+-----------------------------------------+----------------------------+
| ![](media/image1.wmf)                   | **Advisory**               |
|                                         |                            |
| U.S. Department                         | **Circular**               |
|                                         |                            |
| of Transportation                       |                            |
|                                         |                            |
| **Federal Aviation**                    |                            |
|                                         |                            |
| **Administration**                      |                            |
+-----------------------------------------+----------------------------+

+--------------------------------+-------------------+-----------------+
| **Subject:** Guidelines and    | **Date:** DRAFT   | **AC No:**      |
| Procedures for Measuring       |                   | 150/5380-XX     |
| Airfield Pavement Roughness    | **Initiated by:** |                 |
|                                | AAS-100           | **Change:**     |
+--------------------------------+-------------------+-----------------+

1.  **PURPOSE.** This Advisory Circular (AC) provides guidelines and
    procedures for measuring and evaluating runway roughness as
    identified by surface profile data of rigid and flexible airport
    pavements. The guidance in this AC provides technical procedures to
    quantify surface irregularities and to determine how surface
    irregularities may affect specific categories of airplanes.

2.  **APPLICATION**. The FAA recommends the guidelines and standards in
    this AC for evaluating the roughness of new and existing paved
    surfaces. In general, this AC is not mandatory and does not
    constitute a regulation. It provides one, but not the only,
    acceptable means of meeting the requirements of Title 14 Code of
    Federal Regulations (CFR) Part 139, Certification of Airports,
    Paragraph 305, should airport users or personnel report pavement
    roughness, irregularities, or variations. Mandatory terms such as
    "must" used herein apply only to those using Airport Improvement
    Program (AIP) or Passenger Facility Charge Program (PFC) funds.
    However, the FAA strongly encourage all airports to follow the
    guidance in this AC.

    a.  **PRINCIPAL CHANGES.** This is a new AC.

3.  **RELATED READING MATERIAL.** Appendix 1, Bibliography, lists
    further guidance and technical information.

4.  **METRIC UNITS.** To promote consistency with International Civil
    Aviation Organization (ICAO) guidance, the text and figures include
    both metric and English dimensions. Dimensions are provided first in
    metric units. Readers should keep in mind that English units are
    based on operational significance and may not be exact equivalents.

5.  **COMMENTS OR SUGGESTIONS** for improvements to this AC should be
    sent to---

Manager, Airport Engineering Division

Federal Aviation Administration

ATTN: AAS-100

800 Independence Avenue SW

Washington DC 20591

6.  **COPIES OF THIS AC.** The Office of Airport Safety and Standards
    makes its ACs available to the public on the FAA website
    (www.faa.gov).

You can request a printed copy of this AC and other ACs from---

> U.S. Department of Transportation
>
> Subsequent Distribution Office
>
> Ardmore East Business Center
>
> 3341 Q 75th Avenue
>
> Landover MD 20785

Michael J. O'Donnell

Director of Airport Safety and Standards

**TABLE OF** CONTENTS

[FORWARD iii](#forward)

[CHAPTER 1. INTRODUCTION TO AIRPORT PAVEMENT ROUGHNESS
1](#chapter-1.-introduction-to-airport-pavement-roughness)

[1.1 PURPOSE OF ADVISORY CIRCULAR 1](#__RefHeading___Toc209504373)

[1.2 IMPORTANT FACTOS IN EVALUATING PAVEMENT ROUGHNESS.
1](#important-factos-in-evaluating-pavement-roughness.)

[a. Pavement Surface Irregularities. 1](#__RefHeading___Toc209504375)

[b. Airfield versus Highway Roughness 1](#__RefHeading___Toc209504376)

[c. Categories of Airfield Pavement Roughness.
1](#__RefHeading___Toc209504377)

[d. Passenger Comfort. 2](#__RefHeading___Toc209504378)

[e. Factor Affecting Safe Airplane Operations.
2](#__RefHeading___Toc209504379)

[f. Pilot Response and Feedback. 2](#__RefHeading___Toc209504380)

[g. Surface Texture. 2](#__RefHeading___Toc209504381)

[h. Construction Standards. 2](#__RefHeading___Toc209504382)

[CHAPTER 2. EVALUATING SINGLE EVENT BUMPS IN RUNWAY PAVEMENT
3](#chapter-2.-evaluating-single-event-bumps-in-runway-pavement)

[2.1 INTRODUCTION TO SINGLE EVENT BUMP EVALUATION
3](#__RefHeading___Toc209504384)

[2.2 BOEING BUMP EVENT IDENTIFICATION PROCEDURE.
3](#boeing-bump-event-identification-procedure.)

