Competing business aircraft aerodromes in the London region have renewed their attack on the safety of RAF Northolt in northwest London for civilian operations, on the grounds that the results of a safety audit of Northolt was withheld from a judicial review of their case in January.

At that time, the judge ruled that civil use of Northolt was legal, but stated that the Civil Aviation Authority (CAA), not the Ministry of Defence (MoD), was responsible for the safety of civil users of the military aerodrome.

Since that time, a freedom-of-information request has unearthed MoD-commissioned reports on the commercial feasibility of expanding the use of Northolt by regional airlines and business aircraft, up to 50,000 movements a year. At present, regional airlines do not use Northolt but business aircraft do, and the aerodrome is cleared for 20,000 movements a year.

Biggin Hill

London Biggin Hill Airport

The review of the commercial viability of increased Northolt civil operations was completed by Ernst & Young in February 2012, and the company had subcontracted to Mott MacDonald the task of reviewing Northolt’s compliance with the CAA’s regulations for licensed aerodromes (CAP168), and International Civil Aviation Organisation’s Annex 14 on the same subject. The Mott MacDonald report is clear in stating that, as it currently operates, Northolt would not qualify to be a licensed aerodrome, explaining: “The number and degree of infringements of the CAA/ICAO obstacle-limitation surfaces is such that we do not believe the CAA would license or EASA-certify Northolt as suitable for public transport use based on its existing declared distances [runway lengths] and method of operation.” It points out that if the declared runway lengths were reduced by displacing the thresholds, it would increase the runway end safety areas and also raise the obstacle limitation surfaces so that fewer obstacles, but still some of them, encroached. This would, however, render the airport unsuitable for fuel-laden long-range business jets. Both existing runway ends of the sole usable runway 07/25 are close to major public roads, so there is no opportunity to extend them.

Meanwhile, civilian business jets continue to use Northolt, working with performance demands that the military is allowed to accept. These would, however, be illegal for civil operations at competing aerodromes such as Biggin Hill and Oxford, which is why the latter are pressing the legal case. The risks listed in the Mott MacDonald report not only affect the operators, but also road traffic and residential properties beneath the approach and departure paths. has released the body of the report, but has redacted the conclusions and recommendations.

In a statement issued to Flightglobal, the MoD says: "RAF Northolt’s aerodrome safety standards are fully regulated by the MAA, a recent judicial review confirmed that no changes are required in relation to current aerodrome standards which are fully published and promulgated to civil users who operate at the aerodromes."

Source: Flight International