Air Beat Magazine - Journal of the
Airborne Law Enforcement Association
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FIXED WING OPS: Then & Now
by Mark A. Forror
Although some law enforcement agencies were flying search-and-rescue
(SAR) missions well before the end of World War II, the oldest aviation
units in law enforcement generally can trace their histories back to the
late 1940s.
America’s post-war love affair with the automobile meant that patrol cars
were no longer enough to stay a step ahead of drivers on the nation’s
highways. By 1949, with the helicopter still in its infancy, the speed and
range of fixed-wing aircraft made the airplane ideal for patrolling long
stretches of highway.
New York State Police
The Aviation Unit of the New York State Police was one of the first law
enforcement agencies to use aircraft to patrol the ground. In 1939, NYSP
operated a Fleet biplane as a flying club airplane that was sometimes
pressed into service to search for escaped criminals. However, the club
aircraft was never regarded as an official division of the state police.
The real origin of the NYSP Aviation Unit can be traced back to the
1960s. We’ve had airplanes officially since1968, and it started almost
exclusively in aerial speed enforcement on the New York Throughway says
Capt. Ken Rogers, the unit’s chief pilot. At first we were flying daytime
VFR with a Cessna 172. Now we’re flying King Airs with sophisticated
avionics and de-icing equipment.
The NYSP currently operates six fixed-wing aircraft: a Partenavia P68, a
Beech King Air 350 and B200, two Cessna 206Us, and a 1967 Cessna 172H. The
172H, which is the original aircraft that started the NYSP’s Aviation Unit,
has a high-performance, constant-speed propeller and a Lycoming O-360
engine. Average annual flight time on the airplanes is about 1,800 hours.
The unit has 33 pilots, with paramedics or other pilots serving as
observers. The division operates 13 helicopters in addition to the six
fixed-wing aircraft. Airplanes currently perform such missions as spotting
forest fires upstate, executive transport, some speed enforcement, prisoner
transport, and transportation of organ transplant teams to hospitals.
The fixed-wing fleet carries infrared cameras, GPS navigation, radar
altimeter, scalable radios, multifunction displays, weather radar,
horizontal situation indicator (HSI), TCAS, autopilot and IFR avionics
suite.
Since the terrorist attacks in New York in 2001, the department has been
stepping up its long-term surveillance of harbors and other areas that may
be vulnerable to future attack.
Mainly we use helicopters for that, but we have used fixed-wing aircraft
on occasion,” Rogers says. “Every time they’ve raised alert levels, we’ve
gone on active patrols, particularly in the southern part of the state.
Some of the areas targeted for heightened surveillance include railroad
yards, bridges, reservoirs, airports, and power plants. The advantage of the
fixed-wing aircraft over the helicopter is its endurance and fuel
efficiency, which makes long surveillance missions more cost-effective, he
says.
Texas DPS
In 1949, the same year that the Nevada Highway Patrol was formed, the
Texas Department of Public Safety (DPS) started with a single Navion
airplane piloted by Max Westerman. A patrolman for DPS License and Weight
Service, Westerman was transferred to the Texas Rangers before becoming the
service’s first pilot.
By January 1953, the airplane, based in Austin, was so much in demand
that the DPS added a second pilot. From 1953 to September 1967, the Texas
DPS Aircraft Section remained a two-pilot operation, though the fixed-wing
fleet was upgraded to two twin-engine Cessna 310s and a Lockheed Lodestar.
DPS also purchased a twin-engine Cessna 320 and stationed it in Midland,
Texas. In 1968, DPS lease- purchased its first helicopter, a Bell 47G.
During the 1970s and into the 1980s, DPS operated a number of different
Cessna twins and single-engine aircraft. These included several models in
the Cessna 400 series, single-engine 210s and 206s and even a military
surplus Cessna T-41. Today, the agency’s fixed-wing fleet consists of three
210s, four 206s, and one twin-engine Turbo Commander 1000—a drug seizure
aircraft acquired in the late 1980s.
The unit’s basic mission has changed from predominantly highway patrol
and transport to narcotics enforcement. In 1984, DPS acquired another
aircraft, a Cessna 210, which also was seized in anti-narcotics operations.