[a. Basic Procedure. 3](#__RefHeading___Toc209504386)

[b. Maximum Straightedge Length 3](#__RefHeading___Toc209504387)

[c. Minimum Straightedge Length. 3](#__RefHeading___Toc209504388)

[d. Number of Straightedges Associated with a Survey Interval.
5](#__RefHeading___Toc209504389)

[e. Recommended Survey Interval. 5](#__RefHeading___Toc209504390)

[f. Recommended Survey Location. 5](#__RefHeading___Toc209504391)

[g. Use of Inertial Prolilers with Highpass Filtering
5](#__RefHeading___Toc209504392)

[2.3 EVALUATION OF BOEING BUMP PARAMETERS.
6](#evaluation-of-boeing-bump-parameters.)

[a. Bump Evaluation Procedures. 6](#__RefHeading___Toc209504394)

[b. Evaluation Criteria. 6](#__RefHeading___Toc209504395)

[2.4 DEVELOPMENT OF THE BOEING BUMP INDEX.
7](#development-of-the-boeing-bump-index.)

[a. Need for Boeing Bump Index. 7](#__RefHeading___Toc209504397)

[b. Development of Software to Compute the Boeing Bump Index
8](#__RefHeading___Toc209504398)

[c. ProFAA Software. 8](#__RefHeading___Toc209504399)

[d. Comparison with hte Original Boeing Bump Procedure.
8](#__RefHeading___Toc209504400)

[2.5 PAVEMENT ROUGHNESS EVALUATION USING THE BOEING BUMP INDEX.
9](#pavement-roughness-evaluation-using-the-boeing-bump-index.)

[a. Boeing Bump Index Evaluation Criteria.
9](#__RefHeading___Toc209504402)

[b. ProFAA Reporting of Boeing Bump Index.
9](#__RefHeading___Toc209504403)

[2.6 TEMPORARY PAVEMENT TRANSTIONS DURING CONSTRUCTION.
10](#temporary-pavement-transtions-during-construction.)

[CHAPTER 3 USING ProFAA SOFTWARE 11](#chapter-3-using-profaa-software)

[3.1 DEVELOPMENT OF ProFAA SOFTWARE. 11](#__RefHeading___Toc209504406)

[3.2 DATA INPUT INTO ProFAA 11](#__RefHeading___Toc209504407)

[a. Data Format Conversion. 11](#__RefHeading___Toc209504408)

[b. ProFAA Input and Output Formats 11](#__RefHeading___Toc209504409)

[c. Data Format Conversion Example. 12](#__RefHeading___Toc209504410)

[d. Use of the Convert Profile Format Program.
14](#d.-use-of-the-convert-profile-format-program.)

[e. Compute the BBI. 14](#e.-compute-the-bbi.)

[APPENDIX 1. BIBLIOGRAPHY 17](#appendix-1.-bibliography)

# FORWARD

This AC represents a first step towards defining and implementing basic
pavement roughness criteria for airfield pavements. The criteria
presented in this version of the AC is intended to address isolated bump
events and does not address cyclic or harmonic events which can have a
substantial impact on airplane components and operations. Future
research in this area will attempt to define limits for gravitational
forces experienced by airplane components (landing gear, wings, etc) and
occupants.

This page intentionally left blank

# 

# CHAPTER 1. INTRODUCTION TO AIRPORT PAVEMENT ROUGHNESS

[]{#__RefHeading___Toc209504373 .anchor}**1.1 PURPOSE OF ADVISORY
CIRCULAR**. This AC provides airport operators with procedures to
evaluate a pavement surface profile in terms of roughness and the impact
pavement roughness may have on civilian airplanes.

## 1.2 IMPORTANT FACTOS IN EVALUATING PAVEMENT ROUGHNESS.

[]{#__RefHeading___Toc209504375 .anchor}**a. Pavement Surface
Irregularities.** Airport pavement surfaces must be free of
irregularities that can impair safe operations, cause damage, or
increase structural fatigue to an airplane. Engineers refer to these
surface irregularities as pavement roughness or lack of smoothness. Due
to large differences in airplane size and performance, the aviation
industry has struggled with exactly how to quantify roughness in terms
that have meaning to airplane operations.

[]{#__RefHeading___Toc209504376 .anchor}**b. Airfield versus Highway
Roughness.** The highway industry defines pavement smoothness/roughness
in terms of the ride quality experienced by a passenger. Automotive
manufacturers design suspension systems to reduce the impact of common
surface irregularities and improve overall ride quality. In contrast,
the primary purpose of an airplane suspension system is to absorb energy
expended during landing. Airplane suspension systems have less capacity
to dampen the impact of surface irregularities due to the magnitude of
the energy that must be addressed during landing. Airfield pavement
roughness is defined in terms of fatigue on aircraft components
(increase stresse and wear) and/ or other factors which may impair the
safe operation of the aircraft (cockpit vibrations, excessive g-forces,
etc.).

