An object was tracked by radar. An unidentified object was tracked by radar only by two witnesses at an airfield for eight hours.
I. Description of Incident
From 1045Z to 1900Z, the GCA radar at Rhein-Main picked up radar returns whose speed varied from 100 to 120 mph. The measured altitudes were from 200' to 500'. Both GCA operators have had two years experience. Ground observers were sent to location of returns, but could not see anything in the air.
One operator had seen a similar situation while stationed in Alaska and it was thought to be caused by icing conditions.
The weather was reported as 7/8 mile visibility, light fog, ceiling 400' - 600', overcast, with a ground temperature of -3°C.
II. Discussion of Incident
The reported maneuvers and speeds of the radar returns are similar to those that have occurred at Washington National Airport.
No data on inversions are available, but similar sightings have been due to weather.
HI. Conclusion
Returns due to weather.