MH370: Fire / Decompression theory

©Simon Gunson for VT

Journalist Florence de Changy recently invited me to set out my Electrical Fire/Decompression theory for her upcoming book. Now that the ATSB report of 3 December 2015 reaffirms MH370’s flight ended with double engine flame out, hypoxic flight south must be considered. This also invalidates any detour through the Straits of Malacca and dramatically extends fuel endurance further south

Were it true that MH370 had made a turn west from Penang and another south around Sumatra, then hijacking or suicide could be a logical conclusion, but the evidence for these claims is now rejected by fresh evidence. A hypoxic jet with unconscious crew can’t make intricate turns

ATSB’s report suggests MH370 suffered an electrical fault which disabled both ACARS and Mode S Transponder. This appears to have happened not at IGARI but further north at BITOD where Vietnamese SSR radar last spotted MH370. It seems the pilots Zaharie and Farriq both knew they had a communications problem and tried to establish VHF voice contact around 17:30 UTC as detected by Japan Airlines Flight JAL750.

MH370 had to be commanded by autopilot to turn back on a heading for Kuala Lumpur in a conscious decision. Flightaware’s ADS-B receiver network detected MH370’s transponder one last time at 06:9298N, 103.5901E. This location was 21nm north of IGARI and was not along the flight path to BITOD, so therefore was not some sort of simple error repeating MH370’s earlier location. This detection happened at 17:50 UTC . Logically the timeline suggests MH370 turned back from Vietnam at 17:35 UTC near  08:11N, 104.32E at 35,000ft. At this location MH370 was theoretically just visible from Songa Mercur oil rig, where Mike J McKay spotted a distant aircraft on fire.

Based on a hastily abandoned statement made to China Times’ Taiwanese journalist Wu Kwei Fung by the US Embassy in Kuala Lumpur, I believe a distress call was detected from MH370 at 17:43 UTC declaring an intention to make an emergency landing because their cabin faced disintegration.

Although Malaysian Police subsequently distorted the timeline, original reports by eight people of a frightening loud noise east of Marang Beach seem to describe a howling sound possibly as pressurised air escaped from MH370 at 17:45 UTC.

Logic suggests an electrical fault developed in the Honeywell Mark III Communications Management Unit (CMU). This processor converts 8-bit data from on-board instruments into TCIP streaming data protocol for transmission by both the ADS-B transponder and by the ACARS system. ACARS usually consists of the #3 digital VHF radio slaved to the CMU controlling it via the pilot’s CPDLC. Fire in the CMU would prevent further data being transmitted but would not destroy the #3 VHF radio. This it appears  permitted ACARS to keep working later in a passive sleep mode.

An analogy we can all understand is like a cell phone left switched on, but not sending any messages, just acknowledging signals sent from a cell tower. This is the same mode ACARS was in after 18:25.

Basis for suspecting the CMU processor is its pivotal relationship to other devices operating on the same left AC power relay. ATSB report dated 26 June 2014, at page 34 describing evidence for a hypoxic flight states:

“Given these observations, the final stages of the unresponsive crew/ hypoxia event type appeared to best fit the available evidence for the final period of MH370’s flight when it was heading in a generally southerly direction:”

Furthermore the ATSB report dated 3 December 2015 page 8 refers to events prior to 18:25 UTC:

“If power from the left IDG was lost then a bus tie breaker would close connecting the left and right AC buses allowing the right IDG to power both. Similarly, if power was lost from the right AC bus then the left AC bus would supply power to both. This power switching is brief and the SDU was designed to remain operational during such power interruptions. To experience a power interruption long enough to generate a log-on request, a loss of both AC buses, or a disabling of the automatic switching would be required.”