[]{#__RefHeading___Toc209504377 .anchor}**c. Categories of Airfield
Pavement Roughness.** The FAA groups airfield pavement roughness into
two categories based on the dimensions and frequency of surface
deviations:

**1) Single Event Bump**. Single event bumps are isolated events where
changes in pavement elevation occur over a relatively short distance of
100 meters (328 feet) or less. Such elevation changes may occur as an
abrupt vertical lip or as a more gradual deviation from a planned
pavement profile. Depending on the operational speed and bump length, an
airplane suspension system may not be able to fully absorb the energy
produced when it encounters a bump. Airplane components and occupants
feel the impact as a shock or sudden jolt.

Basic "straightedge" analysis can easily identify single event bumps.
Riding the pavement in a passenger vehicle might reveal shorter length
bumps, but finding longer length bumps might require a thorough analysis
of the pavement profile.

**2) Profile Roughness.** The FAA defines profile roughness as surface
profile deviations present over a portion of the runway that cause
airplanes to respond in ways that can increase fatigue on airplane
components, reduce braking action, impair cockpit operations, and/or
cause discomfort to passengers. Response depends on airplane size,
weight, and operation speed. Even when roughness does not cause
discomfort to passengers, it may still affect the fatigue life of
airplane components or decrease operational safety of the airplane.
Depending upon airplane characteristics and operating speed, an airplane
may be excited into harmonic resonance due to profile roughness which
can increase inertial forces or vibrations within the airplane
structure. One example is resonant response in a 4-wheel truck pitch
mode which elevates friction in the pivot joint.

In some cases, driving a pavement in a passenger vehicle can reveal
profile roughness.

[]{#__RefHeading___Toc209504378 .anchor}**d. Passenger Comfort.**
Airport pavement roughness is **not** defined by perceived ride quality
or passenger discomfort. Although important, passenger discomfort due to
pavement surface irregularities is often not a significant issue since
the degree of discomfort is small and the time of exposure is limited to
a few seconds. Further, passenger discomfort often occurs during takeoff
and landing operations when engine noise, aerodynamic noise, and/or
horizontal acceleration or deceleration otherwise distract the
passengers.

[]{#__RefHeading___Toc209504379 .anchor}**e. Factor Affecting Safe
Airplane Operations.** Stress on airplane components, reduced braking
action, and the ability to view cockpit instrumentation can impact the
safe operation of an airplane. Pavement surface irregularities may cause
enough vibrations in the cockpit that pilots cannot focus on critical
instrumentation or have difficulty manipulating the controls during
takeoff or landing. Pavement surface irregularities can also cause
increased stress on critical airplane components, which increases the
risk of premature failure. Airplane response to surface irregularities
can reduce braking capacity as the airplane responds to vertical
acceleration. These factors can occur individually or in combination,
depending on airplane response.

[]{#__RefHeading___Toc209504380 .anchor}**f. Pilot Response and
Feedback.** Pilot observations and complaints are an important factor in
determining pavement roughness. Although pilot observations do not
directly indicate that structural fatigue of airplane components is
occurring, they are often the first sign that something is wrong with
the pavement profile. The procedures in this AC use pilot observations
to establish basic criteria for evaluation of pavement roughness.

[]{#__RefHeading___Toc209504381 .anchor}**g. Surface Texture.** Pavement
roughness, as discussed in this AC, is not the same as pavement texture.
Pavement texture is the micro texture of the immediate pavement surface
which contributes to friction between the airplane wheel and the
pavement surface. Pavement texture and pavement grooving is not a source
of roughness. See ASTM E 867-04, Terminology Relating to
Vehicle-Pavement Systems, for definitions of texture.

[]{#__RefHeading___Toc209504382 .anchor}**h. Construction Standards.**
When constructed in accordance with the design standards of AC
150/5300-13, Airport Design, and the construction standards of AC
150/5370-10, Standards for Specifying Construction of Airports an
airfield pavement should not have issues with surface irregularities.
However, as a pavement ages, the surface profile may vary from the
original design standards due to factors such as frost heave or subgrade
settlement.

# CHAPTER 2. EVALUATING SINGLE EVENT BUMPS IN RUNWAY PAVEMENT

[]{#__RefHeading___Toc209504384 .anchor}**2.1 INTRODUCTION TO SINGLE
EVENT BUMP EVALUATION**. Undesirable elevation changes on runway
pavements can increase stress on airplane components, reduce braking
action, make it difficult for pilots to read cockpit instrumentation,
and/or cause discomfort to passengers. Typically, large wavelength bumps
are the most prevalent but are not usually visible to the naked eye. The
most critical bump height associated with these large wavelength bumps
depends on the relationship between the wavelength and the natural
frequency of the aircraft. Single step type bumps---or a vertical
deviation with zero length, i.e. a vertical lip or fault in the pavement
surface--- rarely cause problems in service because the step size is
usually within the acceptable range, as noted in Figure 2-3.

