Are there any active aircraft still in service (bar for historical air shows etc) that still require the following roles?
- 2 pilots
- 1 Flight Engineer
- 1 Navigator
- 1 Radio Operator
Are there any active aircraft still in service (bar for historical air shows etc) that still require the following roles?
The An-124 is listed as requiring a crew of 8: pilot, copilot, navigator, chief flight engineer, electrical flight engineer, radio operator, and two loadmasters. This includes all of the roles on your list, including 2 flight engineers. The An-225, if it flies again, appears to have a similar crew requirement.
Other aircraft that are still in service with the 5 crew positions you listed:
As noted in the comments, modern technology has made it possible for even large aircraft to be operated by just 2 pilots. The radio operator position is particularly hard to find still being used. You're looking for something both older and complex, maybe not even not technologically advanced for its time, that hasn't been made completely obsolete. That seems to be a specialty of Russian aircraft.
There are also military aircraft with crews of at least 5 but the extras are usually combat positions not directly related to the positions you list.
Notable mentions:
The E-3 has a flight crew of 4 but when flying missions some of the additional crew could be considered radio operators.
The P-3A mission crew of 12 includes the 5 positions listed. US Navy P-3Cs combined the navigation and radio functions. There are still some countries flying the P-3A. Other aircraft with similar missions from that era may include similar positions.
Older C-130's, the H models (with 4-blade props, distinct from the J-model Herks with 6 or 8-blade props) nominally have a crew of 5: 2 pilots, a flight engineer, a navigator, and a loadmaster. That will go up to 6, with 2 loadmasters, for airdrop or certain other missions. The aircraft can also be flown with just 4 - no navigator, but that's limited to fairly short flights, typically "beating up the pattern" for multiple approaches and landings for the pilots.
Once those airplanes are retired and the whole fleet is J-models, the engineers & the navigators will no longer be found in the C-130 community, other than a few special mission birds (i.e. gunships) that will still have navs in their mission crew.
The Tupolev Tu-95MS strategic bomber is still in service with the Russian Aerospace Forces. It usually carries a crew of 6 to 7; pilot, co-pilot, flight engineer, communications system operator, navigator, tail gunner, plus sometimes another navigator. Source: Wikipedia.
B-52 has a crew of 5: pilot, copilot, navigator, weapon officer, and Electronic Warfare officer.
Older Il-76, crew of 5, though loadmaster is included into the crew, I believe