I’m very interested in military history particularly the WWII period. I’ve been doing some reading regarding B-24 heavy bombers used by the US Army Airforces and noted that some bombers had an eleventh crew member whose job was “radar observer”. I’m aware that ground radar installations were used to track incoming enemy aircraft, but am wondering what an airborne radar unit would have been used for. I’m guessing that airborne radar was used as some kind of a bombing aid, but am not sure. Does anyone know?
Beginning, I think around November of 1944, but I can’t immediately find my reference to see how far off I am, the USAAF experimented with using radar to bomb through heavy cloud cover. I suspect that it was not extremely accurate in the early days, but it would certainly have required a special operator.
However, if I were to guess at a more frequent use of radar operator, I would tend to expect it to find it on anti-submarine warfare aircraft–of which the B-24, with its somewhat longer range than the B-17, was a principle weapon. That use of radar on planes used a different variety of radar than the later attempt to distinguish landforms (basically simply looking for periscopes and conning towers poking up out of the waves), and was used extensively beginning in 1943. It would not surprise me to discover that a separate radar operator was included in the crew, at least until the radar scopes were simplified to require less specialized training. (Another aspect of the radar scopes was that the phosphor light in the dark confines of a plane tended to obliviate night vision, and even created a period of adjustment when looking up from the scope into daylight, so that the radar operator tended to be a different crewman than the bombardier who might need to make visual sightings to line up the target once detected by radar)
As tomndebb mentions, late in the war in Europe some B-24’s were equipped with Western Electric H2X “Mickey Mouse” (later just “Mickey”) radars for use by Pathfinder (formation-leading) planes. The unit was installed in place of the ball turret. These missions were flown in or over clouds or overcast to inhibit flak aimers and German fighters. The bombardier would identify the target by its radar signature and signal the entire formation to toggle the bombs all at once. Dunno how the crew total adds up - normally it was 10, but eliminate the ball turret gunner and add the Mickey operator and that’s still 10 - maybe Pathfinder crews carried a second navigator?
A relative who flew B-24’s as a radio operator / top turret gunner told me about a mission they flew behind a Mickey-equipped Pathfinder, to a hydrogen plant in Germany. They never saw the ground after takeoff, just toggled the bombs on command, and when turning for home away from the target, saw an orange glow appear through the clouds from below.
GCA was entirely passive as far as the airplance was concerned. All of the radar was on the ground and the ground operators talked the pilot down to visual contact with the runway. GCA would still work that way. I think GCA has been superceded by automatic landing systems at airports with ILS.
I know only what I read about B-24’s.
One B-24 “radar operator” would be the guy who operated the British-developed OBOE blind bombing system in a special Pathfinder plane. This system used two ground transmitters one with a beam directed over the target and another offset in geometry so as to provide a crossing beam at the proper bomb release point. The Pathfinder followed the first beam until intersecting the second which was the release point.
The only “radar” equipment in the air in OBOE was a special receiver to detect and decode the ground signals. The whole thing was pretty secret and Pathfinder crews were formed in special squadrons and assigned to missions when needed. You took off, joined up and then met the Pathfinder plane at a preset time and location. The system was quite accurate but relatively short range.
There was a follow up system called MICKEY with which I am totally unfamilliear. The writer of my cite apparently isn’t too clear on it either but it’s the best cite I could find on short notice.