This chapter provides guidance on evaluating a pavement surface profile
to identify potential single event surface deviations that can affect
airplane operations. The guidance, based on fully loaded jet transport
airplanes operating at near-rotation speeds (130 to 200 knots), is
appropriate for runway applications. It provides conservative results
for areas of pavement with slow moving traffic such as taxiways or
aprons.

The derivation of the guidance is described in Boeing Document D6-81746,
Runway Roughness Measurement, Quantification and Application -- The
Boeing Method. The aviation industry and International Civil Aviation
Organization (ICAO) refer to this procedure as the "Boeing Bump" method.

## 2.2 BOEING BUMP EVENT IDENTIFICATION PROCEDURE. 

[]{#__RefHeading___Toc209504386 .anchor}**a. Basic Procedure.** The
basis of the Boeing Bump method is to construct a virtual straightedge
between two points on the longitudinal elevation profile of a runway and
measure the deviation from the straightedge to the pavement surface. (
NOTE: A virtual straightedge is an imaginary line between two points on
the profile and is not intended to imply a physical tool or mechanism.)
The procedure reports "bump height" as a maximum deviation (positive or
negative) from the straightedge to the pavement surface as illustrated
in Figure 2-1. Bump length is the shortest distance from either end of
the straightedge to the location where the bump event is measured. The
procedure plots bump height and bump length against the acceptance
criteria in Figure 2-3.

[]{#__RefHeading___Toc209504387 .anchor}**b. Maximum Straightedge
Length.** The Boeing Bump procedure considers straightedge lengths
(wavelengths) up to 120 meters (394 feet). Because the Boeing Bump
procedure targets isolated bump events, "wavelength" terminology is
replaced with "bump length". Research cited by Boeing has demonstrated
that bump lengths in excess of 120 meters (394 feet) do not contribute
to dynamic airplane response or negatively impact the airplane.

[]{#__RefHeading___Toc209504388 .anchor}**c. Minimum Straightedge
Length.** The minimum length of the straightedge depends on the sample
spacing or survey interval of the profile data. The minimum length is
equal to twice the survey interval. The method requires a minimum of
three profile data points to obtain a deviation from the straightedge,
as demonstrated in Figure 2-2. The outer two points define the ends of
the straightedge, and the interior point provides a profile deviation.
The FAA standard for sample spacing is 0.25 meters (0.82 feet) for
evaluation of the Boeing Bump. Therefore, the minimum straightedge
length is 0.5 meters (1.64 feet).

![](media/image2.wmf){width="6.497916666666667in"
height="4.4430555555555555in"}

FIGURE 2-1. Schematic of Bump-Height Measurement

![](media/image3.wmf){width="5.813888888888889in"
height="3.0722222222222224in"}

FIGURE 2-2. Minimum Straightedge Determination

[]{#__RefHeading___Toc209504389 .anchor}**d. Number of Straightedges
Associated with a Survey Interval.** The number of straightedges
associated with any survey point depends on the dimension of the survey
interval. Each point may have Ns straightedges associated with it,
where:

Ns = (Maximum Straightedge Length / Survey Interval) -- 1

Where:\
Maximum Straightedge Length = 120 meters (394 feet)\
Survey Interval = 0.25 meters (0.82 feet) units consistent with
straightedge

For FAA standard configuration:

Ns = (120 /0.25) -- 1 = 479

At any profile sample point, the procedure allows construction of a
straightedge with (a) the beginning of the straightedge at the sample
point, (b) the end of the straightedge at the sample point, or (c) the
sample point at any increment along the length of the straightedge. With
each possible straightedge configuration, the procedure calculates bump
height and bump length, as defined here:

(**1) Bump Height.** Bump height equals the maximum vertical distance
from the straightedge to the profile sample point for all positions of
the straightedge along the profile. Units are centimeters (inches).

(**2) Bump Length.** Bump length equals the smallest of (a) the distance
from the bump height position to the start of the straightedge or (b)
the distance from the end of the straightedge to the bump height
position. Units are meters (feet).

[]{#__RefHeading___Toc209504390 .anchor}**e. Recommended Survey
Interval.** The accuracy of the Boeing Bump procedure, or its ability to
represent field conditions, increases as the survey interval decreases.
Because the accuracy of the procedure changes if the survey interval
changes, the FAA requires a survey interval of 0.25 meters (0.82 feet)
for evaluation of the Boeing Bump.

[]{#__RefHeading___Toc209504391 .anchor}**f. Recommended Survey
Location.** Airplane gear location relative to the centerline of a
runway varies from airplane to airplane but it is not necessary to
exactly match the location of the airplane gear with the location of the
surface profile. The FAA recommends measuring the runway surface profile
along the centerline and at a lateral offset (left and right) that
approximates the aircraft using the airport. A 3.05 meter (10 feet)
offset can effectively address Airplane Design Group (ADG) II and III
airplanes, while a 5.22 meter (17.5 feet) offset can address ADG IV, V,
and VI airplanes. Take measurements at all locations if traffic at a
given facility contains all airplane groups. Evaluate each profile in
accordance with paragraph 2.3. Avoid obvious surface deviations such as
a longitudinal joint or a row of lights unless their impact on roughness
is being evaluated.

