Members of the independent group of experts have come to the defense of Australian air investigators in the wake of a 60 Minutes program purporting to have solved the mystery of missing Malaysia Airlines flight MH370.

The 60 Minutes program gathered a panel of experts to discuss the fate of the missing airliner and concluded it was a murder-suicide involving a controlled ditching by one of the pilots, probably Captain Zaharie Ahmad Shah, at the end of the flight.

There was nothing new in this or any of the other theories presented in the 60 minutes program but it generated a surprising level of global media coverage and spawned a series of attacks on the integrity of the search.

Several experts who have followed the MH370 search closely were critical of the program and the way it focused on the controlled ditching scenario.

Debris hunter Blaine Gibson, who was responsible for finding significant wreckage from the aircraft, accused the 60 Minutes show of completely ignoring “all the debris I and other private citizens found, with the sole exception of the flaperon”

“According to one panelist, the fuselage is intact underwater,’’ he said “However I and other private citizens have found on beaches and held in our hands many shattered pieces of interior cabin debris.

“This debris proves that the fuselage tragically shattered on impact and is not intact underwater.

“Additionally, 60 Minutes ignored the largest piece of 370 debris recovered, the Tanzania wing flap, which was examined thoroughly by ATSB and other professional engineers and experts and determined to have been most likely in a retracted mid-flight position, not deployed.

“This debris evidence points to a high-speed forceful impact, and goes against the controlled glide intact ditching theory that 60 Minutes is pushing.”

US scientist Victor Iannello said he had watched the episode twice and found nothing new in terms of evidence or insights.

“What I did see were some of the experts confusing speculation with facts, and cherry-picking evidence to support their pet theories while carefully omitting contradicting evidence,’’ he said.

Iannello noted a large part of the program was devoted to panelist and Canadian investigator Larry Vance’s theory that the captain hijacked the plane conducted a successful ditching with the engines running, a theory first proposed in 2016.

“What was omitted is that we do have pieces of evidence that refute some of Mr Vance’s claims and should at least cast a shadow of doubt on many of his conclusions,’’ he said.

Among the issues Iannello believes should have been raised is an ATSB study showing that the flaps were likely retracted, recovered parts showing deformation from a high energy impact and a final satellite communications log-on that was consistent with the fuel running out in both engines.

Vance deals with these issues in a new book that has also fired up a long-running campaign by The Australian newspaper attacking the ATSB-led search. The book is a more detailed explanation of the argument he first raised with 60 Minutes in 2016 but it remains at odds with views of the ATSB and other experts.

Vance’s criticism of the ATSB’s handling two pieces of recovered wreckage — a wing component known as a flaperon and another called the right outboard flap — has been seized upon by proponents of the ditching theory to launch fresh attacks on the bureau.

Vance claims the flaps were extended when the plane hit the water, something a pilot would do in preparation for a controlled ditching.

The ATSB’s analysis found they were most likely retracted, adding weight to its argument the most likely end-of-flight scenario was that the unpiloted plane ran out of fuel and entered into a spiral dive.

This end of the flight is important because it helped define the search area.

A spiral uncontrolled dive would put the plane’s crash site closer to the seventh arc defined by a final “handshake” between the plane’s systems and a geostationary satellite. A controlled ditching would put it further away.

Experts used a sophisticated analysis of satellite signals and simulations conducted by Boeing to reach their conclusion the plane ran out of fuel and spiraled into the sea in series of phugoids, wave-like motions where an aircraft pitches up and then pitches down.

They concluded that the highest probability search area was likely to be relatively close to a seventh arc. This did not include every possible scenario but the bulk of those thought to be most likely at the time.

Nor was the ATSB alone in reaching these conclusions.

The group defining the search area involved the UK Air Accidents Investigation Branch, Boeing, the Defence Science and Technology Organisation, Malaysia’s Department of Civil Aviation, satellite company Inmarsat, the US National Transportation Safety Board and technology company Thales.

The original search area was 60,000 sq, kms and was later expanded to 120,000 sq. km. Searching it took two years and failed to find the wreckage at a cost to the three governments involved — Malaysia, Australia and China —of $A200m.

Contrary to some media reports, however, Malaysia picked up the lion’s share of this. It paid $A120m, leaving Australia to pay $A60m and China $A20m.

There were several developments during the search, the most important of which was the discovery of debris on the east coast of Africa and on islands off the African coast.

