As far as I know, all radio amateurs are assigned privileges on
as a function of the class of licence they hold. These privileges differ from one jurisdiction to another.
When may a licencee operate beyond the privileges of their licence class yet within the privileges of a higher class of licence in that jurisdiction?
Is there any such scenario?
In the US, any person may operate under the direct supervision of an operator of a higher class. This is how the GOTA (get-on-the-air) stations work at field day, but it's applicable at any time.
In most cases when operating in foreign countries under e.g. CEPT you do not gain any additional bands, but in some cases you may gain some additional operating ability because either the country authorizes specific extra bands through something other than CEPT or because their band does not exactly overlap with ours.
Any licensee (any service) may use any means necessary if normal channels are down if necessary for the protection of life or property against imminent danger. This is not quite what you asked because it does not grant them the privileges of a higher license class, rather "any means necessary".
Recent graduates from one license class to another receive temporary operating privileges, signing CALLSIGN/AG or CALLSIGN/AE for new general or extra privileges as needed, until their upgrade is officially noted on the FCC ULS.
Many countries allow case-by-case exceptions for experimental purposes, such as permission to operate on an additional band for people experimenting with LF and MF communications.
Some countries allow operators to use a repeater controlled by a higher-class licensee to access extra bands, for example if a general class licensee has a repeater input on 2 meters or 440 and output on 10 meters, a technician using that repeater may have his signal repeated into a band that he could not transmit on directly.
Generally speaking, and of course with the caveat that this may vary from country to country, a person may operate a radio station they normally are not licensed for, when doing so under the supervision of a properly licensed individual.
Examples may include, but not be limited to, for example:
I myself first got on the air even before I had my own license permitting VHF and up only through a local club, where under supervision I could operate the club station on HF. And I dare say I did fairly well doing it, too.
There is also the implicit assumption in the question that amateurs are limited in the transmission modes they are allowed to use. This is not always the case. For example, since before I got my license, Swedish amateurs regardless of license class have not been limited in terms of operating mode, as long as the transmissions meet the other criteria such as instantenous transmitted frequency, power output, spectral purity, non-interference, and so on. Particularly, band plans are not legally enforced. (You're likely to upset a lot of people if you start transmitting narrow-band FM on the digital modes center frequency 14070 kHz, but as long as you don't cause interference for other users -- which in such a case seems pretty likely that you would -- you are perfectly within your rights legally to do so as a Swedish amateur.) This may be particularly pronounced in countries where the only difference in requirements between various license classes has been or is the level of Morse code proficiency required.
In the United States, FCC Part 97 Subpart E provides for essentially unlimited operations in the case of emergency communications. For example, amateurs may transmit on commercial or government channels if they are experiencing an emergency:
No provision of these rules prevents the use by an amateur station in distress of any means at its disposal to attract attention, make known its condition and location, and obtain assistance.
If "normal communication systems are not available", this expands to essentially any radio transmission that concerns immediate safety of human life and property:
No provision of these rules prevents the use by an amateur station of any means of radiocommunication at its disposal to provide essential communication needs in connection with the immediate safety of human life and immediate protection of property when normal communication systems are not available.
If you read further on in that subpart, there are a variety of other situations where amateurs are also able to use additional operating privileges, though in more limited ways (e.g. the Alaska-Private Fixed Service, or the Radio Amateur Civil Emergency Service).
This answer applies to the USA and any other areas where the FCC has jurisdiction.
The most precise answer to this question is never. There are a few cases mentioned in other answers, but they lack the fundamental distinction that a properly licensed operator, operating within the privileges of his license, is the control operator. A person other than the control operator may be supervised by the control operator in operating the equipment, but it is always the control operator who is in charge, and it is the control operator's privileges that may be used. The control operator is fully responsible for all activities of the station.
In cases where a person other than the control operator is at the mic (or on the key, or typing a data message), you must observe the restrictions on Third Party Messages. Specifically, you may not send a message for someone (to include letting them speak the message themselves) to any country except those listed by the FCC as having the appropriate Third Party arrangements in place.
In the case of a licensed ham operating at a club or other special event station where someone with a higher license class is acting as control operator, if ham with a lower license is operating outside their own privileges based on the privileges of the control operator, their status is exactly the same as someone with no license operating under the control operator's supervision. The control operator must always be responsible, and the Third Party Communication rules still apply.
(There is also an exception in case of emergency, but a great many parts within the Code of Federal Regulations -- including 47 CFR 97, the part regulating amateur radio -- have an emergency provision that jettisons most or all of the rules in case of a bona fide emergency.)
Source:
