The final variant of the F-14 was the F-14D Super Tomcat. The F-14D variant was first delivered in 1991. The original TF-30 engines were replaced with GE F110-400 engines, similar to the F-14B. The F-14D also included newer digital avionics systems including a glass cockpit and replaced the AWG-9 with the newer AN/APG-71 radar. Other systems included SJU-17 Naval Aircrew Common Ejection Seats (NACES) and Infra-red search and track (IRST).