3
$\begingroup$

Can the Class-E-to-surface designation indicated by the dashed magenta lines outside the dashed blue circle at Eagle County Regional airport (KEGE) be ignored when the tower is open?

Likewise at Marshall AAF (KFRI)?

Normally we would consider a dashed magenta line that does not actually enclose the airport whose approaches it protects to denote a Class-E-to-surface "extension", i.e. E4 airspace. The "extension" would be described in the E4 section of the "Airspace Designations And Reporting Points" document (FAA Order 7400.11C), typically with no comment about effective hours. Meanwhile, if the tower is not open 24 hours, the area in the dashed blue circle will be typically described in the Class D section of Order 7400.11C and ALSO in the E2 section of 7400.11C, with a note in each section to see the A/FD for the effective hours of that designation.

Here is an example of an airport with airspace designated in this manner: KMFR. The relevant pages in JO 7400.11C are E-80, E-189, and D-65. The dimensions of the E-2 airspace are identical to the dimensions of Class D airspace, except for the absence of any altitude ceiling on the Class D. The E-4 "extensions" are in effect 24/7, whether the tower is open or closed.

But at KEGE and KFRI that's not what was done. There is no listing for the airspace within the dashed magenta line in the E4 section of JO_7400.11C.

Instead, a single area of Class-E-to-surface "Surface Area designated for an airport", i.e. E2 airspace, is defined that includes the area in the dashed blue circle AND the area in the dashed magenta line that abuts the dashed blue circle. (Page E-70 KEGE, page E-16 KFRI).

There's a note that the dates and times that the E2 will be in effect will be published in the A/FD: for example, for KEGE we read "This Class E airspace area is effective during the specific dates and times established in advance by a Notice to Airmen. The effective date and time will thereafter be continuously published in the Airport/Facility Directory. AMENDMENTS 11/23/06 71 FR 46077 (Revised)"

Naturally, the airspace in the dashed blue circle is also described in the Class D section of Order 7400.11C (page D-59 KEGE, page D6 KFRI), with a note to see the A/FD for the effective times.

The A/FD (for KEGE) says "AIRSPACE: CLASS D svc 1400–0200Z‡; other times CLASS E."

No E4 airspace has been designated for KEGE or KFRI.

So the area in the dashed blue circle is Class D when the tower is open and E2 when the tower is closed. And the area enclosed by the dashed magenta line, has, oddly, been designated not as E4 airspace as per normal practice, but rather as part of the same E2 airspace that is only in effect when the tower is closed. So it seems that the entire E2 airspace should vanish when the tower is open, and should therefore simply become Class G up to 700' AGL.

Surely this is not what is actually intended.

Is the intention that the area inside dashed magenta border but outside the dashed blue circle stays E2 the whole time, while the area inside the dashed blue circle and below 9100' MSL at KEGE or below 3600' MSL at KFRI falls out of the E2 as if it were cut with a cookie cutter, and turns into Class D, when the tower is open?

Here's one problem with that idea--

There are about twenty other airports in the US where the airspace designation is similar to KEGE and KFRI, but a little different. One such example is KUNV-- University Park at State College PA-- --for the others, see this related answer: What are all the US airports where E4 "extensions" change to E2 and become part of a larger E2 "surface area" when the tower closes for the night?.

Taking KUNV as an example, the airspace enclosed by the dashed magenta lines is designated in order 7400.11C (page E-171) as E4 airspace, with a note to see the A/FD for the effective hours. There's ALSO a designation of E2 airspace (page E-37) that includes the exact same airspace AS WELL AS the area in the dashed blue circle, with a note to see the A/FD for the effective hours. And the area in the dashed blue circle is also described in the Class D section of Order 7400.11C (page D-23), with a note to see the A/FD for the effective hours.

The note in the A/FD simply says "AIRSPACE: CLASS D svc 1100–0300Z‡; other times CLASS E."

Clearly, in this case it was felt that the entire E2 airspace would vanish as a single unit when the Class D airspace was in effect, hence the need to also have an E4 airspace designation to protect the airspace in the dashed magenta projections when the tower is open.

The same situation applies at the other 20 airports listed in the linked answer.

Added note-- it is interesting to note that on the FAA's LAANC map for authorization for sUAS (drone, model airplane) flight the projecting "extensions" at KEGE and KFRI are NOT covered by the grid squares that indicate the areas where pre-authorization is required. All other E2 airspace IS covered by the grid square that indicate that pre-authorization is required, EXCEPT for part-time E2 airspace that changes to E4 whenever the adjacent control tower is open, i.e. the twenty or so airports described above. This tends to suggest that the airspace is the dashed magenta line at KEGE and KFRI is not treated as E2 airspace when the tower is open, at least in relation to FAR 107.41. However this doesn't really bear on whether this airspace still functions as some form of Class-E-to-surface airspace when the tower is open in relation to other FAR's. One shouldn't read too much into the depiction on the LAANC map.

See also this related question: May an ultralight vehicle pass directly above KEGE at 9200 MSL at 1600Z with no prior authorization without violating FAR 103.17?

Are there any other airports where the airspace designations have been set up similar to KEGE and KFRI?

