FAA AAR-410 December 5, FAA Airport Pavement Roughness R&D u Gordon Hayhoe, AAR-410, FAA William J. Hughes Technical Center, Atlantic City, New Jersey, U.S.A. u Continue development and maintenance of ProFAA (in process). u Develop a standard for CA Profilograph simulation (in process). u Compare measured and simulated aircraft response (data analysis in process). u Conduct a pilot subjective rating study using the FAA 737 full-motion simulator (planning).

FAA AAR-410 December 5, ProFAA Computer Program u Intended to provide analysis of airport pavement roughness by computing indexes and simulating aircraft response. u An inertial profiling system was developed for measuring runway and taxiway longitudinal elevation profiles from threshold to threshold. u Constant profile measurement speed not necessary. u Profiles are not absolute – somewhere between absolute and normal high-pass filtered. u Suitable for high-speed aircraft simulation.

FAA AAR-410 December 5, Profile Measurement FAA Methodology Standard High- Pass Filter Methodology Measurement speed – profile measured from zero speed to zero speed

FAA AAR-410 December 5, ProFAA Computer Program Basic Index Display

FAA AAR-410 December 5, Airport Pavement Profile Data Measured At u Sixteen Airports u U.S.A. and Foreign u 4 Large Hub, 3 Medium Hub, 5 Feeder 4 Foreign large international u Flexible and Rigid Pavements u Runways and Taxiways

FAA AAR-410 December 5, Straightedge versus Profilograph

FAA AAR-410 December 5, Straightedge versus Boeing Bump

FAA AAR-410 December 5, FAA TC Boeing QC Instrumented Aircraft, N40 u The FAA WJHTC operated a fully instrumented Boeing until it was damaged about five years ago during an arrestor bed test. u Measurements were made with N40 in 1997 on a runway and taxiway at a medium size regional airport. u At the same time longitudinal profile measurements were made with the FAA profiler. u The data from these test is now being analyzed to compare measured airplane responses with simulated responses.

FAA AAR-410 December 5, Why Wait Until Now to Analyze the Data. u Development of pavement thickness design procedures and associated full-scale traffic testing consumed most available R&D resources. u The AAR-410 budget has recently been increased and a significant portion of the increase is assigned to roughness work over at least the next three years.

FAA AAR-410 December 5, N40 on Jacks in the Hangar

FAA AAR-410 December 5, Installation of Axle Strain Gages

FAA AAR-410 December 5, Installation of Axle Strain Gages

FAA AAR-410 December 5, Installation of Axle Strain Gages

FAA AAR-410 December 5, Main Gear Force Calibration

FAA AAR-410 December 5, Interior and Instrumentation Racks

FAA AAR-410 December 5, Speed Sensor on Nose Gear

FAA AAR-410 December 5, N40 on Jacks in the Hangar

FAA AAR-410 December 5, Variables Measured on N40. u Vertical and side forces and torque at each wheel on main and nose gears. u Speed at nose gear. u Three-axis accelerations at aircraft cg and floor of cockpit. u Inertial guidance system outputs. u Displacement of control surfaces, throttle, etc.

FAA AAR-410 December 5, Tests Run November 3 and 4, 1997

FAA AAR-410 December 5, Tests Run December 12, 1997

FAA AAR-410 December 5, Tests Run December 12, 1997

FAA AAR-410 December 5, Tests Run December 12, 1997

FAA AAR-410 December 5,

FAA AAR-410 December 5,

FAA AAR-410 December 5,

FAA AAR-410 December 5,

FAA AAR-410 December 5, These are Preliminary Steps u Continuing work will include variation of simulation parameters such as: u Flexible body modes. u Pitch moment of inertia for cockpit comparisons. u Strut model parameters – primarily Coulomb and hydraulic friction. u Modify simulation program to accept varying speed.

FAA AAR-410 December 5, u Includes damping forces due to: u Velocity squared hydraulic damping. u Strut seal Coulomb friction. u Strut bearing Coulomb friction due to strut inclination. u Two-to-one breakaway-to-sliding friction. u All wheels lumped into one equivalent wheel. u Unsprung mass is ignored. u Gas compression spring. u Linear tire spring with linear damping. ProFAA Computer Program Strut Model

FAA AAR-410 December 5, Subjective Pilot Rating Study Using Full-Motion Simulator - Objectives u Develop a rating scale for pilot subjective response to vertical cockpit vibrations excited by longitudinal pavement surface elevation disturbances. u The scale to range from very smooth to exceedingly rough. u Identify on the rating scale limits for cockpit vibration resulting in uncomfortable conditions and unacceptable conditions. u A similar project has been proposed to ACRP but using field data.

FAA AAR-410 December 5, Why Use a Simulator and Not Operational Airplanes u For u Test repeatability. u Rapid change in profile characteristics. u Cost. u Safety. u Against u Concerns about simulator fidelity. u Difficult to change cockpit characteristics.

FAA AAR-410 December 5, FAA Full-Motion 727 Simulator, Now replaced with a 737 Simulator. Located at Oklahoma City

FAA AAR-410 December 5, Previous Experience u AAR-410 has run projects on the FAA 727 simulator for about 15 years. u High-speed exit geometry and lighting configurations. u High-speed ground handling. u Airplane landing into and arrestor bed. u General lighting and visual guidance studies. u The person responsible for simulator operation has a Ph.D. in human factors as well as being a National Resource Specialist in Simulators. u E1927 “Conducting Subjective Ride Quality Pavement Ratings.

FAA AAR-410 December 5, Subjective Pilot Ratings - Schedule u FY06 (funding obligated) u Develop scope and test plan. u Establish procedures for setting roughness profiles in the simulator computer program. u Develop preliminary rating scale and questionnaire. u FY07 u Continue test plan, etc. u Preliminary simulator study with a small number of pilots to test the scales and other procedures. u Finalize procedures. u FY08 u Run the full experiment with the necessary number of subjects and profiles. u Analysis and report