San Francisco Runway 28R

There are many variables which affect the touchdown shock level of an aircraft.  These include:

  1. Descent or sink rate
  2. Forward and side velocities
  3. Roll, pitch, and yaw angles and corresponding rates
  4. Weight and center of gravity
  5. Cross wind, wind shear, gusts, etc.
  6. Runway contact loads
  7. Aircraft landing gear design
  8. Structural dynamics of the aircraft and launch vehicle system

The aircraft’s kinetic energy at touchdown is dissipated by the landing gear, primarily by the struts.    Each strut is filled with oil that is forced at a controlled rate through an orifice as the strut is compressed on touchdown.  An efficient landing gear design thus reduces the loads transmitted into the airframe during landing.

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A portion of the aircraft landing shock analysis can be performed using the surface roughness from San Francisco Runway 28R.   The runway has since been resufaced, but the historical data may still be used for conservatism.

The data is given in terms of Runway Length(ft) & Elevation(ft).

The original measured data is given at  SF28R.txt

The data with the severed bump modification (smoothing) is given in:  SF28R_severe_bump.txt

* * *

See also:

Aircraft Acoustics & Hard Landings

FAA AC 25.491-1

Federal Aviation Administration, FAR Part 25, Airworthy Standards: Transport Category Airplanes, Subpart C, Section 25.473.

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– Tom Irvine

One thought on “San Francisco Runway 28R

  1. In general aviation aircraft the Emergency Locator Transmitter (ELT) is set to a limit of acceleration (I assume to be a peak acceleration). I have no information on what the sampling rate is, nor the filtering, if a time history is used. I also wonder what the low-pass filter frequency is set to, since filtering significantly affects peak responses.

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