The potentiometer sensors installed on Executive Airlines ATRs were similar to
the potentiometer sensors used on the EMB-120; therefore, they were susceptible to the
same problems that previously prevented accurate data from being recorded on the
EMB-120. However, at the time of the accident, Executive Airlines only performed
functional checks of the FDR system every 3,000 flight cycles. As evidenced by company
maintenance data, it is possible that FDR functional checks performed every 3,000 flight
cycles will only occur once every 1.5 years. As noted previously, after the accident,
Executive Airlines began conducting FDR functional checks every 1,000 flight cycles.