The airport challenged a decision by the DETR to issue a certificate under the provisions of the Land Compensation Act 1973 in respect of claims by the local residents.
The claim against the airport was launched by a Mr Thomas and his wife. They claimed that the value of their house, which they had owned since 1988 dropped as a result of the expansion and that they ended up selling it in 1997 for less than it would otherwise have been worth.
They alleged the property was 'blighted by aircraft noise and movement' following relocation to the airport in 1995 of two naval helicopters from Portland, Dorset, and relocation elsewhere in the airport of six aircraft owned by Plymouth School of Flying.
The airport argued that the environment secretary in issuing the compensation certificates failed among other things to take into account the fact that helicopters had continuously used one of the airport's runways since January 1997 without any safety or environmental constraints and without any reductions in the capacity of the airport.
The airport also claimed he had drawn incorrect inferences about the operational ability of the helicopters.
However, Mr Justice Dyson in dismissing the airport's challenge said the question of use of the runway was irrelevant.
He said the question the secretary of state needed to address was whether the changes at the airport amounted to 'a substantial addition to, or alteration of, a taxiway or apron' and was an addition or alteration whose purpose was to make provision for a greater number of aircraft'.
He said he was satisfied that the secretary of state had considered this question properly and had been entitled to issue the certificate.