Repairing Runway Roughness

Repairing Runway Roughness – Walking Through the Process

By Michael Gerardi

Using aircraft simulation, APR can quickly identify the location of runway roughness and quantify its level of roughness.  Another great aspect of this technology is the ability to help design corrective action to correct a problem.  In this article, I want to demonstrate how APR uses aircraft simulation to help repair an area of roughness.

As with any other runway project, it starts with collecting the pavement’s profile data using APR’s Auto Rod and Level.  Using aircraft simulation, APR’s analysts will identify the location of an event area causing pilot and passenger complaints.  As seen in Figure 1, the runway has a lot of grade associated with it, making it challenging to see any details of the pavement.  The inset plot shows the profile plotted with the grade removed around the bump’s location.  This inset plot shows a bump approximately 120 feet long by 2 inches (37m by 5cm) in amplitude.  As shown in Figure 2, when simulating a 737-800 performing a takeoff operation, quite a bit of aircraft response was generated – enough to consistently produce pilot and passenger complaints.

Article_Rough Profile

Figure 1. The roughness event is located approximately 2,500 feet from the beginning of the runway. The insert is an enlarged plot of the roughness event plotted with the grade removed.

Article_Poor Aircraft Response

Figure 2. Simulating a Boeing 737-800, moderate aircraft response is predicted at the Pilot’s Station (upper band) and at the Aircraft’s Center of Gravity (middle band) after it encounters the roughness event as seen in the pavement profile (lower band).

The next step in the process is to analytically fix the problem.  Looking at the event area, the analyst will optimize a repair – balancing the amount of material to be removed verses the resulting ride quality for that repair.  Figure 3 shows the repaired profile compared to the before profile.  Figure 4 illustrates the ride quality of the repaired profile illustrating a much improved ride for the pilot and passengers.

Article_Repaired Profile

Figure 3. Here is a plot that displays the repaired profile.  APR’s analysts can manipulate the measured profile to optimize the repair to minimize pavement down time and repair costs.

Article_Improved Aircraft Response

Figure 4. When simulating a takeoff operation using the 737-800 model on the Repaired profile, aircraft response is predicted to be dramatically improved.  This repair will extend the pavement’s life by reducing the dynamic loads as well as reduce the wear and tear on operating aircraft.

The capability of analytically repairing runway roughness using aircraft simulation is unique to APR.  Not only does this iterative process optimize the pavement repair, saving money and pavement down-time, it also reduces the dynamic loading on the pavement and the wear and tear on the aircraft.  If you would like to talk about pavement repair for a situation similar to this, please contact us.

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