Ahmedabad/New Delhi, June 14 -- In the twisted metal and charred debris of what was once one of India's most advanced passenger jets, investigators began on Friday the meticulous work of unravelling how 33 seconds of flight ended as the nation's deadliest aviation disaster in three decades. As teams from India's Aircraft Accident Investigation Bureau worked through the debris field of Air India flight 171 at Ahmedabad's BJ Medical College, the aviation regulator separately ordered the carrier to step up specific safety inspections --- a set of pre-flight checks of six critical aircraft systems that experts believe could indicate possible theories being explored for the air crash probe. The probe - which will focus on a range of possibilities and scenarios spanning equipment problems, pilot error and weather conditions - will take into account what some officials said are apparent anomalies, although they added it was still too early to make a conclusion. The landing gear remained extended during the plane's brief ascent and flap components found scattered on nearby roads appeared improperly positioned for take-off, potentially robbing the aircraft of critical lift, one official said, asking not to be named. Officials confirmed on Friday they recovered one of the two blackboxes from the rooftop of the hostel mess building, while a team from Boeing arrived in Ahmedabad to assist the investigation. Parts of the plane's two General Electric GEnx engines are being sent to the United States for analysis. "The wreckage will be moved to a storage facility for reconstruction by Air India, the AAIB, the U.S. National Transportation Safety Board (NTSB), and other agencies," according to an official familiar with the investigation. The DGCA directive, issued barely 24 hours after Thursday's disaster that killed 241 people, mandates inspections of fuel parameters and fuel flow systems, electronic engine control mechanisms, hydraulic systems, and take-off parameters-all critical to an aircraft's ability to maintain controlled flight during the vulnerable take-off phase. Experts noted the targeted nature of these inspections. "The order by the DGCA seems to have indicated their suspicion of all that could have led to the B787-8 crash on Thursday," said Amit Singh, an aviation expert. "While the checks mentioned by the DGCA are all performed by the pilots before take-off, they are only a few of the total checks performed. This could imply the regulator may have learnt about snags or probable issues with the aircraft," he added, reiterating the need to wait for more clues. International aviation experts said the recovered flight recorders should provide crucial answers within days about what caused the Dreamliner to lose altitude just 33 seconds after take-off. Paul Fromme at the U.K.-based Institution of Mechanical Engineers said the flight data recorder contains information on engine and control settings, apart from voice records of cockpit conversations. "This should show quickly if there was a loss of engine power or lift after takeoff and allow a preliminary determination of the likely cause for the crash," Fromme, who heads the professional association's Aerospace Division, told the Associated Press. Aviation safety consultant Jeff Guzzetti, a former crash investigator for both the U.S. National Transportation Safety Board and Federal Aviation Administration, told AP that investigators should be able to answer important questions as soon as next week if the flight data recorder is in good condition. Guzzetti said key issues likely include whether flaps and other settings were correct, whether engines lost power, and whether the crew correctly inputted information about outside temperature and aircraft weight. "A mistake in the data that the crew put into the plane's system could result in the flaps and slats being set incorrectly," he said. Aviation consultant Bob Mann told Bloomberg it appeared the 787 Dreamliner wasn't able to achieve sufficient thrust as it travelled nearly the full length of an 11,000-foot runway-a distance that should have been more than adequate for take-off. That could stem from aircraft misconfiguration prior to take-off or erroneous weight data entered into the plane's computer system that determines power requirements, Mann said. "If the weight is high compared to the actual number, you end up with a very aggressive take-off. If the weight is low compared to the actual, you end up with not enough commanded power." On the ground in Ahmedabad, civic officials began using excavators to clear burnt trees, electricity poles, and charred building materials from surrounding streets, but all aircraft debris remains untouched. "Nothing from the crash site can be accessed by anyone except AAIB," said a former DGCA official, adding: "Everything is evidence here." On Friday, he Boeing 787's stabiliser section remained lodged in the second floor wall of the mess building, a surreal sight made more haunting by one of the aircraft's landing gear wheels stuck beside it. On Friday, the Boeing 787's stabiliser section remained lodged in the second floor wall of the mess building, a surreal sight made more haunting by one of the aircraft's landing gear wheels stuck beside it. Across the hostel complex, Gujarat police and Air India officials stood guard over scattered aircraft components - wings, rudders, and even passenger luggage, some intact, others bearing blood stains. The debris field spans eight buildings over approximately 200 meters, all now sealed off as a crime scene of sorts where every fragment could hold clues to the disaster. "In the early hours of the crash, some parts of the plane had to be moved physically to take out the bodies. Some victims were stuck or buried under the debris," said a fire officer at the scene....