Definition

A combination flight recorder installed on the aircraft which is capable of automatically deploying from the aircraft. (source: ICAO)

Reasons for Development

Obtaining flight data recorder (FDR) and cockpit voice recorder (CVR) content as quickly as possible after an aircraft accident is crucial in determining the causes and contributing factors, and, more importantly, in developing safety recommendations to prevent similar accidents. Some historic accidents and more recent events — such as the disappearance of Malaysia Airlines Flight 370 in 2014 and the crash into the Atlantic Ocean of Air France Flight 447 in 2009 — have shown that in some accident scenarios, timely recovery of these flight recorders proved to be impossible. When an accident occurs in a remote area, over water or at an unknown location, recovering the flight recorders can be a significant challenge. Therefore, the development of deployable flight recording systems (DFRS) for commercial aircraft has begun.

Description

Composition

The system consists of:

• Flight recorder equipment, containing FDR and CVR information
• An emergency location transmitter (ELT) and a strobe light to facilitate the discovery of the unit
• A buoyant hardened container that protects the equipment and ensures flotation in case of water impact
• A deployment mechanism that ensures fast and reliable detachment in case of an accident

How It Works

• Sensors detect the start of a crash
• Deployable unit releases from the aircraft. If the aircraft is in the air, aircraft movement assists the separation of the device. If the aircraft is underwater, the unit surfaces due to being lighter than water.
• Deployable unit lands safely away from the crash site. If it lands on water, it can float indefinitely.
• The ELT transmits the location and ID of the aircraft emergency beacon via satellite to SAR authorities.
• The unit acts as a homing device for rescue crews.
• SAR personnel recover survivors and the deployable recorder.

Mounting and Deployment

The device is usually mounted in the vertical fin of an airplane. The outer surface is flush with the fin's skin to ensure that there is no effect on the aircraft's aerodynamics.

Deployment is triggered by significant structural deformation or an impact with water. In the event of an airborne deployment, the spring mechanism in the housing case pushes the recorder into the slipstream, where its shape acts as an aerofoil and ensures it is carried away from the aircraft.

Benefits

• Provides recorded data in case the aircraft is inaccessible after an accident
• Provides location information to rescue crews
• Backup in case of failure of permanently affixed flight recorders

Related articles

• Flight Data Recorder (FDR)
• Cockpit Voice Recorder (CVR)