Aircraft
Noise
One of
the most vexing problems that airports must contend with is the noise that
aircraft operations cause for those who live nearby an airport. During a recent discussion with members
of the Santa Ynez Airport Authority and pilots who operate out its airport the
subject of noise and the complaints that are generated by passing aircraft was
the number one concern to those who want to be good neighbors.
The
main sources of aircraft noise are from the passing of the aircraft through the
air, the noise produced by the engine, and finally noise from the
propeller. Upon takeoff, propeller
driven aircraft use all available power from the engine to accelerate and
climb. During this takeoff and climb segment the engine is operating at full
throttle or nearly so, and the propeller, if controllable, is positioned to a
high rpm setting to produce the most thrust. When the propeller is at this high
rpm the tips may reach speeds of nearly the speed of sound. At this speed the propeller causes a
very loud noise and this is the greatest source of noise produced.
At the
Santa Ynez Airport aircraft are directed by a sign at the entrance to Runway 26
to turn to a heading of 210 degrees after takeoff to avoid homes. Pilots can
also climb at best angle of climb airspeeds in order to gain as much altitude
as possible in the shortest distance.
The noise footprint of the aircraft will diminish as the aircraft
climbs.
Bad
Weather Effects
Landing
aircraft generally make left traffic for Runway 26. This means that their approach on downwind takes them over
the neighborhood adjacent to and just north of the Santa Ynez River. A landing aircraft while reducing power
on it's engine for landing must also decrease the pitch of the propeller by
placing the propeller control in the high rpm position. This is necessary for safety, as the
engine and or propeller must be able to produce maximum power and thrust in the
event of a rejected landing. This
is another instance that the noise footprint is enlarged, as the aircraft will
be operating with its propeller at the higher rpm.
Noise
complaints are also prevalent when weather conditions require aircraft to
approach the airport using published instrument approach procedures. These procedures are published by the
Federal Aviation Administration and must be flown with precision by pilots as
they are guiding their aircraft solely by the instruments on the panel. Often
pilots have no visual reference to the ground and are flying in clouds. At
these times the pilot must exactly follow the procedure to ensure the safety of
those on the aircraft as well as people on the ground.
A pilot
flying an instrument approach to Santa Ynez Airport in lowered visibility will
generally approach the airport from the west using the VOR (very high frequency
omni-range) approach or the GPS (Global Positioning System) runway 8 approach.
These approaches start near Buellton and the aircraft will fly a line over
Solvang, and then Santa Ynez before reaching a point that a safe landing can be
made on Runway 8. On these approaches the aircraft may descend to as low as 400
feet above the airport. In the case of a missed approach or a circling approach
the aircraft might have to apply high power settings right over homes in Santa
Ynez.
The
aerial photo of the valley shows some of the fixes or intersections that
approaching aircraft use during an approach to Santa Ynez Airport. The flight
path is shown which ends at the approach end of Runway 8. An aircraft making a
missed approach will apply full power and then make a turn to the northwest
while climbing away from the airport area.
Aircraft
departing during low weather conditions or on instrument flight plans will also
climb out over Santa Ynez at high power settings. This causes its noise footprint
to be extended over much of the township.
Reducing
Noise is Nearly Impossible
Although
the latest aircrafts have made many improvements in reducing noise it is nearly
impossible to eliminate the noise footprint of aircraft operating at high power
settings.
Helicopters
operating at Santa Ynez Airport are also a source of noise complaints. The
County of Santa Barbara bases the Sheriff's Department helicopter here. There
is also a firefighting helicopter based here and the noise produced by these
public safety vehicles has become a source of complaints. It should be noted
that when these aircraft operate late at night the mission might be one to save
a life.
Fly
Safe,
Robert
"Captain Bob" Perry
Titan Tornado II SS N899HC