The SDU (satellite tracking antennae), CMU, ACARS & Transponder all draw power from the Left AC bus Relay. Of these four devices mentioned, the transponder came back online at 17:50 UTC when MH370 was detected again briefly at FL350, 06.9298N, 103.5901E (source Flightaware ADS-B network). Presumably therefore the transponder did not cause this power outage. We know the SDU kept working after 18:25. We know that ACARS resumed working at 18:25. That leaves only one device which did not resume function at 18:25. ACARS did not stop working. It did however stop transmitting onboard data.

Not only that but the airline tried to place three Sat Phone calls to MH370 via an ACARS channel. Each phone call goes through a self test boot up protocol before the call is established. During this call both at 18:29 and later at 23:13 MH370 returned an error code for Power management failure in the forward relay to the cockpit.

This seems irrefutable proof there was a catastrophic electrical failure caused by the CMU.

Events suggest there was a fire leading to decompression, that it was extreme, intense and fast. In less than a minute it seems heat melted a small hole in the skin of the airliner. Pilots would have been preoccupied trying to isolate electrical power to the fire. It is probable they silenced the master caution alarm so they could think and this would have prevented a second alarm to warn them of decompression.

If so, then they were not aware of decompression and failed to react appropriately donning oxygen masks. The irony of this scenario is they could have survived decompression and the fire would have self extinguished at 35,000ft from lack of oxygen.

One lesson may emerge from this is that a decompression alert must rise above confusion in the cockpit and override all other alarms. Perhaps it should be an oral warning like the “Terrain, Terrain, Pull-Up”alert pilots get when too low, so that crews are told what to do?

At 35,000ft it would have taken just 30 seconds for pilots to lapse into unconsciousness. Passengers at the rear would have had oxygen masks drop automatically, so others in the cabin may have remained conscious. Ambient Temperature above the Gulf of Thailand would have plummeted to minus 44 degrees Celsius inside the cabin.

Evacuation of pressurised air would have robbed any fire of oxygen and therefore self extinguished. The crew may also have successfully isolated components at the seat of the fire before they were incapacitated. The Boeing 777 however is also designed to automatically repair and re-route electrical functions without human intervention. As long as the autopilot kept functioning, MH370 would have kept flying.

Assuming damage was minor and the autopilot remained operable, MH370 would have simply continued flying towards Kuala Lumpur. Upon crossing over the last co-ordinates it was given, the autopilot would simply continue to fly the same magnetic heading it had previously.

This scenario conflicts with alleged turns and flight west through the Straits of Malacca, or the so called major turn south around the western tip of Sumatra. In fact according to my scenario MH370 likely crossed Sumatra somewhere near Dumai.

Electrical failure in the cockpit raises serious questions about Malaysian radar claims. Many Malaysian Air Force radar sightings were highly improbable & contradictory. For example one that military radar saw MH370 climb to 45,000ft above IGARI before diving west below radar detection. JACC Chairman Air Marshal (ret) Angus Houston declared on 24 June 2014 that examination of radar data by two Thales Raytheon radar engineers had discounted this sighting.

An alleged military radar image shown to next of kin at the Lido Hotel on 21 March 2014 presented by Malaysian Government officials was also dismissed as untrue by the ATSB report of 3rd December 2015. Before this was dismissed, it was obvious the timelines from that image clashed with timelines of radar sightings disclosed in the interim report of 8th March 2015 entitled “Factual Information”.
More importantly when ACARS contact with INMARSAT resumed at 18:25 UTC, the BTO (signal delay distance from satellite) and BFO (Doppler) values for MH370 also clashed with alleged radar data. The BTO distance from the satellite at 18:25 UTC was just 275nm from IGARI when radar data suggested it should have been at least 437nm from IGARI.

BTO values just three minutes later at 18:28 UTC infer MH370 suddenly leapt westwards at more than 5,000 mph (Mach 6.6). For the same period the Doppler values (BFO) were reducing when they should have been increasing. This inferred MH370 was flying away from the satellite when BTO values showed the opposite. Clearly there was some massive electrical disruption on board MH370.

it appears fire caused ACARS to stop transmitting data around 17:27 UTC and it did not log back on again until 18:25 long after the decompression when electrical components cooled to a functional temperature. However intense cold may have caused a reduction in BTO transmission delay by reducing electrical resistance inside MH370’s circuitry. For this reason all BTO values after 18:25 were falsely displaced closer towards INMARSAT.

