IFR and Bravo

[spiderweb]

You know, it's funny. Through the years, I've heard about how "unfriendly" some places are, but when I went there it all seemed good and routing made sense from a traffic standpoint.

Mark, I think people who are unused to Bravo perhaps misinterpret a quick, businesslike approach as "unfriendly."

 

[Dave S.]

OK...so here's a crazy one...my IFR clearance leaving KOAK (Oakland) was to climb to 3000 feet on the Nimitz 5 DP and then to expect higher from ATC. Thing is, 3,000 feet is the bottom of the SFO Bravo and they didn't even mention Bravo. I intentionally flew 20 feet lower than assigned. When I switched to ATC, they then cleared me to 4,000 feet, which is the bottom of the next Bravo shelf. Again, I flew 20 feet under the Bravo.

Question is...why would ATC give a clearance that's in theory at the bottom of the Bravo and if flown as assigned is a violation without additonal Bravo clearance? Why wouldn't they just clear to 2,900 and 3,900 respectively?

If you are on an IFR clearance you are under the command of FAA ATC. They are one unit. When controller flies you through a Class B you are cleared into the area. The controller is coordinating with the approach controller whose jurisdiction the Bravo is in the background. Nothing is busted. Unless the controller violates the airspace without coordination. In that case it’s the controllers violation, not yours.

Tex

 

[Hank S]

Couldn't be that ATL is the busiest airport in the world eh?

The ATL Bravo goes to 12,500 and keeps out most folks not making short transits to airports under the Bravo airspace; NY Bravo, with three busy airports, goes to 7000 and allows transient IFR and VFR traffic to pass through . . .

 

[mscard88]

The ATL Bravo goes to 12,500 and keeps out most folks not making short transits to airports under the Bravo airspace; NY Bravo, with three busy airports, goes to 7000 and allows transient IFR and VFR traffic to pass through . . .

Based in ATL 24 years, have flown into all the NY area airports also. Different arrival and departure routes between the two areas, ATL also provides approach service for MCN and CSG. ATL basically has arrivals and departures like spokes on a wheel. Just take a look at the arrival and departure procedures. Regardless, that's how they roll. Go VFR at 13,5 over the top. Or skirt around below the B at the lower altitudes, VFR.

 

[labbadabba]

Mark, I think people who are unused to Bravo perhaps misinterpret a quick, businesslike approach as "unfriendly."

Living in NYC for 8 years after growing up in the Midwest I think this is pretty accurate. New Yorkers aren't unfriendly. At all. I think the ratio of a-holes vs. nice guys is the same wherever you are. Ask a New Yorker how to get anywhere on the Subway and you'll get 5 different people chipping in. If you look lost anywhere outside of Times Sq someone will notice and help.

That said, people move fast and usually have some place to be so they may not always be pleasant for lack of a better word. New Yorkers spend a LOT of time on foot amongst masses of people and thus have a different sense of empathy and humanity that doesn't exist in other cities where people only get around in their cars going from garage to garage while limiting their sole interaction with the rest of humanity to whatever can be viewed on their iThingy.

 

[gasfiltered]

Try filing a flight plan that takes you through CLT.

Even if they clear you ‘as filed’ CLT TRACON will find a way to reroute you before you get there.

East-West is no problem. I flew there all summer, every day, multiple times/day was cleared across midfield at 5000 (both ways). Only once in probably close to 200 flights did we have to go around.

North-South, on the other hand, I will agree with you 100%, never had to go outside the limits of the Bravo, but they kept us (rightly so) way away from their downwind.

I was really impressed with the CLT controllers, especially compared to ATL controllers, who make even the most hostile places like Chicago feel like grandma's house. I hate ATL.

 

[flyingcheesehead]

OK...so here's a crazy one...my IFR clearance leaving KOAK (Oakland) was to climb to 3000 feet on the Nimitz 5 DP and then to expect higher from ATC. Thing is, 3,000 feet is the bottom of the SFO Bravo and they didn't even mention Bravo. I intentionally flew 20 feet lower than assigned. When I switched to ATC, they then cleared me to 4,000 feet, which is the bottom of the next Bravo shelf. Again, I flew 20 feet under the Bravo.

Question is...why would ATC give a clearance that's in theory at the bottom of the Bravo and if flown as assigned is a violation without additonal Bravo clearance? Why wouldn't they just clear to 2,900 and 3,900 respectively?

As others have mentioned, an IFR clearance implies a Bravo clearance.

However, your "fly 20 feet low" trick didn't actually do you any good. ATC sees your altitude only at a 100-foot resolution, so they had no idea you were 20 feet below the Bravo. Not to mention, allowable altimeter error of 75 feet means you may have still been technically in the Bravo. But, as you know now, it doesn't matter.

CLT for example, will let you go over the top of the Bravo on Flight Following, but if you want to stay IFR, they’ll route you the long way around regardless of altitude.

Chicago is the same way. There's no way to avoid going to the KELSI intersection it seems.

