Naval Air Station Joint Reserve Base Fort Worth (abbreviated NAS JRB Fort Worth) (IATA: FWH, ICAO: KNFW, FAA LID: NFW) includes Carswell Field, a military airbase located 5 nautical miles (9 km; 6 mi) west of the central business district of Fort Worth, in Tarrant County, Texas, United States. This military airfield is operated by the United States Navy Reserve. It is located in the cities of Fort Worth, Westworth Village, and White Settlement in the western part of the Fort Worth urban area. (Wikipedia)

NAS Fort Worth hosts Lockheed Martin's F-35 production facilities and as such, many Lightning II jets are flown on test flights. Both foreign and domestic jets can be seen, including types outside of the F-35 such as F-16s in maintenance. Foreign F-35s that can be seen include Belgian, Finnish, British, Japanese, and Dutch jets while American units remain common sights. 

In addition to any new build F-35s being tested before delivery, NAS Fort Worth also hosts the 24th Fighter Squadron flying F-35As. Known locally as the Spads, they fly near daily and frequently conduct unrestricted climbs during launch. More exotic aircraft such as the now endangered F/A-18C flying with VMFA-112 are based at NAS Fort Worth, making frequent appearances at the nearby Fort Worth Alliance (KAFW) airport. Other aircraft based at KNFW include both USN and USMC C-40As (737-700), C-130-30s, KC-130Js, and Beech 200s. Rare visitors include E-6Bs, E-3s, B-52s, special mission C-130s, and QF-16s.

To assist in the testing of F-35s at NAS Fort Worth, the US Armed Forces have contracted Mirage F-1 chase planes from Airborne Tactical Advantage (ATAC) which frequently fly out with new build F-35s. Unfortunately, no Mirage F-1s were seen on this latest trip.

Spotting at NAS Fort Worth is made easy by the local Walmart parking lot and a roundabout which allows for viewing over the fence at the side of the road. Bringing a ladder for the Walmart parking lot is essential in order to see over the fence, though it does not have to be a large one. Generally, focal lengths of 100 - 600mm are recommended for spotting here. Walmart parking lot is recommended for morning spotting and the roundabout is recommended for afternoon spotting for best lighting.

It is worth noting that the days during which I spotted at KNFW were very humid, producing the vapor seen in the F-35 launch pictures and the wingtip vortices seen in the C-130 photos. These same weather conditions cannot be expected when spotting at KNFW and are overall rare.