Bockenfield Aerodrome Ltd & Anor v Scott Clarehugh

An express easement permitting aircraft to use airspace at a safe height must be construed objectively in its documentary, factual and commercial context. “Safe height” protects people, buildings, animals and other expected uses of the servient land, but does not prevent the dominant owner from reasonably insisting on a stable approach and adequate clearance for landing and take-off.

Trees planted by the servient owner may substantially interfere with an airspace easement where they materially reduce the available flight path. An easement may require the servient owner to remove or reduce an obstruction which the owner has created. The doctrine of derogation from grant may apply to an express grant, but its obligation is no wider than the easement itself. A measured duty of care did not arise where the trees were not a hazard to the claimant’s land and the claimant controlled the relevant flight paths.

The claimant operated a leasehold airfield adjoining land owned and occupied by the defendants for a woodland burial business. A 1993 conveyance granted the airfield an unrestricted right to use, at a safe height, the airspace above the retained land for aircraft flying in circuit and arriving at or leaving the airfield.

The claimant alleged that trees planted on the defendants’ land interfered with the easement, derogated from the grant of the airfield and breached a measured duty of care. It sought an injunction requiring removal or reduction of trees and damages for alleged loss of use and profits. The principal issues were the construction of the easement, substantial interference, derogation from grant, the existence of a measured duty of care, damages and relief.

1. Construction. The easement was construed objectively against the legal and factual background existing in 1993. It permitted aircraft to overfly the retained land, while in circuit or landing or taking off, at a height safe for people, animals, buildings, machinery, materials and crops reasonably expected on agricultural land. It did not confer a right to use the defendants’ land as a run-off area or to fly at an unsafe height. The pilot had to assess the safe height according to the conditions on the ground.
2. Substantial interference. The applicable question was whether the trees substantially interfered with the exercise of the easement as reasonably required by the claimant, assessed by convenience rather than necessity: [2012] EWCA Civ 247. The claimant could reasonably insist on an approach sufficiently close to 3 degrees to permit a stable landing, provided aircraft crossed the boundary at least 20 feet above the ground. The trees forced steeper approaches, reduced safety margins and caused turbulence. They therefore substantially interfered with the easement.
3. The passive nature of an easement did not assist the defendants. The interference resulted from trees planted and maintained by the servient owner. The defendants had a positive obligation to desist, achievable only by removing or reducing the intrusive parts of the trees.
4. Derogation from grant. The doctrine applied to an express grant, although its scope was no wider than the express easement. The trees at the runway ends rendered the airfield substantially less fit for its intended use and therefore derogated from the grant. The evidence did not establish that Merlin Wood made the airfield substantially less fit, so that part of the claim failed.
5. Measured duty of care. The duty did not arise. The trees were not a hazard to the claimant’s land, and the claimant and its pilots controlled the flight paths. The claim was also unnecessary because the defendants were already subject to an obligation not to interfere with the easement. The court observed that the doctrine appeared to remain connected with nuisance and ordinarily concerned neighbouring landowners.
6. The principal damages claims failed for lack of causation, credibility and supporting evidence. Only £14,222 for lost fuel-sale profit was recoverable, reflecting supported losses in 2018 and 2019.
7. An injunction and declaration were ordered in principle. The defendants were required to remove or reduce trees between the lines marked 1 on Plan B so that aircraft could cross the boundary at 20 feet and achieve the permitted approach. The precise terms, costs and consequential matters were left for a further hearing.