7. Appendix F - Maintenance ProgramKalispell City Airport — North End Surfacing Improvements
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Final Report Appendix F
Prepared for the
The City of Kalispell
In cooperation with the
Montana Aeronautics Division
Prepared by
Robert Peccia & Associates
Helena, MT
February 2006
Kalispell City Airport Improvements Program
1.0 INTRODUCTION
2.0 PAVEMENT FACILITIES............................................................................
2
2.1 Purpose of the Pavement Section.......................................................
2
2.2 Causes of Pavement Section Deterioration .......................................
3
2.2.1 Oxidation......................................................................................
3
2.2.2 Moisture........................................................................................
3
2.2.3 Thermal Expansion and Contraction .......................................
4
2.2.4 Weeds............................................................................................
4
2.2.5 Repetitive Wheel Loading..........................................................
4
2.2.6 Fuel and Oil Spillage...................................................................
5
2.3 Types of Pavement Surfaces................................................................
5
2.3.1 Bituminous Chip-Seal.................................................................
5
2.3.2 Bituminous Plant -Mix (Dense Graded) ....................................
5
2.3.3 Modified Bituminous Plant -Mix (Dense Graded) ..................
6
2.3.4 Bituminous Porous Friction Course (Open Graded) .............
6
2.4 Types of Pavement Maintenance........................................................
7
2.4.1 Crack Sealing...............................................................................
7
2.4.2 Weed Control...............................................................................
9
2.4.3 Snow Removal.............................................................................
9
2.4.4 Sweeping Pavement....................................................................
9
2.4.5 Fog Seals.......................................................................................
10
2.4.6 Chip Seals.....................................................................................
10
2.4.7 Plant -Mix Overlays.....................................................................
10
2.4.8 Coal Tar Seals...............................................................................
11
2.4.9 Painting.........................................................................................
11
2.4.10 Patching Potholes and Raveling ..............................................
12
3.0 ELECTRICAL SYSTEMS.............................................................................
12
3.1
Systems to be Tested and Inspected ...................................................
12
3.1.1 Runway and Taxiway Systems .................................................
12
3.1.1.1 Regulator.........................................................................
13
3.1.1.2 Cable.................................................................................
13
3.1.1.3 Lighting Transformers...................................................
13
3.1.1.4 Lighting Fixtures............................................................
13
3.2
Beacon.....................................................................................................
13
3.3
Glide Slope Indicator Systems............................................................
14
3.4
Radio Control........................................................................................
14
3.5
Equipment Enclosures..........................................................................
14
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Kalispell City Airport Improvements Program
4.0 DRAINAGE FACILITIES ............................................................................ 14
4.1 Open Channels ...................................................................................... 14
4.2 Drop Inlets, Manholes, and Culverts ................................................. 14
4.3 Erosion Control ..................................................................................... 15
5.0 INSURING COMPATIBILITY WITH CURRENT AIRPORT
LAYOUT PLAN AND PART 77 ................................................................. 15
5.1 Airspace Obstruction Control ............................................................. 15
5.2 Locating Buildings, Utilities, and Other Airport Facilities ............. 16
5.3 Surrounding Land Use Compatibility ............................................... 16
6.0 RECOMMENDED MAINTENANCE PROGRAM ................................. 16
Appendix A: Spring/Fall Facility Checklist
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Kalispell City Airport Improvements Program
Every year millions of dollars are spent on airport improvements around the country.
Proper maintenance ensures the quality of this investment for years to come. Studies by U.
S. Army Corps of Engineers Construction Engineering Research Laboratory (USACERL)
show asphalt pavements exhibit a period of slow aging followed by a rapid deterioration
(see Figure 1). In fact, they contend it takes about 75% of the pavement's life to lose 40% of
its quality. Amazingly, the next 40% drop in pavement quality normally occurs in just 12%
of the pavement's life. Using preventative maintenance on "good" quality pavement gives
the best possible pavement performance per dollar. (see the example $1 & $4 repair options
shown in Figure 1).
loo
Excellent
g
$1 .00Invested In Preventative Maintenance
Very Good
AW am I'm ft
40% Drop
Tp In Quality
a Goad
c
O 55
$4 After
75% Of Life The F - Read
Fair
0
2 40
40% Drop
a Par
In Quality
E
v
Improved
25
�✓ Poa
aintenanC
Cee Cycles
12% Of
0
Life
Failed
e
flinne
Figure 1 - Extended Pavement Life Cycle
even published an Advisory Circular (AC 15015380-6) entitled "Guidelines and Procedures
for Maintenance of Airport Pavements". They currently assist with the funding of
pavement maintenance at a 95% share, with only 5% local match required.
