Lydd and Hythe
Known firing and range activity was checked. No relevant missile launch was identified as the source.
NEAR LYDD, KENT · 21 APRIL 1991
The radar contact was real. But was it the same object?
Captain Achille Zaghetti reported a brown, missile-like object crossing near his Alitalia MD-82. London ATC then found an unidentified primary radar return. The famous story joins them. The surviving file does not do that so neatly.
OPEN UK NATIONAL ARCHIVES FILE DEFE 24/1953 ↗FLIGHTAZ284 · Milan–London
AIRCRAFTMD-82 · I-DAWC
ALTITUDE≈ FL220 / 22,000 ft
THE VISUAL ENCOUNTER
A few seconds over Kent.
On 21 April 1991, Alitalia flight AZ284 was descending toward London Heathrow from Milan. Near Lydd, Captain Achille Zaghetti reported a brown or khaki object crossing in the opposite direction.
He described it as missile-like or cigar-like, apparently without wings and without obvious exhaust. The sighting lasted only a few seconds.
WITNESS SIZE ESTIMATE≈ 3–5 m
VERTICAL SEPARATION ESTIMATE≈ 1,000 ft
VISUAL DURATIONA few seconds
The 3–5 m size and ~1,000 ft separation are Zaghetti's visual estimates. They were not measured by radar.
THE SECOND PILOT
Corroboration — but not two equivalent files.
Zaghetti said he immediately alerted his copilot and that the copilot also saw the object. That is meaningful corroboration.
But the surviving research has not recovered a separate signed copilot deposition. The captain's formal report is the primary witness document currently locked.
Correct: “Zaghetti reported that his copilot also saw it.” Too strong: “two pilots independently filed matching signed reports.”
AIR OCCURRENCE M40/91
London ATC did record an unidentified primary return.
CAA Air Occurrence Report M40/91 documents the aviation-safety response. Controllers were advised of the missile-like sighting, and defence authorities, military radar, coastguard, police and Army helicopter units were contacted.
The report records a primary radar response behind the Alitalia aircraft. The contact tracked northeast and had no positive identification. A radar replay was arranged later that evening.
That is genuine contemporaneous sensor evidence.
THE LIMIT
Primary return does not automatically mean “Zaghetti's object.”
The timing is relevant. The geometry is the problem.
Explanatory geometry only.
The visual crossing was near the aircraft. The suspected radar return appeared roughly ten nautical miles behind after the encounter.
THE 10-NAUTICAL-MILE PROBLEM
The radar target was not sitting at the visual crossing point.
The suspected primary return was reconstructed roughly 10 nautical miles behind AZ284 after the close visual encounter.
Zaghetti's object had passed near the aircraft on an opposite heading. The surviving radar plots are poor, and the suspected radar target is not completely unambiguous in the public copies.
That means the strongest defensible statement is narrower: an unidentified primary contact appeared behind AZ284 shortly after the visual event. The file does not prove that it was the same object.
THE RADAR ANNOTATION
“Possible slow-moving target.”
One archived plot carries the annotation “Possible slow-moving target – Cruise Missile??”
That wording cuts directly against the popular claim that radar caught the visual object racing away after a near collision. If the suspected contact was being interpreted as slow-moving, then one clean continuous high-speed trajectory becomes much harder to defend.
The surviving radar material also does not establish exact altitude, physical size, acceleration or a continuous three-dimensional track.
WHAT THE BRITISH AUTHORITIES CHECKED
The obvious missile explanations did not survive the inquiry.
Sea Dart and naval possibilities
Known naval missile activity was investigated without producing a match.
Re-entry / orbital possibilities
No known space-related activity was found that explained the report.
Those checks rule out the specific known activities examined. They do not prove that no unknown or covert military system could ever have existed.
BALLOON?
The MOD thought an ordinary meteorological balloon was a poor fit.
The MOD's closing assessment said Zaghetti's description did not correspond with what would normally be expected from a meteorological balloon.
That weakens the standard weather-balloon explanation. It does not eliminate every possible stray balloon, aerostat or lightweight drifting object — especially if the slow radar return was separate from the visual object.
AIR SAFETY
Serious enough to investigate. Not a formal Airprox Board case.
The occurrence was initially treated as an “air miss” or possible near-collision concern. But the surviving CAA correspondence says Alitalia later agreed it was not, strictly speaking, an airmiss, while remaining more serious than a routine incident.
No completed formal Airprox Board investigation has been established.
Do not turn this into an official board ruling that a UFO nearly hit the airliner.
THE RECORD THAT WASN'T CAPTURED
RAF Neatishead's recorder was unserviceable.
RAF Neatishead reported that its Vinten radar-recording camera was not working on the day of the event.
That is frustrating because one potentially useful military radar record was therefore never captured.
But missing evidence is not evidence of suppression. The source says the recording camera was unserviceable. That is the claim the page should preserve.
EVIDENTIAL LOSS
Real
A potentially valuable military radar recording was unavailable.
WHAT THE MOD FINALLY SAID
Unidentified.
On 16 July 1991, the MOD told the CAA that UK air-defence departments had examined the information but could not confirm the identity of the object reported by the Alitalia crew.
Known missile and specific ordinary explanations had not produced an identification. The MOD therefore treated the report as an unidentified flying object and closed the occurrence.
That is a significant historical conclusion. It means the available inquiry did not identify the object. It does not mean the MOD confirmed an extraordinary craft.
THE REAL MYSTERY
One event — or two unresolved things in the same few minutes?
A close missile-like object
Zaghetti reported a short opposite-direction crossing near the MD-82 and said his copilot also saw it.
An unidentified return behind the aircraft
The primary contact existed, but appeared roughly 10 NM behind and was annotated as a possible slow-moving target.
British authorities could not explain the visual report with the known missile, range, naval, space or ordinary meteorological-balloon possibilities they checked. Yet the surviving radar record still does not provide the perfect second view that later retellings imply.
So the strongest question is: did AZ284 produce one event seen visually and imperfectly caught on radar — or did a dramatic visual encounter and a separate unidentified radar return overlap in time?
SOURCE ROOM
Follow the aviation file.
UK National Archives — DEFE 24/1953OFFICIAL MOD / CAA INVESTIGATION CHAIN
CAA Air Occurrence Report M40/91CONTEMPORANEOUS AVIATION-SAFETY RECORD · PRIMARY RADAR RESPONSE
Captain Achille Zaghetti's formal reportPRIMARY VISUAL WITNESS DOCUMENT
LATCC radar replay / plot materialUNIDENTIFIED PRIMARY CONTACT · HIGH-GENERATION PLOTS REMAIN PRIORITY
MOD / MATO correspondenceMISSILE / RANGE / NAVAL / SPACE CHECKS + UNIDENTIFIED CLOSURE
RAF Neatishead equipment-status correspondenceVINTEN RECORDING CAMERA REPORTED UNSERVICEABLE
Exact aircraft I-DAWC — later photographIDENTIFIES THE INCIDENT AIRFRAME · PHOTOGRAPH RIGHTS REMAIN WITH PHOTOGRAPHER