Most of the aircraft we seized were sold at auction and the proceeds went
to new equipment for officers and other equipment used to help fight the war
on drugs, says Pilot/Sgt. Tim Middleton.
The money is pooled in a Seized Funds account, from which various
departments are allowed to draw. That money helps fund current operations,
which includes criminal surveillance, traffic enforcement (spotting
aggressive drivers, etc.), criminal investigations, transportation of
personnel and equipment, prisoner transport, and SAR.
Nevada Highway Patrol
A division of the Nevada DPS, the Nevada Highway Patrol’s aircraft unit
began in 1984 as a federally funded program dedicated exclusively to
enforcing the federally mandated 55 mile-per-hour speed limit. A result of
the Arab oil embargoes, the national speed limit was a fuel-saving measure
imposed on all interstate and federal highways in 1974. The task of ensuring
the state’s compliance with the federal law fell on the Nevada Highway
Patrol. The law required 50 percent of the state’s drivers to regularly obey
the new speed limit.
“In Nevada back then we had a problem with our 50 percent compliance
rate,” says Pilot Sgt. Pete Onorato, the NHP’s senior pilot. Enforcement was
necessary so we wouldn’t lose our federal highway funding. We provided the
manpower and covered the personnel costs, and the feds provided the aircraft
and maintenance.”
At first the unit operated a Cessna 172RG, but added a 182RG two years
later. The speed-enforcement mission quickly ran headlong into regional
issues. In the state’s wide-open rural areas, the 55 mph limit was the first
time Nevada highways ever had a speed restriction, and enforcement officers
had trouble keeping up with violators.
As recently as last year, the NHP flew 135 speed enforcement missions
resulting in 4,644 citations. Although that money does not go to the NHP
directly, Onorato says, it still benefits the aviation unit indirectly by
freeing up state funds for law enforcement programs.
When the federal government lifted the speed restriction in 1993, it
stopped funding the aviation unit, but transferred the airplane titles to
the NHP on the condition that the airplanes would continue to be used for
law enforcement purposes.
Today, the NHP has added a few new missions, but the unit’s basic tasking
remains largely unchanged. The two principal missions are now speed
enforcement and prisoner transport. How the NHP apportions its assets to
each mission varies greatly by region. In Reno, about 80 percent of the
missions are dedicated to speed enforcement, and 20 percent to prisoner
transport. In Las Vegas, however, that ratio is flipped, with 80 percent of
the missions going to prisoner transport and out-of-state extraditions.
Statewide, the mix is about 60/40 in favor of speed enforcement missions.
Prisoner transports have benefited the most from fixed-wing operations.
In the past, a prisoner from the eastern part of the state who was wanted on
a warrant in Reno would have to be transported 400 miles by car. Prisoners
were handed off from trooper to trooper as the prisoner crossed patrol
divisions. With airplanes, the transport process is far less complicated,
and prisoners have fewer opportunities for escape. In the past 12 months,
the
NHP transported 84 prisoners statewide.
Other missions include assistance in ground pursuits, SAR, and “blood
runs”, or the transport of whole blood and plasma to hospitals for the
benefit of critically injured patients.
The NHP’s aircraft unit continues to operate the same aircraft it started
with, though the aviation division is studying the possibility of acquiring
a new Cessna 206 in the near future.
Santa Barbara Sheriff’s Department
The Santa Barbara Sheriff’s Department is a relatively young operation.
The aviation unit was formed in December 1996 with a Cessna 172RG seized
from a narcotics bust and two military surplus OH-58 helicopters.
“The fixed-wing aircraft was mostly for patrol as a backup for the
helicopters, says Deputy Dave Wight, acting chief pilot. We did some
surveillance with it and we did some administrative transport with it, but
it was mainly a backup for our helicopters. In February, the unit acquired a
surplus UH-1 helicopter, but the Sheriff has not yet determined what its
mission will be.
When the aviation unit was organized, Sheriff Jim Anderson was a private
pilot, so he used the Cessna to travel to the capital in Sacramento for
meetings with state officials. Since then, the Sheriff has replaced the
172RG with a Cessna 206H. The 206H is used for ground patrol support, SAR,
VIP transport, surveillance and photographic missions.
However, the aircraft’ primary mission remains transport. The airplane is
now available to any county government supervisor who requests it. Some
county government officials who have used the airplane in the past include
probation officers, fire department officers and planning commissioners.
