Yazılım Yoğun Uçuş Kontrol Sistemlerinde Sertifikasyon Güvencesi ve Operasyonel Öğrenme: Airbus A320 ELAC Arızaları Üzerine Çok Boyutlu Bir Analiz

Abstract

Yazılım ağırlıklı “fly-by-wire” uçuş kontrol sistemleri, yüksek sertifikasyon ve geliştirme güvencesi süreçlerinden geçirilerek tasarlansa da, nadir çevresel etkiler, yazılım sınır koşulları ve operasyonel etkileşimler bazı emniyet risklerinin ancak operasyon sırasında ortaya çıkmasına neden olabilmektedir. Bu çerçevede bu çalışma, “Airbus A320 Elevator Aileron Computer (ELAC)” sistemi arızalarını detaylı olarak ele almakta ve tasarım güvencesi, operasyonel emniyet performansı ile sürekli uçuşa elverişlilik arasındaki ilişkiyi incelemektedir. Analiz, 2025 yılında ABD’de meydana gelen spesifik bir hava aracı emniyeti olayının hemen ardından EASA tarafından acil kodlu bir uçuşa elverişlilik direktifinin (EASA AD No. 2025-0268-E) yayımlanması ve bu olaya ilişkin Avrupa Birliği Havacılık Emniyeti Ajansı (EASA) ile ABD Federal Havacılık İdaresi (FAA) tarafından gerçekleştirilen müteakip düzenleyici faaliyetlerden hareketle yapılandırılmıştır. Çalışma, birbirini tamamlayan üç analitik boyutu bir araya getirmekte olup bunlar sırasıyla Airbus “fly-by-wire” anomalilerine ilişkin “NASA Havacılık Emniyeti Raporlama Sistemi (ASRS)” raporlarının yapılandırılmış değerlendirmesi, söz konusu acil uçuşa elverişlilik direktifini tetikleyen olayın vaka temelli analizi ve bahse konu olguya yönelik Sistem Teorik Süreç Analizi (STPA) ile İsviçre Peyniri (Swiss Cheese) modeli kullanılarak gerçekleştirilen sistem emniyeti değerlendirmesidir. Bulgular, hava aracı sertifikasyonunun emniyetin nihai ve değişmez kanıtı olarak değil, operasyonel veriler, olay incelemeleri, düzeltici faaliyetler ve tasarım iyileştirmeleriyle sürekli olarak beslenen uçuşa elverişlilik yönetimi döngüsünün temel bir unsuru olarak görülmesi gerektiğini göstermektedir. Sonuç olarak, çalışma ELAC vakası üzerinden yazılım yoğun aviyonik sistemlerde sürdürülebilir emniyetin ancak tasarım varsayımlarının operasyonel öğrenme yoluyla düzenli biçimde sınanması ve gerektiğinde güncellenmesiyle sağlanabileceğini ileri sürmektedir.

Keywords

• Airbus a320
• Fly-by-wire
• Uçuş kontrol sistemleri
• NASA ASRS
• STPA
• İsviçre peyniri modeli

Ethical Statement

Bu araştırmada hayvanlar ve insanlar üzerinde herhangi bir çalışma yapılmadığı için etik kurul onayı alınmamıştır.

Certification Assurance and Operational Learning in Software-Intensive Flight Control Systems: A Multidimensional Analysis of Airbus A320 ELAC Failures

Abstract

Although software-intensive fly-by-wire flight control systems are designed through rigorous certification and development assurance processes, rare environmental effects, software boundary conditions, and operational interactions may cause certain safety risks to emerge only during service. Within this context, this study addresses failures of the Airbus A320 Elevator Aileron Computer (ELAC) system and examines the relationship between design assurance, operational safety performance, and continuing airworthiness. The analysis is structured around the issuance of an emergency airworthiness directive by EASA (EASA AD No. 2025-0268-E) immediately after a specific aircraft safety event that occurred in the United States in 2025, as well as the subsequent regulatory actions undertaken by the European Union Aviation Safety Agency (EASA) and the U.S. Federal Aviation Administration (FAA). The study integrates three complementary analytical dimensions: a statistical analysis of NASA Aviation Safety Reporting System (ASRS) reports related to Airbus fly-by-wire anomalies; an event-based examination of the systemic failure that triggered the relevant emergency airworthiness directive; and a system safety assessment of these anomalies using Systems-Theoretic Process Analysis (STPA) and the Swiss Cheese Model. The findings indicate that aircraft certification should not be regarded as the final and immutable proof of safety, but rather as a fundamental component of a continuing airworthiness management cycle that is continuously informed by operational data, event investigations, corrective actions, and design improvements. Consequently, through the case of ELAC systemic failures, the study argues that sustainable safety in software-intensive avionics systems can only be achieved by regularly testing and, when necessary, updating design assumptions through operational learning.

Keywords

• Airbus a320
• Fly-by-wire
• Flight control systems
• NASA ASRS
• STPA
• Swiss cheese model

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