Staying in class B on a Vis app

[luv2fly]

Lets start a list of ILS app that the GS will take you out of the bottom of Class B. I am aware that the FAA has changed most, but I think there is still a few out there.

With all the vis going on it would be nice to have a list of places that the stepdowns need to be followed at least for a bit to insure FAR compliance re: staying within the confines of class B

 

[HalinTexas]

Help me here. Where does it say that you have to stay in the confines of a class B? As far as I know, you just have to follow the regs for whatever airspace you're in. You must be thinking of MDW.

 

[set essential]

It's somewhere in Part 91 under operations in Class B airspace.

 

[purduedchi]

I don't believe that just being on the published step downs will ensure staying within Class B airspace. These steps downs are only to ensure obstacle clearance...that's pretty much the only reason they are there. I know for all class B airports we are given a 10-1 page (I think that is that chart #) that depicts the class B airspace altitudes and boundries. It's up to the pilot to know where he/she is. It's almost like departing from an airport underlaying the Class B...200 knots or slowest clean climb speed until the Class B. From what I can recall, then only thing that you would need to change if going below the Class B on a vis app is your speed...so if it's close, then slow to 200. I do know that PHL will let you know when you are departing the Class B(going below) while they are vectoring you for the visual. Maybe they should all do that.

 

[Ralph Wiggums]

Help me here. Where does it say that you have to stay in the confines of a class B? As far as I know, you just have to follow the regs for whatever airspace you're in. You must be thinking of MDW.

At the risk of being flamed, I've never seen this requirement in print, either.

FWIW, I was bored one day in a hotel in LAS when I looked at the ILS 25L approach to see what differences there would be in Class B protection, etc. if one followed the GS vs. the step-downs from PRINO to the runway.

News flash: The instant you leave 8000' inside of PRINO following the step-down profile, you are descending below the floor of the Class B. PRINO is 21 DME from LAS, but the floor of the Class B doesn't drop from 8000' to 6500' until 20 DME, so for 1 NM, you are below the Class B.

If you remain at 8000' after passing PRINO and intercept the GS before descending, you will still descend below the Class B, but it will only be for about the first 40' or so of the descent. Following the GS the rest of the way results in descending below the 6500' floor of the Class B between about 15.5 and 15.0 DME from LAS, after which time you remain in the Class B until touchdown.

So, following the step-downs exactly puts you below the Class B for 1 NM, while following the GS put you below the Class B for less than 0.5 NM.

These were back-of-the-envelope calculations using a 3 degree GS and a TCH of 64', so someone correct me if I'm wrong. But it appears to me that either way you fly this approach, you're gonna leave and reenter the Class B.

 

[The Prussian]

Somewhere I remember reading where clearance for a visual approach to the primary airport for which the Class B airspace is based upon, is not a clearance to descend below the lateral limits of Class B airspace. Visuals to secondary airports (ie. MDW) you will of course drop below Class B confines, in which case you need to observe the speed limits.

 

[rptrain]

91.131(a)(2) Unless otherwise authorized by ATC, each person operating a large turbine engine-powered airplane to or from a primary airport for which a Class B airspace area is designated must operate at or above the designated floors of the Class B airspace area while within the lateral limits of that area.

 

[m80drvr]

It will also be printed in the ops specs for your company under the authorization to conduct visual approaches.

Las Vegas 25L ILS had that problem but I believe that the FAA lowered the floor the B to fix it. I don't really worry about it much though. Just add it to the list of thins the FAA can bust you on if they feel like it. I just stay at the published altitudes.

 

[luv2fly]

It will also be printed in the ops specs for your company under the authorization to conduct visual approaches.

Las Vegas 25L ILS had that problem but I believe that the FAA lowered the floor the B to fix it. I don't really worry about it much though. Just add it to the list of thins the FAA can bust you on if they feel like it. I just stay at the published altitudes.

Exactly what I was talking about, but I think we still have a few approaches that following the GS will take you out of the B if you are following it outside the GS intercept point.

 

[SWA GUY]

Exactly what I was talking about, but I think we still have a few approaches that following the GS will take you out of the B if you are following it outside the GS intercept point.

So fly the GS 1 dot high....

And if the GS takes you out of the Bravo airspace....then the person that designed the ILS is an idiot.