Cloud-based intelligence compensates for a critical conflict in real-time damage monitoring—sacrificing computational scale for rapid response—providing a solution for scenarios requiring massive computing power such as long-term optimized O&M and life cycle management of aircraft [
111]. Most life cycle health management tasks belong to regression tasks in supervised learning (e.g., remaining useful life [RUL] prediction), while semisupervised or unsupervised learning paradigms are adopted for extreme scenarios lacking prior data. Characterized by reliance on large-scale long-time series historical monitoring data, these tasks require network architectures with capabilities of long-term temporal dependency capture, deep feature mining, and global pattern fitting. Wang et al. [
112] proposed a self-supervised learning foundation model (BasGPT). This model leverages deep feature extraction and multidimensional data fusion to perform full-life cycle diagnostics for cross-type bleed air systems. It addresses the challenges of data scarcity for new aircraft types (e.g., C919) and poor cross-type compatibility, enabling the transfer of diagnostic knowledge from mature aircraft types to new ones (Fig.
6E). Predicting the RUL of structural components using historical data is a critical module in long-term aircraft monitoring and predictive maintenance [
113]. Leveraging large-scale server clusters and distributed computing architectures, flexible smart skins not only receive and transmit real-time data but also integrate historical flight parameters, maintenance records, and material fatigue test data. This breaks through the storage and computing power limitations of airborne embedded systems, avoiding problems such as low RUL prediction accuracy and simplistic O&M schemes caused by insufficient local computational scale. Dagal et al. [
114] integrate ANN with failure mode and effects criticality analysis (FMECA). By combining the nonlinear fitting capability of ANNs and the systematic risk analysis framework of FMECA, they compensated for the poor interpretability of stand-alone NNs, while using engine sensor data (e.g., temperature, pressure, and vibration) to predict failure probability, maintenance duration, and costs (Fig.
6F). Li et al. [
115] developed a probabilistic individual aircraft tracking model based on dynamic Bayesian networks, which captures the temporal evolution patterns of structural damage via probabilistic modeling. It is capable of predicting crack lengths over the next 10,000 cycles in the width of the 95% confidence interval, realizing crack evolution tracking and RUL prediction. Supported by the powerful computing power of the cloud, multitype aircraft data collaboration and algorithm iteration enable the construction of more universal and accurate health management models. For example, based on federated learning technology, while protecting the data privacy of each airline, damage data of smart skins from different aircraft types can be aggregated to optimize the generalization ability of RUL prediction algorithms [
116]. This results in a 15% to 20% reduction in prediction errors compared to a single airborne model, while improving prediction stability by more than 25% under different operating conditions [
117,
118]. Raouf et al. [
119] achieved landing gear fault diagnosis and RUL prediction based on multi-AI technologies, covering fault detection and isolation, RUL prediction, and maintenance decision-making, realizing full-life cycle health management (Fig.
6G). Basora et al. [
120] proposed a semisupervised anomaly detection framework. Utilizing a semisupervised learning paradigm to extract implicit degradation features from unlabeled data, this method resolves the issue of anomaly identification in data-scarce scenarios. It addresses the key challenge of limited fault samples in the full-life cycle health monitoring of aircraft fleet cooling units, reducing the overall fleet maintenance cost by 15%. In addition, linking the health assessment results output by the model with the airline’s O&M system can generate globally optimal maintenance plans by integrating flight scheduling data, ensuring flight safety while minimizing O&M costs to the greatest extent [
121]. A comparison of typical models for different detection tasks is presented in Table
5.