This maintenance program is intended to make the airport owner aware there are certain
maintenance items that should be performed periodically to not only protect their
investment but to provide the public with a safe and efficiently operated airport. A quality
airport is a benefit to the community in which it is located --so take good care of it.
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Kalispell City Airport Improvements Program
2.0 PAVEMENT FACILITIES
2.1 Purpose of the Pavement Section
The primary purpose behind constructing an asphaltic concrete pavement section at an
airport or on a roadway is to distribute the force of the wheel loading that reaches the
underlying subgrade (native soil).
As Figure 2 illustrates, the resultant loading that is distributed over the subgrade (no
pavement section) is substantially greater than the loading on the subgrade in Figure 3
(typical pavement section).
4,000 LBS
SUBGRADE (NATIVE SOIL)
1.000 LBS / SQ. IN.
Figure 2 — Concentrated Wheel Load without Pavement
4,000 LBS
BITUMINOUS SURFACE COURSE
BITUMINOUS PRIME COAT
CRUSHED AGGREGATE
BASE COURSE
SUB -BASE COURSE
SUBGRADE (NATIVE SOIL)
100 LBS / SO. IN.
Figure 3 — Distributed Wheel Load with Pavement
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Kalispell City Airport Improvements Program
The numbers in these figures are only hypothetical examples of how a pavement section
distributes the force of a single wheel loading over a larger area of the subgrade. The 4,000
pound force above would be an approximation of a 12,000 pound aircraft with tricycle gear
and equal distribution of its weight on all three tires.
The subgrade has the poorest load -supporting properties of all the pavement section
materials. These subgrade properties vary widely from airport to airport, thus causing the
required pavement sections to vary widely from airport to airport. Pavement sections are
designed on a site -specific basis depending upon subgrade properties, design loading,
drainage, and frost penetration.
2.2 Causes of Pavement Section Deterioration
There are many elements that contribute to the deterioration of a pavement section. On
most General Aviation (GA) airports in Montana the following items are considered to be
the primary causes of the pavement section deteriorating.
2.2.1 Oxidation
Oxidation is a chemical reaction that occurs within the asphalt cement when subject to the
atmosphere and ultraviolet radiation for long periods of time. It is a slow, constant process
that, if not curbed by some means, will eventually result in a brittle, crack -susceptible
pavement surface that is unable to distribute the loads as effectively as it should. In
addition, oxidized pavement begins to lose the rocks, or "chips", reducing traction and
creating a foreign object debris (FOD) hazard. These loose chips can damage propellers,
and are especially harmful when ingested by jet engines.
2.2.2 Moisture
Moisture -related deterioration is, perhaps, the number one cause of pavement
deterioration at small airports in Montana. Moisture can enter the pavement section from
all directions. It will enter from above by seeping through cracks in the paved surface,
from the sides by seeping in from saturated runway shoulders, and from below by capping
natural evaporation and/or high ground water . The load supporting properties of the
base course, subbase course, and subgrade materials become greatly affected by the
presence of moisture. The subgrade's load supporting properties are the most susceptible
to changes in the moisture content. In severe cases the subgrade's load supporting
potential may be reduced by a factor of four or five. What this means is that a subgrade
capable of supporting 100 pounds per square inch under normal moisture conditions may
only be able to support 20 to 25 pounds per square inch under saturated moisture
conditions. Use of the runway under saturated conditions can cause the subbase course to
actually be pushed into the underlying subgrade, resulting in a weakened pavement
section and rutting.
Excess moisture in the pavement section during the fall, winter, and spring can result in
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Kalispell City Airport Improvements Program
severe frost heaves, excessive cracking, alligator cracking, and spalling of the pavement
edges.
2.2.3 Thermal Expansion and Contraction
All construction materials are subject to thermal expansion and contraction to varying
degrees, and paved surfaces are no exception. Pavement contracts in the winter and
expands in the summer. The amount of expansion and contraction of a particular paved
surface depends on the physical composition of the pavement (i.e., asphalt type, asphalt
content, aggregate gradation, etc.), construction procedures, and the climate of the area
where the pavement is located.
In some pavements the differential movement between winter and summer can vary as
much as 3 to 4 inches per 100 feet of pavement. Unfortunately, there has not yet been a
pavement developed that can completely withstand this type of movement without
cracking. Some types of pavement resist thermal cracking better than others, and these will
be discussed later. The development of thermal cracks in the pavement allows water to
penetrate into the pavement section and compounds the moisture -related deterioration.
2.2.4 Weeds
The growth of weeds along the edges and through the middle of the pavement surface can
cause an incredible amount of damage in a short period of time. The pavement is broken
apart by vegetation's roots, thus allowing water to penetrate the surface more readily and
resulting in the growth of more weeds. Weeds commonly grow in the cracks in the
runway after enough topsoil has blown into them to support their growth. The weeds, if
left uncontrolled, can fracture and spall the edges of the cracks to the point where a simple
crack seal treatment will not suffice; and some major reconstruction may be required.
2.2.5 Repetitive Wheel Loading
Deterioration of the pavement section due to the repetitive wheel loading of aircraft is
almost negligible at most of the GA airports in Montana. Most destruction done by wheel
loadings is caused by "excessive" wheel loading, usually attributable to a snowplow truck
or heavy construction equipment. One must bear in mind that most small airports are
designed for aircraft of 12,500 pounds or less, and are not designed for a large snowplow
loaded full of sand or a loaded piece of construction equipment. Excessive use of these
types of equipment will result in the eventual rutting of the pavement surface. The speed
at which this occurs will largely depend on the moisture content of the material under the
pavement surface and whether or not the ground is frozen.
The airport manager should be aware of the design strength of the airport's pavement and
should make a conscious effort to allow its use only by those aircraft and equipment that
fall within the design strength.
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Kalispell City Airport Improvements Program
2.2.6 Fuel and Oil Spillage
Spilling fuel, oil, and other solvents on the pavement tends to permanently soften the
asphalt in the mix and allows the aggregate to be easily dislodged under traffic and
snowplowing, leaving pock -marked areas in the pavement which will allow water to more
readily penetrate the surface. Spills result in a direct and immediate degradation of the
pavement.
2.3 Types of Pavement Surfaces
Before discussing the recommended maintenance techniques for pavement surfaces, let us
discuss the four common types of asphalt surfaces found on GA airports around the state
and some advantages and disadvantages of each.
2.3.1 Bituminous Chip Seal
A runway with a chip -seal bituminous surface is constructed of alternating applications of
an asphalt bituminous material and aggregate (chips). The bituminous material is applied
by using an oil distributor truck; the chips are then spread over the top of the oil using a
mechanical chip spreader that is then followed by rollers to firmly embed the chips in the
bituminous material. On new construction, three separate applications of bituminous
material and aggregate are usually applied resulting in a finished pavement surface of
between one inch and one and one-half inches thick. This type of surface is referred to as a
"triple shot." A final application of bituminous material, called a fog seal, is usually
applied to the finished triple -shot to anchor any loose chips left on the surface. The triple -
shot contributes little or no strength to the underlying base course, subbase course, and
subgrade. Its primary purpose is to protect the underlying material from moisture, to
provide a smooth, all-weather operating surface, and to provide a friction surface to avoid
hydroplaning. Of the four pavement surfaces discussed, the triple -shot ranks in the middle
for resisting cracking.
2.3.2 Bituminous Plant -Mix (Dense Graded)
Plant -mix bituminous pavement is a combination of bituminous materials and well -graded
aggregate that are hot -mixed in a batch plant and applied to the surface using an asphalt
paving machine. Precision screed controls on paving machines produce very smooth
riding paved surfaces. Well -graded aggregate coated with an asphalt binder compacts to a
strong moisture barrier which caps the pavement foundation.
The high structural strength of a dense -graded mix reduces base course quantity
requirements in an initial application, and allows thin -lift maintenance overlays. The
moisture seal preserves base course and subgrade integrity and extends the pavement
section's functional life. The smooth surface that gives good ride quality also slightly
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Kalispell City Airport Improvements Program
increases hydroplaning potential, unless groves are cut in the finished surface to aid
drainage. Non -rubberized plant -mix bituminous surface is usually the least effective
surface for resisting cracks.
2.3.3 Modified Bituminous Plant -Mix (Dense Graded)
Rubberized plant -mix bituminous pavement includes rubber as well as bitumen in the
binder to provide all the advantages of a dense graded mix with additional flexibility and
reduced brittleness.
