Guidance interpreting sectional map, please

[Skybuyer]

Good area for study. It is the area I fly in most often. Pop quiz if you're up for it...
Legally as per the FAA and controlled airspace, can I fly a drone In Center City Philadelphia, and to what maximum altitude? Bonus points: Let's say you have your Part 107 license and can meet all regulations (i.e. flight over people, maintaining VLOS), how high can you fly in the immediate vicinity of the Comcast Technology Center? That is the tallest building in Philadelphia and is shown on the sectional.

I confess, I couldn't even find the Comcast center on the map no matter how hard I looked. I even, after giving up tried to dial into the location with a standard map and still can't determine where it is on the Sectional. Also, isn't the center of Philly Class B space? The floor just off the airport is 300ft and ceiling is 7000. The only thing I can find that would hint to be the Comcast Center that I know to be 1121ft is a box just N of Willaimsport that sawys 112.0 PNE... but only a guess. What exactly is VOR N Philadelphia?

You wanna flesh this map out for me? So much information.

 

[brett8883]

I confess, I couldn't even find the Comcast center on the map no matter how hard I looked. I even, after giving up tried to dial into the location with a standard map and still can't determine where it is on the Sectional. Also, isn't the center of Philly Class B space? The floor just off the airport is 300ft and ceiling is 7000. The only thing I can find that would hint to be the Comcast Center that I know to be 1121ft is a box just N of Willaimsport that sawys 112.0 PNE... but only a guess. What exactly is VOR N Philadelphia?

You wanna flesh this map out for me? So much information.

I just lined up the google map with the chart and followed the waterway up and picked out the tall building

The shelf of the class B in this area is 1500-7000. It would be kinda nice if you could search Shy Vector by address or landmark

 

[PhantomFandom]

If it is the one on Arch St it is not in the controlled airspace.

Yes that is exactly the one. I could have given more clues but since I gave the exact name of the building and the fact that it is the tallest building in Philadelphia, that should have been ample information, and it was.

Correct, it is NOT in the Class B PHL controlled airspace 8 NM inner circle. You can see that the FAA was nice enough to carve out a nice wedge from the Class B Surface to 7000 airspace, so it accommodates most of the city. This is the downtown area of the city which is known by everyone in the area as Center City. There are many skyscrapers in that area so it makes sense that both the FAA and airlines would not want to have flight paths at low altitudes right through there.

If you are referring to the lighted tower of 1153 MSL then I believe you can go to 1553 MSL with Part 107.

Yes that is the one. So we "might" be able to fly up to a maximum of 1553 feet MSL (1522 feet AGL) as long as we are within a 400 foot radius of the building itself. HOWEVER, there is Class B airspace directly above our heads at that spot with a lower limit of 1500 feet. So the actual answer is that we can only fly up to 1499 MSL (1468 AGL) in order to stay out of Class B airspace. So before takeoff, make sure to set that maximum altitude in your app to no more than 447 meters.

Interesting situation is that the Comcast Tower (different building) right across the street is 973 feet AGL so it creates a nice oval shape surrounding both buildings which would allow you to fly up to 1173 feet AGL over a decent size area.

Of course would have to check for TFRs

Nice addition! Always check TFRs in the area since parts of Center City are within the TFR for sporting events. The stadiums (football, baseball, basketball, and hockey) are all just about 3.5 miles from the Comcast Towers. As such they are just outside the sporting event TFR but other TFRs can and do pop up.

Thanks for posting the question - hopefully I got it right - if not it shows me I have more research to do

Yes you got it mostly right. Just needed to check the Class B airspace above the building, which is the limiting factor in this case. Thanks for contributing.

 

[PhantomFandom]

The class B starts at 1500 feet so you could go up to 1499 feet.

Absolutely correct, as long as you stay within a 400 foot radius of the building.

 

[PhantomFandom]

I confess, I couldn't even find the Comcast center on the map no matter how hard I looked. I even, after giving up tried to dial into the location with a standard map and still can't determine where it is on the Sectional.

Sometimes it is difficult to find actual landmarks on the sectional. In this case, being the tallest building in the city it is clearly marked on the sectional as a lighted tower with a height of 1153 MSL. Thanks @brett8883 for the detailed pictures showing exactly where it is!

Also, isn't the center of Philly Class B space? The floor just off the airport is 300ft and ceiling is 7000.

See my post #23 above describing why it is not in the Surface to 7000 inner radius. Note that the Class B airspace starts at surface and not 300 feet. The area you are referring to is just a small cutout near a wildlife area.

What exactly is VOR N Philadelphia?

Are you referring to the VOR for NE Philadelphia? That is another smaller airport just to the northeast. Its airspace does overlap somewhat with PHL but does not stretch over into Center City.