$\endgroup$
  • $\begingroup$ I am curious as to why you haven't contacted the FAA directly on this and the other related questions. $\endgroup$ – MikeY Jun 13 at 18:55
  • $\begingroup$ @MikeY-- I am currently waiting for a reply on one query, but stay tuned for more-- $\endgroup$ – quiet flyer Jun 13 at 19:23
  • $\begingroup$ A more polite title might be "Is the Class-E-to-surface airspace near Eagle County Regional airport (KEGE) and Marshall AAF (KFRI) still in effect when the tower is open?" but I guess that would invalidate the existing answers wouldn't it-- $\endgroup$ – quiet flyer Jul 4 at 19:37
0
$\begingroup$

The short answer is "No." The explanation: Class E airspace is not related to tower operations, it's related to ATC. In this case, the dashed area of the Class E is protecting the precision approach to runway 25. The surrounding shaded magenta area is the transition zone.

$\endgroup$
  • $\begingroup$ Well, I understand that, but things are a little weird in these two cases. Contrasting these two examples with KENA in Alaska may be enlightening-- at KENA the "extensions" are designated as E4 w/ a note to see A/FD for effective hours, and are ALSO part of a chunk of airspace designated E2 that includes inner circle as well as the extensions w/ a note to see A/FD for effective hours. The D also has a note to see A/FD for effective hours. In that case the extensions would appear to clearly be E4 when tower is open and ratchet up to E2 when tower is closed. $\endgroup$ – quiet flyer May 7 at 15:54
  • $\begingroup$ Actually, the KENA case looks identical to the KUNV case. Not the normal way to do things, but they at least seem much less ambiguous (and less anomalous) than KEGE. At KEGE are we really supposed to assume that when the tower opens, only the area in the dashed circle stops being E2, not the area out in the extensions, even though the whole chunk of airspace is delineated as one single unit of E2 on page E-170 of the Airspace Designations document? If that would be accurate, wouldn't the same be true at KENA and KUNV? But if it is, why even bother with the E4 designations at these 2? $\endgroup$ – quiet flyer May 7 at 16:16
  • $\begingroup$ I honestly think you are trying to find complication where there isn't any. Class E is about the specifics of operations around the field and in each case it may be different. $\endgroup$ – Juan Jimenez May 8 at 8:17
0
$\begingroup$

No. The Class E surface area is part of approach corridor for the instrument approaches into that airport so additional control and weather minimums are needed for this. As such that block of airspace remains Class E 24 hours a day, whether the tower at KEGE is operative or not.

$\endgroup$
  • $\begingroup$ Then why, in the description of the E2 airspace in order 7400.11C (page E-171) faa.gov/documentLibrary/media/Order/JO_7400.11C.pdf , is there a note to see the A/FD for the effective hours? (Read the whole question carefully.) It seems to me that if the idea was that the E2 was meant to be in effect 24/7 , but for some limited portion of that E2 airspace to be automatically superseded by the Class D when the Class D was active, the note to see the A/FD for effective hours should have been only attached the Class D description, to avoid any ambiguity as to what happens to (ctd) $\endgroup$ – quiet flyer Jun 9 at 13:17
  • $\begingroup$ (Ctd) It seems to me that if the idea was that the E2 was meant to be in effect 24/7 , but for some limited portion of that E2 airspace to be automatically superseded by the Class D when the Class D was active, the note to see the A/FD for effective hours should have been only attached the Class D description, to avoid any ambiguity as to what happens to the outlying portions of the E2 when the Class D is in effect. $\endgroup$ – quiet flyer Jun 9 at 13:23
  • $\begingroup$ This airspace is a very odd case. Was there any operational reason that they didn't just set it up the normal way, (example KMFR) where the outlying portions are described in the E4 section of JO 7400.11C with no notation about effective hours, while the inner circle has identical descriptions (except for altitude ceiling) in the Class D portion of JO 7400.11C and also in the E2 portion of JO 7400.11C, with a notice to see the A/FD for effective hours attached to each? As far as I know KEGE is the only airport in the whole US whose airspace has been set up in this odd manner. $\endgroup$ – quiet flyer Jun 9 at 13:27
  • $\begingroup$ The answer above appears to address the operational reason why it would make sense to have Class-E-to-surface airspace near KEGE 24/7, but not to address the specific reasons raised in the original question (and comments above) as to why this interpretation is problematic. $\endgroup$ – quiet flyer Jun 9 at 13:46
0
$\begingroup$

It appears that the best description of the airspace designations at KEGE and KFRI is that they exactly like the 21 other airports listed here What are all the US airports where E4 "extensions" change to E2 and become part of a larger E2 "surface area" when the tower closes for the night? , except that no E4 description has been provided to cover the area in the rectangular projection to the east during the time that the tower is open and the E2 airspace is not in effect.

Technically, as the descriptions have been written, it appears that there is no Class-E-to-surface airspace in the dashed magenta projections when the tower is open.

It's not clear whether this is an oversight (mistake), or whether the airspace planners simply made a presumption at KEGE and KFRI that all the E2 airspace would remain in effect 24/7 except for the particular portion that is superseded by the Class D when the tower is open. In the latter case, it's not clear that that presumption is actually consistent with what was actually published in the "Airspace Designations and Reported Points" document.

At KEGE I've verified that local ATC treats the airspace as if there is Class-E-to-surface airspace in the projection to the east 24/7, and the same is surely true at KFRI. Whether there has been a mistake in the airspace designations or not, it makes no sense for the airspace within the dashed magenta extensions at these airports not to be treated as Class-E-to-surface airspace when the control tower is open.

It would be interesting to know of any other airports where the airspace designations have been handled in this manner.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.