Published Date: 2012-02-28
| Postmortem Analysis | |
|---|---|
| Timeline | 1. The software failure incident related to the F-22 Raptor's oxygen system malfunction occurred in November 2010 [Article 10181]. 2. The incident of F-22 Raptor pilots experiencing blackouts due to oxygen system issues happened between October and May [Article 12054]. 3. The Air Force's F-22 Raptor fleet was grounded for four months in 2011 due to incidents of lack of breathable oxygen [Article 78805]. |
| System | 1. On-Board Oxygen-Generation System (OBOGS) [10181, 10181] 2. Oxygen-supply systems [12054] 3. Oxygen-distribution system [78805] |
| Responsible Organization | 1. The software failure incident in the F-22 Raptor stealth fighters was caused by a malfunction in the planes' oxygen-generation systems, specifically a leak in the cooling system that blocked air from reaching the pilots [Article 10181]. 2. The faulty oxygen-supply systems in various aircraft, including the F-22 Raptor, were identified as a major cause of physiological symptoms experienced by pilots midair, leading to hypoxia and decompression sickness [Article 78805]. |
| Impacted Organization | 1. The United States Air Force [5720, 12054, 78805, 10181] |
| Software Causes | 1. The failure incident with the F-22 Raptor stealth fighters was primarily caused by a malfunction in the planes' oxygen-generation systems, specifically a leak in the cooling system that allowed cooling fluid to enter the oxygen system, blocking air from reaching the pilots [10181]. 2. Another potential software cause was an interaction between contaminants and the materials in the On-Board Oxygen-Generation System (OBOGS) that the service had yet to uncover [10181]. |
| Non-software Causes | 1. Faulty oxygen-supply systems in the F-22 Raptor stealth fighters [12054, 78805] 2. Cooling system leak in the F-22 Raptor [10181] 3. Interaction between contaminants and materials in the On-Board Oxygen-Generation System (OBOGS) [10181] 4. Problem with a valve connecting the oxygen system to the pilot's mask [10181] 5. Toxic nitrogen as a possible culprit [10181] |
| Impacts | 1. The F-22 Raptor fleet was grounded multiple times due to oxygen system malfunctions, leading to limitations on flying altitudes and routine patrols being forbidden [5720, 12054, 10181]. 2. Pilots reported experiencing hypoxia and decompression sickness, with some even blacking out or becoming disoriented mid-air, leading to concerns for their safety and lives [5720, 12054, 10181]. 3. The grounding of the F-22 Raptors impacted the Air Force's dogfighting fleet, cutting it in half and affecting operational capabilities [5720]. 4. The incidents raised concerns about the reliability and safety of the F-22 Raptor and its oxygen system, leading to investigations and attempts to address the issues [5720, 12054, 10181]. 5. The failures and malfunctions in the F-22 Raptor's oxygen system resulted in a fatal crash in Alaska, highlighting the serious consequences of the software failure incident [12054, 10181]. |
| Preventions | 1. Implementing regular inspections and maintenance of the oxygen-supply systems in the aircraft to prevent wear and contamination, as recommended by Navy officials [Article 78805]. 2. Developing sensors and alarms in the oxygen systems to alert pilots of issues like insufficient oxygen or particle contamination, as done in the redesigned oxygen concentrators for the T-6 trainer aircraft by the Air Force [Article 78805]. 3. Addressing potential leaks in the cooling system that could block air from reaching pilots, as identified by investigators looking into the F-22 Raptor's oxygen-generation system [Article 10181]. 4. Ensuring proper functioning of the valve connecting the oxygen system to the pilot's mask to provide adequate warning and response time in case of issues [Article 10181]. |
| Fixes | 1. Replacing faulty oxygen-supply systems with new hardware and software in the T-6 Texan trainer aircraft by early 2019 [Article 78805]. 2. Equipping every Raptor pilot with a heartbeat monitor and installing an extra charcoal filter in the oxygen generator (although the charcoal filters were later found to be faulty and removed) [Article 12054]. 3. Investigating and addressing a leak in the Raptor's cooling system, which was blocking air from getting to pilots [Article 10181]. | References | 1. Article 5720 gathers information about the software failure incident from the U.S. Air Force and various Air Force officials. 2. Article 12054 gathers information about the software failure incident from Maj. Jeremy Gordon, Capt. Josh Wilson, Rep. Adam Kinzinger, and Air Force doctors. 3. Article 78805 gathers information about the software failure incident from officials from the United States Air Force and Navy, Lt. Gen. Mark Nowland, Representative Michael R. Turner, and Brig. Gen. Edward L. Vaughan. 4. Article 10181 gathers information about the software failure incident from Lt. Gen Herbert "Hawk" Carlisle, the Air Force Scientific Advisory Board, and investigators from the Air Force. |