Most missions are flown IFR. Both pilots and TFOs must have a minimum of
18 months field experience to be accepted into the training program. As a
prerequisite for assignment to the unit, pilots must be instrument rated.
Wight says the Sheriff’s Department has considered acquiring a larger
aircraft to be used exclusively for the transport of officials. Both the
Sheriff and the Santa Barbara County Board of Supervisors have expressed
interest in buying a Cessna Caravan or Raytheon King Air. However, recent
operations and budgetary considerations have put that plan on hold for now,
Wight says.
Lee County Sheriff’s Office
Two years ago, the Lee County Sheriff’s Office was an all-helicopter
operation. In January 2004, the Aviation Unit flew more total hours aboard
its fixed-wing airplanes, though it still operates one MD 500 and one OH-6
helicopter. The unit has learned that low-and-slow high-wing aircraft, such
as the Maule, actually make better surveillance platforms than most
helicopters.
“For surveillance, the fixed-wing aircraft is unmatched,” says Chief
Pilot Robert Roper. “It’s not going to replace the helicopter, but we’re
getting more hours over the county, and that allows us to spend more time in
the air without adversely affecting our budget. For the cost of one hour in
the helicopter, we can fly ten hours in the Maule. We’re actually looking at
expanding our personnel because of the lower cost.”
In addition to its MD 500 and OH-6 helicopters, the sheriff operates
three fixed-wing aircraft: two Maule single-engine airplanes, an M-5-180C
and an MX-7-180A and a twin-engine Cessna 337 Skymaster. The fleet is based
at Buckingham Airfield in Lehigh Acres, Florida, about five miles from Fort
Myers.
“The early missions were primarily narcotics surveillance,” Roper says.
“We had such good success with the Maule that we started thinking about
putting a FLIR on it.” Today, the Lee County
Sheriff’s Office uses a FLIR 7500 that goes back and forth between the two
aircraft. Maule will display the Sheriff’s MX-7-180 equipped with a new FLIR
8500FW on the floor at this year’s ALEA conference in Charlotte, North
Carolina.
Lee County operates a FLIR 7500 with laser illuminator. The future goal,
Roper says, is to have canine officers equipped with night-vision goggles
(NVGs) on the ground, so that the
airplane can “paint” the suspect with the laser illuminator and direct
ground
officers to the suspect at night.
“Right now, we fly predominantly during the day, but we want to expand to
nighttime operations, so that we can assign TFOs full time,” Roper says.
Although helicopters have come to dominate police aviation during the
past couple of decades, there are still some missions that fixed-wing
aircraft can do better or more cost-effectively than rotorcraft. Where
range, endurance, platform stability, or maintenance and fuel costs are
important issues, the fixed-wing aircraft will continue to occupy small but
useful operational niches in airborne law enforcement.
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Does Your Mission Profile Include Flying Low & Slow?
Learn why this flight regime can turn unexpectedly deadly.
by Mike Smotherman, FCI Training
During a recent nighttime flight in instrument meteorological conditions
(IMC), a pilot flew a GPS runway 35, circle-to-land runway 17 approach, not
realizing that something was terribly wrong. /p>
A witness reported that the airplane's downwind leg was two to three
times closer to the runway than normal. The airplane’s turn radius to final
approach was also much smaller than normal and the turn was relatively flat.
The airplane appeared to be traveling at a relatively slow airspeed during
the approach, and engine RPM didn’t increase during the turn. As the
airplane turned toward final approach, the witness said its attitude
instantaneously changed from relatively wings level to wings vertical. The
aircraft stalled and stuck the ground short of the runway.
Examination of the wreckage confirmed this. The airplane impacted the
ground almost vertically and, upon impact, was facing the opposite direction
of the landing runway. Weather at the time included winds from 080 degrees
true at six knots, visibility 2.5 miles in mist, an overcast ceiling at 300
feet AGL, and a temperature and dewpoint of 32 degrees Fahrenheit. No
pre-impact mechanical malfunctions were found. The National Transportation
Safety Board (NTSB) determined the probable cause of the stall/spin was the
pilot’s failure to maintain adequate airspeed during the turn to final
approach. Contributing factors included low ceilings and night lighting
conditions.
