Draft:Olympic Airways Flight 3838

Olympic Airways Flight 3838

SX-ECH, the aircraft involved in the accident
Accident
Date	14 September 1999 (1999-09-14)
Summary	Pilot-induced oscillations
Site	Over Călinești, Teleorman, Romania 44°04′48″N 25°12′12″E
Aircraft
Aircraft type	Dassault Falcon 900B
Operator	Olympic Airways for the Hellenic Air Force
IATA flight No.	OA3838
ICAO flight No.	OAL3838
Call sign	OLYMPIC 3838
Registration	SX-ECH
Flight origin	Ellinikon International Airport, Athens, Greece
Destination	Bucharest Henri Coandă International Airport, Bucharest, Romania
Occupants	13
Passengers	10
Crew	3
Fatalities	7
Injuries	4
Survivors	6

Olympic Airways Flight 3838 was a flight operating for the Hellenic Air Force that experienced multiple pilot-induced oscillations while over southern Romania on 14 September 1999, killing seven people. The aircraft—a Dassault Falcon 900B flying from Ellinikon International Airport in Athens, Greece—was flying to Bucharest Henri Coandă International Airport in Bucharest, Romania, for the Interbalkan Conference of Foreign Ministers and was carrying Greek deputy foreign minister Giannos Kranidiotis. While descending through 15,000 ft (4,600 m), the autopilot disconnected, causing an unfavorable stabilizer trim situation. In response to the disconnection, the pilot flying attempted to correct the pitch of the aircraft by use of the control column. However, this resulted in ten separate pitch oscillations with g-forces that exceeded the maneuvering load factor for the aircraft. As a result, six of passengers on board, including Kranidiotis, were killed and one additional passenger died three days after the accident. The investigation, conducted by the Romanian Civil Aviation Inspectorate, concluded several factors that led to the accident. As the aircraft was climbing out of Athens, the pilots received a warning related to the aircraft's pitch system. The, the pilots did properly identify and evaluate the failure and used inappropriate checklists only designed for training. As the aircraft was descending, the pilot flying exerted enough force on the control column to disconnect the autopilot's pitch channel, which caused a conflict between the autopilot trim and manual stabilizer. The continued force on the control column led to the beginning of the pilot-induced oscillations; the passengers not wearing their seatbelts during the oscillations resulted in widespread injury.

Background

Aircraft

The elevator control surfaces on a Dassault Falcon 900

The aircraft involved in the accident was a 12-year-old Dassault Falcon 900B, with registration SX-ECH and manufacturer serial number 026. It was powered by three Honeywell TFE-731 turbofan engines. The aircraft was registered to the Hellenic Air Force but operated by Olympic Airways on the day of the accident.

The primary flight controls on the Dassault Falcon are hydraulic-powered. Control inputs from the cockpit go through a series of physical rods and bellcranks that cause the movement of servoactuators in the rudder, elevators and ailerons. Artificial flight-control feel on the flight controls is achieved through the artificial-feel unit (AFU). One part of the AFU is the automatic spring-load adjusting system, known as the Arthur Q unit (Arthur unit), which adjusts the artificial feel on the control column depending on the elevator position and airspeed. At low airspeeds, the Arthur unit adjusts the artificial feel to require little force to move the control column and elevators, while at high airspeeds, the Arthur unit adjusts the artificial feel to require high force to move the control column and the elevators. A system called the box Arthur pitch system (BAP) monitors the difference between the position of the Arthur unit actuator and the position of the horizontal stabilizer. If the difference between the two passes a certain threshold, a lock will activate, a "PITCH FEEL" warning light will activate in the cockpit, and the Arthur unit will revert back into the low-speed position. The "PITCH FEEL" light will deactivate when the slats are extended or when the airspeed is less than or equal to 210 kn (390 km/h).

Passengers and crew

The aircraft was flown by two captains. The pilot-in-command (PIC) and pilot flying was 46-year-old Yiannis Androulakis. Androulakis had 8,239 total flight hours, 270 of which were on the Dassault Falcon. The co-pilot (F/O) and pilot not flying was 44-year-old Grigoris Sinekoglou. Sinekoglou had 7,465 total flight hours, 231 of which were on the Dassault Falcon. Both captains had valid airline transport pilot licences issued by the Hellenic Civil Aviation Authority. Additionally, they had substantially more experience and passed proficiency checks on the Boeing 737-400.

In addition to the two members of the flight crew and the flight attendant, the Dassault Falcon was carrying Giannos Kranidiotis, the deputy foreign minister of Greece. In addition to him was his 23-year-old son, his personal guard, a cameraman from the Hellenic Broadcasting Corporation (ERT), two ERT journalists, the director of the minister's office, a journalist from Vradyni, a minister advisor, the wife of the foreign ministry spokesperson, and an aircraft engineer. All were on board for a flight to the Interbalkan Conference of Foreign Ministers that was to be hosted in Bucharest.

