Generally there are two ways to get an interpretation of regulations from the FAA.
The first (less-formal) way would be to call or email your local FSDO with your question -- they will usually get back to you pretty quickly with a verbal opinion or an email (on the two occasions I've contacted the local FSDO I've gotten an answer within 1-2 days).
Interpretations from your local FSDO are essentially valid within their coverage area (if you get an opinion from Farmingdale in New York the folks in Los Angeles, California may not honor it).
The second (very formal) way is to write an actual on-paper letter to the FAA's office of the chief counsel requesting a legal interpretation of some specific regulation(s) and mail it to their office:
Office of the Chief Counsel 800 Independence Avenue SW Washington, DC 20591
This request should be as specific as you can make it, for example:
May the FAA hold a person who performs maintenance on an aircraft responsible for the proper performance of that maintenance under 43.13(a) and (b) when that person was not the person who made the maintenance record entry required by 43.9?
If your request is inspired by some ongoing action (say a warning letter) you should reference it and include a copy to help speed things along.
The FAA's legal staff will chew on the request for a while, and eventually produce a legal interpretation (the linked interpretation, which answers the example question above, took about 5 months, and it is a relatively simple interpretation - The more complex the regulation that needs to be interpreted the longer it will probably take).
Counsel interpretations are organization-wide precedent, and on occasion they can overrule opinions/decisions from a FSDO. They are effective "The Final Word" on how regulations are to be applied (unless overturned in court).
Can anyone explain how a Boeing 777-200 can vanish without a trace? How can it simply disappear without any indication of an in-flight emergency from the flight crew? Does its disappearance and lack of any physical evidence suggest a catastrophic in-flight emergency which unfolded so rapidly that it caught the flight crew off guard and unable to send a distress signal? Is it possible for someone other than the flight crew to disable its transponder or alter its radar signature to render it undetectable?
Can someone explain why the aircraft would fly in an arc using the satellite as a reference point? Have I missed something?
How does someone request a letter of interpretation from the FAA if a particular situation surrounding a regulation or policy is not clear?
Is there a Canadian law or regulation which requires me to have my Radiotelephone Operator's Restricted Certificate (Aeronautical) on-board the aircraft with me? This is what I've found so far... service only where the person holds an appropriate radio operator certificate [...] However, I can't find a regulation saying I need the piece of paper with me. An example of the wording Canada uses in its regulations to say that you need to actually have the document with you is at CARS 401.03 (1)(d) (regarding pilot licences): the person can produce the permit, licence or rating
rating. The person must comply with the following application and pilot certification procedures: ... (6) The applicant must appear in person at a FAA Flight Standards District Office or to an Examiner with his or her logbook/training records and with the completed and signed FAA Form 8710-1. (7) There is no practical test required for the issuance of the “SIC Privileges Only” pilot type rating. What exactly is an SIC type rating used for and how can someone get a "type rating" without any kind of practical test?
Why has someone not designed a landing wheel with a fin or fins on it so that the air will start the wheels turning before the wheels touch the ground? Wouldn't that preserve the tires longer from wear? Or would it make the control of the aircraft more dangerous in some circumstances, such as rain or snow, to have the wheels already turning when landing? If so, perhaps the fins could be manually or computer controlled for various weather conditions.
I thought the shape of the wing gave an airplane upward lift. How can it fly if it's upside down?
What is the best way to keep logbook entries backed up? Should I photocopy or scanned image in computer suffice? Can an Excel spreadsheet or other software/apps be used? In case a logbook is lost or (unfortunately) destroyed, should all entries from the backup be rewritten in a new logbook? Also, when one has 100s or 1000s of hours, spreading over several logbooks, how much importance the older logbooks will have? Would someone go over every page to make sure that this individual actually have 1375.2 hours (as an example)? Thanks.
Suppose that an aircraft is in an exigency or emergency solely related to aviation (ie not a medical situation). Moreover, suppose that some airline passenger believes that he/she can help in the cockpit. Since the cockpit door is locked for security, how can he/she volunteer their services and enter the cockpit to try to help? In these possibly final moments, it's conceivable that someone..., in their attempts to recover from a stall, the first officer pushed his yoke upwards (fatefully) while the reserve copilot pushed his yoke downwards (correctly). Consequently, both opposite actions nullified
Does the FAA regulate drones at this time? Maybe they regulate only a certain class / size of UAV / UAS? Is drone regulation to the level that traffic is managed through ATC?