Performance Graded (PG) Asphalt Cement Binders are a new approach to asphalt mix
design. Rather than specifying the types and proportions of asphalt binder ingredients, the
final mix in a PG binder must meet or exceed specified performance standards. The
driving force behind PG asphalts is the assumption that subjecting a completely mixed
binder to standardized test procedures (viscosity, shear, creep, strain, toughness and
tenacity tests) is a better way to assure quality than simply starting with good ingredients
and hoping the mixture turns out. PG binders allow producers the freedom to select their
ingredients while assuring the consumer of performance they expect.
Additional flexibility makes for a more durable pavement in extreme climates and better
crack resistance. Additional pliability in modified asphalts allow thinner, less expensive
maintenance overlays that minimize reflective defects. Rubber in the asphalt binder makes
the mix sticky and harder to hand -work during application, possibly decreasing aesthetics
slightly. Modified plant -mix is somewhat more expensive than non -modified mix.
2.3.4 Bituminous Porous Friction Course (Open Graded)
The porous friction course (PFC) is hot -mixed in a batch plant similar to the plant -mix
surfaces described above except a coarser aggregate blend is mixed with bituminous
materials. PFCs add virtually no structural strength and do not seal moisture away from
underlying courses, so they are only used as thin lifts over existing pavement. The coarse
aggregate mix leaves a network of small drainage holes that let water drain through the
PFC to an underlying watertight pavement. Water then travels laterally until draining off
the edges.
The PFC's subsurface drainage virtually eliminates hydroplaning. The coarse surface
improves traction even when dry, and still provides a smooth ride. With the use of a
rubberized bituminous material in the mix, a PFC provides superb crack resistance. Over
time, the course under a PFC begins to crack and allow moisture into the pavement's
foundation. To avoid serious frost damage potential, the PFC must be milled off before
applying a thin lift maintenance course, then reapplied. These additional long range costs
must be weighed against the PFC's excellent all weather traction and crack resistance.
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Kalispell City Airport Improvements Program
2.4 Types of Pavement Maintenance
Although the maintenance required for a particular type of pavement surface may vary
drastically from airport to airport, the following recommendations will, hopefully, provide
enough information that you, the airport owner, can identify the problems applicable to
your airport and will be able to apply the recommended maintenance to that problem.
2.4.1 Crack Sealing
The importance of keeping excess moisture out of the pavement section cannot be stressed
enough. Cracks in the pavement surface provide a direct route for water to infiltrate into
the underlying section and should, therefore, be sealed periodically.
There are many different ways and many products that can be used to seal cracks. For
extremely cold temperatures experienced in Montana, we recommend a very high quality,
hot -applied rubberized crack sealant. This material costs slightly more than other crack -
sealing products, but if applied correctly, the product will perform longer without failure.
The preparation of the crack prior to sealing is the most important step in assuring a good
job. If done incorrectly, not even the best crack seal materials available can be expected to
perform as they should.
The first step in crack preparation is called routing. Routing is the process of cutting a
groove in the pavement along the cracks alignment. Routing of the crack allows enough
crack sealant to penetrate the crack so the sealant can withstand the thermal expansion and
contraction experienced in the summertime and wintertime, respectively. Figure 4
illustrates the differential movement that must be absorbed by a crack seal material applied
in an un-routed crack compared to that of a properly routed crack. Research by the
Montana Department of Transportation has shown a "4 to 1" route (about 11/2" wide by
3/8" deep to be the most effective route profile).
As exemplified in Figure 4, the crack sealant material placed in the unrouted crack is
required to stretch to three times its original width, whereas the crack sealant material
placed in the same crack after routing is only required to stretch one third more than its
original width in the routed "reservoir". In summary, the lower the stretch factor a crack
sealant has to endure, the greater its chance of remaining an effective moisture barrier. All
cracks to be sealed should be routed if possible.
Figure 4 — Unrouted vs. Routed Crack Expansion Comparison
Routing may not always work well on previously sealed cracks or thin pavement sections
such as chip seals or PFC's. The old sealant in previously sealed cracks usually gums -up
the cutter bit enough it is not able to make a controlled cut. Due to the large aggregate in
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Kalispell City Airport Improvements Program
�....._ 1/4" j 3/4„
EXPANSION OF AN
UNROUTED CRACK
SUTN4MER WINTER
..................... �....... l 11�" i „
... ....................................._ �.
