens (as it did with Mr. Pisarek, who wrecked his Aztec by landing with one main wheel in the snow and the other on the plowed runway at night with 1/16 mile ground vis), the FSDO is most unlikely to ever hear about it, no less do anything about it.
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I thought they busted a guy where one end of the runway (and of course the one with wx reporting) was covered in fog, but the other end was CAVU. He landed on the clear end. Inspector was present, and they busted him for it because the A?OS was reporting IMC.
 
EdFred said:
I thought they busted a guy where one end of the runway (and of course the one with wx reporting) was covered in fog, but the other end was CAVU. He landed on the clear end. Inspector was present, and they busted him for it because the A?OS was reporting IMC.
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do you have any more information on this? Where it happened, etc?
 
EdFred said:
I thought they busted a guy where one end of the runway (and of course the one with wx reporting) was covered in fog, but the other end was CAVU. He landed on the clear end. Inspector was present, and they busted him for it because the A?OS was reporting IMC.
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When you find the case and the details, let us know. Until then, I'll stick with what it says in the regulations and the case I cited.
 
Cpt_Kirk said:
Scenario:

Rain showers are moving off the field. Field is IFR because of rain on AWOS equipment. You are VMC on a straight in RNAV approach. You have the entire runway and field environment in sight 5 miles out. Tower reports visibility as 2 miles and increasing. AWOS reports 1/4 mile because of rain and location on field.

Approach mins are 1 mile and 500 feet. Which vis report takes precedence? Is it legal to land? Can't find in FAR/AIM. Only looked for a few mins.
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Is the tower reporting visibility as 2 miles, or tower visibility as 2 miles?
 
kkoran said:
Is the tower reporting visibility as 2 miles, or tower visibility as 2 miles?
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The tower can never know what "in flight visibility" is. That can change between two airplanes on final.
 
I've had this issue at my home field. I had to wait almost 3 hours during my CFI ride for the fog to burn off around the AWSS station. The FAA inspector said it was still IFR even though 90% of the field, including the runway, was unlimited vis.
 
Kritchlow said:
The tower can never know what "in flight visibility" is. That can change between two airplanes on final.
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I didn't say the tower's description of the visibility made a difference regarding the approoah minimums, but I doubt the OP would have asked the question if he understood that the controller's observation is the official one.
 
kkoran said:
I didn't say the tower's description of the visibility made a difference regarding the approoah minimums, but I doubt the OP would have asked the question if he understood that the controller's observation is the official one.
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For aircraft operations, when there is a conflict between the tower reported visibility and the surface reported visibility (usual point of observation) the lower of the two will be used.

In this case, neither one applies.
 
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Velocity173 said:
For aircraft operations, when there is a conflict between the tower reported visibility and the reported visibility (usual point of observation) the lower of the two will be used.
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That is the case with "tower visibility", where the visibility from the control tower is provided in addition to the surface visability, but when the controller, acting as a LAWRS observer, corrects non-representative data from the automated observing system IAW JO7900.5C, Para 2.5.

Velocity173 said:
In this case, neither one applies.
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I concur.
 
kkoran said:
That is the case with "tower visibility", where the visibility from the control tower is provided in addition to the surface visability, but when the controller, acting as a LAWRS observer, corrects non-representative data from the automated observing system IAW JO7900.5C, Para 2.5.


I concur.
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I concur as well. :wink2:
 
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