Skydiving centers or "drop zones (DZs)" are located in nearly every state and many countries. Within a two hour drive of Pittsburgh there are six USPA drop-zones. All do tandem jumps and two have turbine aircraft.

• Alliance Sport Parachute Club, Petersburg, Ohio (43 miles from Pittsburgh, 2 Cessna 206s, 1 Cessna 182), 330-426-2565.

• Skydive Pennsylvania, Mercer, Pa. (50 miles, 1 Cessna 182, 1 Pilatus Porter), 800-909-JUMP.

• Canton Air Sports, Alliance, Ohio (69 miles, 2 Cessna 182s), 330-823-0370, 800-772-4174 weekdays.

• Aerohio Skydiving Center, Rittman, Ohio (100 miles, 1 Cessna 182, 1 Grand Caravan), 330-925-3483.

• Pennsylvania Skydiving University Corp., Reedsville, Pa. (126 miles, 2 Cessna 182s), 866-BLU-SKYS.

• Chambersburg Skydiving Center, Chambersburg, Pa (128 miles, 1 Cessna 182s, 1 Cessna 206), 717-264-1111, 866-JUMP-USA weekdays.

Feel free to ask the DZ about its safety record -- you won't be the first to ask. Drop zones that are USPA Group Members are required to use only USPA-rated instructional personnel and approved skydiving equipment.

It depends on where you jump and what type of aircraft you jump from. The standard altitude in many places is 13,500 feet. However not all DZs have turbine aircraft that get you to altitude quickly. Cessnas, for example, will likely drop you from a lower altitude.

The average jumper falls 1,000 feet for every six seconds of freefall.

Most tandems deploy their parachutes around 5,500 feet, providing approximately five minutes of parachute time.

In the belly-toward-earth flying position of a tandem, approximately 110 mph.

There is no hindrance to breathing while in the air. However, the rush of wind in freefall is noisy and makes it impossible for skydivers to speak verbally to each other. There is a standard series of hand signs that your instructor will teach you to communicate in the air.

Jumpers should be in good health and should not be on medication or substances which could affect judgment or performance. Generally, jumpers should be 220 pounds or less. If you weigh more than this, ask the DZ about its weight requirements when scheduling a tandem.

Parachutes are designed to open, but they may open incorrectly or poor deployment may hinder the opening. In many cases, the situation can be corrected in flight by the skydiver. As a back-up, all skydiving rigs are equipped with a second, or reserve, parachute.

Most DZs require jumpers be 18 years old. With a notarized parent or guardian consent form, some will allow tandem students 16 and older.