 

[PhantomFandom]

I just lined up the google map with the chart and followed the waterway up and picked out the tall building

The shelf of the class B in this area is 1500-7000. It would be kinda nice if you could search Shy Vector by address or landmark

Yes it would be a nice way to look up spots on the sectionals.

Great answer to the questions!

 

[Mavic Mac]

Yes that is exactly the one. I could have given more clues but since I gave the exact name of the building and the fact that it is the tallest building in Philadelphia, that should have been ample information, and it was.

Correct, it is NOT in the Class B PHL controlled airspace 8 NM inner circle. You can see that the FAA was nice enough to carve out a nice wedge from the Class B Surface to 7000 airspace, so it accommodates most of the city. This is the downtown area of the city which is known by everyone in the area as Center City. There are many skyscrapers in that area so it makes sense that both the FAA and airlines would not want to have flight paths at low altitudes right through there.


Yes that is the one. So we "might" be able to fly up to a maximum of 1553 feet MSL (1522 feet AGL) as long as we are within a 400 foot radius of the building itself. HOWEVER, there is Class B airspace directly above our heads at that spot with a lower limit of 1500 feet. So the actual answer is that we can only fly up to 1499 MSL (1468 AGL) in order to stay out of Class B airspace. So before takeoff, make sure to set that maximum altitude in your app to no more than 447 meters.

Interesting situation is that the Comcast Tower (different building) right across the street is 973 feet AGL so it creates a nice oval shape surrounding both buildings which would allow you to fly up to 1173 feet AGL over a decent size area.


Nice addition! Always check TFRs in the area since parts of Center City are within the TFR for sporting events. The stadiums (football, baseball, basketball, and hockey) are all just about 3.5 miles from the Comcast Towers. As such they are just outside the sporting event TFR but other TFRs can and do pop up.


Yes you got it mostly right. Just needed to check the Class B airspace above the building, which is the limiting factor in this case. Thanks for contributing.

Herein lies the problem

When you go to Visualize it: See FAA UAS Data on a MapFederal Aviation Administration. On this site you can see Arch Street is not under controlled airspace - very close to 200', 400' and 0' . So lesson learned - don't trust just one FAA site - always check the charts !
Again - thanks for the quiz

 

[PhantomFandom]

Herein lies the problem

When you go to Visualize it: See FAA UAS Data on a MapFederal Aviation Administration. On this site you can see Arch Street is not under controlled airspace - very close to 200', 400' and 0' . So lesson learned - don't trust just one FAA site - always check the charts !
Again - thanks for the quiz

That is exactly what I always tell people. Never rely on just one source of information. The UAS Facilities chart is technically correct because its goal is to show you where you need LAANC authorization to fly. Since the normal maximum altitude for UAS pilots is 400 feet then it is correct in that regard. The Comcast Towers are outside the surface Class B, and as such you do not need LAANC and can fly legally up to 400 feet.

This sample flight is above the 400 foot max altitude due to the Part 107 rule for structures. As such you must check the sectional to ensure that you are not encroaching on any other controlled airspace. In this specific case you need to stay below the 1500 foot Class B shelf.

 

[Mavic Mac]

This sample flight is above the 400 foot max altitude due to the Part 107 rule for structures. As such you must check the sectional to ensure that you are not encroaching on any other controlled airspace. In this specific case you need to stay below the 1500 foot Class B shelf.

Just out of curiosity do you know if you can get flight authorization to fly the height of that tower +400' under Part 107 ?

 

[PhantomFandom]

Just out of curiosity do you know if you can get flight authorization to fly the height of that tower +400' under Part 107 ?

Definitely not through LAANC. You would need to apply to the FAA for special authorization or waiver. Even then you would need a really good reason and justification to do so.

Remember that is very busy airspace up there. Even though it is highly doubtful any plane would be flying just 400 feet above the top of that building, it would be possible. The approach routes into PHL generally route planes to the North of the city and then down the river to the airport, but again it is all Class B so planes could be there.

 

[Skybuyer]

I look at the other sectional map posted and it is very clear and clean. I might not have known the answer to the questions, but I would have been able to locate the Comcast Center and it is clear on the other map that it is 1122 feet tall. Even with guidance I still can't find it on the map I looked up. Are there different maps published? How will I know I'll get clear maps on the Part 107 test?

I wouldn't have known until now that the "M" figures are buildings. Is there a legend available somewhere to decode the different symbols on the map? Those M's could easily be mistaken by an untrained person (like me) to be mountains. Also.... I don't see the Comcast Center on the original map I presented yet, even though not labeled the height is clear. Can I interpret the 1153 as the height of the tower on the Com Center or does it represent something else?

 

[Mavic Mac]

From Aeronautical Chart Bulletins (FAA site)

Aeronautical information changes frequently; more frequently than every six months. That is why we publish the Aeronautical Chart Bulletin in the Notices Section of the Chart Supplement every 56 days and why it is important that you consult the Notices to Airmen ( NOTAMs ) prior to each flight.

