Factual Report Aviation: Fill & Download for Free

TL; DR — Air Canada chose to lay the majority of the blame on Pearson as he was the captain of the flight. This was successfully appealed. However for a good read, keep reading.I'm not a pilot, but as my dad was a pilot for AC at the time and a union representative, I got the union side of things on this accident. I have also read the TSB report.Some location shorthand:YEG — Edmonton International Airport.YUL — Montreal Dorval International Airport at the time, now Pierre Elliott Trudeau International Airport. Trivia: Pierre was Justin Trudeau's father.YOW — Ottawa International Airport.YWG — Winnipeg International Airport.Facts and events before the accident:The aircraft had a manufacturing defect in the fuel quantity indicator system processor. The fault was one the computer was not programmed to handle so the computer blanked the fuel gauge displays.There were no spare processors available.The day before in YEG a maintenance technician discovered that if he disconnected the channel of the processor with the fault (the processor has two channels) the gauges worked. He pulled the relevant breaker, put a tag on it to warn people to leave it pulled and wrote it up in the log book that the aircraft was cleared to fly so long as the fuel gauge readings were confirmed with a manual drip check. (Like checking the oil level in your car.) The aircraft flew to YUL the next day with no problems.After arrival in YUL, a maintenance technician decided to run his own tests on the fuel quantity indicator system. He reset the breaker which caused the gauges to go blank. After completing his tests he was distracted by the arrival of the pilots and the refueller, did not pull the breaker again nor remove the breaker tag. Neither the pilots nor the refueller noticed the breaker was not pulled and as the gauges weren't working as stated in the log book, the blank gauges were not a surprise.Based on the published Minimum Equipment List (MEL) the aircraft was not legal to operate with the gauges blank. When the pilots pointed this out, the maintenance technicians convinced the pilots that the aircraft was cleared to fly by Maintenance Central. (Later during the investigation it was found that this was total baloney.) The pilots acquiesced to the technician’s explanations however Captain Pearson elected to load all the fuel necessary to fly all the way to YEG; normally they would have only loaded enough fuel to fly to YOW. This decision likely prevented a greater tragedy had the aircraft ran out of fuel on approach to YOW and crashed in a populated area.The necessary fuel was calculated for the trip to YEG with a stop in YOW. As others mentioned the AC 767s were calibrated in metric. The fuel load was thus in kilograms. The refueller's truck measured fuel in litres and all of the other aircraft types in AC's fleet at the time measured fuel in pounds. It is not hard to see where this is going. Kerosene weighs 1.77 pounds per litre but only 0.8 kilograms pet litre. Normally the refueller connects the hose, enters the desired total fuel quantity in kilograms into the aircraft's refueling panel and the aircraft quenches its' own thirst. With the computer inoperative, the fueling had to be done manually including the conversion of litres into kilograms. The refueller and the pilots both used 1.77 instead of 0.8 and the aircraft only had 40% of the fuel load required and the same error was made on the manual drip check.The flight left YUL and during the stopover in YOW the tanks were drip checked again and the same math error occurred.Once airborne and enroute from YOW to YEG the stage was set for one of the best feats of airmanship. Here is brief list of events:About halfway to YEG, the pilots get their first indication of trouble — a low fuel pump pressure warning followed by a second.Pearson wasted no time and diverted the flight to YWG. A descent was started and at about 35,000 ft. one engine quit and shortly after that the second one quit as well. Everyone was now in a large glider with no thrust, no electrical power save for the batteries and no hydraulics. The pilots lost their electronic instruments and had to rely on standby instruments. As Captain Pearson put it, he had less instrumentation than a Piper Cub.Fortunately Boeing built in a failsafe — the ram air turbine. This little gizmo popped into the slipstream and its' propeller driven pump provided limited hydraulic pressure for the flight control surfaces. It would not however power the landing gear or flaps.Between the pilots and ATC they worked on gliding to YWG. As this was the days before ‘green dot’ best glide speed indication (all Airbus pilots know about this,) Pearson had to figure out his best guess for a speed that would produce the best range. As a private glider pilot he had experience to draw on.Eventually they figured out they weren't going to make it. ATC offered Gimli, an retired air force base. F/O Quintal, having been based there when he was in the military, knew the field. They headed for Gimli. What they didn't know was that the runways had been converted into a dragstrip.With no hydraulics to lower the landing gear, the gear was lowered by gravity. The mains clunked into place and locked, but because the nose gear swings forward when it drops, the slipstream did not allow it to lock. This would help later.Approaching Gimli, Pearson realized they were too high. Not wanting to risk running out of altitude or stalling while executing a 360º turn, Pearson drew on his glider experience again and executed a maneuver called a forward slip, where the plane is banked in one direction and the rudder applied in the opposite direction. The result is the aircraft maintains its' heading and speed, but descends much more quickly.Just before touchdown Pearson leveled out and flared, but because there were no flaps, at a much higher speed. He touched down 600 ft into the ideal touchdown zone (usually the first 1000 ft of a runway.) Some tires blew from the high speed and when the nose settled, the nose gear collapsed back into the wheel well and the plane slid on its' nose.The pilots noticed some kids on bikes on the runway (remember the runway is now a dragstrip,) and they see a guardrail that had been installed to create the strip racing