| Category | Option | Rationale |
|---|---|---|
| Recurring | one_organization, multiple_organization | (a) In the case of one_organization, the F-22 Raptor stealth fighters experienced a software failure incident related to their faulty oxygen systems causing pilots to experience adverse physiological symptoms midair. This incident has happened multiple times within the same organization, specifically with the F-22 Raptor fleet. The incidents included problems with the On-Board Oxygen-Generation System (OBOGS) leading to hypoxia and decompression sickness, as well as issues with the oxygen supply system [10181, 12054]. (b) Regarding multiple_organization, similar incidents related to oxygen-deprivation and cockpit-pressurization problems have affected various aircraft in both the Air Force and Navy, including the F-35A Joint Strike Fighter, the A-10 Thunderbolt, the T-45 Goshawk trainer, and the F/A-18 Hornet. These incidents have been reported across different organizations within the military, indicating a broader issue affecting multiple aircraft types and services [78805]. |
| Phase (Design/Operation) | design, operation | (a) In Article 10181, it was reported that the F-22 Raptor stealth fighters had a major problem with their oxygen-generation systems, specifically a leak in the cooling system that was blocking air from reaching the pilots. This issue was identified as a contributing factor introduced during the design phase of the system development [10181]. (b) In Article 12054, it was highlighted that the F-22 Raptor pilots were experiencing adverse physiological symptoms midair due to faulty oxygen systems, leading to blackouts and confusion. The pilots reported feeling disoriented and having difficulty concentrating during flights, indicating a failure related to the operation or misuse of the system [12054]. |
| Boundary (Internal/External) | within_system, outside_system | (a) within_system: - The software failure incident related to the F-22 Raptor stealth fighters' faulty oxygen systems causing pilots to experience adverse physiological symptoms midair is primarily a within_system failure. The issue was traced back to a leak in the Raptor's cooling system, which allowed cooling fluid to enter the oxygen system, blocking air from reaching the pilots [10181]. - The Air Force had been studying the problem for months and identified a defect in the On-Board Oxygen-Generation System (OBOGS) as a likely cause of the issue, leading to hypoxia and decompression sickness [10181]. (b) outside_system: - The physiological symptoms experienced by pilots, such as hypoxia, were caused by factors originating from outside the system, such as fluctuating concentrations of oxygen tied to the oxygen-distribution system [78805]. - The article mentions that the Navy and Air Force are replacing faulty oxygen-supply systems with new hardware and software in their T-6 Texan trainer aircraft to address the issue of hypoxia, which indicates that the failure was influenced by factors external to the system [78805]. |
| Nature (Human/Non-human) | non-human_actions, human_actions | (a) The software failure incident occurring due to non-human actions: - The F-22 Raptor stealth fighters experienced a major problem with their oxygen-generation systems, leading to pilots being unable to breathe. Investigations revealed a leak in the Raptor's cooling system, where cooling fluid was getting into the oxygen system, blocking air from reaching the pilots [Article 10181]. - The Air Force and Navy faced issues with oxygen-deprivation and cockpit-pressurization problems in various aircraft, including the F-22 Raptor, F-35A Joint Strike Fighter, A-10 Thunderbolt, T-45 Goshawk trainer, and F/A-18 Hornet. The physiological symptoms experienced by pilots were attributed to fluctuating concentrations of oxygen tied to the oxygen-distribution system and uncontrolled cockpit-pressurization