1996 Croatia USAF CT-43 crash

United States Air Force Flight IFO-21

A USAF MH-53J Pave Low helicopter hovers near the wreckage of Flight IFO-21. The tail number of the accident aircraft is shortened as 31149.
Accident summary
Date	April 3, 1996
Summary	Controlled flight into terrain, pilot error, poorly designed instrument approach
Site	3 km (1.9 mi) north of Dubrovnik Airport, Dubrovnik, Croatia. 42°35′53.78″N 18°15′7.14″E / 42.5982722°N 18.2519833°E / 42.5982722; 18.2519833Coordinates: 42°35′53.78″N 18°15′7.14″E / 42.5982722°N 18.2519833°E / 42.5982722; 18.2519833
Passengers	30
Crew	5
Fatalities	35 (all)
Survivors	0 (1 initially, died shortly after rescue)
Aircraft type	Boeing CT-43A
Operator	United States Air Force
Registration	73-1149
Flight origin	Zagreb International Airport, Zagreb, Croatia
Stopover	Tuzla International Airport, Tuzla, Bosnia-Herzegovina
Destination	Dubrovnik Airport, Dubrovnik, Croatia

On April 3, 1996, a United States Air Force Boeing CT-43A (Flight IFO-21) crashed on approach to Dubrovnik, Croatia, while on an official trade mission. The aircraft, a Boeing 737-200 originally built as T-43A navigational trainer and later converted into a CT-43A executive transport aircraft, was carrying United States Secretary of Commerce Ron Brown and 34 other people, including The New York Times Frankfurt bureau chief Nathaniel C. Nash. While attempting an instrument approach to Dubrovnik Airport, the airplane crashed into a mountainside. Air Force Technical Sergeant Shelly Kelly survived the initial impact, but died en route to hospital. Everyone else on board died at the scene of the crash.

The aircraft was operated by the 86th Airlift Wing, based at Ramstein Air Base in Germany. Unlike civilian 737s, the military CT-43A version was equipped with neither a flight data recorder nor a cockpit voice recorder.

The official US Air Force accident investigation board report noted several reasons that led the Boeing CT-43A, callsign "IFO-21" (short for Implementation Force), to crash. Chief among the findings was a "failure of command, aircrew error and an improperly designed instrument approach procedure". The inclement weather was not deemed a substantial contributing factor in the crash.

The Boeing CT-43A used for this flight was formerly a T-43A navigator training aircraft that was converted for distinguished visitor travel. The flight was on an instrument flight rules non-directional beacon (NDB) approach, which is a non-precision type of instrument approach, to Runway 12 when it strayed off course. Non-precision approaches are those that do not incorporate vertical guidance. While NDB approaches are essentially obsolete in the United States, they are still used widely in other parts of the world. Because of their infrequent use in the United States, many American pilots are not fully proficient in performing them (a NASA survey showed that 60% of American transport-rated pilots had not flown an NDB approach in the last year). The investigation board determined that the approach used was not approved for Department of Defense aircraft, and should not have been used by the aircraft crew. The board determined that the particular NDB approach used required two operating ADFs, the instrument used to fly such an approach, on board the aircraft, but this aircraft only had one ADF installed. To successfully fly the approach, one ADF was required to track the outbound course of 119° from the Kolocep NDB (KLP), while another ADF was required to observe when the aircraft had flown beyond the Cavtat NDB (CV), which marked the missed approach point. Further, the board noted that the approach was rushed, with the aircraft flying at 80 knots (150 km/h) above the proper final approach speed, and had not received the proper landing clearance from the control tower.