A secret study of UFOs was commissioned by the British Ministry of Defence and codenamed "Condign". A three-volume report is dated December 2000. The MoD uses "unidentified aerial phenomenon", UAP or "whap", instead of "unidentified flying object", UFO. The author, working as a research contractor, has been publicly identified only as having a long history of association with the British RAF and British intelligence. He built a Microsoft Access database from sighting reports for 1987 - 1997. After some statistical analysis presented in Volume 1 of the report, the database was destroyed. Volume 2 provides 25 working papers, certainly not an exhaustive consideration of suspect causes, but including ball lightning, aircraft black projects, earth's magnetic field, balloons, mirages, radar anomalies, etc., none of which are anomalous to science. These were prepared by the author from "authoritative scientific reference sources worldwide". The ET hypothesis is omitted as "very unlikely", and the report position reflects other subjective opinions of the author. Volume 3 contains classified radar performance data, an assessment of relevant technologies for potential military application, and an assessment of UAPs as potential hazards to aircraft. A 22-page Executive Summary constitutes a fourth volume. Conclusions (with "UFO" replacing "UAP" from the British text):
UFO reports provide nothing of value in UK assessment of threat weapon systems
Some UFOs are generated by an unknown phenomenon
No evidence that this phenomenon is extraterrestrial in origin
No firm evidence that an RAF crew has ever encountered or evaded a low-altitude UFO
No evidence for any fatal collision of an aircraft with a UFO in the UK
No artifacts of unknown or unexplained origin have been reported or handed to UK authorities
There is no useful electronic signal, video, or photographic information from UFO sightings
Airline crews are reluctant to make formal UFO reports, and there is evidence that crews are seeing far more than they are reporting
Military crews should not attempt to out-maneuver a UFO during interception; civilian air crews should not maneuver, other than to place the object astern, if possible
There is no intelligence exchange or collaboration of any sort on UFOs between the UK and foreign governments
Applicability of various plasma characteristics to the military should be further studied
Portions of the study report are available at http://www.mod.uk/DefenceInternet/FreedomOfInformation/PublicationScheme/SearchPublicationScheme/UnidentifiedAerialPhenomenauapInTheUkAirDefenceRegionResultOfInternalReview.htm
Source: David Clarke and Gary Anthony, "The British MoD Study: Project Condign"; August 2006 International UFO Reporter 30, 4, pgs. 3-13, 29-32 [Ce]. See also http://www.uk-ufo.org/condign.
See also http://www.foi.mod.uk to search for British UFO information in general on the UFO phenomenon. E.g., try "RAF Cosford 1993".