current language of AIM 3-2-6 is a very recent addition
Quote:
Originally Posted by
martymayes
Stalemate-
The AIM says: "Surface area arrival extensions become part of the surface area and are in effect during the same times as the surface area" (AIM 3-2-6)
I did some checking in old editions of the AIM and found that that line was only added in a revision that became effective May 26, 2016. Nothing like that appears in older editions of the AIM.
Find an AIM from 2014 or earlier, and this line won't be in it.
Though the AIM sheds light on the intent of the FARs, it is not a regulatory document, and there was no relevant change in the FARs or the "Airspace Designations and Reporting Points" document at the time that that line appeared.
Looking at the FARs or the "Airspace Designations and Reporting Points" document as they've evolved through time, I see a consistent meaning.
I find the following to be highly relevant--
"Control Zone extensions" first appeared on the legends of US sectional charts, and on the charts themselves, in mid-to-late 1992-- prior to the September 1993 airspace re-organization. If the authorities had intended for these "Control Zone extensions" to be included within the scope of the language of FARs 91.155c, 91.155d, 91.157a, 91.303c, 101.33a, and 103.17, it would have been very simple to modify these FARs to include the phrase "Control Zone extensions".This was not done. Instead, the old language was left in place until replaced in the September 1993 airspace organization by the new "alphabet" language that we have now.
This clearly indicates that when the "Control Zone extensions" were introduced in mid-to-late 1992, they not meant to fall within the scope of FARs 91.155c, 91.155d, 91.157a, 91.303c, 101.33a, and 103.17, even though much of the airspace now encompassed by the new "Control Zone extensions" had previously been part of a "Control Zone".
Note that prior to the 1993 "alphabet" revision, the language of the FARs was much simpler than what we have now. It did not include awkward phrases like "surface area of controlled airspace designated for the airport" or "surface area of Class E airspace designated for an airport", or other similar phrases. The simple phrase "Control Zones" was sufficient, and could easily have been replaced by "Control Zones and Control Zone extensions" if that had been the actual intention. Due to the simplicity of the language in use at that time, the period after the introduction of the "Control Zone extensions" in mid-to-late 1992, but before the September 1993 "alphabet" revision, provides an unusually clear window into the intended relationship between the newly-created "Control Zone extensions" and the various FARs noted above.
(According to FAR 71.1 effective 1-1-93, the actual delineations of the "Control Zones" and "Control Zone extensions" as of Nov 1 1992 were apparently spelled out in the "Compilation Of Regulations", FAA Order 7400.7A, effective 11-1-92. Another source may be "Airspace Reclassification", FAA Order 7400.9, effective 11-1-91. I haven't seen these particular documents as of yet.)
The modern language of the various FARs noted above is more awkward, but a close examination suggests that at the time of the September 1993 "alphabet" re-organization, the E3 and E4 extensions were still not meant to fall within the scope of FARs 91.155c, 91.155d, 91.157a, 91.303c, 101.33a, and 103.17.
Whether the current authorities still have the same understanding, may be an open question.
(EDIT 6-20-19-- I'm no longer finding all of the argument above quite so convincing. It's possible that when the "Control Zone extensions" first appeared on the charts in 1992, they did not yet have any regulatory significance-- the airspace may have still been officially described as part of a "Control Zone" rather than a "Control Zone extension"-- so there would have been no need to revise the FARs. It's a little unclear-- to say more, one would have to closely examine the airspace description documents from that time. The main point is that when the FARs were re-written to accommodate the September 1993 "alphabet" airspace re-organization, the choice was made to adopt the "designated for an airport" language, which does exclude the E4 airspace. For a better description of the pre-1993 history of the airspace descriptions, visit the outside link https://aviation.stackexchange.com/q...e4-airspace-us )
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Anyway, the original point of this thread was to ask if anyone knew of any oral or written communications from any FAA officials specifically addressing the ultralight issue in relation to E4 extensions, either in relation to some specific airport or in a more general sense -- see post #1-- thanks --
Steve
More thoughts after a little reflection--
Some time has passed since this thread has last been active.