For much the same reason the so called 7th Arc may not be correctly located in the Southern Indian Ocean. This point was raised with ATSB Commissioner Martin Dolan in July 2014, but he was dismissive of such an error. More than a year later however, a $180 million search has failed to locate MH370 on the seabed where ATSB were confident it should be.  Should not more reliance have been placed on a huge trail of floating debris spotted by multiple satellites between 16-25 March 2014?

Northern most of these, two objects, each the size of Boeing 777 wings was 425nm south from the southern end of the seabed search zone.China reverse calculated the drift of objects sighted up to 20 March back to a likely impact on 8th March 2014. China concluded MH370 impacted along an axis between 45.30S, 85.30E and 43.40S, 88.30E within a radius 200-300km from that axis. Before all funding runs out, shouldn’t ATSB shift its search south where China identified in the first place?
Facts suggest MH370’s flight south was hypoxic with an unconscious crew. Upon fuel exhaustion first one engine died and then another. When the first engine died MH370 started to bleed off speed began gradually to lose altitude and then went into a shallow banking turn. As the second engine died MH370 dropped more aggressively into a spiral dive which continued to steepen until MH370 began to exceed safe structural speed (VNE).

During this descent MH370 would have begun to break up. From Flaperon evidence and satellite imagery of two wing sized floating objects it is likely that both main wings separated from the fuselage in mid-air. After impact with the sea it is hard to tell if the tail section housing the flight data recorders sank immediately or drifted down current for some days before sinking?

To find the Black boxes they must first find the wreckage, then follow the debris trail.

The lack of crush damage to the leading edge of the Flaperon presents a dilemma to investigators. Had MH370 ditched in a controlled manner then the Flaperon’s location behind the engine and its pylon would guarantee it would be crushed. In some manner the Flaperon must have impacted the sea at relatively low speed. There is evidence of torsional damage at the inboard hinge, but the maturity of barnacle growth suggests it remained attached to the Right wing and held beneath the surface for weeks or even months.

Possibly the entire Right wing which Reunion Island’s Flaperon was attached to separated from the fuselage in a break up, then fluttered down like a sycamore seed. This explains the lack of crush damage along the Flaperon’s leading edge.

Possibly the Flaperon remained semi attached to the right wing after impact with the sea, before breaking free due to wave actions. The Flaperon does however show signs of a torsional separation at the inboard hinge. I believe it was partially detached from the wing at impact with the sea, but the impact had relatively low forward speed. I further believe after several days, or weeks the Flaperon finally parted due to the action of waves. The Right wing sunk leaving the Flaperon free to drift north and then west taking a different path from the main debris field.

The flaperon being more buoyant was likely influenced more by wind than swell or ocean currents therefore perhaps followed a different path.

I believe owing to greater positive buoyancy the Flaperon’s drift pattern was not characteristic of other floating debris, which may have sunk after just a few weeks. I believe other wing surfaces with honeycomb construction & similar positive buoyancy, perhaps remained attached to the right wing and sank with that wing.

MH370 is a huge puzzle, but investigators have not interpreted the clues correctly because they discarded so many clues too early and rigidly predetermined the evidence.  In particular the JIT Committee in Malaysia has incorrectly assumed MH370 made a detour west through the Straits due to misleading radar sightings. Through fuel endurance calculations this has prevented the investigation considering floating debris spotted by satellite in March 2014.

I posted my scenario because I am often misquoted by people who only hear fragments of what I suggest happened. This is a plausible alternative explanation to suicide or hijacking.

Simon Gunson ([email protected])