The shorted wiring/unlatch motor on/ruptured open forward cargo door/explosive decompression/inflight breakup explanation for AI 182, PA 103, UAL 811, TWA 800. The manufacturing installation of faulty wiring needs to be replaced and the design flaws of omitted midspan locking sectors and non plug cargo doors needs to be corrected.
These Smith AARs and this website are the work of John Barry Smith, an independent aircraft accident investigator not affiliated with any government agency, or regulatory departments, or law enforcement, or attorneys, or manufacturer, or airlines, or publishers, or unions, or media.
John Barry Smith has over fifty years experience in many aspects of aviation and loves airplanes more than most, in particular, the Boeing 747 and its models. The 747 is a magnificent aircraft which has proven itself over the decades to become a truly classic aircraft.
The typical pattern in aviation progress has been to imagine the aircraft, create it in writing, build it with materials, test it by flying, break it by time, find the problem, fix it, fly it, break it, find the problem, fix it, fly it…..
There have been a few aircraft types which have had fatal manufacturing defects and design flaws which were not fixed or modified. Those models did not sell well and were discontinued due to poor sales. The manufacture and export of commercial airliners is a major source of revenue for the business of Boeing and for the USA. Safe airplanes sell better than ones which have accidents from mysterious or controversial causes. All the probable causes can’t be anticipated or fixed but some can and it is the duty of the manufacturer to do so.
There is much pressure on the manufacturer of the aircraft, the airlines that fly them, and the government that oversees them to deny that serious problems exist in accident aircraft and succumb to the temptation to blame others and hope for the best.
There are no conspiracies in the mechanical explanation of shorting wiring causing a cargo door to open in flight. There are no bombs, no bombers, and no agencies conspiring to hide the mechanical explanation. There are just individuals who are acting in their own perceived best interests, mistaken as they are.
The early model Boeing 747s, −100 and - 200, have a manufacturing defect in that faulty wiring, Poly-X type, was installed. The wiring insulation was prone to cracking and chafing and exposing bare wire especially in the presence of moisture. When the bare wires shorted the sparks caused fires which were not uncommon events. Later models, −300 and −400 used a different type of wire.
There is a specific design flaw in the two large main cargo doors of all Boeing 747s; the two midspan latches do not have locking sectors while the bottom eight latches do. These locking sectors are very important to prevent the door latches from being backdriven inadvertently leading to the accidental opening of the cargo door and the catastrophic explosive decompression which follows if at altitude.
There is a general design flaw in all Boeing 747s and indeed in the many thousands of airliners in service today: Non-plug cargo doors. As the aircraft climbs and the pressure differential inside cargo bay and the outside air becomes greater, the force exerted on the doors increases and yet there are only the ten latches and a hinge holding the almost ten foot square door closed. The passenger doors are plug type which means as the pressure differential increases the door becomes harder, if not impossible to open.
All airliners should have plug type doors on all the doors so that they become almost impossible to open in flight regardless of the status of the latches. The seal becomes tighter not looser, as the aircraft climbs to cruising altitude when the door is plug type. With new lighter stronger composite materials available, new cargo doors can be made and installed which will be a vast improvement in strength and safety when designed to also be plug type.
For one Boeing 747-100, the faulty wiring exploited the two design flaws and caused the deaths of nine passengers and almost killing several hundred: UAL Flight 811. It was eventually determined, after first believing a bomb had caused the event, and later an improper door latching by ground crew, that a failed electrical switch or faulty wiring caused the forward cargo door to open in flight causing an explosive decompression. That open cargo door event for UAL Flight 811 left much evidence in the form of cockpit voice recorder data, twisted metal, paint smears, damaged engines, broken cargo door, missing latches, and damage to the fuselage.
It is the belief of John Barry Smith that there are at least three other early model Boeing 747 fatal accidents which were caused by the same reasons: Faulty wiring exploiting design flaws. The causes for those other three are officially given as bomb or center fuel tank explosion.
The evidence from the indisputable, irrefutable event of UAL Flight 811 matches TWA Flight 800, Pan Am Flight 103, and Air India Flight 182 so closely that the one clear cause of one, electrical, is the cause for all.
When a rational, reasonable alternative explanation with support documentation and precedent exists for controversial aircraft accidents, it is the duty of the manufacturer, the airline, and the government to examine and consider such an explanation. Such an explanation is the shorted wiring/unlatch motor on/ruptured open forward cargo door/explosive decompression/inflight breakup explanation for TWA Flight 800, Pan Am Flight 103, and Air India Flight 182.
This website presents that evidence.