US carrier Southwest Airlines has reportedly brought back half of the temporarily grounded 115 Boeing 737-800 aircraft to service. 

Reuters reported that the grounding follows due to aircraft weight data discrepancies. 

In a statement, Southwest Airlines was quoted as saying that ‘out of an abundance of caution, we have temporarily ceased flying the respective aircraft to enter the correct weights of the aircraft in question into the system and reset the programme’.

The Dallas-based airline initially quoted the development covered 130 aircraft, but later stated the correct figure to be 115. 

Boeing and the US Federal Aviation Administration (FAA) refused to comment on the development. 

 In January, the FAA was seeking to fine Southwest $3.92m for alleged weight infractions on 21,505 flights on 44 aircraft between 1 May and 8 August 2018. 

According to the FAA, Southwest operated the flights with incorrect operational empty weights, and centre of gravity or moment data. 

The data is used to determine the numbers of passengers and fuel which can be safely carried and where cargo should be located. 

Meanwhile, the carrier expects the temporary grounding to cause some delays or flight cancellations. 

In June, Southwest Airlines announced it is adding new daily flights in Q4 in hopes of gaining a larger market share of corporate travel amid the coronavirus.