Attrition mostly takes place in the early years of an F-16. This particular F-16, a USAF F-16A built in 1979 crashed 3 years after it rolled off the production line. The tail can still be found at the crash site in the Nevada Desert.
For most products an attrition versus age graph displays a typical "bathtub" curve: high in the first years, as products with manufacturing defects will fail early, then low, then high again as the products near the end of their life. For the F-16, we currently only see the first half of the bathtub curve. Attrition is fairly high in the first 5 years of F-16 airframes and then decreases.
As already indicated, the attrition rate for young airframes is fairly high - 50% of F-16 aircraft losses occurs with airframes that are 6 years old or younger. This does obviously not mean that new aircraft have a 50% chance of crashing - it simply means that halve of the attrition occurs with new aircraft.
The main explanation for this is that young airframes are typically found in air forces just starting F-16 operations (one notable exception is the USAF, which had a more or less continous delivery of F-16s over 20+ years). When starting operations with a new aircraft and training personal, attrition rates are likely to be higher.
The reason why we don't see the attrition rate increasing for older aircraft is that F-16 aircraft are thoroughly monitored and air forces will retire F-16 airframes before they reach their end-of-service-life. Also, many of the older airframes have been through at least one upgrade program or Service Life Extension Program (SLEP), such as the Midl-Life Update (MLU
), Operation Capabilities Upgrade (OCU) or Falcon-Up. These programs bring the airframes back to "as new" condition, further explaining the lack of "upward slope" in the bathtub curve.