5.6
Boreal Laser Inc.
GasFinderAB Operation Manual — Operating Instructions June 17th 2017
Aerial Operation
The
GasFinderAB
measures the concentration of methane in the air passing through the
cell mounted under the helicopter. To detect a leak from a pipeline it is necessary to fl y the
helicopter through the plume of gas which spreads out from the leak. A successful operation
relies on the ability of the pilot to position the helicopter to fl y through the plume of gas.
It is recommended that the Flight Manual Supplement is read before using the system. Please
consult Boreal Laser Inc. for instructions on obtaining a copy of the FMS and other pertinent
regulatory information.
The pilot must ensure that safe operation of the helicopter is the prime consideration.
Position of the track
The optimum track is slightly downwind of the pipeline. The lateral distance is a function of wind
•
speed. With a light wind the plume will tend to rise but a strong wind will keep the plume closer to
the ground. Factors such as buildings and tree lined right-of-ways can complicate matters.
Speed
To ensure that the down wash from the rotor does not mask the cell, a forward speed
•
of 60Kts is preferred. 60Kts is 101 feet/sec and a faster speed may cause diffi culties in
detecting a narrow plume. When the cell is mounted, the V
NE
is 99kIAS or that displayed
on the existing cockpit label, whichever is lower.
Height
The gas concentration will be strongest at ground level and it decreases with height
•
above the ground. However the plume is also narrower at lower levels making it
harder to delineate. In practice it has been found that a height of 100ft(30m) AGL is the
optimum. Low level fl ying is inherently dangerous and a good lookout should be kept for
electrical wires and towers.
Wind
Wind speeds above 20kts are too strong for successful detection as the gas plume can
•
be fl attened and widely dispersed. The optimum speed is 5kts crosswind to the pipeline,
but this rarely occurs so the pilot’s judgement is required to position the helicopter
where the plume will be. Surface wind can be estimated from pressure on the rudder
pedals, smoke from local fi res, fl ags or waves on water bodies. Calm conditions can
result in the plume being anywhere and early morning inversions can keep the plume
very close to the ground.
A smoke bomb can be a good indicator of surface winds.
It is recommended that before using the system on a leak
detection operation, the pilot fl y to a known leak or source
of methane and make some passes to get a feel for the
plume dimensions and the sensitivity of the Boreal Laser
system. The system is capable of measuring differences
of 0.1ppm and detecting a leak of 2scfh and above. Animal
feed lots and landfi ll operations are usually good sources
of methane.
Smoke bomb release
Summary of Contents for GasFinderAB
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