The family of an investment banker from Gerrards Cross who died in a helicopter crash in the Andes has won a High Court action against his employers after a judge found better safety investigations should have been made before the doomed flight took off.

"Devoted" father-of-two, Tomas Dusek, 37, was among a dozen executives who died when their chartered helicopter crashed into the Mama Rosa mountain in Peru and burst into flames in 2012.

Mr Dusek's wife, Angela, and his children, aged five and eight, launched a claim for damages against his London-based employer, StormHarbour Securities LLP, insisting it had failed to ensure the flight was safe.

The judge said Mr Dusek, originally from the Czech Republic, died as the group flew to remote foothills in the Andes to observe a billion dollar hydro-power project on June 6, 2012.

StormHarbour was introducing a consortium of potential investors, headed by Samsung, to the project, with HeliCusco chartered to fly them to the site, which was only accessible by air or via a jungle route on the ground.

But during a leg of the trip between Mazuco and Cusco, the Peruvian operator's Sikorsky S58-ET helicopter got into difficulties at 16,000ft and crashed into Mama Rosa, before catching ablaze. All 12 passengers and two crew died.

Colleagues described Mr Dusek as an “adrenaline junkie” who enjoyed skiiing, bungee jumping and mountain climbing, but also a dedicated family man with plenty of common sense.

Mr Justice Hamblen said the accident was caused by a "lack of knowledge or disregard of aircraft limitations" and the "extremely demanding and unforgiving environment of high mountainous terrain".

He said "deteriorating weather conditions", which caused the pilots to change their planned route, and their "failure to make a timely decision to abort" a bid to reach Cusco also contributed to the disaster.

The judge said the flight operators' decision to leave Mazuco when they did had inevitably resulted in the flight breaching regulations by being airborne under night conditions.

Mr Justice Hamblen said the crew had also "failed to withstand pressure" from their clients - many of whom did not want to miss connecting flights - to depart as quickly as they had.

He said StormHarbour was "in breach of its duty of care in doing nothing to investigate into the safety of the proposed helicopter flight".

The size of the Dusek family's compensation package will now be determined either by agreement or at a further hearing.

Mrs Dusek issued a statement after yesterday's hearing: "Tomas was a wonderful father and a loving and cherished husband.

"When he stepped on board the helicopter as part of his job, we expected and assumed it to be safe, not that he would be putting his life at risk and leaving us devastated by his death.

"We miss him every hour of every day... today's verdict will finally give our family peace that justice has been met for Tom.

"It is also with pride that I can tell my children that today's decision will hopefully change the way that other employers approach business travel to remote regions of the world.

"And if that means that even just one less wife, child or parent suffers what we have had to suffer over the last two-and-a half years, then something positive has come out of this pain."