The Airbus A340, belonging to national flag-carrier TAP, took off at 10.34am en-route for Brazil but was forced to turn back due to mechanical problems. It was carrying 177 passengers and 11 crew.
According to an aviation enthusiast who was tracking the flight, “the plane headed out to sea then turned back towards Lisbon, passed to the west of the airport turned right and passed to the east of the airport and went out into the Ocean to dump fuel.
“It circled for well over an hour then headed north again and then landed at Lisbon over 90 minutes after it’s original departure.”
Newspaper Correio da Manhã reported that “the crew flying the Airbus A340 had not been in the air for more than 15 minutes when they decided, in cooperation with the control tower, to discard the planned route and return to land in Lisbon to fix the problems.”
The causes behind the mechanical failure were being investigated, although it is thought it was due to a problem with one of the four engines.
Website Aviation Herald reported that the incident was in fact due to an “engine fault”, and an engine had been shut down in flight.
The passengers on board flight TP89 later switched planes and continued their journey to their destination on a similar aircraft some nine hours later.
It emerged hours after the incident that the aircraft in question is one of four A340-300s belonging to TAP that in July were given authorisation to extend their service life.
The plane was given the green light by the National Civil Aviation Authority (ANAC), which is now being investigated by the European Aviation regulator.
On 12 July TAP asked ANAC to waive compulsory modifications to components to allow the aircraft to remain in service up into 31,000 flight cycles and 156,000 hours of flight.
Authorisation was given the next day, on 13 July.
However, a spokesperson for TAP was on Tuesday quick to shoot down any concerns in this regard, saying the occurrence was in no way related to the extension of the aircraft’s service as “all airworthiness requirements are guaranteed”.
The spokesperson further stressed “it happened with this aircraft as it could have with any other aircraft.”
TAP’s four A340-300s operate the airline’s long-haul routes to Africa and Brazil.
In related news, on Saturday a British Airways plane was also forced to make an emergency landing at Lisbon airport for “safety reasons” following “technical problems.”
According to website Aviation Herald, the Airbus A320-200, was performing flight BA-2732 from London Gatwick to Lanzarote, (Canary Islands, Spain), and “was en-route (...) about 40 nautical miles southeast of Lisbon (Portugal) when the crew received a smoke detector indication and decided to divert to Lisbon.”
The aircraft was carrying 157 passengers and landed safely in Lisbon at 6.50pm, about 35 minutes after the decision to divert was made.