lanes. He maneuvered using the brakes to rub up against the guardrail and the aircraft managed to stop without hitting anyone.No one was injured during the landing and the aircraft was evacuated using the slides. Because of the nose down attitude, the rear slides were steeper than normal and some passengers were injured sliding down these slides.When the tanks were checked they were dry.The aircraft was patched up enough to be fueled and flown to YWG for repairs and ultimately was returned to service. The Gimli Glider flew until 2008 when it was retired and sent to an aviation boneyard in the Mojave Desert for storage and eventual scrapping.So at what point could all of this been prevented? There were many, these are some:Had there been spare parts on hand.Had the YEG technician documented better.Had the YUL technician not been interrupted and/or returned and pulled the breaker.Had the correct conversion constant been used by 3 people (the pilots and the refuellers) both in YUL and YOW.Had AC ordered its’ 767s with imperial measure.Had AC provided better training on manual refueling procedures for the 767.Had the maintenance technicians not lied to the pilots over the legality of flying the aircraft as it was.Had the pilots refused to operate the flight.As there were so many who made errors along the way, the pilot's union thought it unfair to pin all the blame on Captain Pearson and F/O Quintal. The review board (not the TSB) agreed and their suspensions were overturned.I will also add what one comment mentioned: As I recall my father telling me, Air Canada put six different crews into a 767 simulator and recreated the scenario. None of the six managed to land the aircraft intact. I originally thought the TSB did this, but it was not mentioned in the report. If I'm wrong I'll have to get the memory chips in my head cleaned again.See the TSB's report: https://reports.aviation-safety.net/1983/19830723-0_B762_C-GAUN.pdfIf you don't have the time, here's the Wikipedia entry: Gimli Glider - WikipediaEdit: Wow! 20k views in less than 24 hours. I never thought that 35 years after the fact that the Gimli Glider would still draw such interest. My own is obvious from my father's connection to it and my love of aviation. Thanks for reading!Edit #2: Made some grammatical corrections and some factual changes after re-reading the TSB report to refresh my memory. Also made some readability changes. Thanks again for reading!Edit #3: After some more comments, I've decided to do a Paul Harvey and add the rest of the story. Enjoy and thanks again for reading!

It is too early to answer the question of why a plane that crashed recently did so. Any answer given now would just be wild speculation.Aircraft accidents are investigated by a group of people led by the NTSB (National Transportation Safety Board). The group includes the manufacturer of the aircraft and any other group involved in the accident such as an airline company. I am not sure if military accidents are investigated by the NTSB or the military service involved but the process would be essentially the same.Accident investigations involve collecting all pertinent information and carefully analyzing that information to first determine the facts of the accident and then to determine the probable cause. It usually takes months to assemble a factual report and around a year to reach a conclusion of the probable cause.The bottom line is to learn what caused this aircraft accident we must be patient. It will be determined in approximately the next year and a public report will be issued at that point.Public reports about aircraft accidents include the initial identification of the report which is published within a week or so of the accident, the factual report, and finally the determination of probable cause. All of these reports can be found in the NTSB database here: NTSB Aviation Accident Database & Synopses

Tl;dr — NTSB reports usually turn into roadmaps for follow-on research and investigations that cover the same ground, but only their factual accident reports may be used for legal purposes. Facts are facts; NTSB interpretations of those facts are out of bounds in a courtroom.The rules governing the NTSB and the use of its work products draw a clear distinction between “factual” reports and materials that interpret or analyze factual information. Both of the following definitions come from Part 835 of Title 49, Code of Federal Regulations:“Board accident report means the report containing the Board's determinations, including the probable cause of an accident, issued either as a narrative report or in a computer format (“briefs” of accidents). Pursuant to section 701(e) of the Federal Aviation Act of 1958 (FA Act), and section 304(c) of the Independent Safety Board Act of 1974 (49 U.S.C. 1154(b)) (Safety Act), no part of a Board accident report may be admitted as evidence or used in any suit or action for damages growing out of any matter mentioned in such reports.“Factual accident report means the report containing the results of the investigator's investigation of the accident. The Board does not object to, and there is no statutory bar to, admission in litigation of factual accident reports. In the case of a major investigation, group chairman factual reports are factual accident reports.”So, what’s the real, practical difference between these two similar-sounding products? The simplest and best example I can offer to explain the distinction drawn is to refer to the Air Force’s “safety investigation” and “accident investigation” model. In the U.S. and many other countries, prevention oriented “safety” investigations take priority over all other investigations in terms of controlling and collecting evidence. The relationship between the former and the latter is exemplified by the Air Force approach to serving separate consumers of the same body of knowledge.An Air Force “safety” investigation is conducted to determine what happened as quickly as possible so any immediate threat to readiness (say, the need to ground an entire fleet of aircraft for a previously unrecognized problem) can be remedied as quickly as possible. The safety board gets first dibs on everything related to the aircraft and its crew — maintenance and training records, loading manifests, the results of toxicological