[]{#__RefHeading___Toc209504392 .anchor}**g. Use of Inertial Prolilers
with Highpass Filtering.** Data processing for typical highway and
light-weight inertial profilers includes highpass filtering the
accelerometer signal before integration to avoid offset errors and to
reduce errors due to traveling on changing grades and braking and
accelerating the test vehicle. Highpass filtering can have a significant
effect on the computation of the Boeing Bump Index (see paragrah 2.4a)
and simulated airplane accelerations because these computations take
account of longer disturbances in the profiles than in the computation
of typical highway indexes such as the IRI. Typical highway and
light-weight inertial profilers also generate significant errors if
profiles are measured during acceleration, braking, and cornering of the
test vehicle. Threshold-to-threshold runway profiles are therefore
difficult to measure without introducing significant errors close to the
thresholds. For this reason, the use of inertial profilers that include
highpass filtering is not recommended for measuring profiles which are
to be used for computing BBI indexes or simulated airplane accelerations
on airport pavements.

## 2.3 EVALUATION OF BOEING BUMP PARAMETERS. 

[]{#__RefHeading___Toc209504394 .anchor}**a. Bump Evaluation
Procedures.** Evaluate each combination of bump height and bump length
against Figure 2-3. Figure 2-3 reproduces the criteria presented in
Figure 10 of Boeing Document D6-81746 and shows the boundaries of
Acceptable, Excessive, or Unacceptable pavement roughness associated
with a single bump event. Boeing developed the criteria based upon
operational experience for single bump events describing the general
condition of a runway pavement. The critera do not provide a detailed
analysis of airplane response nor do they attempt to address the problem
of root-mean-square roughness. The critera also do not address the
effects of a series of long wavelength undulation where airplane
frequency response is important. By eliminating the root-mean-square and
frequency response factors, this simplified procedure can be applied to
all jet transport airplanes regardless of structural design or physical
characteristics.

[]{#__RefHeading___Toc209504395 .anchor}**b. Evaluation Criteria.** The
evaluation criteria in Figure 2-3 define operational conditions and
structural impact to the airplane.

**1) Acceptable.** The FAA expects newly constructed or rehabilitated
pavement to result in bump height and length combinations that fall
within the lower region of the acceptable range. Construction tolerances
described in Items P-401 and P-501 of AC 150/5370-10 allow 0.64
centimeters (0.25 inches) in 4.8 meters (16 feet), as indicated in
Figure 2-3. Operations in this range are acceptable for all airplanes.
As a pavement ages, various factors such as frost heave or isolated
pavement failures may lead to bump height and length combinations that
approach the limit of the acceptable range.

Experience indicates that pilots begin reporting excessive roughness as
conditions move closer to the excessive range. When pilot reports begin
to occur, airport operators should start identifying the bump locations
and preparing for corrective actions. These preparations should include
scheduled maintenance activity to monitor the pavement profile.

Whenever roughness is above the acceptable zone, airplane gear fatigue
becomes more critical than passenger discomfort or cockpit acceleration
limitations.

**2) Excessive.** The FAA encourages airport operators to repair
pavements as roughness levels enter the excessive zone. Airplane
response to excessive levels of roughness becomes noticeably intolerable
to both airplane crews and passengers. Roughness of this magnitude will
create acute discomfort for all occupants in the airplane. Instrument
interference in the cockpit may be severe. This roughness level may also
result in a short-term inability to steer the airplane as well as
excessive reduction in nose and main gear fatigue life. Immediate
pavement repairs are necessary at this level but closure of the affected
pavement is not required.

**3) Unacceptable.** Roughness levels in the unacceptable zone warrant
immediate closure of the affected pavement. Repairs are necessary to
restore the pavement to an acceptable level.

![](media/image4.wmf){width="6.4222222222222225in"
height="4.397222222222222in"}

FIGURE 2-3. SINGLE EVENT BUMP - ROUGHNESS ACCEPTANCE CRITERIA

## 2.4 DEVELOPMENT OF THE BOEING BUMP INDEX.

[]{#__RefHeading___Toc209504397 .anchor}**a. Need for Boeing Bump
Index.** Applying the Boeing Bump method to a pavement profile can be a
time-consuming and tedious task because each point in the profile survey
must be evaluated for all possible straightedge lengths. For any
particular case of runway roughness, both bump height and bump length
are significant, particularly when considering strategies for reducing
roughness through maintenance.

To summarize the bump criteria and compare computed bump criteria with
other measures of roughness, the FAA created an additional parameter for
the Boeing Bump procedure. This new index, called the "Boeing Bump
Index" (BBI), is determined by the following process:

\(1\) For a selected sample point in the profile, compute the bump
height and bump length for all straightedge lengths.

