RVR question

[Nightflight]

Its been awhile since I have had to deal with RVR. Here is the question that I ran into.

So lets say you are doing an ILS. For the minimums for the ILS it states you need 1800 RVR.

Now this runway has all the reporting points working. Touchdown, midpoint, and rollout.

Lets say your touchdown states 5000 RVR, midpoint says 2400, and rollout says 1200. Are you legally able to do this approach under 121 and 135?

I thought I remember some exceptions like rollout doesn't matter or something strange, but figure might as well turn to the forums?

Luckily yesterday all the RVR values were above, so it was no question.

 

[ClearedToThe]

Its been awhile since I have had to deal with RVR. Here is the question that I ran into.

So lets say you are doing an ILS. For the minimums for the ILS it states you need 1800 RVR.

Now this runway has all the reporting points working. Touchdown, midpoint, and rollout.

Lets say your touchdown states 5000 RVR, midpoint says 2400, and rollout says 1200. Are you legally able to do this approach under 121 and 135?

I thought I remember some exceptions like rollout doesn't matter or something strange, but figure might as well turn to the forums?

Luckily yesterday all the RVR values were above, so it was no question.

Under 121 (and part 91), for a CAT I ILS only the Touchdown zone RVR is required and CONTROLS. Mid, rollout, and far-end are only advisory (if reported).

Think about it this way if it helps you remember it...

Who cares what anything other than the touchdown zone RVR is? Beyond the touchdown zone, you are (presumably ) on the runway and the "approach" has already be completed.

 

[vheissu]

For 135, touchdown RVR is controlling when it is available. Not sure about 121.

 

[Orange Anchor]

a. Arriving Aircraft

(1) Category I Weather Conditions (1800 RVR or greater)

(a) Touchdown RVR - required (controlling)
(b) Mid/rollout where installed - advisory

Note: Minima below 2400 feet will not be
authorized unless Touchdown Zone (TDZ) and
Centerline Lighting (C/L) are available.

* (2) Category II Weather Conditions (1200 RVR up to but
not including 1800 RVR)

(a) Touchdown required (controlling).
(b) Mid - not required for Category II operations
but is an FAA system requirement for runways
in excess of 8000 feet (see paragraph 7h(2)).
Where installed, provides advisory visibility
information to pilots.
(c) Rollout - required for operations when RVR is
less than 1600 to provide advisory visibility
information to pilots.
(d) The mid RVR transmissometer, if installed, may
be submitted for an inoperative rollout
transmissometer.

(3) Category IIIa Weather Conditions (below RVR 1200 to
RVR 700)
(a) Three transmissometers are required unless it
can be shown that two transmissometers
(touchdown and rollout) can meet the
operational needs for a particular airport.
Where three transmissometers are installed,
touchdown and mid are controlling and rollout
provides advisory visibility information to
pilots. If a runway requires only two
transmissometers, touchdown and rollout are
controlling.

 

[Nightflight]

Sweet, thanks guys :rawk:

 

[Orange Anchor]

Sweet, thanks guys :rawk:

I used to carry a small chart for low vis takeoff and low vis approaches. I kept it in the same pouch as the NASA ASRS form.