CaptainTeezy

Scenario: You are on an instrument approach outside the FAF/OM and the ceiling and vis are both below mins. However you are 10 miles out and can see the entire runway and lighting system. It seems that just a small patch of fog is just over the actual reporting sensor. Can you legally shoot that approach if you can stay visual the whole way?



Another Scenario: I have not been able to find in the regs or my ops specs that Vis is controlling over ceiling if you are going to shoot an approach to land, yet others have told me that you can shoot an approach if the vis is say 10 sm but the ceiling is only 100 feet, if the mins are 1/2 and 200. In fact the only place I have seen the vis is controlling is RVR over SM when it comes to take off.

Thanks all.

ppilot

Scenario 1, probably not. The only way I can think to do this is with a contact approach, and 135 operators are typically not approved for this. This is covered in 135.225(a)(2). If you're approved for VFR (or SVFR for an controlled field) you may be able to cancel and land VFR.

Scenario 2 is covered in 91.175(c)(2). What others are telling you is correct.

aviatorhi

Depends on what the minimums are... might be too low for an approach but high enough for SVFR (Class C/D).

Theoretically you could maintain VFR the whole way in by using your "cockpit cutoff angle" and staying clear of clouds (Class G).

Helps if you and another pilot report the machine as unreliable then it would get NOTAMd and you could do VFR anyway.

The administrator has been of the opinion in the past that 135 required ceiling and vis to begin the approach.

Otherwise since you need to have legit weather before you begin an approach under 135 you'd be hosed (you can't enter the TAA even). As far as 121 goes, I believe the regs would allow you to fly the approach to the FAF without weather being sufficient and continue the approach any time you have the runway and lighting system in sight.

Someone once told me about the "local obscuration" rule for 121 which lets you fly and land off any approach in reported vis no lower than 1/2 mile as long as you can verify it is only a "local obscuration" to the weather equipment which is causing the report to drop below VFR, never looked into that one and it might just be something someone didn't understand, never had a need for it.

CaptainTeezy

91.175c2 talks about going below MDA/DH not starting the approach, plus it is a 91 reg. Maybe I am missing something though...?

ppilot

Unfortunately 135 regs (and 121 I imagine, though I don't know them very well) are not all-encompassing. You are still bound by 91 regs under 135 unless the 135 regs address the same issue differently. You have to look at it sort of like 91 < 135 < Op-Specs.

So, 135.225(a)(2) says that you can't begin an approach unless conditions are above the IFR landing minimums, which are addressed in 91.175, which says you can't operate below DA/DH or MDA unless the visibility is greater than/equal to the visibility minimums prescribed on the approach procedure. It doesn't say anything about ceiling in the regulations (or on the approach plate. The plate just says the minimum altitude to which you can descend without meeting the requirements in 91.175).

Make sense?

Phantom Flyer

I'm coming from a 121 background although I have flown for Part 135 carriers in the past. As a PIC, the only concern you have under 121 and I would imagine 135 as well, is your company issued, FAA approved OpsSpecs. Period. Yes, you have to adhere to Part 121/135 rules but your FAA approved OpsSpecs always determine what you can and can't do. If something isn't clearly delineated in your OpsSpecs, ask your D.O., FAA POI or simply follow 121/135.

Just my two cents devalued to $ 0100098 on today's close.

G'Day Mates

deadstick35

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

__________________
http://www.searchk9.net/helitac/harryreasoner.htm

aviatorhi

91.175(d) says you may not land below the minimums for the approach... but who determines the weather when in flight, I believe that would be the pilot, you may not begin approaches when the weather is below minimums under 135, you may go up to the FAF under 121 (or land off a visual if it's a 1/2 mile at least assuming a local obscuration), you may go past the FAF 121 if the weather is at least minimums and then you are required to determine if the weather is legal when you are at the MAP/VDP/DH etc. etc. and determine if it is legal to land.