\(2\) For each straightedge length, compute the limit of acceptable bump
height (upper limit of the acceptable zone) for the computed bump
length.

\(3\) For each straightedge length, compute the ratio (measured bump
height) / (limit of acceptable bump height).

\(4\) Repeat steps 1 through 4 for all sample points in the profile.

The BBI for the selected sample point is the largest of all values
computed in step 3 for the selected sample point. If the computed index
value is less than 1.0 roughness falls is in the acceptable zone: if it
is greater than 1.0, it fall in the excessive or unacceptable zone.

[]{#__RefHeading___Toc209504398 .anchor}**b. Development of Software to
Compute the Boeing Bump Index**. To assist in the development of a
computer program to calculate the BBI, the FAA created mathematical
models of the lower and upper criteria curves, as given below:

**1) Lower Limit Curve** (upper limit of the acceptable zone)

H = 1.713187 + 0.800872L -- 0.031265L2 + 0.000549L3 (for L \< 20 meters)

H = 6.4 + 0.16L (for 20 \< L \< 60 meters)

**2) Upper Limit Curve** (upper limit of the excessive zone)

H = 2.747222 + 1.433399L -- 0.183730L2 + 0.013426L3 (for L \< 5 meters)

H = 2.7590 + 1.085822L -- 0.053024L2 + 0.001077L3 (for 5 \< L \< 20
meters)

H = 7.775 + 0.20375L (for 20 \< L \< 60 meters)

Where:

H = Bump height (centimeters)\
L = Bump length (meters)

[]{#__RefHeading___Toc209504399 .anchor}**c. ProFAA Software.** The FAA
developed the ProFAA software to help calculate of the BBI. Chapter 3
provides additional information on the use of this software which the
FAA makes available on its website (www.faa.gov).

[]{#__RefHeading___Toc209504400 .anchor}**d. Comparison with hte
Original Boeing Bump Procedure.** The Boeing Bump Index procedure varies
slightly from the original Boeing Bump procedure because the latter
method was based on manual data processing. Further,

\(1\) The bump length defined in Boeing Document D6-81746 is at a local
minimum or maximum. There can be multiple local minima or maxima for a
given straightedge length. Presumably the worst combination of bump
height and length governs with this method.

\(2\) ProFAA bump length is for the combination that gives the maximum
BBI at a profile point, which is not necessarily at a maximum or
minimum.

## 2.5 PAVEMENT ROUGHNESS EVALUATION USING THE BOEING BUMP INDEX. 

[]{#__RefHeading___Toc209504402 .anchor}**a. Boeing Bump Index
Evaluation Criteria.** Evaluation of a pavement profile with the BBI is
similar to that done with the Boeing Bump method. Since the BBI is based
on the same three zones of roughness, the descriptons of these zones in
paragraph 2.3b apply to the corresponding ranges of the BBI.

Figure 2-4 expresses the concepts of Figure 2-3 in terms of BBI versus
bump length. Figure 2-4 recreates the acceptable, excessive, and
unacceptable evaluation zones of Figure 2-3 in terms of BBI. When the
BBI value is below 1.0, the Boeing bump criteria is in the acceptable
zone. Values of BBI greater than 1.0 fall in either the excessive or
unacceptable zones.

![](media/image5.wmf){width="6.336805555555555in"
height="4.325694444444444in"}

FIGURE 2-4 BOEING BUMP INDEX - ROUGHNESS ACCEPTANCE CRITERIA

[]{#__RefHeading___Toc209504403 .anchor}**b. ProFAA Reporting of Boeing
Bump Index.** The ProFAA software calculates the BBI for all survey
intervals in a pavement profile. ProFAA will record each time a profile
exceeds the acceptable and excessive zones and produce a report
indicating each occurrence. Chapter 3 provides additional information
and an example of the BBI calculation output from ProFAA.

## 2.6 TEMPORARY PAVEMENT TRANSTIONS DURING CONSTRUCTION. 

Airports often require that a pavement be available to airplanes between
phases of construction work so pavement construction often occurs in
segments during off-peak hours. As a result pavement projects often take
several phases to complete. During these phases, the pavement surface
may not be uniform and may require temporary ramps to allow aircraft to
transition from elevation to elevation. Most often, this condition is
associated with construction of Hot-Mix asphalt.

Advisory Circular 150/5370-13, Offpeak Construction of Airport Pavements
Using Hot-Mix Asphalt, provides guidance on offpeak construction using
Hot-Mix asphalt. AC 150/5370-13 recommends a 4.57 meter (15 feet) ramp
for each 2.54 centimeters (1 inch) of elevation change. Figure 2-3 shows
how this criterion compares against the upper limit of the acceptable
roughness zone. To avoid exceeding the upper limit of the acceptable
zone, elevation changes greater than 7.62 centimeters (3 inches) require
adjustment of the ramp length.

