This can be a hot button topic, many believe the published traffic pattern at an airport in class G airspace is advisory. Further more there is a common belief that an instrument approach that results in a circling approach can circle any direction. Both are incorrect.
- Murphy (2009): Concerns 14 CFR §91.126(b)(1): even circle-to-land approaches must be conducted in the direction of the airport traffic pattern (to the left if not specified by airport markings otherwise). The pilot must comply with the regulation and does not have the discretion to determine which direction is better for his/her circle-to-land approach based on circumstances (e.g. because the wing blocks the view). On a separate topic, this interpretation also discusses student pilots logging PIC time during their FAA Practical Tests.
- Gossman (2011): Making a right turn to enter a traffic pattern is allowed even if the traffic pattern itself is to the left (e.g. the normal recommended right turn from a 45-degree entry midfield to downwind, see AIM). 14 CFR §91.126(b)(1) primarily applies once you are in the traffic pattern approaching to land.
- Collins (2013): Upholds Murphy (2009), but corrects that ATC does not have authority in Class G airspace to authorize deviations from the left-turn regulation. The “otherwise authorized or required” exception is very narrow and does not include convenience. Noncompliance with the left-turn regulation in the traffic pattern can lead to a suspension of the pilot’s certificate.
- Krug (2014): Concerns 14 CFR §91.126(a) and §91.126(b)(1) that turns at untowered airports in Class G airspace are to be made to the left unless indicated by airport markings or “otherwise authorized or required”. This legal interpretation specifies what “authorized and required” means. In particular, ATC has no authority to do so at an airport in Class G airspace (only at untowered airports where Class E goes all the way to the ground, see 14 CFR §91.127(a)), because it does not control traffic in Class G airspace. An acceptable authorization would have to come from an instrument approach procedure or other FAA regulation. This includes circling approaches after an instrument approach, which cannot be done in an arbitrary direction as stated in Murphy (2009) (the images in the FAA Instrument Flying Handbook do not constitute a general authorization).