ANALISIS KEGAGALAN PADA AUTOBRAKE SYSTEM DISARM ILLUMINTAED AFTER TOUCHDOWN PADA BOEING 737 - 8 MAX

Sistem pengereman otomatis (autobrake system) pada pesawat udara komersial khususnya Boeing 737-8 MAX merupakan komponen vital yang dirancang untuk memberikan deselerasi secara otomatis dan terukur segera setelah roda pesawat menyentuh landasan (touchdown), mengalihkan beban pengereman dari pilot serta meminimalkan risiko runway excursion atau overrun. Sistem ini dikendalikan oleh Antiskid/Autobrake Control Unit dan berinteraksi secara kompleks dengan wheel speed transducer, thrust lever switchpack, speedbrake/spoiler control electronics, brake pedal switches, serta katup-katup hidrolik pengereman. Namun, ditemukannya gangguan operasional berupa Autobrake System Disarm illuminated after touchdown (terpasangnya lampu kuning "Autobrake Disarm" di kokpit saat atau setelah touchdown) mengindikasikan pelepasan pengereman otomatis secara tidak sesuai aturan awal (uncommanded disarm), yang memaksa pengereman beralih ke mode manual secara mendadak. Hal ini berpotensi meningkatkan pilot workload, memperpanjang jarak deselerasi pesawat, serta mengancam keselamatan penerbangan. Penelitian ini bertujuan untuk mengidentifikasi dan menganalisis faktor-faktor teknis maupun operasional penyebab kegagalan tersebut, mengevaluasi efektivitas prosedur troubleshooting di lapangan, menguji kontribusi faktor manusia (human factor), serta merumuskan rekomendasi corrective action yang aplikatif untuk mencegah kejadian berulang. Penelitian kualitatif deskriptif-eksploratif dengan strategi studi kasus ini menerapkan pendekatan Root Cause Analysis yang mengombinasikan alat analisis Diagram Pareto, Diagram Fishbone (Ishikawa), serta analisis 5W+1H. Penelitian berlokasi di PT. Airfast Indonesia (Bandara Internasional Soekarno-Hatta, Tangerang) dalam rentang waktu September 2025 hingga Februari 2026, menggunakan data histori operasional pendaratan pesawat Boeing 737-8 MAX registrasi PK-OFI dan PK-OFM periode 16 Juni 2024 hingga 28 Juni 2026. Data sekunder dihimpun dari Aircraft Maintenance Logbook, Deferred Defect List, Interactive Fault Isolation Manual, Aircraft Maintenance Manual, dan Minimum Equipment List, sedangkan data primer diperoleh melalui wawancara mendalam (in-depth interview) dengan Supervisor, Engineer in Charge, dan Aircraft Maintenance Engineer berlisensi type rating Boeing 737-8 MAX. Dari total konsolidasi data 19 kasus kegagalan teragregasi (16 kasus pada PK-OFI dan 3 kasus pada PK-OFM), hasil pengolahan Diagram Pareto mengungkapkan bahwa kategori No Fault Found merupakan fenomena paling dominan dengan frekuensi mencapai 15 kasus atau sebesar 78,9%, yang mendekati pola rasio 80/20. Sementara itu, dua kategori kegagalan lain yang berhasil dikonfirmasi kerusakan fisiknya dan ditindaklanjuti dengan penggantian komponen masing-masing adalah kerusakan AB Solenoid Pressure Switch sebesar 2 kasus (10,5%) dan kerusakan Brake Pedal Switch sebesar 2 kasus (10,5%). Tingginya proporsi NFF menunjukkan bahwa mayoritas gangguan bersifat tidak permanen (transient/intermittent), sehingga tidak selalu memicu kode kesalahan (fault code) saat pengujian BITE (Built-In Test Equipment) AACU dilakukan di darat. Penelusuran akar masalah secara komprehensif menggunakan Diagram Fishbone pada kategori NFF ini menguraikan kontribusi dari lima elemen utama: pertama, faktor Man disebabkan oleh dokumentasi troubleshooting pada AML yang kurang terperinci, laporan pilot report yang kurang informatif terkait parameter pasti saat disarm, serta keterbatasan pengetahuan teknisi mengenai sifat intermittent fault pada AACU; kedua, faktor Material dipicu oleh tingginya tekanan operasi yang diterima komponen switch secara lanjutan tanpa adanya pemantauan kondisi (health trend monitoring), yang memicu indikasi fluktuatif tambahan pada brake transmitter; ketiga, faktor Method bersumber dari prosedur IFIM Task 32-42-00-810-926 yang masih bersifat teoretis umum dan belum spesifik menelusuri gangguan intermiten, filosofi perawatan komponen kelistrikan autobrake yang masih bergantung pada sistem on-condition tanpa batas usia pakai (hard time replacement), keempat, faktor Environment dipengaruhi oleh kondisi kompartemen wheel well Boeing 737-8 MAX yang tidak dilengkapi pelindung (cover), sehingga jalinan kabel (wiring harness) dan sensor terpapar langsung pada fluktuasi suhu ekstrem serta kelembapan udara; dan kelima, faktor Machine berkaitan dengan keterbatasan sistem BITE AACU dalam merekam fault message yang hilang dengan cepat serta pesan kesalahan BITE yang terlalu umum. Berdasarkan temuan tersebut, rumusan corrective action berbasis kerangka 5W+1H merekomendasikan penerbitan form troubleshooting, penyelenggaraan refresher training teknis secara berkala untuk personel pemeliharaan, pengajuan technical query kepada manufaktur Boeing guna penyempurnaan petunjuk IFIM, pelaksanaan kajian Reliability Centered Maintenance (RCM) untuk menentukan interval hard time replacement pada switch kritis, penegakan SOP troubleshooting berjenjang agar cross-swapping tidak dilakukan, serta kewajiban pencatatan variabel lingkungan pada setiap laporan investigasi guna menekan proporsi NFF dan menjamin kelaikudaraan penerbangan.