The above scenario describes a low, tight traffic pattern in adverse
weather conditions, but these conditions are not unusual for many law
enforcement pilots observing targets. The temptation is great for pilots to
slip into a skid to make the corner, but it can be extremely dangerous under
the right conditions.
If you were on your game, had sufficient airspeed, didn’t encounter any
wind shear and had luck on your side, you probably wouldn’t even know you
were pushing the envelope. But the above accident illustrates just how
deadly this situation can be if you’re not completely aware of your
situation.
Stepping on The Ball
The NTSB’s probable cause of _failure to maintain adequate airspeed,
while technically accurate, may not be very helpful to other pilots. Since
the witness observed that the pilot of the accident aircraft did not use a
steep bank angle to tighten his final turn, it’s a virtual certainty that he
attempted a skidding turn using bottom rudder to _make the corner. Let’s
look a little closer at the aerodynamic ramifications of using uncoordinated
turns.
In coordinated flight, the relative wind meets a straight wing at 90
degrees as seen in diagram 1. Wing designers control stall characteristics
by varying dihedral, wing twist, and so on. The stall will occur
perpendicular to the relative wind, assuming a straight and symmetrical
wing.
As we all learned in ground school, most straight-winged aircraft are
designed to stall at the wing root, which benefits the pilot in two ways.
First, the onset of the stall at the wing root provides an aerodynamic stall
warning as the turbulent air hits the elevator. Second, during this
approach-to-stall, the wingtips are relatively unaffected, so that the
ailerons will remain somewhat effective. But what happens to our
straight-wing airplane if we introduce a slip or skid by using the rudder?
Do the stall characteristics change? To answer this question, we must first
look at the stall characteristics of a swept wing.
Swept Away
Where does a swept wing stall? At the tip of the wing, because the stall
generally occurs perpendicular to the relative wind as shown in digram 2.
But how does this affect what we feel in the cockpit? Since the
approach-to-stall starts at the tip, there will be no turbulent airflow over
the elevator, hence no warning on the yoke or stick. This is why most
high-performance jets will install an artificial stall warning system called
a _stick shaker._ This system is basically a vibrator attached to the yoke
that activates based on approach-to-stall Angle of Attack (AOA). You also
lose aileron authority since the stall is beginning out on the wing tips
near the ailerons.
As we yaw our straight-winged aircraft, we cause the wing to sweep back
with respect to the relative wind, as you can see in the diagram.
What is normally a straight wing in coordinated flight has now taken on
the characteristics of a swept wing. Since the wing tip stalls first, you
will not get the normal approach-to-stall buffet on your elevator, and you
will lose aileron effectiveness at the onset of a stall. The forward (right)
wing in the above diagram will not stall at the same time as the aft (left)
wing, causing a rolling moment to the left.
To get to the bottom of this situation for a straight-wing airplane, we
first have to look at the effects of roll and AOA on the lift
characteristics of an unstalled wing in normal flight.
How does a rolling moment affect AOA on the wings of an aircraft in
normal flight? Diagram 4 above shows that with a left roll, the left wing is
pushed down into the relative wind, effectively increasing the AOA on that
wing. The right wing moves away from the relative wind, effectively
decreasing the AOA on the right wing. Since we are in normal flight,
increased AOA means more lift (see the lift/drag chart in Diagram 5), and
thus the left roll stops due to the increased lift as soon as we remove the
cause of the roll by bringing the ailerons neutral. The aerodynamic
principle involved here is _positive roll damping,_ where a roll or yaw
input is positively dampened back to stable flight.
Negative Roll Damping
But what happens when a rolling moment is induced during stalled flight?
Diagram 5 again shows that with a left roll, the left wing is pushed down
into the relative wind and increases the AOA on that wing. The right wing
moves away from the relative wind, decreasing the AOA on the right wing.
In stalled flight, increased AOA means less lift, and thus, the left
rolling moment will continue due to the decreased lift and will continue to
roll even if the input that caused the roll is removed. The problem is that
the uneven lift is now caused by the differential in AOA on the stalled side
of the lift/drag curve. This is known as negative roll damping, since the
roll will not be dampened out.
Now, let’s apply this concept to our mishap analysis.
According to the accident report, the aircraft was in a left turn to
final. As the pilot slipped into a skid using left rudder to make the tight
turn, the receding wing on the left probably stalled while the advancing
wing was still flying.
