IFR question
 

I occasionally read though interview gouges and there is one question that seems to appear in nearly all of them. They ask WWYD if on an approach and visibility is reported less than minimums and you are outside the FAF or if that happens and you are inside the FAF.

I have searched though my Jeppesen books and of course the FAR/AIM, but have had no luck finding the explanation. My only knowledge on the matter is that you cannot land if the current visibility is less than the prescribed minimum.

Sounds about right to me. Just keep shooting the appch until you see the ALS. (Unless you have a CAT certified a/c?!) That is correct to the best of my knowledge. Sorry if this is very bland....

D

I believe you cannot shoot the approach if Wx is below mins and you are outside the FAF, but if you are inside the FAF and Wx drops below mins, you can continue the approach (and land???)

KiloAlpha: 121.651

That explains why i couldn't find it in the regular FAR/AIM... to the FAR/FC I go. Thanks a million.

haha...oh yeah...gee wizz...forgot about that reg;) hehehe...

Sorry my post wasn't much of a help KA

D

You can continue the approach if reported vis drops below minimums after you pass the FAF, but must discontinue it if drops below mins outside of the FAF. To land, you must have the required FLIGHT visibility (IE if you see the lights at decision height, you continue or you go missed). Doesn't matter what the tower/ATIS is reporting.

Remember too that in the 121 world, ONLY visibility is the limiting factor for flying the approach (IE if you have VV00 and 1/2SM, you can attempt a regular ILS, but if you have CLR and 1/4SM you can't fly the approach).

Of course these rules only apply to commerical ops (Part 91 can attempt the approach in 0/0)

RVR is the ruling factor, if it is available.

What do you mean part 91 can attempt the approach in 0/0? Also I'm in the military and want to know the differeneces to which the Part 91/121/135 etc pertain to.
thanks
Bill

Part 135/121 flying (IE that flying that is for-hire commercial transport purposes: airlines/charter) is bound by a more strict set of regulations than Part 91 (private ownership) flying.

Since part 91 operators are not bound by FAA Operations Specifications, they can choose to attempt an approach, regardless of the weather conditions. That doesn't mean that they will be able to land, but they are welcome to give it a go under the FARs. If the ATIS is reporting Visibility less than 1/4sm and ceilings VV00, and the approach is a standard ILS (1/2 & 200), a part 91 flight can fly the approach down to minimums. If at DH (or MDA), they don't see the required items to continue (that whole list of things like approach lights, REILs, VASI, etc) they must execute a missed approach and figure out what to do.

Part 135/121 operators are bound by additional requirements. In order to attempt the approach, the visibility must be at least at minimums (or better) when the flight crosses the final approach fix. If they don't have the vis when they reach the FAF, they cannot continue the approach. If the vis drops after crossing the FAF, then they can continue to fly the approach down to minimums, at which point they must see the appropriate visual cues to continue, or they must go missed.

There are also some additional differences to part 91 flying (such as takeoff minimums). I think you'll find though that many professional flight departments incorporate the more strict rules into their operations procedures, even if they are part 91 operators.