Accident Overview
N700CM was being vectored for an ILS runway 07 approach when the pilot was instructed to maintain 3,000 feet and informed that the aircraft was following a Boeing 727. The minimum altitude before intercepting the ILS glide slope at the final approach fix/outer marker was 1,900 feet. As the aircraft neared the outer marker, the pilot was cleared for the approach and handed off to the tower. The tower controller told the pilot to descend as published.
Approach and Sequencing
Shortly after contacting the tower, the controller and a supervisor discussed N700CM's altitude and its proximity to the preceding Boeing 727. The controller considered discontinuing the approach, but the supervisor suggested waiting to see if it would work out. Radar data later showed that N700CM was well above the ILS glide slope when cleared for the approach. ATC procedures required the aircraft to be below the glide slope before being cleared. The aircraft was approximately 2.57 miles behind the Boeing 727 but remained above the 727's flight path—and potential wake turbulence—until moments before impact.
Descent and Impact
N700CM subsequently entered an excessive rate of descent and went below the glide slope before crashing into trees approximately 5,800 feet short of the runway. The aircraft was in a wings-level attitude at impact. Both occupants were killed.
Probable Cause Findings
The official probable cause includes two occurrences. Occurrence #1: in-flight collision with object (trees) during approach from the final approach fix/outer marker to threshold (IFR). Findings include weather conditions of low ceiling, fog, and rain; inadequate radar separation by ATC personnel; improper written/verbal instructions by ATC personnel; delayed descent; improper use of planned approach by the pilot in command; missed approach not issued by ATC; inadequate supervision by ATC supervisor; proper glidepath not attained by pilot; missed approach not performed by pilot; excessive descent by pilot; object trees; and improper use of decision height by pilot. Occurrence #2: in-flight collision with terrain/water during uncontrolled descent.