Accident

On 14 September 1999, SX-ECH was scheduled to depart Ellinikon International Airport in Athens at 18:00 UTC to arrive in Bucharest Henri Coandă International Airport in Bucharest at 19:18 as OAL 3838, using the Olympic Airways ICAO airline code and the Olympic Airways call sign. Pre-flight checklists started at 16:50 and the passengers started boarding at 17:45. The aircraft then took off from runway 33 at Athens at 18:16, and the autopilot was engaged 1 minute and 30 seconds later. During the climb and after the flaps and slats were retracted, the "PITCH FEEL" warning light illuminated on the cockpit warning panel. Captain Androulakis disengaged the autopilot in response, checked the forces on the control column, and reengaged autopilot. However, the warning light remained on for the rest of the climb and cruise. At 19:03, the flight started its descent from 40,000 ft (12,000 m) to 15,000 ft (4,600 m) with the autopilot engaged in vertical speed mode. During the descent, the airspeed increased from 240 kn (440 km/h) to 332 kn (615 km/h). 12 minutes later, First Officer Sinekoglou requested further descent clearance from air traffic control (ATC) to 5,000 ft (1,500 m). However, soon after passing through 15,000 ft (4,600 m), the autopilot disconnected, and Captain Androulakis assumed manual control of the aircraft. During the next 24 seconds, aircraft experienced 10 pitch oscillations. During the oscillations, the g-forces sustained reached up to +4.7 g and -3.26 g, which exceeded the maneuvering load factor limits on the Dassault Falcon 900 of +2.6 g and -1 g. In the cabin, the passengers without their seatbelts on were thrown out of their seats along with cabin furniture such as tables and armchairs. Collisions with other objects in the cabin and the cabin celling resulted in serious injury and the death of six people, including Kranidiotis. Captain Androulakis was able to recover from the upset after 24 seconds after reducing power to the engines and descending to 13,000 ft (4,000 m). First Officer Sinekoglou declared an emergency to ATC, stating that they had control problems. ATC provided radar vectors for a visual approach to land on runway 08R at Bucharest Airport, where it landed uneventfully at 19:33. The aircraft taxied to the VIP terminal at the airport where emergency services were provided.

Victims and aircraft damage

Injury type	Passengers	Crew	Total
Fatal	7	0	7
Serious	1	1	2
Minor/None	2	2	4
Total	10	3	13

In addition to Kranidiotis, five other people were killed during the upset. They were Kranidiotis' son Nikolas, ERT journalists Dimitris Pantazopoulos and Nina Asimakopoulou, Kranidiotis' personal guard Nikos Asimakopoulos, and aircraft engineer Michalis Papadopoulos. Three days after the accident, ERT cameraman Panagiotis Poulos died in a hospital in Greece due to head and chest injuries. Everyone else on the aircraft, except for the pilots, were injured.

The aircraft structure was not damaged with the exception of a crack located in the upper fuselage caused by a catering container being ejected from its usual place in the cabin. In the cockpit, the left armrest on the right-hand (first officer's) seat collapsed, several circuit breakers on the circuit breaker panel broke, and several pushbuttons on the cockpit upper panel had traces of blood. The investigation described the passenger cabin as being destroyed. Interior furnishings such as tables and armchairs were severely damaged. Parts from the luggage compartment and aft lavatory were thrown throughout the cabin, piled up on top of one another. Celling light panels, newspapers, dishes, and cellphones covered the cabin floor. In the right galley, several drawers and doors were detached from their hinges along with sink railings. The passenger oxygen masks were out of their compartments and most of the armrests on the passenger seats were ripped off or broken. Additionally, the floor panels, especially near the back of the cabin, were damaged or destroyed.

Investigation

The investigation into the accident was led by the Romanian Civil Aviation Inspectorate, as the accident occurred in Romanian territory. Assisting in the investigation was the Hellenic Civil Aviation Authority, representing the state of registration of SX-ECH (Greece), the Bureau of Enquiry and Analysis for Civil Aviation Safety, representing the state where the aircraft was manufactured (France), the National Transportation Safety Board, representing the state where the autopilot was manufactured (United States). Additionally, representatives from Dassault Aviation, Honeywell, and Olympic Airways provided technical assistance to the investigation.

See also

• Provincetown-Boston Airlines Flight 1039 (1984) – Crashed after malfunction of pitch system
• China Eastern Airlines Flight 583 (1993) – In-flight upset that killed two passengers due to pilot inputs after slat deployment
• Loganair Flight 6780 (2014) – Serious incident after pilots commanded the aircraft to pitch differently to the autopilot