A number of pilots at low-cost airline Germanwings refused to fly today following yesterday's crash in the French Alps that killed all 150 people on board. Their decision came as it emerged the Airbus A320 that dropped out of the sky and ploughed into a mountainside had been grounded over technical fears just 24 hours before. Helicopter  operations continued for a second day in the grim search for debris and bodies - including those of three British nationals  -  that have been scattered over acres of mountain terrain. Reports revealed the aircraft had suffered technical issues, including a landing gear problem, just a day before it was due to fly from Barcelona to Dusseldorf. Scroll down for video . Grief: Germanwings airline employees comfort each other during a ceremony to observe a moment of silence for the victims of the Airbus 320 crash at the company's headquarters in Cologne, Germany . Lufthansa employees observe a minute's silence in Frankfurt, Germany, for the 150 victims who died in the Germanwings plane crash . Burning candles and pins of German airlines Condor, Germanwings and Lufthansa are placed by crew members in commemoration of the victims of Germanwings flight 4U9525 AT the Germanwings headquarters . Urgent safety checks are now being carried out on other A320s, while passengers were left stranded at Heathrow, Stansted and Manchester yesterday after several Germanwings crews refused to work. A spokeswoman for the airline's parent company, Lufthansa, said one Germanwings flight from Dusseldorf to Barcelona was cancelled because the pilots 'don't feel they are in a position to fly'. She declined to say how many pilots declined to work today, adding that all Lufthansa flights were going ahead as planned. Staff at Germanwings and Lufthansa wept during an emotional minute's silence for victims of the disaster at their respective headquarters in Germany this afternoon. A spokesman for the pilots' union Vereinigung Cockpit, Joerg Handwerg, insisted the decision was not because of concerns about safety. 'It has nothing to do with safety. The pilots have friends and colleagues who have died,' Handwerg said on public television. 'That is such a heavy emotional burden that it's better not to get into the cockpit.' Obliterated: Search and rescue teams sift through the wreckage of the Germanwings plane as the recovery operation enters its second day . French mountain troopers are climb a hill near the makeshift helicopter landing pads in Seyne Les Alpes to secure the area for the visit of French President Francois Hollande, German Chancellor Angela Merkel and Spanish Prime Minister Mariano Rajoy . Show of solidarity: French President Francois Hollande (centre) embraces Spain's Prime Minister Mariano Rajoy as German Chancellor Angela Merkel (second right) looks on while they walk on a field near the crash site of Germanwings Airbus A320 near Seyne-les-Alpes . Yesterday, Germanwings had reported 'occasional flight disruptions within its route network' as pilots were too shocked to fly following the news of the crash of an A320 Germanwings jet. It was the first fatal accident in the history of Germanwings and the deadliest on the French mainland since 1974. 'We understand their decision,' said Germanwings executive Thomas Winkelmann. Industry experts also sought to reassure Airbus A320 pilots that they will be safe. Steve Landells, a safety specialist from the British Airline Pilots Association (BALPA) who is himself a former A320 pilot, said the aircraft is ‘incredibly reliable with a good safety record’. Grim task continues: A French Gendarmerie helicopter takes off for another search and rescue operation from Syne Les Alpes after a Germanwings Airbus A320 crashed into a mountainside in the French Alps killing all 150 people on board . He told MailOnline that hundreds of A320s are flying today and pilots should have ‘no qualms getting on one today’. A spokesman from BALPA told MaiOnline: 'BALPA has gained information from the German pilot union that Lufthansa and Germanwings are giving pilots time off for grief. ‘British pilots sympathise with their German colleagues and completely understand. ‘Pilots have to be fit to fly, and if they feel emotionally unfit to fly, it is important they do not take to the air. It appears the company are doing the right thing in supporting them.’ In a separate development, experts claimed the Germanwings plane may have crashed because the windscreen cracked, causing a sudden drop in oxygen levels that rendered the pilots unconscious. Reports circulating on professional pilot forums suggested the black box on the Airbus A320 had been analysed and revealed that a 'structural failure' was responsible for the disaster. This Germanwings Airbus A320 carrying 144 passengers and six crew which crashed in the French Alps . Flight 4U 9525 dropped out of the sky and ploughed into a mountainside in the French Alps at more than 400mph yesterday, killing all 150 people board. In the latest theory to emerge, it is thought the windscreen gave way, incapacitating the pilots and leaving them unable to send out a distress call. That may explain what happened in what top French official Segolene Royal has described as the crucial minute between 10.30am - when the pilots were apparently chatting away - and 10.31am when contact was lost. Flight radar data revealed the plane started its nosedive at 10.31am from an altitude of 38,000 feet. However, experts are also discussing other theories including faulty speed sensors and technical problems related to the age of the aircraft. France's transport minister says work had begun on retrieving vital data from the cockpit voice recorder, although first pictures showed it had been badly damaged and it was not clear how much, if any, information could be analysed. This afternoon, the Foreign Office named 28-year-old Paul Bramley, originally from Hull, as one of the three Britons killed. Another was earlier identified as Martyn Matthews, a father-of-two and businessman from Wolverhampton. Marina Bandres, a Spanish-born mother from Manchester, and her seven-month-old baby, Julian, who is  a British national, were also among those who died.
One Germanwings flight cancelled because pilots 'didn't feel able to fly'
Passengers stranded at UK airports yesterday after crews refused to work .