Another was the refinement of the satellite analysis to show the plane was picking up speed at one point in the descent. It went from a descent rate of between 2900 feet per minute and 15,200 ft per minute to one of 13,800 ft per minute to 25,000 ft per minute (462kmh).

The increasing rate of descent further confirmed the view that the crash was not the result of a controlled ditching and this was strengthened when an analysis of the outboard flap section indicated it was most likely retracted when the plane hit the water.

Flaps are movable panels on the trailing edge of the wing that can be extended to increase the surface area of the wing and increase the lift as the plane slows down to land but are retracted during the flight to optimize the wing’s aerodynamics.

A key component in the puzzle was a fiberglass and aluminum housing, known as a “seal pan’’. This is located at the inboard end of the flap and would normally house an auxiliary support track and carriage assembly used to guide the flap as it extends from the wing.

The support track is fully inserted in the flap when the panel is stowed for flight but progressively withdraws as the flap extends.

Although the support track was lost, presumably in the impact, two aluminum components in the seal pan cavity known as stiffeners showed impact damage and their position was such that the stowed support track was the probable culprit.

“The damage was significant because it was indicative of impact damage and the only component in the vicinity of the stiffeners, capable of independent movement within the seal pan, was the support track,’’ ATSB investigators said. “Measurements of the support track position at the various stages of flap deployment indicated that the track would have to be fully inserted into the flap in the retracted position to be adjacent to the damaged stiffeners.’’

Investigators also found an outwards fracture of the fiberglass seal pan which had started at a location adjacent to the damaged stiffeners.

“The damage was most likely also caused by impact from the support track,’’ the investigators said. “That damage provided further evidence of the support track position within the flap seal pan cavity, indicating that the flaps were retracted at the point of fracture and separation from the wing.’’

The flap seal pan was also fractured adjacent to the rear spar with comparable damage on the spar and a flaperon, an adjacent moveable panel held by French authorities. The investigators saw that the two damaged areas aligned if the flaps were retracted but there was a significant offset if they were extended.

The investigators concluded that the damage to the internal seal pan components was “consistent with contact between the support track and flap, with the flap in the retracted position”. The ATSB analysis was sent to UK investigators at the AAIB and manufacturer Boeing for verification before it was released.

The discovery of the debris also allowed experts at the CSIRO and the University of Western Australia to set up drift studies to help estimate where it may have originated.

As a result of new information from the CSIRO drift study, in late 2016 a meeting in Canberra of global experts proposed a new 25,000 sq. km area based on new information from that research.

This was to the northeast of the original search area but Australia, China and Malaysia ignored recommendations to extend the original search and it looked for a while that the mystery would remain unsolved for some considerable time.

That changed earlier this year when a private company, Ocean Infinity, reached a deal with the Malaysian Government to restart the effort on a “no find, no fee” basis.

By this time the CSIRO had refined its drift study and Ocean Infinity brought impressive new technology to the search that allowed it to cover bigger areas more quickly using a fleet of autonomous underwater vehicles.

Despite a mistaken perception by some that the ATSB is also running this search, it has not been directly involved other than to provide data and advice to OI.

An Ocean Infinity spokesman said recently the company based its search primarily on the CSIRO and UWA drift modeling and it was “agnostic” about the question of whether the crash was controlled or uncontrolled.

That search is due to end shortly and so far has found no sign of the wreckage.

READ MH370 search resumes, hopes high

The lack of a result has brought proponents of the controlled ditching to accuse the ATSB of failing to carry out its responsibilities by ignoring their arguments.

They contend the crash site of MH370 is further from the seventh arc and to the south and say it would have been found by now if the ATSB had listened to them.

The ATSB says it did look closely at a controlled ditching and modeled various scenarios but the concept did not fit the few facts with which it had to work. It also partially searched an area proposed by one of the proponents of a controlled ditching, pilot Simon Hardy.

The release of extracts on Monday from Vance’s book and claims the ATSB’s handling of the flap analysis could involve incompetence sent the campaign against the ATSB’s handling of the search into overdrive.

Vance, now an accident investigation consultant, is a former professional pilot and was Investigator-In-charge for the Canadian Aviation Safety Board (CASB) and the Transportation Safety Board of Canada (TSB). He was the principal author of the TSB’s Manual of Investigation and has had prominent roles in high profile investigations.