Now enter negative roll damping. The uneven lift due to negative roll
damping caused a rapid rolling moment to the left, in the direction of the
applied rudder. Once the roll started, it continued despite removal of the
left rudder input that caused the roll because the ailerons were no longer
effective.
The quickest way for the pilot to correct this left rolling moment would
be to push directly forward on the yoke, which decreases the AOA. The
decreased AOA puts the aircraft below stalled AOA and back into normal
flight, immediately stopping the roll because of positive roll damping. The
pilot could then roll the aircraft back to level flight with the ailerons
and recover from the dive, altitude permitting.
If you’ve never experienced an uncoordinated stall, you should definitely
practice these with an instructor who has expertise in this area. It could
save your life and aircraft.
Mike Smotherman is director of flight training and a check pilot at
FCI Training,
Mesa, Arizona. He also is an air combat and EMT trainer.
(Back to top)
Rotary & Fixed
It is the challenge of law enforcement today
to make sure needs are met with
competence and confidence.
by Nat McClain, Sr.
Chief Pilotbr>
Jacksonville (FL) Sheriff’s Office
As a 32-year veteran of law enforcement with 20 of those years in law
enforcement aviation, I have experienced the expansion of aviation from an
observation platform of reciprocating helicopters and small fixed-wing
airplanes to tactical operations with turbine helicopters and mid-sized
turbo-props and jets.
The potential for effective aviation operations has existed since the
Wright Brothers. However, implementation is a matter of public awareness and
operation skills. It is the challenge of law enforcement today to make sure
that both needs are met with competence and confidence.
For most Sheriff’s offices, there is a public requirement to provide
expeditious transportation of personnel, fugitives and convicts across the
nation. Whether this task is performed by commercial or private means, it
becomes the mission of those that are planning for the future of the
aviation fixed-wing operation. Expense is always the bottom line, however,
the administrator has to take into consideration the cost of safety,
convenience, and control of the situations that dictate our overall
effectiveness.
For those of us who have been in the business of fixed-wing flight
operations for any length of time, there has been a reconciliation of needs
met by the cost of owning, maintaining and operating fixed-wing aircraft.
For some, a small single-engine aircraft will adequately supplement their
transportation needs. For others, there is an apparent need to deploy larger
multi-engine aircraft with the capability of negotiating changing weather
conditions over greater distances and faster speeds.
I once heard and remembered the following axiom, Only a well designed
aircraft, properly maintained, and flown by a competent pilot is acceptably
safe. This equates to a unit’s need to understand the mission and to be
willing to meet those needs by appropriately equipping and staffing its
aviation unit. The Jacksonville Sheriff’s Office in Florida has grown from
small fixed-wing aircraft to larger twin-engine aircraft. The largest at
this time is the C-12 (King-Air B200). Each aircraft not only brought to our
unit unique flight abilities, but also unique skill requirements.
In 1979, regretfully we lost three officers due to a mission mishap in
the crash of our Cessna 411. The response to that incident by our department
was a categorical disapproval of twin-engine aircraft. It was not until
March of 1993 that Chief John Rutherford (now Sheriff) initiated the move to
reinstate the use of multi-engine aircraft, thereby increasing flight
operations and capabilities commensurate to the overall transportation needs
of our community.
Departments that properly access their mission will equip themselves with
the appropriate aircraft, considering the maintenance and operational skills
required to operate safely and efficiently. The administrator needs to be
able to move on a moment’s notice with little or no restrictions. Most
flights can and will be conducted with few layovers. However, when there is
a layover, the flight moves on the following day at the discretion of the
administrator.
Owning and operating aircraft versus contracting personnel for prisoner
transportation has enabled our department to move more appropriately and
cost effectively. Prisoners who are transported by law enforcement aircraft
are more secure and pose much less threat to society.
Complex aircraft are not designed to be expensive; they are expensive
because they are complex. However, complexity to the aviation community
means safety due to more redundant and reliable systems. Keeping the
homeland secure is a task that partly depends on efficient up-to-date
aviation operations. Pro-active planning and implementation is critical to
the overall outcome of efficient public safety. I believe the appropriate
use of fixed-wing aircraft will ensure that outcome.
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