Defect Investigation of Seat Ejection Cartridge for Operating Seat Ejection Mechanism for the Aircraft Applications

Defect Investigation of Seat Ejection Cartridge for Operating Seat Ejection Mechanism for the Aircraft Applications | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Defect Investigation of Seat Ejection Cartridge for Operating Seat Ejection Mechanism for the Aircraft Applications Bhupesh A Parate This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8995276/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 9 You are reading this latest preprint version Abstract This manuscript presents a detailed defect investigation observed in metallic brass cartridge cases used in seat ejection system for fighter aircraft applications. These cartridge cases play a vital role in propelling the ejection seat and pilot safely from a disabled aircraft. The objective of this research study was to identify the underlying factors responsible for occurrence of cracks observed on the cup portion of cartridge cases, particularly those stored under magazine conditions. The findings indicated that the observed defects were primarily associated with factors such as deviation from the prescribed annealing process, elevated zinc content, and excessive hardness. Additionally, the presence of residual stresses induced by cold working was identified as a major contributor, emphasizing the necessity for adequate stress-relief treatment to prevent ageing-induced cracking. The investigation concluded that the failures were attributed to Stress Corrosion Cracking (SCC), a critical degradation mechanism impacting the reliability and safety of brass cartridge cases. The recommendations provided by the technical committee were subsequently incorporated into the engineering drawings and manufacturing specifications to mitigate recurrence. This paper further examines the phenomenon of SCC in brass, highlighting the conditions that promote crack initiation and propagation. It also reviews historical cases, experimental results, and preventive measures, providing insights into the material behavior and environmental factors influencing SCC. Finally, practical solutions for mitigating SCC in seat ejection cartridges are proposed to enhance operational safety and extend service life. defect investigation failures seat ejection cartridge stress corrosion cracking Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Reviews received at journal 10 May, 2026 Reviewers agreed at journal 01 May, 2026 Reviewers agreed at journal 30 Apr, 2026 Reviews received at journal 30 Apr, 2026 Reviewers agreed at journal 29 Apr, 2026 Reviewers invited by journal 29 Apr, 2026 Editor assigned by journal 24 Apr, 2026 Submission checks completed at journal 08 Mar, 2026 First submitted to journal 28 Feb, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8995276","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":633001339,"identity":"cac088fb-0603-4e21-9eaf-ec03bb8e23a4","order_by":0,"name":"Bhupesh A Parate","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA00lEQVRIiWNgGAWjYBACAxiDH0QkFBCvxYBBsgGkxQCfWnQtBgdQLMUDzNnPHvxcUfNHzvj86sQPDwwY5PnFDuDXYtmTlyx55piBsdmNt5slgA4znDk7gYDDDuQYSDawGSRuu3F2A0hLgsFtQlrOvzH+2fDPoH7zjLObfxCn5UaOmWRjm0GCAX/vNuJssZzxLs2ysc/YcMYN3m0WCQYShP1izp97+GbDNzl5/v6zm2/+qLCR55cmoIWBgQdKS4BVShBSjqyF/wAxqkfBKBgFo2AkAgC1WkUQlbGt7AAAAABJRU5ErkJggg==","orcid":"","institution":"Armament Research \u0026 Development Establishment (ARDE)","correspondingAuthor":true,"prefix":"","firstName":"Bhupesh","middleName":"A","lastName":"Parate","suffix":""}],"badges":[],"createdAt":"2026-02-28 12:24:33","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8995276/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8995276/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":108807560,"identity":"d09718a9-eb12-4132-aac1-ec261af9d16a","added_by":"auto","created_at":"2026-05-08 15:30:39","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1268672,"visible":true,"origin":"","legend":"","description":"","filename":"DISECPAPER.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8995276/v1_covered_8e734a5f-71ab-4c1a-86dd-fdf0faa2cc41.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Defect Investigation of Seat Ejection Cartridge for Operating Seat Ejection Mechanism for the Aircraft Applications","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"propulsion-and-energy","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"Learn more about [Propulsion and Energy](https://link.springer.com/journal/44270)","snPcode":"44270","submissionUrl":"https://submission.springernature.com/new-submission/44270/3","title":"Propulsion and Energy","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Open","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"defect investigation, failures, seat ejection cartridge, stress corrosion cracking","lastPublishedDoi":"10.21203/rs.3.rs-8995276/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8995276/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis manuscript presents a detailed defect investigation observed in metallic brass cartridge cases used in seat ejection system for fighter aircraft applications. These cartridge cases play a vital role in propelling the ejection seat and pilot safely from a disabled aircraft. The objective of this research study was to identify the underlying factors responsible for occurrence of cracks observed on the cup portion of cartridge cases, particularly those stored under magazine conditions. The findings indicated that the observed defects were primarily associated with factors such as deviation from the prescribed annealing process, elevated zinc content, and excessive hardness. Additionally, the presence of residual stresses induced by cold working was identified as a major contributor, emphasizing the necessity for adequate stress-relief treatment to prevent ageing-induced cracking. The investigation concluded that the failures were attributed to Stress Corrosion Cracking (SCC), a critical degradation mechanism impacting the reliability and safety of brass cartridge cases. The recommendations provided by the technical committee were subsequently incorporated into the engineering drawings and manufacturing specifications to mitigate recurrence. This paper further examines the phenomenon of SCC in brass, highlighting the conditions that promote crack initiation and propagation. It also reviews historical cases, experimental results, and preventive measures, providing insights into the material behavior and environmental factors influencing SCC. Finally, practical solutions for mitigating SCC in seat ejection cartridges are proposed to enhance operational safety and extend service life.\u003c/p\u003e","manuscriptTitle":"Defect Investigation of Seat Ejection Cartridge for Operating Seat Ejection Mechanism for the Aircraft Applications","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-05-08 11:52:18","doi":"10.21203/rs.3.rs-8995276/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2026-05-11T02:24:48+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"307954577577811844123003771543369504432","date":"2026-05-01T10:56:43+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"108750426911896634243620665509122207134","date":"2026-04-30T17:20:26+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-30T07:37:45+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"209633974252505467762907353456116442482","date":"2026-04-30T02:47:56+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-04-29T10:29:24+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-04-24T08:26:07+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-03-08T15:34:01+00:00","index":"","fulltext":""},{"type":"submitted","content":"Propulsion and Energy","date":"2026-02-28T12:11:43+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"propulsion-and-energy","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"Learn more about [Propulsion and Energy](https://link.springer.com/journal/44270)","snPcode":"44270","submissionUrl":"https://submission.springernature.com/new-submission/44270/3","title":"Propulsion and Energy","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Open","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"767c1fb1-4a96-42c4-8c92-f6667adbb381","owner":[],"postedDate":"May 8th, 2026","published":true,"recentEditorialEvents":[{"type":"editorInvitedReview","content":"","date":"2026-05-11T02:24:48+00:00","index":40,"fulltext":""},{"type":"reviewerAgreed","content":"307954577577811844123003771543369504432","date":"2026-05-01T10:56:43+00:00","index":37,"fulltext":""},{"type":"reviewerAgreed","content":"108750426911896634243620665509122207134","date":"2026-04-30T17:20:26+00:00","index":36,"fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-30T07:37:45+00:00","index":35,"fulltext":""},{"type":"reviewerAgreed","content":"209633974252505467762907353456116442482","date":"2026-04-30T02:47:56+00:00","index":34,"fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-05-08T11:52:18+00:00","versionOfRecord":[],"versionCreatedAt":"2026-05-08 11:52:18","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8995276","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8995276","identity":"rs-8995276","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}