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A look at an actual TAPS report from one of my ights at work. Shows both the positive and negative “g” values that we encountered while ying through smallish, “popcorn,” or “cotton ball” cumulus clouds.
of the atmosphere as the Part 121 folks, so consider these facts:
• In nonfatal accidents, in-f light tur-
bulence is the leading cause of in- juries to airline passengers and flight attendants.
• Each year, approximately 58 people in the United States are injured by turbulence while not wearing their seat belts.
• From 1980 through 2008, U.S. air car- riers had 234 turbulence incidents resulting in 298 serious injuries and three fatalities.
• Of the 298 serious injuries, 184 in- volved flight attendants and 114 involved passengers.
How to Report It
The AIM’s list of turbulence classifi- cations can lead one to believe that the levels of turbulence progress from light chop to light turbulence to moderate chop to moderate turbulence – switching back-and-forth between chop and turbu- lence as the ride gets worse. Despite the “correct” order from the AIM, in practice, most pilots report turbulence as increas- ing in the following order:
Light Chop: Slight, rapid, often rhyth- mic bumps without significant changes in altitude or attitude. Depending on the type of aircraft (i.e. wing load- ing), the ride is tolerable and the seat belt sign is not necessary in transport category aircraft.
Moderate Chop: Slightly greater inten- sity, but still no appreciable changes in altitude or attitude. Typically, it’s time to turn on the seat belt sign in large aircraft, and the cabin crew will stow service carts but remain up-and-about in the cabin. Pilots will query ATC for ride reports.
Light Turbulence: Momentarily causes slight, erratic changes in altitude and attitude (pitch, roll, or yaw). Occupants may feel a slight strain against seat belts or shoulder straps. Unsecured objects may be displaced slightly. The seat belt sign is on, and the cabin crew is seated. Pilots may seek a different altitude or route to escape from the rough air.
Moderate Turbulence: Similar to light turbulence but of greater intensity, al- though the aircraft remains in positive control. Occupants feel definite strains
36 • TWIN & TURBINE / April 2019
Covington Aircraft Engines