testing, physical evidence, etc.Air Force safety investigation boards (SIB) also are allowed to obtain unsworn testimony (i.e., testimony which may not be used against the participant or witness) with a “promise of confidentiality” to understand what happened, who did what, and if perhaps somebody did something they weren’t supposed to or vice versa. The latter is particularly important; if there’s a known issue that requires a specific procedure to be followed and it isn’t, it’s useful to know that up front before wasting time exploring why the procedure didn’t prevent a bad outcome. Similarly, if a pilot did something dumb and admits to it, no time or resources are wasted chasing down various possible mechanical failures that might have led to the observed outcome.According to Air Force Manual 91–223, Aviation Safety Investigations and Reports, “Formal reports present both factual and analytical information for Class A and Class B mishaps. The SIB normally produces a formal safety report with two parts: Part 1, Facts, and Part 2, Board Analysis, Conclusions, and Privileged Material.” SIB reports of aircraft accidents usually contain the following releasable (Part 1) information:Tab A - Safety Investigator InformationTab D - Maintenance Report, Records, and DataTab F - Weather and Environmental Records and DataTab G - Personnel Records (pilot flight and training records, maintenance training records, etc.)Tab H - Egress, Aircrew Flight Equipment (AFE), Impact, and Crashworthiness Analysis (This analysis is accomplished by the AFE member or technical experts and is limited to simply analyzing evidence rather than trying to relate what that evidence might suggest about how the whole sequence of events played out.)Tab I - Deficiency ReportsTab J - Releasable Technical Reports and Engineering Evaluations (Tab J reports are factual and consist of observations (what parts are bent, broken, or burned, etc.), analysis (whether it happened before, during, or after the mishap, and how), conclusions (effect on system function, etc.), and recommendations (methods to prevent the observed condition from re-occurring, etc.). Analysis, conclusions, and recommendations are based on physical evidence, other factual data, and statements made without a promise of confidentiality. They do not include any opinion as to whether or not a particular failure contributed to or caused the mishap.)Tab K - Mission Records and Data (flight plan and flight orders, weight and balance forms, etc.)Tab L - Factual Parametric, Audio, and Video Data from On-board RecordersTab M - Data from Ground Radar and Other SourcesTab N - Transcripts of Voice CommunicationsTab O - Additional Substantiating Data and Reports (think of this as a bibliogrpahy of references used — operating instruction, technical orders, aeronautical charts, etc.)Tab P - Damage Summaries (property losses, clean-up costs, etc.)Tab Q - AIB Transfer Documents (memorandum from SIB President to AIB President regarding the location and disposition of all non-privileged evidence, wreckage, and components involved in the mishap sequence; list of witnesses interviewed by the SIB)Tab R - Releasable Witness Testimony (Testimony from all individuals involved in the mishap and those who were witnesses to the mishap who were not granted a promise of confidentiality.)Tab S - Releasable Photographs, Videos, Diagrams, and Animations (unstaged photos, cockpit diagrams, impact area, route of flight, etc.).Separate from SIBs, Air Force accident investigation boards (AIB) are convened to investigate major mishaps involving loss of life or destruction of/major damage to aircraft, missiles and the like. They follow strict rules regarding the use of evidence and the gathering of testimony.By and large, SIB reports themselves are not releasable to the public, although all of Part I usually appears in its entirety in the subsequent AIB report. The Air Force goes to extreme lengths to keep a firewall between safety investigations and accident investigations, to the point of foregoing the former altogether if the circumstances surrounding a given event are such that significant public interest is expected and accountability demanded as quickly as possible.(Two examples where a safety investigation could have been conducted but wasn’t (and which might have resulted in better “preventive” actions in their respective aftermaths) were the 1994 Black Hawk shootdown incident and the 1996 Croatia USAF CT-43 crash involving the death of Commerce Secretary Ron Brown and thirty-four others. In both cases, a single AIB was convened — the former with Army members, the latter with NTSB support — and all documentation, including testimony was made public upon their completion.)The reason I went into this level of detail is to show that, in the Air Force, two different investigative processes are governed by different rules and have different objectives, but both rely in the same physical and documentary evidence and require access to the same witnesses to function properly. Since the SIB gets everything first, they are obliged to protect the chain of custody of relevant materials; then, having gathered everything they deemed relevant to their investigation, they bundle up all of the factual materials they collected and hand them over to the AIB to help the latter get a running start on their investigation. The AIB may re-interview witnesses or find new ones; they may dig up their own documentary evidence. However, they draw their own fact- and evidence-based conclusions.Now, circle back to the NTSB reports. You should think of the NTSB “board accident reports” as Air Force SIB reports — they blend factual data with interpretations and deliberations on what that factual data tells the NTSB members en banc and their staff about the accident as a whole. On the other hand, NTSB “factual accident reports” are pretty much like Part 1 of an Air Force SIB report, plus anything that’s been placed on the public dockets associated with individual accidents. Like Air Force AIB reports, they’re fair game to use as a starting point for follow-on inquiries by law enforcement, litigants, reporters, or whoever else might have an interest in overlaying their own interpretation on the factual foundation put together from the first moments after the occurrence onward.