Russia has again upgraded its nine 1970s era electronic reconnaissance aircraft, the Il-20. The aircraft is based on the 1960s era four engine Il-18 turbo-prop airliner. The Russians also have about two dozen similar Il-22s, and use them for airborne command posts as well as for scooping up electronic signals. There have been several upgrades for the Il-20 over the years, to enable the aircraft to detect the signals of new equipment. But for the latest upgrade, only two aircraft have gotten the new gear, and the Russians are pondering whether they should upgrade the rest, or develop a new electronic reconnaissance aircraft, perhaps an unmanned one. The Il-20 has a crew of 15. There is also a maritime reconnaissance version, the Il-38, of which about twenty are still flying.