Pascal (unit) dB SPL, or 20 µPa. The airtightness of buildings is measured at 50 Pa. The units of atmospheric pressure commonly used in meteorology were formerly the bar, which was close to the average air pressure on Earth, and the millibar. Since the introduction of SI units, meteorologists generally measure pressures in hectopascals (hPa) unit, equal to 100 pascals or 1 millibar. Exceptions include Canada, which use kilopascals (kPa). In many other fields of science, the SI is preferred, which means Pa with a prefix (in multiples of 1000) is preferred. Many countries also use the millibars. In practically all other
Piper PA-24 Comanche tail, laminar flow airfoil, and all-flying stabilator. The standard fuel capacity of the PA-24-180 was . The flaps were manually actuated, controlled by the same Johnson bar actuator as the Piper Cherokee. The aircraft specifications were for cruise speeds of and fuel burns between 7.5 and 10.5 gph at 55-percent and 75-percent power settings. Full-fuel payload with standard fuel was 715 pounds, with a gross weight of and range with 45-minute reserve of 700 nautical miles. When new, standard, average-equipped Comanche 180s sold between $17,850 (1958) and $21,580 (1964). A total of 1,143 were built. In 1958 Piper introduced a