AviChain: A Permissioned Blockchain Architecture for Tamper-Evident Aviation Maintenance Records with Integrated GRU-Based Remaining Useful Life Prediction

AviChain is a full-stack system combining a Hyperledger Fabric permissioned blockchain with a GRU recurrent neural network for predictive aviation maintenance. Every maintenance event is anchored as a tamper-evident, multi-organisation ledger entry; a two-layer GRU trained on the NASA C-MAPSS FD001 turbofan degradation dataset predicts Remaining Useful Life before each transaction is submitted. On the standard 100-engine FD001 test protocol, the GRU achieves MAE = 11.4 cycles, RMSE = 15.0 cycles, and R² = 0.86 — a 44% reduction in MAE over an ARIMA baseline. Uncertainty is quantified via Monte-Carlo dropout (30 forward passes). The smart contract is deployed in Chaincode-as-a-Service mode across a two-organisation Fabric network with Raft ordering. Source code and trained model weights are included.