changes [Article 78805]. (b) The software failure incident occurring due to human actions: - The Air Force faced criticism for not resolving the oxygen system issues in the F-22 Raptor, despite pilots experiencing blackouts and confusion mid-air. Some pilots refused to fly the aircraft due to safety concerns, and the Air Force threatened to fire any pilot who refused to fly for safety reasons [Article 12054]. - The Air Force admitted that the F-22 Raptor's oxygen system issues were likely due to a defect in the On-Board Oxygen-Generation System (OBOGS). Investigators also pointed towards a possible interaction between contaminants and materials in the OBOGS, as well as a problem with a valve connecting the oxygen system to the pilot's mask [Article 10181]. |
| Dimension (Hardware/Software) | hardware, software | (a) The software failure incident occurring due to hardware: - Article 10181 reports on a software failure incident related to the F-22 Raptor stealth fighters where investigators found a leak in the Raptor's cooling system, which was causing cooling fluid to get into the oxygen system, blocking air from reaching pilots. This hardware issue was contributing to the software failure incident [10181]. (b) The software failure incident occurring due to software: - Article 10181 also mentions that there may be an interaction between contaminants and the materials in the On-Board Oxygen-Generation System (OBOGS) that the service has yet to uncover, indicating a software-related issue contributing to the failure incident [10181]. |
| Objective (Malicious/Non-malicious) | non-malicious | (a) The articles do not mention any malicious software failure incidents where the failure was due to contributing factors introduced by humans with the intent to harm the system. (b) Non-malicious software failure incidents are evident in the articles related to the F-22 Raptor stealth fighters. The failures were primarily attributed to issues with the oxygen systems, including malfunctions in the oxygen-supply systems, leaks in the cooling system affecting air supply to pilots, defects in the On-Board Oxygen-Generation System (OBOGS), and problems with the valve connecting the oxygen system to the pilot's mask [5720, 12054, 10181]. These failures were not intentional but rather resulted from technical issues and design flaws in the aircraft's systems. |
| Intent (Poor/Accidental Decisions) | poor_decisions, accidental_decisions | (a) The software failure incident related to the F-22 Raptor stealth fighters' faulty oxygen systems and the resulting physiological symptoms experienced by pilots can be attributed to poor decisions made by the Air Force. Despite evidence of oxygen deprivation and multiple incidents of blackouts or near-blackouts among pilots, the Air Force ordered its pilots to keep flying the jets [Article 12054]. The Air Force also faced criticism for its lack of progress in addressing the physiological issues affecting pilots, with lawmakers expressing disappointment in the handling of the situation [Article 78805]. (b) The software failure incident involving the F-22 Raptor's oxygen-generation system issues, which led to two fleet-wide groundings and potential pilot fatalities, can be linked to accidental decisions or unintended consequences. Investigators discovered a leak in the Raptor's cooling system that was blocking air from reaching pilots, along with potential interactions between contaminants and materials in the On-Board Oxygen-Generation System (OBOGS) [Article 10181]. Additionally, problems with the valve connecting the oxygen system to the pilot's mask were identified, potentially leading to inadequate warnings or response time for pilots [Article 10181]. |
| Capability (Incompetence/Accidental) | development_incompetence | (a) The software failure incident occurring due to development incompetence: - The F-22 Raptor stealth fighters experienced issues with their oxygen-generation systems, leading to pilots facing hypoxia and decompression sickness [5720]. - The Air Force struggled to identify the exact cause of the problem, with investigators pinpointing a leak in the Raptor's cooling system that was blocking air from reaching pilots [10181]. - The Air Force admitted that there was no definitive cause identified for the incidents related to the oxygen system malfunctions [12054]. (b) The software failure incident occurring accidentally: - The Air Force and Navy faced challenges with oxygen-deprivation and cockpit-pressurization problems in various aircraft, including the F-22 Raptor and F-35A Joint Strike Fighter, for at least a decade [78805]. - The source of the physiological symptoms experienced by pilots was initially a mystery, with no single root cause identified across different airframes or within specific airframes [78805]. - The Air Force and Navy have been working to replace faulty oxygen-supply systems with new hardware and software in their T-6 Texan trainer aircraft to address the ongoing physiological issues faced by pilots [78805]. |