# CHAPTER 3 USING ProFAA SOFTWARE

[]{#__RefHeading___Toc209504406 .anchor}**3.1 DEVELOPMENT OF ProFAA
SOFTWARE.** The FAA's ProFAA software can accept input data from various
formats, convert the input data into the preferred format, and calculate
the BBI and other pavement roughness parameters.

[]{#__RefHeading___Toc209504407 .anchor}**3.2 DATA INPUT INTO ProFAA**.
ProFAA accepts data files in binary format for a single profile at 0.984
inches (25 millimeters) spacing. The numbers for the elevation samples
are stored sequentially in IEEE 754 single precision floating point
format. The sample spacing is assumed to be constant and distance
information is not included. The files are designated by the
three-letter extension "pro". After the profile has been read into
ProFAA, and the BBI computation selected, the softare lowpass filters it
with a sixth-order Butterworth filter at a cutoff frequency of 0.6096
cycles/inch (2 cycles/meter) and takes every fourth sample to give a
sample spacing of 0.25 meter (0.8202 feet). The software then runs the
profile through a subroutine for calculating BBI and displays the
results on the output screen, as described later.

[]{#__RefHeading___Toc209504408 .anchor}**a. Data Format Conversion.**
Since the profile data file format accepted by ProFAA is not commonly
output by commercial profile equipment, and different formats are used
by different equipment manufacturers, the software includes a conversion
utility program called "Convert Profile Format" to convert the most
common profile data formats to that required by ProFAA. Figure 2-5 shows
a screen shot of the program with an example conversion displayed. The
output files always have the linear trend removed by forcing the start
and end samples to be zero.

[]{#__RefHeading___Toc209504409 .anchor}**b. ProFAA Input and Output
Formats**. Table 2-1 lists available input and output formats associated
with ProFAA. The software allows any combination of input and output
formats.

  ----------------------------------- -----------------------------------
  Input Format                        Output Format

  ERD                                 ProFAA

  ASTM                                ERD

  ProFAA                              ASTM

  Text                                Text

                                      CSV
  ----------------------------------- -----------------------------------

TABLE 2-1. INPUT AND OUTPUT FILE FORMATS FOR CONVERT PROFILE FORMAT

**ERD** Format developed at the University of Michigan Transportation
Research Institute.

**ASTM** F Format specified in ASTM E2560 developed from the Federal
Highway Administration's ProVAL file format.

**ProFAA** Format used by the ProFAA software.

**Text** Single column (CRLF delimiters) of ASCII numerical values
representing elevation values at constant sample spacing. See the
example in paragarph 3.2c.

**CSV** Comma delimited list of ASCII numerical values representing
elevation values at constant sample spacing. See the example below.

This is an example of the first 27 samples of a profile converted to CSV
format: Note the first sample is zero.

0.000000,-0.009628,-0.050756,-0.068883,-0.060211,-0.065839,-0.076467,-0.081894,-0.088522,-0.073250,-0.080278,-0.078406,-0.070933,-0.069461,-0.074489,-0.084417,-0.085144,-0.096472,-0.104800,-0.105828,-0.095856,-0.094983,-0.105911,-0.089639,-0.108767,-0.099394,-0.112622,-

![](media/image6.png){width="5.927083333333333in"
height="5.927083333333333in"}

FIGURE 2-5 SCREEN SHOT OF CONVERT PROFILE FORMAT PROGRAM

[]{#__RefHeading___Toc209504410 .anchor}**c. Data Format Conversion
Example.** Figure 2-5 shows an example where the input file is in Text
format and the output is in ProFAA format. Table 2-2 shows data for the
first 7.62 meters (25 feet) of this profile. The data was originally
prepared in a spreadsheet and included the longitudinal distance
associated with each profile data point (column A). As noted in
paragraph 2.2a, the longitudinal spacing must be constant. To prepare
the data for the ProFAA software, the distance data was removed and the
file saved in text format (see column C in Table 2-2).

The required sample spacing for ProFAA is 25 millimeters (0.082021 feet)
and the sample spacing of the input file is 1 foot (0.305 meter). The
software uses inches as the unit for output file elevation values and,
in this case, feet are the units of the elevation values in the input
file. Therefore, the value entered in the "Elevation Scale Factor" text
box shown in Figure 2-5 is 12 inches/foot. As another example, if the
input file units had been inches, then a value of 1 inches/inch would be
entered in the elevation scale text box, or, if the input file units had
been cm, than a value of 1 / 2.54 (= 0.3937) inches/cm would be entered.

