KJKAN Rookie

# 1

Scenario...

IFR aircraft was at 3000' direct to the IAF RNAV 36 approach, the aircraft was going straight in at the IAF and not to do the published holding pattern that the approach has. The crossing altitude for the IAF is AT OR ABOVE 2300.

The aircraft was just over an obstruction that was 3000....so once he is flying away from that obstruction you can descend the guy to 2300 and clear him for the approach.

Now...if the aircraft is still over the 3000' obstruction and you want to clear him for the approach, can you tell the aircraft to cross the IAF AT OR ABOVE 2300, cleared RNAV RWY 36 approach?

You didn't assign an altitude below the MVA because you said at or above...?!?

I'm guessing this is a gray area at best and probably better technique would be to tell the aircraft to cross the IAF at 3000 cleared RNAV.

Thoughts?

meatasaurusx Senior Member Chi-town

# 2

I would imagine that the obstruction is in the approach plate so the pilot should know that it is there. Also, by saying cross the IAF at or above 2300 means the pilot can stay at 3000 if they want to. What if you cleared him by saying "Maintain 3000 until established on the final approach course, cleared RNAV 36 approach". That seems like it would cover your bases as well. I'm curious to hear what others think though, I can't say I know 100% if what I said is right.

KJKAN Rookie

# 3

Yeah, you would be legal to do this all day long...I'm just curious if you can do the other...obviously this would cover your butt...but I'm always curious as to other interpretations...

I guess in the long run, having an attorney rip apart these tapes, you don't want any type of confusion, cause they will hammer you with that....

Just trying to stir some discussion.

atcpookie Rookie

# 4

Roddy_Piper Resident Knucklehead SW Vegas

# 5

"at or above 2300" is 2300, 2301, 2302,...,3000. so it does include an altitude below the MVA. that would be an illegal clearance. you need to ensure the aircraft is at an altitude above the MVA, MIA, MEA, etc until established on a segment of the approach.

if he's not quite to the IAF then he's not quite on a segment of the approach yet. so in that case you can't use the IAF altitude of 2300, u need to use the MVA of 3000.

as already stated, "maintain 3000 until IAF" is a clean clearance. or u could wait until your out of the MVA and issue "cross IAF at 2300" as long as the next MVA is 2300 or less.

is the obstruction the controlling obstruction for that MVA? is there a carat above the obstruction symbol? if so, there's ways to descend when you past the obstruction but still in the higher MVA box (or circle more than likely).

towerflower Junior Member Palm Coast, FL

# 6

You also have 5-9-4 with a note at the end.

NOTE-
1. The altitude assigned must assure IFR obstruction
clearance from the point at which the approach clearance
is issued until established on a segment of a published route
or instrument approach procedure.

RoughRiderCATCC71/98-01 Newcomer Myrtle Beach, SC

# 7

1. If the obstruction is depicted, then as soon as the a/c passes the obstruction, you can clear the a/c for the approach while still in the mva circle.

2. To clear the a/c prior to reaching the obstruction(3000' mva in this case), you MUST assign an altitude to ensure proper separation from the obstruction in the approach clearance. ex. "N12345 proceed direct and cross NORTH at or above 3000', cleared GPS RY36 approach"

3. Just wait until you've cleared the obstruction mva and clear the a/c as published.