Each aircraft had radar information at door rupture/opening. Cargo door coming off DC-10 was seen on radar. Cargo door on B747 was tracked to surface of ocean, UAL 811. Pan Am 103, and TWA 800 both had radar anomalies just before destruction, AI 182 was too far away for primary radar returns to show any anomaly.
"Navy radar near Honolulu tracked debris that fell from
the airplane when the cargo door was lost. Refinement of the radar
data led to a probable 'splashdown' point in the ocean."
Radar tape unavailable but would show primary return of door after
it departed aircraft.
NTSB/AAR 92/02 Page 26
"The Shannon Air Traffic Control Centre was in contact
with VT-EFO and recorded radio communications with the aircraft.
At the time of the accident. 5.4 seconds of noise was recorded,
and the transponder signal seen on the radar scope was lost from
the aircraft. This signal which displays aircraft altitude showed
no deviation before disappearing from the radar scope."
Canadian Aviation Safety Board Air
India 23 June 1985, page 20
"There was a single primary return received by both Great
Dun Fell and Claxby radars approximately 16 seconds before SSR
returns were lost." This image matches the radar plot of
TWA 800 showing cargo door as primary return.
UK AAIB Report 2/90 Page C-11
"The last secondary return from the aircraft was recorded
at 19:02:46:9 hrs, identifying N739PA at flight Level 310, and
at the next radar return there is no SSR data, only 4 primary
returns."
UK AAIB Report 2/90 Page 34
"But law enforcement and aviation officials were particularly
perplexed by an unidentified ''blip,'' signaling the presence
of some object, that appeared on air traffic control radar near
the plane just before the crash, a senior law enforcement source
said. Authorities were repeatedly replaying recordings of the
radar transmission ''but we are stymied,'' the source said."
News Reports from Associated Press,
Reuters, major newspapers, press releases from NTSB, FBI
Radar tapes show mystery blips near TWA 800. The image matches
the Pan Am 103 radar plot of radar anomaly just before destruction.
800radarbipdoor.html