When to make a full instrument approach?

[Lead Sled]

Right, but I mean if RVR is reporting below mins, then just because I break out and see the other end of the runway (maybe a mile long or more) I still can't land. In this case, RVR could get me busted for landing below mins, even though I could clearly see across the field. I'm not talking about getting busted for shooting the approach. I'm talking about busting for landing. Hell, part 91, I can go missed and back down the glide slope all day long if it's 0/0...just can't land...You can't legally land if RVR is reporting below mins...at least that's how it was always laid out to me. Flight visibility over-rules tower visibility, but RVR over-rules "flight" visibility.

Minitour...
Thanks to the miracle of cut & paste, I've inserted the appropriate exerpts from the FAA's website. I've highlighted the appropriate passages:
"§ 91.175 Takeoff and landing under IFR.

(a) Instrument approaches to civil airports.

Unless otherwise authorized by the Administrator, when an instrument letdown to a civil airport is necessary, each person operating an aircraft, except a military aircraft of the United States, shall use a standard instrument approach procedure prescribed for the airport in part 97 of this chapter.

(b) Authorized DH or MDA. For the purpose of this section, when the approach procedure being used provides for and requires the use of a DH or MDA, the authorized DH or MDA is the highest of the following:

(1) The DH or MDA prescribed by the approach procedure.

(2) The DH or MDA prescribed for the pilot in command.

(3) The DH or MDA for which the aircraft is equipped.

(c) Operation below DH or MDA. Except as provided in paragraph (l) of this section, where a DH or MDA is applicable, no pilot may operate an aircraft, except a military aircraft of the United States, at any airport below the authorized MDA or continue an approach below the authorized DH unless—

(1) The aircraft is continuously in a position from which a descent to a landing on the intended runway can be made at a normal rate of descent using normal maneuvers, and for operations conducted under part 121 or part 135 unless that descent rate will allow touchdown to occur within the touchdown zone of the runway of intended landing;

(2) The flight visibility is not less than the visibility prescribed in the standard instrument approach being used; and

(3) Except for a Category II or Category III approach where any necessary visual reference requirements are specified by the Administrator, at least one of the following visual references for the intended runway is distinctly visible and identifiable to the pilot:

(i) The approach light system, except that the pilot may not descend below 100 feet above the touchdown zone elevation using the approach lights as a reference unless the red terminating bars or the red side row bars are also distinctly visible and identifiable.

(ii) The threshold.

(iii) The threshold markings.

(iv) The threshold lights.

(v) The runway end identifier lights.

(vi) The visual approach slope indicator.

(vii) The touchdown zone or touchdown zone markings.

(viii) The touchdown zone lights.

(ix) The runway or runway markings.

(x) The runway lights.

(d) Landing. No pilot operating an aircraft, except a military aircraft of the United States, may land that aircraft when—

(1) For operations conducted under paragraph (l) of this section, the requirements of (l)(4) of this section are not met; or

(2) For all other part 91 operations and parts 121, 125, 129, and 135 operations, the flight visibility is less than the visibility prescribed in the standard instrument approach procedure being used.

(e) Missed approach procedures. Each pilot operating an aircraft, except a military aircraft of the United States, shall immediately execute an appropriate missed approach procedure when either of the following conditions exist:

(1) Whenever operating an aircraft pursuant to paragraph (c) or (l) of this section and the requirements of that paragraph are not met at either of the following times:

(i) When the aircraft is being operated below MDA; or

(ii) Upon arrival at the missed approach point, including a DH where a DH is specified and its use is required, and at any time after that until touchdown.

(2) Whenever an identifiable part of the airport is not distinctly visible to the pilot during a circling maneuver at or above MDA, unless the inability to see an identifiable part of the airport results only from a normal bank of the aircraft during the circling approach."

Please show me where RVR is even mentioned. What is mentioned is Flight Visibility. In other words, if you got the vis from your seat you can land.

'Sled

 

[Swerpipe]

Please show me where RVR is even mentioned. What is mentioned is Flight Visibility. In other words, if you got the vis from your seat you can land.

'Sled

Hi Sled,

You are absolutely correct. The only problem is that since flight visiblity forecasts or reports are not issued, when you are flying Part 135 or Part 121 and you are about to cross the FAF, you need to have the report of RVR or visibility be at or above the minimum that applies to flight visibility because otherwise you are not legal to shoot the approach. Once inside the FAF and you get to DH or MDA then the flight visibility is controlling. This is all for Cat 1 for Cat 2 and or 3 the RVRs are controlling. So RVR is not mentioned but for Part 121 or 135 it is controlling even for Cat 1 approaches (need to be at or above minimum for dispatch and for crossing the FAF inbound)

 

[Lead Sled]

Hi Sled,

You are absolutely correct. The only problem is that since flight visiblity forecasts or reports are not issued, when you are flying Part 135 or Part 121 and you are about to cross the FAF, you need to have the report of RVR or visibility be at or above the minimum that applies to flight visibility because otherwise you are not legal to shoot the approach. Once inside the FAF and you get to DH or MDA then the flight visibility is controlling. This is all for Cat 1 for Cat 2 and or 3 the RVRs are controlling. So RVR is not mentioned but for Part 121 or 135 it is controlling even for Cat 1 approaches (need to be at or above minimum for dispatch and for crossing the FAF inbound)

Swerpipe...
That is correct; however, this discussion pertains to Part 91 operations only. I think that who ever explained this to Minitour was confusing the Part 121/135 and Part 91 requirements. Under Part 91, you are indeed allowed to start the approach, regardless of the weather reports (or lack of the same) and, if you get to the DH/MDA and have the appropriate visual references you are legal to land.

