From the instructions"
There was hope since the beginning of the A-10 program that an enhanced variant of the aircraft could be developed for the Air Force.
this hope was based on the original air force A-10 system specification that was written in 1972 and stated that the vehicle design shall allow for ease of growth
to a 2 seat version for training with combat capability and night adverse weather attack.
In 1978 the DOD made funds available for the development of a Night/Adverse Weather (N/W) variant of the A-10.
The N/AW development effort was jointly funded by the defense department and Fairchild/Republic 5 million and 2 million respectively.
As part of this effort Fairchild leased the first DT&E A-10 aircraft from the Air Force for the purpose of modifying it into a 2 seat variant designated the N/AW evaluator.
As Fairchild had allowed for expansion of the original design, the amount of rework to be performed on the aircraft would not be drastic.
The N/AW version was built primarily as a reaction to the fact that the Soviet forces in Europe devote about 40% of their training to night operations.
Current A-10's could operate at nght using illumination flares, but that activity would be nullified by reduced visibility.
As a result a requirement existed for evaluating a version that could fly in all types of weather.
The rework began in April of 1978 at the Farmingdale plant and took over 13 months to complete.
The N/AW version was 2000 lbs heavier than the conventional A-10 with the addition of the second cockpit station for the weapons systems operator (WSO).
The extra station included a duplicate of the forward cockpit except for the HUD controls and the titanium tub.
Flight controls would be duplicated with the addition of an extra yaw stick.
New avionics added to the N/AW evaluator were a multimode radar and a forward looking infrared (FLIR).
The multimode radar had modes for target indication, ground mapping, terrain tracking and target detection.
The threat detector function could detect radar signals from a surface to air missile battery or a radar directed anti aircraft gun.
The FLIR presented a realistic image of the terrain on the HUD (heads up display) and could be used for target identification for the 30mm gun, INS updating and as a secondary terrain avoidance monitor
to the multimode radar.
Besides the second cockpit, the N/AW differed from the A-10A in that the fin and rudder were modified.
The N/AW fin rudder were enlarged to improve lateral stability and control.
The aircraft was delivered to Edwards AFB for flight testing, which began on May 4th 1979.
The initial flights were were devoted to air worthiness checks in the area of control handling from both cockpits.
Also new equipment such as the low altitude warning sensors were checked out in the various types of terrain and structures on the ground.
After the initial flights, tactical evaluations were were carried out that included low altitude flying target detection and gun attacks.
The primary objective of the air force with the N/AW was to see if the additional equipment could be handled by one pilot.
This could lead into enhanced single seat A-10's being developed by retrofitting the A-10 fleet.
Fairchild was coming from a different perspective as it felt the N/AW was a 2 man job.
Cost estimates for converting an A-10 to the 2 seat configuration was about $500,000 for the basic structural work and another million dollars for the additional night/adverse weather equipment.
The Air Force however were looking into the possibility of having single seat A-10's converted into N/AW aircraft.
In the event the LANTERN (low altitude time infrared navigation) system was proposed for the A-10ending the need for the N/AW specialized aircraft as the LANTERN enhanced
pilot capability for night time flying.
Throughout the next decade the LANTERN proposal would go through several design alterations and several nomenclature changes with the end result that no enhanced system was put into the A-10 before
the end of production.
There was also a proposal for a 2 seat trainer when the Air Force asked for trade studies on such an aircraft.
This was different from the N/AW evaluator as the second seat would be added for training purposes only and no advanced electronics would be added to this version which was designated as the A-10B.
Data collected from flight testing of the N/AW evaluator provided the Air Force with enough information to make a decision.
The Air Force requested that 20 A-10B aircraft be tacked onto the original order of 713 aircraft.
If additional A-10B's were needed, then existing A-10A's would be converted.
The proposed A-10B version was cut by congress in 1983. They felt along with several Air Force officials that the A-10A was already simple enough to fly and that a trainer version was not needed.
The final count for A-10 production was 713 aircraft.
The only 2 seat version for the A-10 program was the N/AW aircraft which still exists today, but only as a museum piece at Edwards AFB.
The inability of Fairchild/Republic to obtain an extension to the existing A-10 contract, along with the Air Forces cancellation of the company's other prime program,
the controversial T-46A trainer program forced it to close in early 1987.
The rights of the A-10 program, along with 116 engineers were obtained by Grumman Aerospace in late 1987.
In the late 1980's there was discussion about transferring A-10's to the Army.
Instead a slightly modified version for reconnaissance designated the OA-10 was developed.
This variant required minimal modification to existing A-10's with the external difference being what was carried under the wings.
Instaed of bombs and missiles, the OA-10 carried white phosphorus rockets for marking targets for other aircraft to destroy.
The OA-10 would still carry a full load of ammunition for the 30mm cannon fro self defense.
There were 2 groups of A-10's that were converted to AO-10 standards and these were stationed at Davis/Monthon AFB in Tucson Arizona.