The automatic braking system (autobrake system) on commercial aircraft, particularly the Boeing 737-8 MAX, represents a critical sub-system engineered to deliver automatic, controlled, and consistent deceleration immediately after touchdown, thereby reducing pilot workload during rollout and minimizing the risk of runway excursions or overruns. Controlled by the Antiskid/Autobrake Control Unit (AACU), the autobrake operates through complex interactions with wheel speed transducers, thrust lever switchpacks, speedbrake/spoiler control electronics, brake pedal pressure switches, and hydraulic braking valves. However, in line operations, the uncommanded illumination of the "AUTO BRAKE DISARM" amber light during or immediately after touchdown poses a significant operational hazard, as it unexpectedly disengages the automatic system and reverts braking control to manual mode. This condition increases the flight crew's workload at a critical flight phase, extends landing distances, and compromises overall operational safety. This research aims to systematically analyze the technical and operational factors triggering autobrake disarm events, evaluate the efficacy of current field troubleshooting procedures, assess the contribution of human factors, and formulate comprehensive corrective actions to prevent recurrence. Adopting a qualitative exploratory-case-study approach, this study utilizes Root Cause Analysis (RCA) combining Pareto Diagram analysis, Fishbone (Ishikawa) cause-and-effect mapping, and the 5W+1H analytical framework. Conducted at PT Airfast Indonesia (Soekarno-Hatta International Airport, Tangerang) from September 2025 to February 2026, the study investigates landing operational failure records of Boeing 737-8 MAX aircraft registered as PK-OFI and PK-OFM between June 16, 2024, and June 28, 2026. Secondary data were gathered from Aircraft Maintenance Logs (AML), Deferred Defect Lists (DDL), the Interactive Fault Isolation Manual (IFIM Task 32-42-00-810-926), the Aircraft Maintenance Manual (AMM), and the Minimum Equipment List (MEL), complemented by primary data collected through in-depth qualitative interviews with certified Line Maintenance Supervisors, Engineers-in-Charge, and Aircraft Maintenance Engineers holding Boeing 737-8 MAX type ratings. From a total consolidated dataset of 19 aggregated failure incidents (16 cases on PK-OFI and 3 cases on PK-OFM), the Pareto analysis reveals that the No Fault Found (NFF) / Intermittent classification represents the most dominant category, accounting for 15 cases or 78.9% of total events, closely mirroring the classic 80/20 Pareto principle. The remaining confirmed physical component failures comprise Autobrake Solenoid Valve Pressure Switch failures at 2 cases (10.5%) and Brake Pedal Switch (S762/S763) failures at 2 cases (10.5%). The high prevalence of NFF cases indicates that the majority of disarm events are transient or intermittent in nature, frequently leaving no persistent fault codes during ground Built-In Test Equipment (BITE) inspections of the AACU. Comprehensive root cause investigation via the Fishbone Diagram across the NFF/Intermittent category delineates contributing factors across five main dimensions: first, the Man factor stems from insufficiently detailed troubleshooting entries in maintenance logbooks, incomplete pilot reports regarding exact disarm parameters at touchdown, and limited technician familiarity with AACU intermittent fault behaviors; second, the Material factor is driven by continuous high hydraulic operating pressures on pressure switches causing transient signal fluctuations without active condition monitoring; third, the Method factor arises from the generalized, theoretical nature of IFIM Task 32-42-00-810-926 in isolating intermittent electrical faults, an exclusively on-condition component replacement policy lacking hard-time interval limits, and misconceptions regarding the sequence of cross-swapping components; fourth, the Environment factor is influenced by the unshielded design of the Boeing 737-8 MAX wheel well compartment, exposing wiring harnesses and sensor connectors directly to extreme ambient temperatures, humidity, and environmental contamination; and fifth, the Machine factor relates to BITE limitations in capturing short-duration electrical transients and the overly broad nature of AACU fault messages. Based on these findings, the 5W+1H framework formulates targeted corrective actions, including the establishment of standardized troubleshooting forms and pilot reporting guidelines, periodic technical refresher training for maintenance personnel, submission of technical queries to Boeing for IFIM task expansion, execution of Reliability Centered Maintenance (RCM) studies to define hard-time replacement limits for critical switches, enforcement of tiered troubleshooting SOPs to prevent premature component cross-swapping, and mandatory environmental logging during inspections to mitigate NFF occurrences and enhance fleet airworthiness and flight safety.

Kata Kunci: Autobrake System, Boeing 737-8 MAX, Autobrake Disarm, Root Cause Analysis, Aircraft Maintenance.