My first thought was the ATR 42 Surveyor. :confused:

another now historical aircraft during a show with a lot of fire, F-111

And, of course, the Tongans have some different civil aircrafts too.
But I have found some strange information (see the link below):

http://3rdlevelnz.blogspot.com/2011/01/a3-land-10-days-in-tonga.html

Note the image of Beech D18 N500MK there, and read the title below the image of N500MK (click the photo to enlarge). Maybe, this information is mistake ?

I think it’s a mistake or maybe it was leased for a short period to Tonga.
http://www.airport-data.com/aircraft/N500MK.html

the remarks under this picture will add some more confusion to this aircraft. 🙂
http://jetphotos.net/viewphoto.php?id=5640719

some birds carry other birds

SR.A/1

a black cat with a bunny

and another dog

and land on one wheel