Please read the following table in HTML format from a webpage and then answer the question in detail according to the table. Each table cell is defined by a <td> and a </td> tag. Each table row starts with a <tr> and ends with a </tr> tag. 'rowspan=m' and 'colspan=n' represents a cell spaning over 'm' rows and 'n' columns.

Webpage title:
List of aircraft operated by Braathens
Table title:
Fleet
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > Type </th><th colspan=1 rowspan=1 > Origin </th><th colspan=1 rowspan=1 > No. </th><th colspan=1 rowspan=1 > Introduced </th><th colspan=1 rowspan=1 > Retired </th><th colspan=1 rowspan=1 > Notes </th></tr>
<tr> <th class="highlighted"  colspan=1 rowspan=1 > Douglas C-54 Skymaster </th><td colspan=1 rowspan=1 > USA </td><td colspan=1 rowspan=1 > 6 </td><td colspan=1 rowspan=1 > 1947 </td><td colspan=1 rowspan=1 > 1966 </td><td colspan=1 rowspan=1 > Used military versions of the Douglas DC-4, the C-54 were bought for charter services to the Far East and South America. </td></tr>
<tr> <th class="highlighted"  colspan=1 rowspan=1 > Douglas C-47 Dakota </th><td colspan=1 rowspan=1 > USA </td><td colspan=1 rowspan=1 > 2 </td><td colspan=1 rowspan=1 > 1947 </td><td colspan=1 rowspan=1 > 1964 </td><td colspan=1 rowspan=1 > C-47, a converted military version of the Douglas DC-3, was bought for short-haul charter, mostly to Europe. They were occasionally used in Norwegian services from the 1950s, before being replaced with the F27. </td></tr>
<tr> <th class="highlighted"  colspan=1 rowspan=1 > de Havilland DH.114 Heron </th><td colspan=1 rowspan=1 > UK </td><td colspan=1 rowspan=1 > 7 </td><td colspan=1 rowspan=1 > 1952 </td><td colspan=1 rowspan=1 > 1960 </td><td colspan=1 rowspan=1 > The aircraft were bought to allow Braathens SAFE to start internal services, with their small size allowing Braathens to serve regional airports. </td></tr>
<tr> <th class="highlighted"  colspan=1 rowspan=1 > Fokker F27-100 Friendship </th><td colspan=1 rowspan=1 > Netherlands </td><td colspan=1 rowspan=1 > 8 </td><td colspan=1 rowspan=1 > 1958 </td><td colspan=1 rowspan=1 > 1977 </td><td colspan=1 rowspan=1 > Braathens was the second airline to take delivery of the airliner, and allowed the DC-3s and Herons to be retired. The Friendships were put into the main domestic routes, and by 1960, all Norwegian flights were being flown using F27s. </td></tr>
<tr> <th class="highlighted"  colspan=1 rowspan=1 > Douglas DC-6A/C </th><td colspan=1 rowspan=1 > USA </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 1961 </td><td colspan=1 rowspan=1 > 1965 </td><td colspan=1 rowspan=1 > A single aircraft was bought to allow higher-pax Mediterranean charter flights. Unlike the B-series, it had a cargo door, which was not needed for charter flights, and the aircraft was sold parallel with Braathens buying five DC-6B in 1965 and 1966. </td></tr>
<tr> <th class="highlighted"  colspan=1 rowspan=1 > Douglas DC-6B </th><td colspan=1 rowspan=1 > USA </td><td colspan=1 rowspan=1 > 7 </td><td colspan=1 rowspan=1 > 1962 </td><td colspan=1 rowspan=1 > 1973 </td><td colspan=1 rowspan=1 > The aircraft were bought for Braathens' charter services, mostly to the Mediterranean. All were bought used, most of them from Transair. </td></tr>
<tr> <th class="highlighted"  colspan=1 rowspan=1 > Fokker F28-1000 Fellowship </th><td colspan=1 rowspan=1 > Netherlands </td><td colspan=1 rowspan=1 > 6 </td><td colspan=1 rowspan=1 > 1969 </td><td colspan=1 rowspan=1 > 1986 </td><td colspan=1 rowspan=1 > After choosing not to order the 737-100, Braathens became the launch customer of the F28, which replaced the F27 on most Norwegian routes. </td></tr>
