From The Kenya Gazette, 13 April, 1973, page 483, Gazette Notice 1164:
Pursuant to the provisions of regulations 6 and 7 of the East African Licensing of Air Services Regulations, 1965, notice is given that Viking Helicopters Limited [ … ] has applied to the East African Civil Aviation Board for a licence to airlift within Tanzania employees of Terra Surveys Limited together with their equipment and provisions, to be engaged in surveys to be operated by the said Terra Surveys Limited in Tanzania, with two Hughes 500 C types of helicopters, for a period of one (1) year.
Dated at Arusha this 30th day of March, 1973.
On the same day on page 482, Gazette Notice 1163, Terra Surveys Limited applied for a licence to operate
Aerial survey in an area situated in Tanzania between latitudes 2° 30’ and 12° 00’, and longitudes 29° 00’ and 40° 30’ with one DC3 type of aircraft,
for a period of one (1) year.
On July 20th, 1973 in The Kenya Gazette, notification was posted that both licenses were granted as applied for.