UK government fights to keep Gatwick drone chaos report under wraps

The UK's Department for Transport (DfT) is mounting a legal challenge to keep a critical report on the 2018 Gatwick Airport drone chaos hidden from public view, despite an Information Commissioner ruling that most of the document should be released.

The seven-year battle over the so-called "Lessons Report" has now escalated to a tribunal, with government lawyers preparing to argue that releasing details about the incident could compromise national security.

What happened at Gatwick in 2018?

Between December 19-21, 2018, London Gatwick Airport experienced a major disruption when officials claimed multiple drone sightings forced the closure of its runway for 33 hours. The incident, codenamed Operation Trebor, affected approximately 120,000 passengers and grounded around 800 flights.

At the time, reports suggested there were at least 50 drone sightings in the first 24 hours, with Sussex Police later confirming 109 "credible" sightings in total. The airport deployed the Royal Air Force's Falcon Shield drone detection system on December 20, which remained operational until December 24.

The drone industry's doubts

However, numerous experts have since questioned whether a drone was actually present at all. Brendan Schulman, former VP of policy at DJI, stated he was "convinced" there was never a drone near Gatwick after reviewing evidence uncovered through Freedom of Information requests.

Graham Degg, founder of drone industry trade body Unmanned Support, told The Register that weather conditions on the first evening were "unsuitable for covert or overt operation of UAS [unmanned aircraft systems], especially given the technology available in 2018."

Drone enthusiasts have pointed out several inconsistencies:

• The first sightings occurred well after sunset during rainfall
• Very few drones in 2018 had water resistance ratings for flying in those conditions
• It seemed illogical for someone with access to a rain-resistant drone to fly with lights on near an airport
• Leonardo, the company that deployed the Falcon Shield system, later stated no malicious drones were detected during the incident

The lack of photographic evidence has also fueled skepticism. Sussex Police confirmed its investigation cost £790,000 ($1.05 million) but resulted in no convictions or credible evidence.

The Freedom of Information battle

Ian Hudson, a drone expert and contributor to the Airprox Reality Check fact-checking website, has been fighting for the release of the Lessons Report since May 2024. Through hundreds of Freedom of Information requests, Hudson discovered the DfT had five versions of the document but refused to release it on national security grounds.

In July 2024, the DfT's response to Hudson's request appeared to deliberately ignore questions about the Lessons Report, only answering other queries by claiming the information was already public.

The Information Commissioner's ruling

On October 20, 2025, the DfT released what it claimed was the Lessons Report, but the document was almost entirely redacted. The Information Commissioner's Office (ICO) examined the response and published an official decision notice on February 2, 2026.

Information Commissioner John Edwards ruled that the government's attempt to apply the national security exemption (section 24(1)) was invalid. He found the redacted information was "high level" and "unlikely" to lead to security issues, particularly given that drone technology and detection methods have evolved significantly since 2018.

The ICO only agreed with the DfT on one point: the names of three national security bodies mentioned in the report must remain redacted.

Government's appeal

Despite the ruling, the DfT is proceeding with an appeal, which will now be overseen by the Government Legal Department and head to the General Regulatory Chamber first-tier tribunal (FTT). The department argued that releasing the documents could "assist an assailant in harming critical national infrastructure, possibly leading to a significant loss of life."

Hudson hopes the Lessons Report will address how unreliable nighttime sightings of lights can be, noting similar patterns of airport closures without evidence of drones have been reported across the EU, including in Norway.

The case highlights ongoing tensions between government transparency and national security claims, particularly regarding incidents that have shaped drone regulations worldwide. As the tribunal approaches, the drone industry and public alike await answers about what truly happened during those chaotic December days at Gatwick Airport.