1996 Croatia USAF CT-43 crash
USAF MH-53J Pave Low helicopter near the tail wreckage of United States Air Force Flight IFO-21, approximately 3 km (1.9 mi) north of the Dubrovnik Airport in Croatia, April 4, 1996. Note the tail has the American flag above the aircraft registration number, which reads "31149". The full tail number is 73-1149, as mentioned below.
|Date||April 3, 1996|
|Summary||Pilot error, badly designed instrument approach, controlled flight into terrain|
|Site||3 kilometers north of Dubrovnik Airport, Dubrovnik, Croatia|
|Survivors||0 (1 initially, but died later in the ambulance)|
|Aircraft type||Boeing CT-43A (a modified version of the Boeing 737-200)|
|Operator||United States Air Force|
|Flight origin||Zagreb International Airport, Zagreb, Croatia|
|Last stopover||Tuzla International Airport, Tuzla, Bosnia-Herzegovina|
|Destination||Dubrovnik Airport, Dubrovnik, Croatia|
On April 3, 1996, United States Air Force Flight IFO-21, a United States Air Force Boeing CT-43A crashed on approach to Dubrovnik, Croatia, while on an official trade mission. The aircraft, a Boeing 737-253 originally built as a Boeing T-43A navigational trainer and 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 crash, 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 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". Notably 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 IFR 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 U.S. they are still used widely in other parts of the world. Because of their infrequent use in the U.S. many American pilots are not fully proficient in performing them (a NASA survey showed that 60% of U.S. 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.
The crash site, on a 2,300 ft (701 m) hill, was 1.6 miles (2.6 km) northeast of where the aircraft should have been on the inbound course to the NDB. The published NDB approach brings the inbound aircraft down a valley, and has a minimum descent height of 2,150 feet (655 m) at the missed approach point (where they should have climbed and turned to the right if the runway was not in view), which is below the elevation of the hills to the north. The runway is at 510 feet (155.4 m) MSL. Five other aircraft had landed prior to the CT-43A and had not experienced any problems with the navigational aids. There was no emergency call from the pilots, and they did not initiate a missed approach, even though they were beyond the missed approach point when they hit the hill at 2:57 PM local time.
The area of the crash site is identified by a large (10 metre tall) stainless steel cross on Stražišće peak. Hikers can reach the peak via the Ronald Brown path which is named in commemoration of the U.S. Secretary of Commerce who died in the crash.
A memorial room has been installed in the Ronald Brown memorial house in the old city of Dubrovnik. It features portraits of the crash victims as well as a guest book.
- Boeing737.org T-43A page. Retrieved: 29 November 2008
- Hughes, David "USAF, NTSB, Croatia Probe 737 Crash", Aviation Week & Space Technology, 8 April 1996
- Walters, James M.; Sumwalt, Robert L. III (2000). Aircraft Accident Analysis: Final Reports. McGraw Hill.
- Transcript of US Department of Defense News briefing held on 7 June 2006 "Results of the Accident Investigation Report of the CT-43 Accident". Retrieved: 29 November 2008
- "The weather at the time of the approach was reported as 400 feet broken, 2,000 feet overcast, 8 km or about 5 miles visibility, rain, surface winds for 120, 12 knots, because of the weather, the crew is required to fly an instrument approach procedure into Dubrovnik." Transcript of US Department of Defense News briefing held on 7 June 2006 "Results of the Accident Investigation Report of the CT-43 Accident". Retrieved: 29 November 2008
- FSF ALAR Briefing Note 7.2 - Constant Angle Nonprecision Approach Flight Safety Foundation
- DoD news release Archived May 30, 2010 at the Wayback Machine
- Dubrovnik Online website Retrieved: 17 October 2009
- "Ronald Brown memorial house". Retrieved 3 April 2014.