I was cleared at 10,000 feet a few years ago.
27K: Is there any altitude I can request that will avoid me having to go to KELSI?
C90: Let me check... (slight pause)... no.
27K: OK, here's what we're going to do. I'm going to climb up to 10,500, cancel IFR, and you'll give me flight following direct to OSH
C90: That will work. IFR cancellation received. Keep the same squawk.

There is another intersection to the east, but nobody knows about it because it's over the middle of Lake Michigan.

If you have GPS, you no longer have to go all the way to KELSI. You can file the T265 airway (between 4,000 and 8,000 feet) and that gets you around in a slightly shorter manner. I always jump off at the 2nd intersection from the north end of that one because from that point, direct to my home field takes me outside of T265 anyway.

I've gotten through the Bravo three times, but two of them were Sunday nights at midnight. The third was late in the evening on the way home from somewhere, and I was filed around on T265. I was flying along the south side when Center called up and said "Mooney 7ST, this has never happened before, but Chicago Approach just called up and they're going to let you through. Proceed direct Du Page, contact Chicago Approach 1xx.xx..." I didn't get to go direct destination, but they did bring me through the west side of the Bravo. That would never have happened back when I started flying.

BTW, if you want to go over Chicago IFR, you have to be above 15,000 feet - Chicago TRACON controls all the airspace below 15,000 despite the Bravo ending at 10,000. That's not at all unusual for any Bravo airspace - Most Charlies top out at 4000 AGL but their TRACONs control up through 10,000 and even higher in some cases.

 

[flyingcheesehead]

The ATL Bravo goes to 12,500 and keeps out most folks not making short transits to airports under the Bravo airspace; NY Bravo, with three busy airports, goes to 7000 and allows transient IFR and VFR traffic to pass through . . .

New York ATC is fantastic at all levels. I've had superb handling from both N90 and ZNY. N90's airspace is among the busiest and most complex, but they've always been very helpful and not made me go way out of my way. I remember going into KFRG once from the west, got an airway clearance and got to watch Newark arrivals going under me while La Guardia arrivals were going over me. Very cool.

 

[denverpilot]

Mark, I think people who are unused to Bravo perhaps misinterpret a quick, businesslike approach as "unfriendly."

Like all the people who whined about the NY controller spinning Air Lingus in the thread about that.

However, your "fly 20 feet low" trick didn't actually do you any good. ATC sees your altitude only at a 100-foot resolution, so they had no idea you were 20 feet below the Bravo. Not to mention, allowable altimeter error of 75 feet means you may have still been technically in the Bravo. But, as you know now, it doesn't matter.

Mode-S actually has the capability to encode altitude to 25’ resolution, and does, if fed with an altitude encoder that can do it. (Like the new-ish Garmin digital one that’s not connected to the transponder via a Gray-code interface but by serial port.)

We didn’t upgrade our blind encoder, since no need to in our GTX345 install, but you can put it in altitude monitor mode and watch it “roll” the altitude up in very fast steps between the hundred foot below and above if you fly on the arbitrary border inside the blind encoder...

6000..... 6025,6050,6075.... 7000... to kinda show what it looks like time-wise.

Fed with a better encoder with a digital input, it’d just go 6000... 6025... and then back down.

You can tell by watching it, the mainline code inside the transponder is built for 25’. The Grey code only gives it 100’ increments, so it rolls up like a slot machine whenever a bit changes on the Grey code interface. Flip flip flip flip.... it’s fast, but you can see it if you watch closely.

Also means you can turn on that altitude alert display on the transponder and see exactly what pressure altitude the transponder is sending, which is a nice little troubleshooting trick if the controller thinks something has gone out to lunch with the “Mode C”. Or you’re wondering why they think you’re bumping the bottom of the Bravo. (Obviously that last idea is a joke, don’t fly that close, folks...)

I realized recently that it is funny the phraseology of “stop Mode C” or “not receiving Mode C” etc... will probably continue forever in Aviation, considering they’re not receiving only Mode C from my aircraft any more at all, really. What they’re seeing on their screen might be derived from a nice fat DS17 data frame, with even the difference between my barometric and GPS altitudes in it.

Stumbled on this great old article for Mode-S from 2005... for those who want to geek out. Written by a guy at Aeroflex who make the test gear to test the things, and it is so incredibly detailed, but readable, and nice to read without paying to buy the specification documents.

https://www.skillscommons.org/bitstream/handle/taaccct/3516/Mode S.pdf?sequence=5&isAllowed=y

 

[VWGhiaBob]

It’s actually concerning to me that the OP had thought a Bravo clearance would be required when on an IFR flight plan.

From the OP: Sorry you are "concerned". I just got 92% on my written and ace'd the Oral and Practical on the first try with a comment from the DPE that he wished all students were as prepared as I was.

I could tell you 20 other things I've "learned" since getting my IFR ticket that might concern you also. One thing I've learned on this site and the other sites I frequent: Pilots don't remember 100% of what they memorized during their training. I include myself in this group. I dare say some of things I have forgotten might also concern you.

These sites are places we should all feel free to ask questions and not worry that someone will post a negative comment about them.

I will continue to post unless someone throws me off.