<tr> <th class="highlighted"  colspan=1 rowspan=1 > Boeing 737-200 </th><td colspan=1 rowspan=1 > USA </td><td colspan=1 rowspan=1 > 20 </td><td colspan=1 rowspan=1 > 1969 </td><td colspan=1 rowspan=1 > 1994 </td><td colspan=1 rowspan=1 > Braathens was the second customer of the -200 series and the third customer of the 737. The aircraft were originally ordered for the main charter routes, but they gradually took over most of the domestic work. </td></tr>
<tr> <th class="highlighted"  colspan=1 rowspan=1 > Boeing 767-200 </th><td colspan=1 rowspan=1 > USA </td><td colspan=1 rowspan=1 > 2 </td><td colspan=1 rowspan=1 > 1984 </td><td colspan=1 rowspan=1 > 1986 </td><td colspan=1 rowspan=1 > The aircraft were bought for both internal scheduled and international charter use. The aircraft were too large for the domestic scheduled services, but did not have a dense enough seat configuration to make it economic for charter flights. </td></tr>
<tr> <th class="highlighted"  colspan=1 rowspan=1 > Boeing 737-400 </th><td colspan=1 rowspan=1 > USA </td><td colspan=1 rowspan=1 > 7 </td><td colspan=1 rowspan=1 > 1989 </td><td colspan=1 rowspan=1 > 2004 </td><td colspan=1 rowspan=1 > The aircraft were originally intended to be used for charter flights, but Braathens decided to replace all its aircraft with 737 Classics. </td></tr>
<tr> <th class="highlighted"  colspan=1 rowspan=1 > Boeing 737-500 </th><td colspan=1 rowspan=1 > USA </td><td colspan=1 rowspan=1 > 17 </td><td colspan=1 rowspan=1 > 1990 </td><td colspan=1 rowspan=1 > 2004 </td><td colspan=1 rowspan=1 > Boeing developed the -500 with the same capacity as the -200 after requests from airlines including Braathens. The aircraft were delivered between 1990 and 1994, allowing the -200s to be retired. </td></tr>
<tr> <th class="highlighted"  colspan=1 rowspan=1 > Fokker 100 </th><td colspan=1 rowspan=1 > USA </td><td colspan=1 rowspan=1 > 5 </td><td colspan=1 rowspan=1 > 1997 </td><td colspan=1 rowspan=1 > 1999 </td><td colspan=1 rowspan=1 > The aircraft were inherited through the take-over of Transwede. They were used for internal services in Sweden, but sold after Braathens terminated its Swedish operations. </td></tr>
<tr> <th class="highlighted"  colspan=1 rowspan=1 > Boeing 737-300 </th><td colspan=1 rowspan=1 > USA </td><td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > 1997 </td><td colspan=1 rowspan=1 > 1999 </td><td colspan=1 rowspan=1 > The single aircraft was inherited through the take-over of Transwede and used for domestic routes in Sweden. Originally Braathens planned to replace all its Transwede-aircraft with 737-300, but the plans fell short. </td></tr>
<tr> <th class="highlighted"  colspan=1 rowspan=1 > Boeing 737-700 </th><td colspan=1 rowspan=1 > USA </td><td colspan=1 rowspan=1 > 13 </td><td colspan=1 rowspan=1 > 1998 </td><td colspan=1 rowspan=1 > 2004 </td><td colspan=1 rowspan=1 > Braathens expanded its fleet with the -700 ahead of the opening of Oslo Airport, Gardermoen, which allowed the airline to increase its routes considerably. </td></tr>
<tr> <th class="highlighted"  colspan=1 rowspan=1 > British Aerospace 146-200 </th><td colspan=1 rowspan=1 > UK </td><td colspan=1 rowspan=1 > 10 </td><td colspan=1 rowspan=1 > 1998 </td><td colspan=1 rowspan=1 > 2001 </td><td colspan=1 rowspan=1 > The aircraft were inherited through the take-over of Transwede and Malmö Aviation, and allowed the airline to operate at the short runways at Stockholm-Bromma Airport and London City Airport. </td></tr>
</table>
Question:
What was the origin of the skymaster?
Answer:
The airline had 15 types, consisting of more models each from Douglas, Fokker and Boeing, as well as the de Havilland Heron and British Aerospace 146.