Why Leeds Bradford Airport must count ALL night flights

Leeds Bradford Airport has breached the night time flying limit for the last two summers. It is now trying to claim it does not need to count some types of plane towards its allowance because they were not specifically mentioned in the conditions that were written 30 years ago. Its argument is convoluted, relies on cherry picking which version of the national guidelines is relevant and is a huge stretch of the imagination.

In a nutshell…

Planes are certified with a QC value which specifies which noise band it belongs to. QC 1 is noisier than QC 0.5 ,which is noisier than QC 0.25 and so on.

For more information on how aircraft noise is measured, please see How Aviation Noise is Measured.

When the current operating conditions were agreed between the council and the airport in 1993, the category of QC 0.25 did not exist, and, the airport says, therefore, that those planes do not count to the night time flight allowance.

Condition 6

The relevant condition is condition 6, here it is:

Condition 6 – During the night-time period, (2300-0700), no aircraft movements shall take place other than by:-
a. Landings by aircraft classified as falling within Quota Count 0.5 and 1 for arrivals as defined in UK NOTAM S45/1993 issued by the Civil Aviation Authority and any succeeding regulations or amendments/ additions/deletions.
b. Departures by aircraft classified as falling within Quota Count 0.5 for departures as defined in UK NOTAM S45/1993 issued by the Civil Aviation Authority and any succeeding regulations or amendments/ additions/deletions.

The airport’s claim is that planes certified as QC 0.25 don’t “fall within” QC 0.5 and therefore are not allowed to fly because the condition says no other planes may fly. The airport wants the planes to not be allowed to fly in order for its CLEUD 2 application to work. If it can prove that those planes have been in use unlawfully for years (despite saying the opposite for all of those years) it can apply for immunity from enforcement. This also means that the planes would not count towards the night time flight allowance.

But if you compare the DfT definitions of QC bands in 1993 vs 2007 onwards, you can see that in 1993 QC 0.5 included anything below 90 dB down to 0 dB. And later, when QC 0.25 and QC 0.125 were introduced, the DfT simply subdivided QC 0.5 into smaller bands. So, 84 to 86.9 dB (what is now QC 0.25) was clearly “within” QC 0.5 in 1993.

Noise Bands 1993 QC 1993 Noise Bands 2007 onwards QC 2007 onwards
Exempt: 0 – 87 EPNdB and less than 11.6 tonnes Exempt: only small planes used for airport inspection purposes
0 – 90 EPNdB 0.5 0 – 81 EPNdB 0
81 – 83.9 EPNdB 0.125
84 – 86.9 EPNdB 0.25
87 – 89.9 EPNdB 0.5
90 – 92.9 EPNdB 1 90 – 92.9 EPNdB 1
93 – 95.9 EPNdB 2 93 – 95.9 EPNdB 2
96 – 98.9 EPNdB 4 96 – 98.9 EPNdB 4
99 – 101.9 EPNdB 8 99 – 101.9 EPNdB 8
Greater than 101.9 EPNdB 16 Greater than 101.9 EPNdB 16


The correct reading of condition 6 says that ALL planes are allowed to fly and must count towards the night time flight allowance (apart from Exempt).

So, because QC 0.25 planes are allowed to fly by condition 6, then they must count towards the night time flight allowance as do all other flights defined in condition 6. And this means that no breach has occurred, therefore CLEUD 2 is invalid because the flights have always been lawful. See Certificates of Lawful Existing Use or Development (CLEUDs).

The airport could also make two big problems for itself by pursuing this crooked argument:

Problem 1: interaction between CLEUD 2 (23/07490/CLE) and CLEUD 3 (23/07491/CLE)

If the council accepts the airport’s argument in CLEUD 2 that QC 0.25 cannot fly, then it also accepts that QC 0.125 cannot fly as it also would not “fall within” QC 0.5. This category is widely used today, especially with the smaller passenger turbo-props and jets and private charter jets. To get around this, the airport applied via CLEUD 3 to keep the 1993 definition of exempt planes. That would have allowed QC 0.125 and QC 0 planes to continue to fly primarily because of their low weight. Now that the council has recently rejected CLEUD 3, it has declared that the latest definition of exempt planes is the correct one and the 1993 version has been superseded. This means, according to the airport’s interpretation of the conditions, that anything below QC 0.5 is prohibited at night. This creates a problem for any private charter or shuttle that wants to operate before 7am or after 11pm. These planes would need to be monitored by the council and prohibited from flying at night. This is the situation today – until and unless the council rejects CLEUD 2, any night flights below QC 0.5 are illegal.

GALBA’s legal advice is that all flights below QC 0.5 are allowed and must count towards the night time allowance. This is the pragmatic and reasonable interpretation that accords with the spirit and the plain reading of the conditions.

Problem 2: QC is just a label, it’s the noise that matters

The second problem arises from a current consultation by the DfT about night flight restrictions which proposes to rebase the QC system so that the noisiest aircraft are moved into the categories QC8 and QC16, and current QC0.125, QC0.25, QC0.5 are to be moved to QC1 to QC4, with the possibility of future proofing the system by creating QC categories for aircraft that do not yet exist. https://www.gov.uk/government/consultations/night-flight-restrictions-at-heathrow-gatwick-and-stansted-airports-between-2022-and-2024-plus-future-night-flight-policy/night-flight-restrictions,

Consequently, there is likely to be a time in the near future where the current QC labels will change again and Leeds Bradford Airport will end up in a position where it cannot fly any planes at all, given its attempt to reinterpret its current conditions in such an extremely inflexible and pedantic way, because QC 0.125 to QC 0.5 will no longer exist. Caveat emptor.

Leeds Bradford Airport is big enough already