"License to learn": And boy have I learned a lot since getting my ticket. Looking forward to learning even more! My fellow pilots on this awesome site have helped me immensely, and for that I'm truly grateful!

 

[Jmcmanna]

Despite talking to C90 they forgot to hold one jet (out of the many) at 9000 and he climbed into us and generated a TCAS RA.

I'm still not sure why letting us go through the class B at 6000 or some altitude is better than having us buzz around on the periphery of the class B VFR in the direct path of the departures which all need to be held down.

6000 isn’t a great altitude because it is used in-house to move IFR traffic north and south over the top of O’Hare above the departures and below the arrivals. It wouldn’t bother most controllers to work some VFR traffic over the top of ORD, but when it is busy (which is a lot of the time), and multiple aircraft begin requesting class B transitions, the controllers’ workload climbs a lot.

From an ATC standpoint, underneath the class B is best because it allows the high performance traffic going into and out of ORD operate above you while keeping you close to your desired route of flight. Going over the top at 10.5, like someone said, can’t be stopped by ATC, but you are above the highest density of traffic (near the airport) while everyone is low, and by the time departures are approaching 10,000, traffic is spread out a bit more. At 6000, you’re literally in the middle of everything.

 

[flyingron]

6000 isn’t a great altitude because it is used in-house to move IFR traffic north and south over the top of O’Hare

I never got within ten miles of ORD.

above the departures and below the arrivals.

Negative. ORD was in a west configuration. Again, they had to hold the departures at 9000 to keep them from climbing into me (except for the one they missed. 6000 or 8000 would have kept me out of both traffic streams.

 

[Jmcmanna]

Not negative. Arrivals start at 11 or 12,000 and descend to 7000 from several arrival routes around the airspace. Departures climb to 5000 in every direction except within a 90 degree cutout which marks the arrival area (where arrivals descend below 7000). It doesn’t matter if O’Hare is West or East, the altitudes are the same.

10-15 west of ORD, traffic is climbing through 6000. Leaving airliners down at 5000 for 15-20 miles is not better than letting them climb to 9000, where they will be on top of slower moving traffic departing off ORD, MDW, DPA, etc. the operation works because the ORD traffic climbs above the other IFR traffic off the satellites.

15 west of O’Hare at 3500’ or below keeps you underneath everything. A simpler operation is usually a safer one. Where ATC “forgot” someone and an air carrier got an RA...if you weren’t there, the conflict wouldn’t have existed, which is the point of having class B airspace...to reduce the number of potential conflicts between users of the primary airport of the class B and other airplanes transiting the area. When someone is let into the mix who is not moving with the flow of traffic, it adds workload, and the risk of a human making a mistake increases. Class B airspace is a risk-management tool.

 

[Captain]

They say it right there when you pick up your CLEARANCE.

"ATC clears NY0U to KXYZ via runway heading, vectors to ABC as filed..."

The only further clearance you need is a clearance to land when you get there. It's also why if they want you to stop they need to amend your clearance by giving you a new clearance limit. Now you're cleared via whatever your doing to that point and must stop upon reaching.

 

[PaulS]

Don't you need to be cleared for the approach before you are cleared to land while on an instrument plan?

 

[flyingron]

You seem to misunderstand the situation, the departures were trying to climb through 10-11,000 on my flight route. They had to be held at 9000 to keep them from climbing into me. Can't see why letting them climb OVER me at 8000 wouldn't have been preferable.

 

[Jmcmanna]

Ah. Because a B738 going to MSP will climb great, but the A321 going to LAX in the summer time? Maybe they’ll be able to get on top of you, maybe not. I have had some trouble getting above RFD’s airspace with some a/c types on hot days this summer. If ORD is launching westbounds side by side on 250 and 270 headings, and there is a MDW westbound out there, vectoring might not work until they are further away from the airport...when in doubt, I stay down.

 

[flyingron]

Wrong direction. I was at 10'5 over the Lakeshore.

 

[Jmcmanna]

Okay...in that case at 6-10K you’d be in the middle of the arrival area...aircraft entering the downwind are descending to 9000 or 7000, depending on their assigned runway. At the shoreline the glide path might be around 4-5000’, but it assumes that aircraft on final aren’t above the glide slope (it happens all the time), and at 6000 you block aircraft on both downwinds. Traffic landing 27R can’t turn base until they are at 4000’...if they can’t start down out of 7000 until past the shoreline, they’ll be out of arrival’s airspace before they get to 4000’. 28C traffic descends to 5000’ over downtown. 27L landers turn final at 7000’.

Regardless of the configuration, decades of moving 3000 airplanes in and out of ORD every day has made it unlikely that a way to safely and consistently move VFR aircraft through the class B has been overlooked.

 

[flyingron]

I WASN'T VFR. Again, I was IFR and I inquired if there was any altitude I could request that would avoid having to go to KELSI. I only became VFR after that answer was no. I them buzzed along the top of the class B listening to them hold ORD departuers at 9000 except for the MD80 I watched climbing across my path that suddenly descended and reported he got a TCAS RA (I was the traffic).