'Sled

 

[HMR]

Mini,
FWIW- Lead Sled has more time inside the FAF on low vis approaches than I have total time. If you ever have the pleasure of hanging out with him (I have)- bring a notebook.

 

[Swerpipe]

Part 91 World

Swerpipe...
That is correct; however, this discussion pertains to Part 91 operations only. I think that who ever explained this to Minitour was confusing the Part 121/135 and Part 91 requirements. Under Part 91, you are indeed allowed to start the approach, regardless of the weather reports (or lack of the same) and, if you get to the DH/MDA and have the appropriate visual references you are legal to land.

'Sled

You are right Sled. Hey about weather reports, correct me if I'm wrong but the only weather report needed Part 91 is the airport's altimeter setting or the altimeter setting for an airport authorized for the IAP.

 

[Lead Sled]

You are right Sled. Hey about weather reports, correct me if I'm wrong but the only weather report needed Part 91 is the airport's altimeter setting or the altimeter setting for an airport authorized for the IAP.

That's correct, you don't need any weather per se, just an altitmeter setting.

'Sled

 

[minitour]

That's correct, you don't need any weather per se, just an altitmeter setting.

'Sled

Thanks for clearing it up man...I always wondered where they got the RVR thing...

So...I guess technically if the required vis was 1/2 and the runway was 5,000' and you landed....all you'd have to say is "saw the end of the runway", right?

-mini

 

[Lead Sled]

One More Time - SLOWLY

So...I guess technically if the required vis was 1/2 and the runway was 5,000' and you landed....all you'd have to say is "saw the end of the runway", right?

Mini...
You keep on trying to make this overly complicated. (I can't believe I said that after reading my entire answer. ) I guess that you what you said was correct; however I want you to understand that the only end of the runway that you have to see is the approach end, not the departure end.

When operations are being conducted under Part 91, all you need is an appropriate altimeter setting in order the initiate the approach and descend to either the DH or MDA.

In order to continue the descent below the MDA or DH you must be (Reference 91.175):
1. Continuously in a position from which a descent to a landing on the intended runway can be made at a normal rate of descent using normal maneuvers. This is to prevent pilots from lingering at the DH or MDA, hoping to catch a glimpse of the runway in time to chop the power and drop like a brick. It also prohibits the pilot from continuing an approach below the MDA or DH if he loses sight of the runway environment at any time after descending below the MDA or DH

2. The flight visibility must not be less than the visibility prescribed in the standard instrument approach being used. This is the part that allows Part 91 operators to take a look see. However, the FAA will more than likely take a dim view if a pilot claims that his inflight visability was significantly better that what the tower was reporting. This isn't a license to cheat the system, just an acknowledgement that conditions can and do vary somewhat from location to location.

3. Assuming you arrive at the MDA or DH at a position and attitude where you won't have to put on an airshow if you continue the descent to the runway, you must have at least one of the following visual references for the intended runway is distinctly visible and identifiable to the pilot:

(i) The approach light system, except that the pilot may not descend below 100 feet above the touchdown zone elevation using the approach lights as a reference unless the red terminating bars or the red side row bars are also distinctly visible and identifiable.

(ii) The threshold.

(iii) The threshold markings.

(iv) The threshold lights.

(v) The runway end identifier lights.

(vi) The visual approach slope indicator.

(vii) The touchdown zone or touchdown zone markings.

(viii) The touchdown zone lights.

(ix) The runway or runway markings.

(x) The runway lights.

Simply put, when you arrive at the MDA or DH, you look up and if you can see any one or more of the above listed items and you are legally allowed to continue the approach to the runway. When it comes to low vis approaches, they are definately easier at night. The various approach and runway lights are easier to pick out. Once you've got those in sight you're good.

Again, when it comes to landing, the restriction is flight visibility and that is determined by the pilot, not the tower. However, the same cautions previously mentioned as to the use of flight visability apply here as well.

'Sled

 

[BHMFr8Dog]

When to make a full instrument approach?


Remembering back to the CFI days...
When NOT to execute a PT...

S - Straight In (to approach course)
H - Holding pattern in lieu of PT
A - DME ARC to FAF
R - Radar vectors to FAF
P - Published NoPT route

Don't have an AIM with me to reference the para numbers, sorry.

 

[bafanguy]

Mini,


A good source of info on this particular FAR/subject is in "Amendment 91-173" that was issued when this FAR appeared with Change #42, circa 1980. It's part of the ton of paper stuff that comes with changes to the paper edition of Part 91....pages of small print...looks like you wouldn't want to read it, but it's important. I don't know if you can get it online, but if you can, it'll answer a lot of questions about the FAA's intent and thought behind this FAR.

They also put out one when Part 121 was amended covering this same subject.

Hope this helps.