In particular, he was the deputy investigator in charge and author of the investigation report into the crash of Swissair 111 at Peggy’s Cove, Nova Scotia, in 1998.

The Swissair MD11 was brought down after faulty wiring caused the plane’s flammable insulation to catch fire during a flight from New York to Geneva. The aircraft struck the ocean at an estimated speed of 300 knots (555kmh) and disintegrated instantly. Investigators ultimately estimated about two million pieces of debris were recovered and brought ashore.

Vance uses his experience with the MD-11 crash to argue that a high-speed crash would have seen MH370 explode due to hydrostatic pressure, generating tens of thousands of pieces of debris rather than the small number that have been so far been identified as being from MH370.

The ATSB has never speculated on the impact speed or the plane’s attitude when it hit the water. A major reason for this is that the phugoids in the downward spiral would see the plane changing speed as it pitched up and down. Rather than a “death dive”, the Boeing simulations indicated it could take the plane 20 minutes to spiral down.

He backs this up with an analysis from photographs — unlike the ATSB investigators, he has not examined the actual debris — of damage known as “witness marks’’. He contends ATSB failed to properly analyze these and has suggested this could be due to incompetence.

The crash investigator cites 13 pieces of physical evidence that collectively “provide overwhelming and indisputable proof that MH370 entered the water in a flaps-extended (down) pilot-controlled ditching”.

The first is the basically “pristine” condition of the recovered flaperon. A similar argument applies to the right outboard flap.

“If the airplane had entered the water in a high-speed diving crash, the entire airplane would have been destroyed in a blink of an eye,’’ he says. “It would have been impossible for the flaperon to have maintained its normal curved shape at its leading edge and to have maintained its normal curvature along its upper and lower edge.’’

He also argues — as he has previously — the damage along the flaperon’s trailing edge could not have occurred in a high-speed crash with the flaps retracted. The erosion damage, he says, is the result of the force of water being directed down and around the extended flaperon as it was pulled through the water during a controlled ditching.

Shattering damage along the trailing edge of the flap is attributed to multiple impacts with waves during a ditching.

Also consistent with controlled ditching, Vance says, is a compression fracture on the end plate of the flap section and a V-shaped black smudge created by “spanwise” forces (forces along the length of the wing).

“Spanwise forces could not have been created in a high-speed crash,’’ he says. “The spanwise crushing forces were created when the right wingtip dug into the water during a pilot-controlled event.’’

The investigator cites V-shaped black smudges he says were created when the severe spanwise forces caused crushing between the outboard end of the flaperon and the endplate as proof the flaps were extended when MH 370 entered the water.

He says this is because it shows the relative positions of the flaperon and the outboard flap when the crushing occurred.

He also argues that damage around the entry hole for the flap support track — the same one mentioned in the ATSB analysis — was caused when the track and the carriage assembly were pulled out of the hole.

“This could only happen if the wing was going forward, while at the same time the flap was being held back,’’ he says “The flap was extended (down) and was being pulled through the water. It is impossible for that scenario to be created in a high-speed diving crash.’’

There are other signs of buckling and gouging Vance says could only have been caused by forces that would have been impossible in a high-speed dive.

He points to a witness mark left by the aft end of the flap support shows the liberated flap was flailing during the landing and moving toward the retracted position, he adds.

“In order for this flap to move “up” in the instant it was liberated, it had to have started in a down (extended) position,’’ he says.

There is also the absence of damage in the seal pan end-plate: Vance says this would have occurred if the flaps were retracted.

He also addresses a range of other issues in the 144-page book, including alternative theories such as an onboard fire and an explosive decompression.

The ATSB has yet to respond to Vance’s various claims but its investigators are understood to be unimpressed by the analysis and angry about aspersions in it. They believe some of Vance’s interpretations of the witness marks, made without examination of the actual debris, are incorrect.

The re-igniting of the long-running debate has led to some scurrilous allegations against the bureau and at least one Senator has promised to grill ATSB officials when they come before a Senate estimates committee on Tuesday.

This will be a good opportunity for the bureau, which is highly respected in the global industry, to put its case and set the record straight.

There have been confident claims the mystery has been solved but that will never be the case until the plane is found — and possibly not even then.

However, finding a readable flight data recorder should at least put an end to the ongoing battle about the controlled ditching debate.