Ever watch the Swat Kats?
Not an attempt to flame, you'll pick up some important points.
As others have waxed longsome on the issue, the idea is to reduce combat load on long-range, deep-penetration and strategic-bombing missions and thereby reduce pilot fatigue and ameliorate safety. It is also to reduce collateral damage by ensuring pin-point accuracy of delivery. With the advent of laser-guided weapons this has become a doubling concern. LGB's are expensive- to the tune of a crore, and certainly can't be wasted.
The lineage extends right back to the 70's, when the USAF, with its F-15's preferred the single-seater variant, while the Navy with it's F-14 prefered a double-seater. Then, target acquisiton depended heavily on the NFO and on-board aircraft radar because ship-board radar was still primitive. With the F-15's, target acquisition using onboard systems was not as important as the F-14 because the missions could include large powerful ground-based radar systems for aiding target acquisition. Later, the F-15E 'Strike Eagle' was developed as a long-range, high speed interdictions platform without having to rely on escort or electronic warfare aircraft. The added combat functions and work load necessitated a twin-seater aircraft. The NFO tracked and engaged multiple radar contacts, relieving the naval aviator of that duty. Today, with the heavy automation of radar systems, that is no longer much of a concern, still naval air-arms and air forces may find it prudent to install dual systems on their aircraft because of the information overload stemming from advances in electronic and avionic onboard systems. Hence, the Tranche 2 twin-seat Typhoon, Finnish Patria-constructed twin-seat Hornet fighter jets, the Naval LCA, etc. The trade-off ofcourse is diminished performance because of the added weight of an extra seat.
With respect to precision-guided munitions, the taskedness of delivering within the 'weapons basket', the problems of interruptions in autonomous designation via smoke, cloud or fog, and the desirability of uninterrupted designation for more than sub-optimal accuracy (and the resulting attenuating circumstances therewith owing to increased vulnerability to enemy SAM's from decreasing to a medium altitude, especially on SEAD missions) makes the case for a twin-seater more concrete. With respect to India, this will give you an idea of why twin-seat fighter are of increasing concern to us:
India tests laser guided bombs successfully
January 21, 2010 19:25 IST
India on Thursday carried out two successful flight trials of laser-guided bombs (LGBs) for the Indian Air Force to test the effectiveness of the guidance and control systems at the Chandipur integrated test range in Orissa.
"Two flight trials were conducted at Integrated Test Range, Chandipur, to test the effectiveness of the guidance and control systems of the LGBs," a Defence Ministry release said in New Delhi.
IAF officers flew their aircraft and released the LGBs as per prescribed standard operating procedures. "On-board systems in both the trials worked satisfactorily and the mission objectives have been met," the release added.
Bangalore-based Aeronautics Development Establishment (ADE) has developed the guidance kit for 1000-pound LGBs and these are designed to improve accuracy of air-to-ground bombing by IAF.
The ADE has already carried out a number of tests on the LGBs both through simulation and flight tests over the last few years to reach the required performance levels.
"The bomb, once released, by the mother aircraft at appropriate range, will seek the target and home on to it very accurately and with high reliability. All the necessary on-board components are sourced from Indian industry," it said.
Instruments Research and Development Establishment, another DRDO lab in Dehradun, has partnered ADE in the project.
http://news.rediff.com/report/2010/jan/21/india-tests-laser-guided-bombs-successfully.htm
More:
http://www.defencetalk.com/india-tests-laser-guided-bombs-23804/
http://theasiandefence.blogspot.com/2009/06/iai-seals-deal-to-provide-griffin-3.html
In the context of stealth fighters, the requirements of dynamic adjustment, timely ordnance deployment so as to reduce RCS at bay door openings, and acquainting flight times for defensive weapons and target acquisition via guidance systems (while the weapon is still attached to the aircraft) impose even greater requirements and elicit even greater bearings on pilot-fatigue. This will give you a clue as to what happens when pilot-fatigue takes over:
http://www.highbeam.com/doc/1P2-8123942.html
India's also recently upgraded its 100+ Jaguar fighters to dual-seater based on precisely that operational doctrine:
Indian Air Force to induct twin-seat Jaguar fighters
Dated 28/3/2006
Ambala Airbase: Indian Air Force's Jaguars are all set to get more teeth, an extra set of 32 to be precise. How does a Jaguar get more teeth? Well, if it's the one in the air, by creating room for a second fighter pilot on board.
The Indian Air Force is now inducting twin-seater Jaguar fighters for more destructive firepower. Potential adversaries better watch out as there is double trouble in store for them.
The Indian Air Force Jaguar squadrons are now opting for twin-seater variants to add muscle to their deep strike capability. It is like two beasts rolled into one. The objective is to deliver bombs with deadly accuracy.
"Precision strikes is the future of the Indian Air Force as no country today will stand for collateral damage," Air Officer Commanding-in-Chief, Western Air Command Air Marshal AK Singh says.
The pilot in the rear cockpit will be the weapon systems operator tasked with ensuring pin-point bombing. The other pilot will then be left free to steer the aircraft through dense enemy air defences.
Indeed, the new cockpits are so crowded, and information overload so heavy that a second pilot is deemed a necessity on complex missions in well-defended areas.
"Twin-seater helps you to share the load and delivger it more precisely because you have to not only worry about target but other aircraft closing on to you," Commanding Officer of 14 Sqn, Wing Commander RR Tyagi says.
Jaguars, both old and new, will be equipped with laser-guided bombs for accuracy. "Laser-guided bomb costs you to the tune of a crore and certainly can't be wasted," Air Marshal AK Singh adds.
Pin-point precision attacks are the future of the Indian Air Force. And its Jaguars are being modified to strike the fear Of God and the Air Force in the heart of the enemy.
http://www.india-defence.com/reports/1629