Descending on an instrument approach

azaviator08

New Member
If you are cleared for an approach say an ILS approach, can you break off the approach anytime you have the runway environment in sight or should you go all the way down to DH and pick up the glide slope and follow that down. Same thing with nonprecision, if you have runway environment in sight can you break off the approach and descend down??
 
If you are cleared for an approach say an ILS approach, can you break off the approach anytime you have the runway environment in sight or should you go all the way down to DH and pick up the glide slope and follow that down. Same thing with nonprecision, if you have runway environment in sight can you break off the approach and descend down??

Are you descending before the published let down fix on the approach you mean?
 
I always just call the field in sight, and continue to fly the needles until I am in close. No reason not to, barring any short runway or other unusual landing requirements. The legal requirement of having the runway in sight is in relation to continuing an approach past DH, so I'd say that if you already have that prior to that point, you are more than legal to take over with a visual approach of some kind. That being said, I'd be careful about this in bad weather, as you can certainly put yourself in extremis if you end up in IMC again after you have knocked off the ILS. Trying to dodge low level bad weather below the published GS is no place I want to be. You need to be sure that you can maintain sight of the runway environment for the remainder of the approach AND that you can remain in a safe position to land at all times as well (ie no unusual heroics to keep in sight)
 
If you are flying an ILS, just stay on the GS all the way down. It will deliver you right to the 1000ft markers, every time. On non precision use either the VASI/PAPI or at the VDP to start the descent while visual.
 
When you say "break off the approach" do you mean going missed like with a series of practice approaches, or do you mean break off the approach as in "circle to land"?
 
By breaking off the approach I just mean stop following the needles and proceed VFR to the runway.

That implies that you have VFR weather minimums (3/1-5-2, or as required) appropriate to the class of airspace you are operating in. "Proceed VFR" is not the same thing as "proceed visually". If I have the field in sight on an intermediate segment and can get a visual approach, I'll ask for one. Otherwise, I'm going to execute the procedure, and follow the needles until a safe landing is assured.
 
That implies that you have VFR weather minimums (3/1-5-2, or as required) appropriate to the class of airspace you are operating in. "Proceed VFR" is not the same thing as "proceed visually". If I have the field in sight on an intermediate segment and can get a visual approach, I'll ask for one. Otherwise, I'm going to execute the procedure, and follow the needles until a safe landing is assured.

right, a visual approach is still IFR.
 
right, a visual approach is still IFR.

Yep. So is a contact approach, but I'm leery discontinuing an approach once I'm past the final approach fix if I didn't have the field in sight before the FAF. There's probably nothing prohibiting it, but it doesn't sound like a key to a long and prosperous career*.

* Sidesteps, circling excluded, of course.
 
exactly...to what purpose?

I take it back.

14 CFR 91.177 - Minimum altitudes for IFR operations said:
(a) Operation of aircraft at minimum altitudes. Except when necessary for takeoff or landing, no person may operate an aircraft under IFR below—
(1) The applicable minimum altitudes prescribed in parts 95 and 97 of this chapter.

Part 97 describes instrument approach procedures. Descent below an intermediate segment altitude is arguably not required for takeoff or landing, and would probably constitute careless or reckless operation in anything other than perfect visual conditions. Too, if you've been cleared for an approach, you are expected to comply with its minimum altitudes.
 
If you are cleared for an approach say an ILS approach, can you break off the approach anytime you have the runway environment in sight or should you go all the way down to DH and pick up the glide slope and follow that down. Same thing with nonprecision, if you have runway environment in sight can you break off the approach and descend down??

Precision approach: follow the needles all the way down.

Non-precision approach: if there's a VDP, don't descend below MDA until the VDP. If there's no VDP, then you can descend as early as you like, so long as you're not busting any other minimum altitudes (i.e. don't go below the FAF minimum altitude until you're past the FAF).
 
By breaking off the approach I just mean stop following the needles and proceed VFR to the runway.

You can do anything you want when you have the runway in sight. You don't have to tell the guy in the tower/approach that you have the runway in sight.
But let me ask this: So what if you follow the needles down or "proceed VFR"...what part of your approach is going to change? You should be maintaining a stabilized approach from this situation regardless what aircraft your in. So to me, the point is moot. You're stabilized, making small changes only to stay on the GS/LOC and when you pop out of the clouds, whether 2000 ft about the field or 100 ft your approach should not change.
 
I can't think of any good reason to break off the approach either vertically or laterally, just because i see the runway. I'd still follow the procedure.

Furthermore, if i've been cleared for an approach, wouldn't intentionally disregarding the navigation guidance be akin to a pilot deviation?
 
I can't think of any good reason to break off the approach either vertically or laterally, just because i see the runway. I'd still follow the procedure.

Furthermore, if i've been cleared for an approach, wouldn't intentionally disregarding the navigation guidance be akin to a pilot deviation?

Yes. Unless you receive an amended clearance from ATC, you are expected to comply with ATC instructions.

Shades of the localizer approach at Hawthorne, CA, where a mandatory altitude is depicted due to proximity with the Los Angeles final.
 
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