| Duration | permanent, temporary | (a) The software failure incident related to the F-22 Raptor's oxygen system malfunctions can be considered as a permanent failure. The issues with the F-22's On-Board Oxygen-Generation System (OBOGS) have persisted over the years, leading to multiple groundings of the fleet [5720, 10181]. Despite efforts to address the problems, such as adding backup oxygen systems and conducting investigations, the root cause of the oxygen system malfunctions remained elusive, indicating a persistent and ongoing software failure [10181]. (b) The software failure incident can also be seen as a temporary failure due to specific circumstances. For example, the Air Force and Navy have been working on replacing faulty oxygen-supply systems with new hardware and software in their T-6 Texan trainer aircraft by early 2019 [78805]. This suggests that the issue with the oxygen systems in these specific aircraft is being addressed with a planned solution, indicating a temporary nature of the failure in those particular systems. |
| Behaviour | crash, omission | (a) crash: - Article 10181 reports on a software failure incident related to a crash where the system lost state and did not perform its intended functions. The F-22 Raptors experienced issues with their On-Board Oxygen-Generation System (OBOGS), leading to hypoxia and decompression sickness, potentially causing blackouts and crashes [10181]. - Article 5720 mentions that two Raptors have crashed since the jet entered service in 2005, indicating a crash-related software failure incident [5720]. (b) omission: - Article 10181 discusses a software failure incident related to omission, where the system omitted to perform its intended functions at an instance(s). The cooling fluid leak in the F-22 Raptors' oxygen system blocked air from reaching pilots, leading to hypoxia and decompression sickness [10181]. (c) timing: - There is no specific information in the articles that directly relates to a software failure incident due to timing issues. (d) value: - There is no specific information in the articles that directly relates to a software failure incident due to the system performing its intended functions incorrectly. (e) byzantine: - There is no specific information in the articles that directly relates to a software failure incident due to the system behaving erroneously with inconsistent responses and interactions. (f) other: - The articles do not provide information on a software failure incident related to other behaviors not covered in options (a) to (e). |
| Layer | Option | Rationale |
|---|---|---|
| Perception | None | None |
| Communication | None | None |
| Application | None | None |
| Category | Option | Rationale |
|---|---|---|
| Consequence | death, harm | (a) death: The consequence of the software failure incident was the death of Capt. Jeffrey Haney in a crash in Alaska in 2010, which was attributed to hypoxia and decompression sickness caused by a malfunction in the F-22 Raptor's On-Board Oxygen-Generation System (OBOGS) [10181]. |
| Domain | information, government | (a) The failed system was intended to support the production and distribution of information. The F-22 Raptor fighters experienced software failures related to their oxygen systems, leading to issues such as hypoxia and decompression sickness for pilots [5720, 12054, 10181]. (l) The failed system was also related to the government industry, specifically the U.S. Air Force. The F-22 Raptor is a military aircraft, and the software failures in its oxygen systems led to grounding of the fleet and concerns about pilot safety [5720, 12054, 10181]. (m) The failed system could be categorized under the defense industry, as it directly impacted the operational capabilities of the U.S. Air Force's fleet of F-22 Raptor fighters [5720, 12054, 10181]. |
Article ID: 5720
Article ID: 12054
Article ID: 78805
Article ID: 10181