EXPANSION OF A
ROUTED CRACK
SUMMER WINTER
CrackSealant �..::.:.;.] Bituminous Surface CoLu se Foam Backer Rod
a PFC, Attempted routing usually leaves a ragged edge with little or no ability to control
route width or depth. Routing a chip seal usually just removes the chips and doesn't create
a quality bonding reservoir. In these cases, the cracks can only be blown clean and dry. An
experienced professional should be consulted before the routing technique is abandoned.
Once all the cracks have been routed, the next step is to clean the crack of all dust and
moisture by means of blowing, brushing, or gouging. The most poplar method is blowing,
with an air wand and trailer -mounted air compressor. Without proper cleaning the crack
sealant material will not adhere to the sidewalls of the pavement and will develop sidewall
tears that will have to be refilled.
On airports where weed growth within the pavement cracks is a problem, the cracks
should be treated with an application of a soil sterilant prior to cleaning and sealing.
The crack sealing process, including routing, described above costs approximately $1.00
per lineal foot when contracted.
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Kalispell City Airport Improvements Program
2.4.2 Weed Control
The control of weeds in and around the paved surfaces of an airport is a simple matter of
periodically sterilizing along the edges of all pavement and in those cracks that support
weed growth. By sterilizing the first foot or two outboard of the pavement edges, weeds
will be prevented from breaking the edges of the pavement off and better drainage of
surface water away from the pavement edge will be promoted.
If the airport is not financially capable of crack sealing periodically, the weeds within those
cracks should at least be tended to each year. Allowing weeds to grow within the cracks
causes disintegration of pavement around the crack thereby making future sealing
operations less effective, or impossible.
It is suggested that the soil around each light fixture and Precision Approach Path Indicator
(PAPI) unit also be sterilized when sterilizing the soil around the paved areas. This will
make these items more visible to aircraft and mowers alike.
2.4.3 Snow Removal
A good portion of the moisture -related pavement deterioration at airports is due to
improper snow removal. Snow that is only removed from the pavement and is allowed to
stand in banks along the pavement edge acts as a dam during the spring melt. Water that
would normally flow out away from the pavement edge to the ditch line is blocked by the
bank of snow and instead soaks into the ground and saturates the pavement section.
Although it takes more time and effort, it is recommended to plow the snow at least 15 feet
off the edges of all paved surfaces (i.e., five feet outside the light line on lighted airports).
On the ends of each runway the snow should be plowed off the safety area, and no banks
should be allowed to accumulate.
Steel snowplow blades can damage paved surfaces. Perhaps the best options to prevent
this damage from occurring are by using either polymer snowplow blades or rotary -type
augers. Most small airports are plowed by County forces, however; and these two options
are not practical. In that case, perhaps requesting them to slow down and lighten their
load might diminish surface damage.
2.4.4 Sweeping Pavement
The accumulation of sand, rocks, and other debris on the pavement surface can accelerate
surface deterioration. When planes and maintenance equipment operate over these rocks,
the wheel loadings are concentrated on top of the rock and greatly increase the force
exerted on the pavement. Sand, in effect, can act like an abrasive sand paper after many
repetitive wheel loadings.
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Kalispell City Airport Improvements Program
Most of the debris is dragged onto the pavement surface during snow plowing operations.
It is suggested that the paved surfaces be swept clean of all debris in the springtime after
the snowplow operations have concluded and before the aircraft operations increase. The
cost of sweeping the paved surfaces will probably prove to be less than the cost of repairing
chipped propellers or a jet engine if a loose rock is ingested.
2.4.5 Fog Seals
A fog seal is an application of a bituminous material that is sprayed on the pavement
surface to help curb the oxidation process, improve the moisture protection of the
pavement sections, and to keep chips anchored to the surface. The fog seal is composed of
bituminous material (asphalt), an emulsifier (soap), and water. The fog seal can usually be
applied in one day provided the weather is hot and dry, and the airport can normally be
used the next day.
The fog seal provides excellent preventative maintenance for all pavement types in
excellent to good condition. A good fog seal can extend the life of the pavement an
additional three to five years at a cost of $0.25 - $0.30 per square yard.
2.4.6 Chip Seals
A single -shot, chip seal bituminous surface treatment is applied in three steps. The first is
the direct application to the paved surface of a heavy shot of bituminous material called a
seal coat. The second step, immediately following the first, is the application and rolling of
aggregate material called "chips" into the seal coat. The bituminous material is allowed to
cure around the embedded chips. After curing, the surface is thoroughly broomed to
remove loose chips before a final seal coat is applied to anchor the chips in place.
