Narrative:

Aircraft Y and aircraft X were established on the ILS runway xx approach when the event began. Aircraft Y recognized a landing gear indicator light while on a 5 mile final and in communication with tower. At the time; aircraft X was approximately 7 miles in trail also cleared for the instrument approach. On the 5 mile final; aircraft Y turned due north towards aircraft X and leveled at 2;500 MSL. This missed approach procedure is a climbing left turn to 4;000 MSL towards the VOR. This was the first pilot deviation. I immediately canceled aircraft X's approach clearance and turned him eastbound; away from aircraft Y. Aircraft Y advised that he intended to assume military assumes responsibility for separation of aircraft (marsa) with aircraft X in order for aircraft X to conduct a visual inspection on the landing gear. The weather conditions were 4 miles visibility due to rain and ceiling broken at 3;200. I could not maintain vertical separation in hopes of the aircraft getting close enough to establish visual separation; 2;500 MSL is the lowest MVA in the area and 3;500 would put one of the aircraft in the clouds. My plan of action was to use 500 ft vertical separation and use divergence to get the aircraft within visual range of each other. I decided to use 500 ft separation because 1;000 ft was unfeasible and 500 ft would prevent the worst case scenario; a collision. With aircraft X at 3;000 MSL and aircraft Y at 2;500 MSL I began to vector them at one another while maintaining course divergence and; in turn; legal separation until they could declare marsa. Aircraft Y declared 'radar contact' with aircraft X and stopped responding to radio communications. Aircraft Y then deviated from the assigned heading and navigated on his own towards aircraft X. Aircraft X advised me he was communicating with aircraft Y on an internal frequency. Both aircraft began maneuvering of their own accord over a nearby airport and descended out of their assigned altitudes. They descended as low as 2;000 MSL. That is 500 ft below the MVA. I repeatedly instructed them to maintain assigned altitudes. Eventually they advised me that they had assumed marsa and would maneuver on their own over the second airport as the ceiling was highest there. Later; they wanted a split up to proceed inbound to the first airport. I cleared aircraft X for a visual approach into the first airport and aircraft Y executed the ILS approach and landed safely. Recommendation; this was an unusual occurrence due to the complexity of the event. The combination of an emergency situation; poor weather conditions; and pilot deviation lead to the culmination on this event. A better way to handle this may have been to shut down the first airport. The MVA over the first airport is 2;000 MSL. Had they assumed marsa over the first airport then 2;000 ft would have been a safe altitude to conduct a visual inspection of the landing gear. In order to do that; the pilots needed to communicate and work with us. I wasted a lot of time trying to re-establish radio communications when I could have been thinking of an alternate plan to help them.

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Original NASA ASRS Text

Title: TRACON Controller described a confused occurrence involving two military jets on approach; one experiencing a gear problem that eventually resulted in MARSA separation and MVA infractions.

Narrative: Aircraft Y and Aircraft X were established on the ILS Runway XX Approach when the event began. Aircraft Y recognized a landing gear indicator light while on a 5 mile final and in communication with Tower. At the time; Aircraft X was approximately 7 miles in trail also cleared for the instrument approach. On the 5 mile final; Aircraft Y turned due north towards Aircraft X and leveled at 2;500 MSL. This missed approach procedure is a climbing left turn to 4;000 MSL towards the VOR. This was the first pilot deviation. I immediately canceled Aircraft X's approach clearance and turned him eastbound; away from Aircraft Y. Aircraft Y advised that he intended to assume Military Assumes Responsibility for Separation of Aircraft (MARSA) with Aircraft X in order for Aircraft X to conduct a visual inspection on the landing gear. The weather conditions were 4 miles visibility due to rain and ceiling broken at 3;200. I could not maintain vertical separation in hopes of the aircraft getting close enough to establish visual separation; 2;500 MSL is the lowest MVA in the area and 3;500 would put one of the aircraft in the clouds. My plan of action was to use 500 FT vertical separation and use divergence to get the aircraft within visual range of each other. I decided to use 500 FT separation because 1;000 FT was unfeasible and 500 FT would prevent the worst case scenario; a collision. With Aircraft X at 3;000 MSL and Aircraft Y at 2;500 MSL I began to vector them at one another while maintaining course divergence and; in turn; legal separation until they could declare MARSA. Aircraft Y declared 'RADAR contact' with Aircraft X and stopped responding to radio communications. Aircraft Y then deviated from the assigned heading and navigated on his own towards Aircraft X. Aircraft X advised me he was communicating with Aircraft Y on an internal frequency. Both aircraft began maneuvering of their own accord over a nearby airport and descended out of their assigned altitudes. They descended as low as 2;000 MSL. That is 500 ft below the MVA. I repeatedly instructed them to maintain assigned altitudes. Eventually they advised me that they had assumed MARSA and would maneuver on their own over the second airport as the ceiling was highest there. Later; they wanted a split up to proceed inbound to the first airport. I cleared Aircraft X for a Visual Approach into the first airport and Aircraft Y executed the ILS approach and landed safely. Recommendation; this was an unusual occurrence due to the complexity of the event. The combination of an emergency situation; poor weather conditions; and pilot deviation lead to the culmination on this event. A better way to handle this may have been to shut down the first airport. The MVA over the first airport is 2;000 MSL. Had they assumed MARSA over the first airport then 2;000 FT would have been a safe altitude to conduct a visual inspection of the landing gear. In order to do that; the pilots needed to communicate and work with us. I wasted a lot of time trying to re-establish radio communications when I could have been thinking of an alternate plan to help them.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.