Certificates of Lawful Existing Use or Development (CLEUDs)

After GALBA stopped Leeds Bradford Airport changing the night time flying rules in its 2020 planning application, the airport is now trying to do it by the back door, avoiding public scrutiny, by applying for a set of Certificates of Lawful Existing Use or Development (CLEUDs) which will have the same effect if granted.

What is a CLEUD?

A CLEUD is a planning application to make something lawful because you have been doing it for a period of time, even though you were not allowed to do it in the first place. A classic example of a CLEUD is when a farmer builds a house on their land without seeking planning permission, then, a few years later, asks for a certificate to make the building lawful.

If they can prove that it has been there for the qualifying period of time and that nobody has objected, then a certificate will be granted.

In the case of Leeds Bradford Airport, because it involves operations rather than buildings, the qualifying period is 10 years. For a CLEUD application to be legal, it must outline the specific rule that has been broken and it must provide clear evidence that the rule has been broken continuously for a period of 10 years.

A CLEUD is not open to public scrutiny. It is decided by council planning officers behind closed doors, which may be OK for small developments, but is completely the wrong mechanism to change night time flying rules which will have an impact on 100,000s of people.

The airport’s CLEUDs refer in detail to QC (Quota Count) noise ratings of the planes it flies. You can find out more about how aviation noise is measured here.

Now on its third attempt to change the night flight rules, the airport is looking increasingly desperate and confused
Leeds Bradford Airport applied for five CLEUDs in September 2023.

These were scrutinised by GALBA and many holes were found in the evidence which meant that they would have to be rejected by Leeds City Council planning officers. So, in October 2023, the airport withdrew the CLEUDs and submitted four new CLEUDs with new evidence.

GALBA has scrutinised the new evidence and found as many holes in it as the previous set of CLEUDs and has submitted its findings to Leeds City Council in a legal letter.

We’re pleased to say that the council has already rejected two of LBA’s four new applications. We expect decisions on the remaining two in the summer of 2024. With such a lack of credible evidence, we believe the remaining CLEUDs cannot be granted and the council must reject them.

Will Leeds Bradford Airport be so brazen that it tries for a third time? Or will the airport appeal against the council’s decisions?

Each time it reapplies for changes to the night flight regime, it loses credibility and looks increasingly desperate.

... it is a criminal offence for any person, for the purpose of procuring a particular decision on a CLEUD application to “knowingly or recklessly” make a statement “which is false or misleading in a material particular” (s.194(1)(a) TCPA 1990).

A CLEUD is not clarification.

Contrary to the line frequently used by the airport, a CLEUD is not a way to seek clarification, it is simply a request to certify that a failure to comply with a planning condition is lawful.

There are other mechanisms available to seek clarification on planning issues through the High Court, but it’s GALBA’s guess that Leeds Bradford Airport doesn’t want these issues scrutinised in front of a judge.

If Leeds Bradford Airport really wanted clarification, for example, that they are allowed to fly the latest generation of planes, they could write to the council and ask that question. We’re sure the council would agree as long as the planes are counted towards the night time flight allowance – and nobody would object to that!

But that is not what the airport is asking for. It is specifically asking for the latest generation of planes to be excluded from the night time flight allowance, meaning they could fly in unlimited numbers.

What is concealment?

Concealment is when the applicant conceals information from the planning authority in order to prevent an enforcement action.

In our example of a farmer building a house on their land, if they built it behind a haystack, and then later removed the haystack and sought a certificate to make it lawful, that would be concealment. Obviously the haystack prevented the local planning authority from discovering the building’s existence during the qualifying period.

In the case of Leeds Bradford Airport’s CLEUD applications, there are many reports from 2008 to 2015 in which the airport reported inaccurate flight data and declared that it had not breached the conditions. This is concealment because the council reasonably took the reports on face value. Now the airport is saying it had breached the conditions in each and every year from 2008 to 2019.

The reports can be viewed here.

Leeds Bradford Airport has submitted four CLEUD applications:

Application 1 – To allow noisier planes to take off at night

Relevant Condition

Condition 4 – this application seeks to allow noisier planes of QC 1 to take off in the night time period. Night time takeoffs have been limited to QC 0.5 since 1993. This is an extremely backward step and introduces a noise regime that would be worse than it’s ever been. In the years prior to 1993 there was a total ban on night flights from 10pm to 7am.


The airport’s evidence does not prove continuous breach of this condition for 10 years. There are many gaps in the data that mean the application cannot be approved.

And in any case, the airport declared in its flight reports to the council that it did not breach this condition – which is concealment.

Application 2 – To allow QC 0.25 planes to be immune from the night time cap


Condition 6a and 6b – this application seeks immunity from flying planes of QC 0.25 from the night time flight allowance. These planes have been in use since 2007, but increasingly the latest generation of planes (Boeing Max, Airbus Neo) are QC 0.25 and will comprise the majority of flights over the next few years.


First, QC 0.25 planes are allowed by condition 6 as they are included in the existing permission for QC 0.5 planes. So there has been no unlawful activity therefore nothing to certify as lawful. For more information on this, see Why the airport must count ALL night flights.

Second, the evidence provided contradicts other evidence in previous applications and contradicts the flight reports provided to the council so cannot be relied on.

And in any case, the airport declared in its flight reports to the council that it did not breach this condition – which is concealment.

Application 3 – To clarify which version of the DfT’s definition of exempt planes is valid

This application has been rejected.

Application 4 – To clarify if flights delayed into the night period can be immune from the night time cap

This application has been rejected.


Leeds Bradford Airport is big enough already