The chip seal coat works well on an existing chip seal bituminous surface and on plant -mix
bituminous surfaces. It is not only used on the plant -mix bituminous surface to improve
the moisture protection of the pavement section but to increase surface friction and reduce
hydroplaning. This type of seal will not remove any of the surface irregularities in a
pavement. The cost of a good chip seal is approximately $1.50 per square yard depending
on the availability of aggregate material. The FAA does not support chip seals.
2.4.7 Plant -Mix Overlays
Plant -mix overlays are a maintenance technique used to prolong the life of a pavement
which shows no evidence of serious localized trauma or structural failure (e.g. spalled
cracks, rutting, alligator cracking, swells, depressions). A thin overlay applied while
pavement is in good condition can provide much more economical extension of usable life
than extensive measures applied to a fair or poor condition surface. The two common
types of plant -mix overlays utilized today are the dense graded overlay and the open
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Kalispell City Airport Improvements Program
graded (PFC) overlay. Both types will provide a "level -up" that can remove most small
surface irregularities.
The FAA has discouraged use of open graded overlays in recent years. They contend the
additional costs of removing the PFC before placing future maintenance layers, outweighs
their superior all weather traction and crack resistance properties in most cases. The PFC
overlay can be applied on any of the four pavement surfaces and normally costs about
$4.50 per square yard.
Improved crack resistance of Performance Graded and rubberized dense graded mixes and
their place in ongoing preventative maintenance programs have brought dense graded
overlays into favor with the FAA and many pavement engineers. Research continues to
show that the lowest pavement life -cycle costs are achieved with preventative maintenance
overlays on good quality pavement. Dense graded mixes can be placed in 2" lifts at ten-
year intervals to counter surface aging and replace lost strength. A dense grade overlay
strengthens a pavement section significantly more than an equivalent thickness PFC.
Modified asphalt cement adds strength, gives excellent crack resistance, and can be
grooved to provide all weather traction if required. A 2" thick dense grade overlay can be
applied over any pavement type except PFCs and costs about $3.80 - $4.20 per square yard.
2.4.8 Coal Tar Seals
A coal tar seal is an application of a coal tar pitch emulsion that will protect the pavement
from the harmful effect of fuel or oil spillage. The coal tar seal is applied around the
fueling areas and under each tie -down area. When fuel is spilled on this material, it will
evaporate before penetrating into and damaging the underlying pavement. The coal tar is
usually allowed to cure for several weeks before pavement markings are applied.
Coal tar can be applied straight or can be mixed in a sand slurry to improve traction or the
ability to fill the voids in a porous friction course. This application costs roughly $15.00 per
square yard for small quantities.
2.4.9 Painting
Runway, taxiway, and apron pavement marking should be repainted before they become
so difficult to see they are a safety hazard. Painting can be accomplished using hand rollers
or County spray trucks or a professional marking contractor can be hired. It is important
to remember, whatever means of application is chosen, to keep the application light.
Excessive amounts of paint can cause the pavement to crack along the paint's edge due to
differential thermal movement between the white and adjacent black pavement. Painting
costs, when contracted usually range $0.50 to $1.50 per square foot.
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Kalispell City Airport Improvements Program
2.4.10 Patching Potholes and Raveling
Occasionally, potholes and isolated areas of pavement raveling will occur in a pavement
surface. Potholes should be patched immediately to prevent water accumulation that will
continue to erode the subgrade and/or enlarge the hole by freeze -thaw action. Potholes
and raveled areas are a continual source of foreign object debris (FOD) that could damage
propellers or jet impellers, creating both a safety issue and a major liability for the airport!
Unfortunately, the sweeping necessary to reduce loose debris generates additional debris.
The edges of potholes have low structural strength, and tend to slough off in small pieces
with traffic or sweeping action.
Methods of patching potholes and raveled areas depend upon the type of pavement
surface involved. For chip seal bituminous surfaces and plant -mix bituminous surfaces, a
hot -mix patch is preferred. However, a cold -mix patch is usually easier to obtain and will
suffice. The area to be patched should be cleaned of all loose aggregate, dust, and moisture
before patching. A light tack coat of bituminous material is applied to the edges and
bottom of the pothole and then the patch material should be shoveled into the patch area,
compacted, and smoothed. The hotter the day, the better.
