The relationship between dubiously certified imported radios (e.g. Baofeng) and US radio services is a complex one. Baofeng products are radios which are not ex

The relationship between dubiously certified imported radios (e.g. Baofeng) and US radio services is a complex one. Baofeng products are radios which are not exactly any "type" of radio, and are technically illegal for most applications, but are dubiously legal in some cases for amateur radio use (this relates to an odd detail of FCC regulations with regards to type certification of devices, some Baofeng models are legal but others are not). The bottom line is that it's complicated, but they are capable of receiving and transmitting on amateur bands and they are very cheap, so they are often used for that purpose. This requires some caution as Baofeng models are more properly intended for business-band use (but are usually not certifiable for that purpose in the US) and so do things like default to wideband. A lengthier explanation is that, put somewhat simply and as a result somewhat incorrectly, in the amateur radio service the certification belongs to the operator, while in most other services the certification belongs to the radio. This means that any radio may be used in the amateur service if it is operated by a licensed individual, which is useful since amateur radio operators will often make use of hand-built radios or radios manufactured for other services and modified. From this perspective, it is legal for a licensed amateur operator to use any arbitrary radio. However, it is generally not legal to sell any radio which is not certified under some part of the FCC regulations. Most Baofeng models have never been certified under any part of the FCC regulations and cannot be for various reasons (e.g. face programmability which is prohibited for most land mobile services). This results in a bit of a "fruit of a poison tree" situation: while it is not necessarily illegal for a licensed amateur operator to use a UV-5R, that UV-5R was mostly likely sold in violation of the regulations. FCC enforcement on this issue has been very lax, but the action taken recently against Rugged Radios (a reseller of Baofengs) suggests to some that the FCC may be intending to clamp down. There is some practical implication as some independent labs and amateurs have concluded that Baofeng models do not meet FCC regulations with regards to spurious emissions and harmonics and therefore may interfere with licensed use of bands. Aviation radio is wideband AM for historic reasons, most cheap handhelds like Baofeng models are FM only. Fortunately dedicated aviation handhelds are fairly inexpensive and can be found with useful features like aviation dual plugs for your headset and even VOR display.