My thoughts have changed a little, but not much--
In JO 7400.11C (the "Airspace Designations and Reporting Points" document), the AIM, the Pilot-Controller glossary, and many other places, the FAA seems to have acquired the habit of using the phrase "Surface Area" or "surface area" in a rather strange way, referring to an actual chunk of airspace with a vertical dimension as well as a horizontal dimension. Furthermore, many examples can be found where the horizontal extent of the airspace named as a "Surface Area" or "surface area" is construed not to include E4 Class-E-to-surface "extensions". The "Airspace Designations and Reporting Points" document is one such example.
Nonetheless, the plain language of FAR 103.17 and many related regulations suggests that within the context of those regulations, "surface area" simply means the surface footprint of a given column of airspace whose bottom is in contact with the surface. For example other regulations suggest that class B or class C airspace also can have a "surface area", even though this term is not used in JO 7400.11C in relation to these airspace types. "Within the lateral boundaries of the surface area" simply means any airspace above the surface footprint of a given column of airspace whose bottom is in contact with the surface, without regard to altitude. In this context, if we were discussing the "surface area of Class E airspace" near a given airport, it would not seem incongruent to assume we were including any adjacent E4 "extensions", despite the fact that JO 7400.11C and numerous other FAA materials follow a different practice. All things considered, it would seem to be a matter of some ambiguity-- a conflict between what the plain language of the FARs seems to suggest on first reading, and what is suggested by the convention followed in JO 7400.11C and other FAA materials in reference to Class E airspace in particular.
If we do embrace the idea that the use of the term "surface area" does not automatically exclude E4 "extensions" in the context of FAR 103.17 and other FARs with similar language, the critical point then boils down to the phrase "designated for an airport". While this phrase seems to have been superfluously retained in several recent regulations that don't even address Class E airspace (for example FAR 91.225 (e)(2)), it seems to have originally appeared in the post-"Alphabet" re-organization (post September 1993) version of FAR 103.17 and other regulations with related language as a way to indicate that the only type of Class-E-to-surface airspace encompassed by the said regulation was E2 airspace. E4 "extensions" were not meant to be included. E2 airspace is the only kind of Class-E-to-surface airspace that is named or described in the "Airspace Designations and Reporting Points" document as being "designated for an airport". If this distinction were not intended, there would have been no reason to include the phrase "designated for an airport" or any other similar phrase in FAR 103.17 and other regulations with similar language; it serves no other purpose whatsoever.
This understanding is consistent with the understanding expressed in the 2010 response from the FAA ATO Western service center re obtaining SVFR clearance in E4 "extensions" as referenced in post #30 http://eaaforums.org/showthread.php?...ll=1#post75340 , and the January 10 2018 FAA internal memo from Scott Gardner re sUAS (commercial drone) operations in E4 "extensions" (old link not working at present -- instead see https://jrupprechtlaw.com/section-10...rtain-airspace ). In both cases, E4 airspaces were understood NOT to be encompassed by the language of the relevant regulations, which had language similar to (in the former case) or identical to (in the latter case) the language of FAR 103.17.
It will be interesting to see whether the FAA continues to stay consistent with this line of reasoning in the future. There are some ambiguities in new rules regarding recreational sUAS operation (recreational model airplanes and drones) that they'll need to address one way or another. So, stay tuned.
Steve
Finding E4 airspace on the sectional chart
* Hang on I'll get to it-- you can skim through the first part of this post if you don't want to read another re-hash of the issue of interest--
* Considering that FAR 103.17 has been around in its current format for over 20 years (since the 1993 airspace re-organization), it seems surprising that the FAA has never come out with a hard-and-fast interpretation of FAR 103.17 in relation to E4 airspace. I've now asked them for an interpretation/ clarification. (A little over a month ago.) We'll see whether or not they think it is worth responding to. Depending on what they say, I might regret ever asking.
* If they don't deem the matter worthy of a response, I'll take it as an indication that the logic of the January 2018 "Gardner memo" (internal FAA memo referenced in previous posts) re FAR 107.41 (commercial "drone" operation) also applies to FAR 103.17, and that there is therefore no restriction against operating an ultralight within the E4 or E3 or E3a airspace, using due caution not to cause a hazard to other traffic of course.
* Keep in mind that the way the language of FAR 103.17 is constructed, if the E4/E3/E3a airspace were construed to be off-limits to ultralights, there would be no vertical limit of any kind on this prohibition, because the regulation says "within the lateral boundaries of". The same is true of E2 airspace as well, where there is no dispute that ultralights may not fly without prior authorization. It's kind of absurd that the E2 circle around a small airport creates a barrier to ultralight flight all the way up to 18,000', but that is in fact the way the regulation is written. In the case of an airport that is Class D during the day and changes to E2 Class-E-to-surface when the tower closes, you can operate an ultralight with no prior authorization above the Class D ceiling when the tower is open, but not when it is closed. A little weird, but that's the way regulation is written. As to whether this would ever be enforced in actual practice, who knows.
* It's also surprising that the FAA has said so little over the years on the related issue (related by virtue of similar language in the relevant regulations) as to whether or not a Special VFR clearance may be issued in such a way that it is valid for the E4/E3/E3a "extensions"-- various ATC centers seem to follow very different practices in this regard. (I called several facilities and asked some questions.) I have asked the FAA for clarification on this as well. (I have seen one FAA letter from the ATO Western Service Center, referenced in some of the prior posts, stating that due to the language of regulations, Special VFR clearance may not be authorized for an E4 extension. This is seems to support the suggestion that FAR 103.17 does not require authorization for ultralight flight in these areas, although the language of the SVFR regulation is not exactly identical to the language of FAR 103.17.)
* Anyway back to the question in the previous post-- this may help--
* "E4" is basically synonymous with "extension", or more precisely, "extensions" may be either E4, E3, or E3a. Examples are given below. Throughout this thread I've often used "E4" as shorthand for all the extensions; the comments also would apply to E3 and E3a extensions.
* In the vast majority of cases, E4 airspace is depicted on the aviation sectional charts by a dashed magenta line that does NOT actually surround the airport whose approaches are being protected. It adjoins another dashed magenta or dashed blue circle or other shape that does actually surround the airport whose approaches are being protected.
* Here are some examples of E4 airspace-- look specifically at the airspace within the dashed magenta line that does NOT surround the airport whose approaches are being protected. The airspace within the dashed magenta or dashed blue line that DOES surround the airport is E2 or D airspace and that's not what we are talking about here:
http://vfrmap.com/?type=vfrc&lat=38....19.995&zoom=10
http://vfrmap.com/?type=vfrc&lat=40....24.108&zoom=10
http://vfrmap.com/?type=vfrc&lat=42....22.874&zoom=10
http://vfrmap.com/?type=vfrc&lat=42....06.464&zoom=10
* Note that the first two examples above, KTVL and KACV, are oddballs. It is very unusual to have an E4 extension adjoin full-time E2 airspace. In such a case it is much more common to see all the airspace designated as E2, as per KONP in the link below. The normal reason that an E4 extension would adjoin E2 airspace is that a tower has closed for the night and the Class D circle has been designated to revert to E2 airspace when the tower is closed. However, it's possible that there has been a recent change in policy in regard to airspace design and the KTVL/ KACV situation will become more common in the future.
* None of the airspace enclosed by the dashed magenta line here is E4 airspace. It is all E2 airspace. There is no dashed magenta line that does NOT enclose the airport:
http://vfrmap.com/?type=vfrc&lat=44....24.058&zoom=10
* E3 and E3a airspace is depicted like E4 airspace but the dashed magenta "extension" abuts Class C or Class B airspace, respectively, which is depicted differently than the dashed blue or dashed magenta circles in the examples above.
* Here is an example of E3 airspace--the dashed magenta boundary extending toward the northeast:
http://vfrmap.com/?type=vfrc&lat=37....93.389&zoom=10
* To keep things simple most of my comments in this thread just mentioned E4 airspace, but all the same points would apply to E3 and E3a as well. Of course there may be OTHER restrictions on operating an ultralight in those areas-- for example if they are over a "congested area" of a city or town, of if there is simply too much traffic for an ultralight to operate there without creating a hazard to other aircraft.
Extra credit-- I've found three other "oddball" cases where the outlying projections are designated as E4 and the inner circle is designated as full-time E2, but you would never know it by looking at the sectional chart, because it just shows one dashed magenta line around the whole area. In my opinion this should be considered to be a mistake on the chart-- or at the very least the depiction is not consistent with what was done for KTVL and KACV (first two links above). These 3 other cases are KSGU, KBIH, and KTPL. Note the "hang gliding" symbol within the E2 circle at KBIH-- presumably this is an instance where the "prior authorization" for ultralight flight required by FAR 103.17 is often granted.
Hope that helped--
Steve