Patching a bituminous porous friction course surface can be accomplished using the above -
described hot -mix or cold -mix; however, it is preferred to use a hand -mixed version of the
PFC. By saving some of the PFC aggregate used to construct the project originally, a
person can combine this aggregate with asphalt (CMS-2) in a bucket and mix up a patch
material very similar to the original mix.
To insure the least amount of moisture -related pavement damage and erosion damage, the
airport's field drainage system should be checked periodically for obstructions that will
reduce the effectiveness of the system. The following system components should be
considered.
Whether serving as a storm drainage channel or an irrigation channel, all open channels
should be maintained free of all sticks, sediment, and vegetative growth that will restrict
the flow of water. Most open channels serve as the outfall for the rest of the system; and if
they are restricted, the water may back all the way up through the system and cause
flooding elsewhere.
3.2 Drop Inlets, Manholes, and Culverts
Usually located at the upstream end of the drainage system are the drop inlets, manholes,
and culverts. If these facilities are not functioning properly, the water will not be able to
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Kalispell City Airport Improvements Program
enter the system and flooding is imminent. These facilities need to be checked frequently
for plugging by grass clippings, sticks, sediment, and ice. Some of the worst flood damage
occurs in the early spring when the drainage facilities are still blocked with ice. Ground -
level grades around drop inlets must also be maintained to insure that water will not pond
around the inlet.
3.3 Erosion Control
Erosion control facilities include the establishment of a good stand of grass and the placing
of rock rip -rap on steep banks and steep channel slopes. A well -established stand of grass
will protect the native soil from both wind and water erosion and will reduce the amount
of sediment that deposits in the other drainage facilities. On certain steep banks and
channel slopes the placement of rock rip -rap is required instead of, or in addition to, the
grass to keep the soil from eroding.
The airport's turf areas should be mowed regularly for drainage, safety, and aesthetic
reasons. Mowing will allow the surface water to flow away from the pavement's edge
more readily. It is suggested the grass be cut at least one to two passes beyond the ditch
lines that parallel the paved surfaces and also be cut around any inlets and outlets to
drainage facilities. Vegetation should be mowed regularly enough that runway lights
always remain visible. The grass should be mowed short in the safety areas off each
runway end to insure the safety of errant planes.
Before federal funding can be obtained on future FAA projects, the airport owner must be
able to demonstrate that the airport facilities are still compatible with the ultimate growth
of the airport. If the airport owner insures that any and all growth of facilities between
FAA projects is consistent with what is depicted on the current approved Airport Layout
Plan (ALP) and Part 77, they will have no problems demonstrating compatibility. If the
airport owner chooses not to follow the ALP and Part 77 and also chooses not to coordinate
any new construction with the FAA, it may find itself with an airport that is no longer
eligible for federal funding. A few recommendations to insure future eligibility for federal
funding are set forth below.
4.1 Airspace Obstruction Control
One item most often found incompatible with the ultimate airport growth is allowance of
construction of an object that penetrates the imaginary surfaces depicted on the Part 77
Airspace Chart. Allowing construction of such an object within the approach surfaces can
be devastating on future eligibility for federal funds, not to mention the liability and FAA
compliance problems that may be encountered. Before allowing construction of an object
Maintenance Program 13
Kalispell City Airport Improvements Program
that may affect airspace quality, the owner should contact the FAA and file a "Notice of
Proposed Construction or Alteration" and let the FAA determine its compatibility.
4.2 Locating Buildings, Utilities, and Other Airport Facilities
The airport owner must also insure that any facilities constructed on airport property be
compatible with the ultimate airport improvements. Whether the facility is a hangar, a
light pole, or a wind cone, there is a right and wrong place to construct such items. Again,
it is suggested that the airport owner contact the FAA and file a "Notice of Proposed
Construction or Alteration" before construction begins.
4.3 Surrounding Land Use Compatibility
Compatible land use surrounding an airport can be assured either by outright ownership
of the property, or by both airspace and land -use zoning. Ownership is generally only
feasible if the land is leased for income generating compatible uses such as farming,
industrial, and business parks. The airport's infrastructure investment may be protected
with a combination of airspace and land use zoning that vigorously defends the Part 77
Airspace and land underneath it, while encouraging compatible airside and non-airside
development. Zoning is easiest to enact before it is needed; before there are competing
residential or other non -compatible development proposals.