  --------------- ------------------- --------- -------------------------
  Data as                                       Data as stored in Text
  originated in                                 format (distance data
  Spreadsheet                                   omitted)
  format (notice                                
  that distance                                 
  data was                                      
  included)                                     

  A               B                             C

  Distance (feet) Elevation (Feet)              Example 1-foot spacing

  0               -0.0003                       -0.0003

  1               0.0125                        0.0125

  2               0.000                         0.000

  3               -0.0033                       -0.0033

  4               -0.0085                       -0.0085

  5               -0.0207                       -0.0207

  6               -0.0358                       -0.0358

  7               -0.0351                       -0.0351

  8               -0.0482                       -0.0482

  9               -0.042                        -0.042

  10              -0.0512                       -0.0512

  11              -0.0499                       -0.0499

  12              -0.0649                       -0.0649

  13              -0.0548                       -0.0548

  14              -0.0548                       -0.0548

  15              -0.0554                       -0.0554

  16              -0.0548                       -0.0548

  17              -0.0551                       -0.0551

  18              -0.0679                       -0.0679

  19              -0.0597                       -0.0597

  20              -0.059                        -0.059

  21              -0.064                        -0.064

  22              -0.0574                       -0.0574

  23              -0.0604                       -0.0604

  24              -0.0682                       -0.0682

  25              -0.0646                       -0.0646
  --------------- ------------------- --------- -------------------------

TABLE 2-2. SAMPLE DATA AS SHOWN IN FIGURE 2.5

### **d.** Use of the Convert Profile Format Program. 

**(1)** Press the "Read File" button to bring up a standard Windows file
selection dialog box.

**(2)** Select the file. Once the program converts it, you can load it
into ProFAA.

**(3)** Press the "Plot" button to plot the input and output files on
the screen so you can verify the conversion visually. If the input file
has multiple profiles---e.g. columns of data for left, center, and right
profiles---enter the profile to be plotted in the "Plot Channel No."
text box. The numerical value entered must correspond to the column
where the data is stored.

When the input sample spacing is larger than the output sample spacing,
the conversion process fits cubic splines through the input profile
points and calculates the output elevation values from the cubic splines
at the output sample spacing. When the input sample spacing is smaller
than the output sample spacing, the software lowpass filters the input
profile to prevent aliasing and fits cubic splines to the filtered input
profile points. The output elevation values are then calculated from the
splines at the output sample spacing.

### **e.** Compute the BBI.

**(1)** To compute the BBI for the profile in the output file (in this
example, "Example 1-ft Spacing -- 1.pro"), start ProFAA, read the file
into the program, and select the Boeing Bump Index in the list of
indexes. Figure 2-6 shows a screen shot of ProFAA after these operations
have been carried out.

![](media/image7.png){width="6.179861111111111in" height="3.8625in"}

FIGURE 2-6. SCREEN SHOT OF ProFAA SHOWING THE EXAMPLE\
PROFILE AND THE BBI COMPUTED FROM THE PROFILE

The profile is quite rough with a maximum BBI of 0.973 about 3139 meters
(10,300 feet) from one end.

\(2\) To examine the rough section in more detail, press the "Zoom"
Button and click to the left and right of the section to be zoomed.
Figure 2-7 shows the result.

![](media/image8.png){width="6.485416666666667in"
height="0.7173611111111111in"}

FIGURE 2-7 ZOOMED PORTION OF THE BBI PLOT

\(3\) Right click the mouse pointer at a position in the zoomed plot
where you want the value of the BBI to be read. A second view of the
plot in the vicinity of the clicked point will appear in one of the
picture boxes below the BBI plot with relevant information on the
calculation, including the position of the straightedge from which the
BBI was calculated. Figure 2-8 shows the result when the mouse pointer
was right clicked at the position of the maximum BBI.

![](media/image9.png){width="6.485416666666667in"
height="0.7173611111111111in"}

FIGURE 2-8 DETAILS OF THE BBI AT A SELECTED POINT

The following information is displayed in the title of the plot:

Boeing Bump Index = 0.973 (Acceptable)

H (Bump Height) = 2.53 in (6.43 centimeters)

L (Bump Length) = 27.9 ft (8.5 meters)

EL (Straightedge length) = 108.3 ft (33 meters)

If the BBI is in the excessive or unacceptable zones the program
replaces the "Acceptable" indication in the BBI line with either
"Excessive" or "Unacceptable."

# 

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# APPENDIX 1. BIBLIOGRAPHY

**1.** Document No. D6-81746, *Runway Roughness Measurement,
Quantification, and Application--The Boeing Method,* Boeing Commercial
Airplane Group--Airport Technology Organization, Seattle, Washington,
2002. Available on frequently asked question (FAQ) section of the Boeing
website (http://www.boeing.com/commercial/airports).

**2**. Report No. FAA‑RD‑80‑55, *Procedures for Condition Survey of
Civil Airports*, U.S. Army Engineer Waterways Experimental Station,
Vicksburg, MS, May 1980.

**3**. AC 150/5320-12, *Measurement, Construction, and Maintenance of
Skid Resistant Airport Pavement Surfaces* (current version).