 

[PhantomFandom]

Even with guidance I still can't find it on the map I looked up. Are there different maps published? How will I know I'll get clear maps on the Part 107 test?

There is only one OFFICIAL and current VFR sectional. I don't know where your copy came from but it definitely looks off. The other one is what a current sectional should look like.

The sectionals in the workbook for the exam are not up to date but that's not important. What is important is that they are clear and will have the information you need to properly answer the questions.

I wouldn't have known until now that the "M" figures are buildings. Is there a legend available somewhere to decode the different symbols on the map?

Yes the legend is on every sectional map itself and will also be provided to you in the workbook for the exam. I can see how it looks like an M but that is actually the symbol for multiple obstructions. See how it applies from the VFR sectional legend portion below...

Can I interpret the 1153 as the height of the tower on the Com Center or does it represent something else?

Yes that is correct. It is the altitude (MSL) of the tallest obstruction among that cluster of obstructions. Remember this "map" is for pilots and the important part of the obstructions is the altitude you need to fly so that you don't hit them. So it really doesn't matter which one of the towers it refers to, since they are so closely clustered. If a pilot flies above that altitude in that vicinity then they won't hit those buildings.

In my example we know it applied to the building in question because it is the tallest building in Philadelphia, and if you look up that building its official height correlates to the sectional within 1 foot.

 

[Skybuyer]

There is only one OFFICIAL and current VFR sectional. I don't know where your copy came from but it definitely looks off. The other one is what a current sectional should look like.

The sectionals in the workbook for the exam are not up to date but that's not important. What is important is that they are clear and will have the information you need to properly answer the questions.


Yes the legend is on every sectional map itself and will also be provided to you in the workbook for the exam. I can see how it looks like an M but that is actually the symbol for multiple obstructions. See how it applies from the VFR sectional legend portion below...

View attachment 108733

Yes that is correct. It is the altitude (MSL) of the tallest obstruction among that cluster of obstructions. Remember this "map" is for pilots and the important part of the obstructions is the altitude you need to fly so that you don't hit them. So it really doesn't matter which one of the towers it refers to, since they are so closely clustered. If a pilot flies above that altitude in that vicinity then they won't hit those buildings.

In my example we know it applied to the building in question because it is the tallest building in Philadelphia, and if you look up that building its official height correlates to the sectional within 1 foot.

Thank you. I will add the legend to my study notes. It seems the map I found is quite poor in comparison.

There is one bit of confusion on your map. Typically drone operations are not permitted within 5 miles of an airport without authorization (Class B), but there is a "cutout" in the Philly area where the Comcast Center resides. Is that typical and because the Comcast Center is so high that it caused the deviation in the air space? If so can you elaborate? And if that is the case where it is no longer Class B, would that put it in Class E space, thus allowing the drone pilot to fly 400 feet above the tower 1521 if flying within 400 feet of the structure?

 

[PhantomFandom]

Typically drone operations are not permitted within 5 miles of an airport without authorization (Class B)

The 5 mile radius rule no longer applies to UAS operations. That was before the FAA re-authorization act. The current regulations just require you to follow the regulations regarding controlled airspace, which is exactly what we are looking at on the sectional chart. Airspace differs from one place to the next depending on many factors. In this case the inner Class B circle is an 8 NM radius.

but there is a "cutout" in the Philly area where the Comcast Center resides. Is that typical and because the Comcast Center is so high that it caused the deviation in the air space?

I can't say that there is a "typical" scenario and that's why it is always important to have current charts for the exact area where you plan to fly. In this case it seems to be that the cutout is there so that other VFR operations can take place in the area without infringing on controlled airspace. Such traffic would include helicopters and general aviation fixed wing aircraft. Being there often I can tell you that there are frequently news helicopters hovering directly above the city. They can do so without any special clearance as long as they fly below 1500 feet.

hus allowing the drone pilot to fly 400 feet above the tower 1521 if flying within 400 feet of the structure?

Please see post #23 above regarding the actual altitude to which you can fly there.

 

[brett8883]

I look at the other sectional map posted and it is very clear and clean. I might not have known the answer to the questions, but I would have been able to locate the Comcast Center and it is clear on the other map that it is 1122 feet tall. Even with guidance I still can't find it on the map I looked up. Are there different maps published? How will I know I'll get clear maps on the Part 107 test?

I wouldn't have known until now that the "M" figures are buildings. Is there a legend available somewhere to decode the different symbols on the map? Those M's could easily be mistaken by an untrained person (like me) to be mountains. Also.... I don't see the Comcast Center on the original map I presented yet, even though not labeled the height is clear. Can I interpret the 1153 as the height of the tower on the Com Center or does it represent something else?

View attachment 108729

SkyVector: Flight Planning / Aeronautical Charts is what I use and where that came from. It is somewhat interactive so you can click on things and get more information