The recommended maintenance program for the Kalispell City Airport has been divided
into general and major maintenance portions. General maintenance items include periodic
crack sealing, weed sterilizing, snow removal, pavement sweeping, grass cutting, electrical
system inspections, drainage facility inspections, etc. Major Maintenance includes an
approximate five-year cycle of pavement care. Major maintenance items include fog seals,
chip seals, thin -lift overlays, coal tar seals, and painting. Reconstruction options include a
thick (Y-4") overlay; a mill in place, compact, and repave; or a remove and replace.
Pavement reconstruction and periodic pavement maintenance work are eligible for FAA
funding. When maintenance options cease to be productive or economically viable,
pavements are reconstructed.
An airport maintenance budget, Figure 5, has been included to aid the City of Kalispell
Airport Advisory Board in their budget administration. Costs have been included for both
the general maintenance and major maintenance work items. A lump sum amount of
$4,000 was assumed for annual general maintenance work. All costs listed in the airport
maintenance budget are in 2005 dollars, and no inflationary adjustments have been made.
We have provided the City of Kalispell Airport Advisory Board with a "Spring/Fall
Airport Facility Checklist" in Appendix A of this report. We would recommend that twice
a year the Airport Manager appoint someone to conduct an airport facility inspection using
Maintenance Program 14
Kalispell City Airport Improvements Program
the enclosed checklist as a guideline. As the inspection is being made, notes should be
taken as to what facilities will require maintenance and to what extent the maintenance
should be performed. These checklists should be saved for future reference. The Airport
Manager should also obtain copies of the FAA's recommended weekly inspection reports
to aid them in controlling any and all airport safety hazards as they develop.
The Airport Manager is reminded that this recommended maintenance program is
provided as a general budgeting tool only and the time frames and costs chosen for
maintenance are subject to change. The City of Kalispell Airport Advisory Board is
advised to consult a competent airport engineering firm prior to undertaking any of the
major maintenance work tasks.
Maintenance Program 15
Kalispell City Airport Improvements Program
Appendix
. pr L
a�
Airport Facility Checklist
Kalispell City Airport Improvements Program
SPRINGNALL FACILITY CHECKLIST
This checklist should be completed and presented to the City of Kalispell Airport Advisory
Board on a bi-annual basis. Maintenance activities can then be planned accordingly.
Weekly checklists, as provided by the FAA, should also be obtained and completed to
provide a closer check on safety -related facility requirements.
Pavement Facilities
1. Are there any pavement cracks that need to be sealed? Yes No
Estimated amount = lineal feet
Comments:
2. Are there any weeds that need to be sterilized? Yes No
Location:
Comments:
3. Are there any potholes or raveled areas that need to Yes No
be patched?
Location:
5
I
a
a
Comments:
Is pavement sweeping needed?
Yes
No
Comments:
Are the runway pavements in good condition?
Yes
No
Comments:
Are the taxiway pavements in good condition?
Yes
No
Comments:
Are the apron pavements in good condition?
Yes
No
Comments:
Is the coal tar seal around the tie -down areas and
Yes
No
fueling areas cracked and in need of another application?
Comments:
Are the pavement markings in good condition? Yes No
Comments:
Airport Facility Checklist ll
Kalispell CitvAiroort Imorovements Proaram
Drainage Facilities
1. Are all open channels cleaned of flow -restricting Yes No
debris?
If no, location:
Comments:
2. Are all culverts clean? Yes No
If no, location:
Comments:
3. Any evidence of erosion? Yes No
If yes, location:
Comments:
1
2.
3
1
4
Other Facilities
Is the perimeter fence in good condition?
If no, what repairs are needed?
Comments:
Are the hangar areas being kept clean and neat?
Comments:
Are the signs to the airport all in place and legible?
(The sign closest to the airport should say "Did
you close your flight plan?" on the back.)
Comments:
Have any airspace obstructions been allowed to
develop?
If yes, location:
Height:
Comments:
Have any new on -airport facilities been constructed
since the last inspection?
If yes, description:
Location:
Yes No
Yes No
Yes No
Yes No
Yes No
Airport Facility Checklist 111
Kalispell City Airport Improvements Program
Height:
Was FAA notified prior to construction? Yes No
Comments:
3. Is the surrounding land use compatibility being Yes No
maintained?
Comments:
4. Are there any non -aeronautical uses on airport Yes No
land as designated on the Exhibit "A"?
Date Inspection Made:
Airport Facility Checklist IV