An Ethiopian Airlines Boeing 767 lost communications with Air Traffic Control (ATC) while over the Balkan States on October 15th. The cargo freighter registered ET-ALO was performing flight number ET-3717. The aircraft departed Liege Airport (LGG) in Belgium at 15:58, over three hours behind schedule. During the flight, communications were lost for over an hour. Following the alarming flight, the aircraft landed safely on runway 07R at 23:37 at Addis Ababa Bole International Airport (ADD) in Ethiopia.

Lost communications

The flight crew had been in contact with ATC since departing LGG with no complications. While traveling through Croatian airspace, the pilots were in contact with Zagreb Center. After being handed off to another controller, the flight crew stopped communicating with ATC. The controllers tried to reach the flight crew on multiple frequencies, including the guard frequency, which is reserved for emergency use. All attempts to contact the pilots were to no avail. ATC even solicited the assistance of other aircraft to try and reach the pilots.

The pilots aboard the Ethiopian flight took proper action and continued to follow their flight plan. After departing Croatian airspace, the airplane traversed Bosnia and Herzegovina, Montenegro, and Albania before entering Greek airspace. Once over Greece, Athens Center attempted to contact the flight crew and announced that fighter jets would be scrambled to intercept the freighter. No response was heard from the pilots.

Over the Mediterranean Sea, Just north of the Egyptian border, fighters intercepted the Ethiopian flight. Upon interception, the cargo pilots began reporting on the correct frequency with ATC, and contact was restored. ATC reportedly reprimanded the pilots for their lack of proper communication. Thankfully, the flight landed safely, and no injuries were reported in association with this incident.

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Root cause

No official cause has been reported concerning the communication discrepancy. What is known is that the aircraft was unresponsive for over an hour, beginning with a routine frequency change, and was not reestablished until the cargo jet was intercepted. The airline has not made any official statements regarding the incident. Simple Flying has reached out to Ethiopian Airlines regarding the cause of the event. This article will be updated once a response has been received.

A disruption in communication between an aircraft and ATC will always result from an equipment malfunction, pilot error, or transmissions being blocked by some external variable, such as being out of range. It is unlikely that any external variable could have disrupted communications in this instance, as the aircraft was well within range of many operating ATC frequencies, and many other aircraft had no communication difficulties.

An equipment malfunction is a common cause of communication disruptions. However, no reports have been released indicating that an equipment malfunction contributed to the interruption. That leaves pilot error as the only other possible cause. It is unlikely in this instance that the pilots would have accidentally lost contact with ATC as there were many frequencies they could contact for assistance if needed, including the international guard frequency. Regardless the actual cause for the communication disruption will remain unknown to the public until an official report is released.

What do you think of this communication disruption? Let us know in the comments below.

Source: Aviation Herald, FlightRadar24

• 

  Ethiopian Airlines

  IATA/ICAO Code:

  ET/ETH

  Airline Type:

  Full Service Carrier

  Hub(s):

  Addis Ababa Bole International Airport

  Year Founded:

  1945

  Alliance:

  Star Alliance

  CEO:

  Mesfin Tasew Bekele

  Country:

  Ethiopia