Background
Before takeoff, the pilot of XA-KUT was briefed that the weather at Houston Hobby (HOU) was IFR with indefinite ceiling zero, sky obscured, visibility 1/16 mile in fog. Forecast conditions indicated IFR until 0900 CST, gradually improving to marginal VFR by 1100 CST with 1,000 feet broken ceilings, 5 miles visibility, and fog. The flight departed at 0900 CST.
Flight
Arrival at HOU was delayed due to weather. The crew requested an ILS approach, intending to divert if a missed approach became necessary. The runway visual range (RVR) was variable. After being cleared for the ILS runway 04 approach, the pilot was advised that RVR had dropped to 1,400 feet. Switching to tower frequency, the flight received landing clearance and was again told the RVR was 1,400 feet.
Accident
While on final approach, the pilots were alerted to a low altitude alert. Despite the warning, the aircraft continued below the decision height (DH), struck a 70-foot power line approximately 6,500 feet short of the runway, and crashed. The copilot was killed, and seven other occupants sustained injuries, three of them serious.
Investigation
No preimpact malfunction of the aircraft or its systems was found. The ILS was flight-checked; only a minor discrepancy concerning the outer marker width was noted. The DH was 200 feet AGL, and the minimum RVR for the approach was 2,400 feet.
Probable cause as determined by the official investigation:
- In-flight collision with object (power line) during approach from FAF/outer marker to threshold
- Weather conditions: low ceiling, fog, obscuration
- Weather below approach/landing minimums
- Improper IFR procedure by the pilot in command
- Decision height not identified by the pilot in command
- Object: wire, transmission
- In-flight collision with terrain/water during uncontrolled descent