Cross arms interfering with possessor's airspace. Ratio: A
landowner is entitled to freedom from permanent structures which in ay
way impinge upon the actual or potential ordinary use and enjoyment of
land.
Intrusion by flight: recognition of public interest. Debate as
to how to resolve:
- Should not be trespass but nuisance or negligence.
- Zone of effective possession, only if flight comes about within
this zone it is a trespass. (Canadian view - most favourable
in Canada - question of balance of both parties' interests)
- Intrusion at any height by an aircraft is a trespass but there is
a privilege of legitimate and reasonable flight (US view).
1988: Didow v. Alberta Power
Transmission lines constitute a trespass of airspace.
Fifty feet off the ground, the cross-arms of an Alberta Power
transmission line protruded six feet over the Didows' farm. The
Didows objected that in addition to being unsightly, the cross-arms and
the lines attached to them would interfere with aerial spraying and
seeding operations, the use of tall machinery, and tree planting in the
area.
Relying on the thirteenth-century Latin maxim cujus est solum,
ejus est usque ad coelum et ad infereos (to whomsoever the soil
belongs, he owns also to the sky and to the depths), the Didows argued
that the cross-arms constituted a trespass of their air space. The
Alberta Court of Appeal agreed.
In his judgment for the court, Justice Haddad explored the extent to
which a landowner has rights tot he airspace above his land. EArly
common law cases confirming the Latin maxim had determined that signs,
telegraph wires, eaves, or any other artificial or permanent structures
hanging over another's land should be forbidden as trespasses.
That the owner was not using his land, and was therefore not damaged by the
trespass, was irrelevant: "[A] landowner is entitled to freedom
from permanent structures which in any way impinge upon the actual or
potential use and enjoyment of his land."
On the other hand, as the utility had argued, some recent cases
regarding airlines had demonstrated that airspace is public
domain. The judge concluded that such decisions would not apply to
transmission lines: air traffic generally takes place much further from
the ground, is transient, and does not directly interfere with the use
of one's property. And a low-flying aircraft, he noted, might
indeed commit a trespass.
The utility also argued that public policy considerations should
permit it to intrude over private property. Furthermore, it noted,
"tens of thousands of miles of transmission lines across Alberta
occupy private property." But the court was not swayed.
"[I]f there are many miles of transmission liens already
trespassing the air space above private property without any leave or
licence, they will not transform an unlawful practice into a lawful one.
