Vibration & condition indicators
Order and spectral analysis yields gear and bearing indicators — FM0, FM4, NA4, sideband energy and bearing defect frequencies — from raw vibration.
Gearbox · rotor · shafts · bearings
Condition-Based & Predictive Maintenance
The Rotorcraft Predictive Maintenance Platform brings health monitoring and remaining-life prediction to helicopters separated by half a century of avionics — from first-generation analogue airframes to current-generation, HUMS-equipped types — behind one type-agnostic model.
“The expert in maintenance does not wait for the part to fail — he reads the warning the machine has already given.”
The Challenge · One fleet, three eras
Indian rotary-wing operators fly aircraft separated by fifty years of avionics. First-generation types are analogue airframes with fixed time-between-overhaul limits and no onboard health monitoring — large, ageing fleets carrying high maintenance burden. Current-generation types are modern airframes whose variants carry a Health & Usage Monitoring System. One platform must serve a data-rich modern type and data-poor legacy types without forcing them into the same assumptions.
First-generation analogue types have instruments only — no recorded health data.
Maintenance driven by hours and calendar, not by observed condition.
A large legacy fleet beyond its design life, being progressively replaced.
Multi-channel vibration, usage and exceedance data ready to exploit.
The Approach · OSA-CBM / ISO 13374
RPMP follows the internationally recognised six-layer condition-monitoring reference model. Each layer is a single-responsibility service: data flows forward as immutable events, every stage enriches the picture, and condition-monitoring layers stay dormant for tails that lack the input data — without affecting the rest.
Receive and normalise every source — HUMS files, engine/usage data, manual captures, retrofit feeds — into one validated record.
Signal processing into condition indicators — gear/bearing CIs, oil-debris trends, rotor-balance coefficients, usage severity.
Compare features to limits and per-tail baselines; emit nominal / caution / warning states and anomalies.
Fuse states into a single, explainable component health index that always resolves back to its evidence.
Estimate remaining useful life — physics + data fused — always with a quantified uncertainty band.
Turn health and RUL into a recommended action and horizon — inspect, limit or replace. Advisory only; humans decide.
Capabilities
Every modality is mapped to the failure modes it detects, and every output is traceable to the evidence and algorithm version that produced it — the property that makes analytics-driven decisions acceptable for airworthiness review.
Order and spectral analysis yields gear and bearing indicators — FM0, FM4, NA4, sideband energy and bearing defect frequencies — from raw vibration.
Gearbox · rotor · shafts · bearings
Chip-detector and lab oil analysis quantify ferrous and non-ferrous wear — the strongest early warning when fused with vibration.
Available to all types · incl. legacy
Derives blade adjustments to minimise vibration — computed automatically from HUMS, or from portable-analyser surveys on legacy types.
1/rev & n/rev · track split
Classifies flight into severity regimes so fatigue life is credited by what the aircraft actually did — not just hours flown.
Safe-life consumption · severity
Physics-based fatigue and data-driven degradation fused into a remaining-life estimate — published with a confidence band, never a bare number.
Hybrid digital twin · UQ
Every assessment lists its drivers and links to source data, so a certifying engineer can audit it. Human-in-the-loop throughout.
Airworthiness-ready evidence
Inside the algorithms
Diagnosis extracts condition indicators from vibration, oil and usage data; prognosis projects them to a remaining life with quantified uncertainty. Every method below is industry-standard for rotorcraft transmissions, and every output is traceable to the evidence that produced it.
Turn raw signals into condition indicators, then into a state.
Detection · fixed limits · per-tail SPC · Mahalanobis · isolation forest · autoencoder · fleet-relative outlier
Fuse physics and data into a remaining-life distribution.
Every estimate is a distribution — the advisory acts on a conservative quantile, with SHAP-style driver attributions.
Crack-growth and cumulative-damage models give a life estimate from first principles — ideal for the data-poor legacy fleet.
Particle and Kalman filters carry a full posterior, handling non-linear, non-Gaussian wear.
Gaussian processes and recurrent networks sharpen the estimate as run-to-failure history accumulates.
Legacy Hybrid Strategy
Because the legacy fleet has no onboard sensing, RPMP never assumes a vibration feed exists. Data availability is a per-tail property, and the platform degrades gracefully: usage-based prognostics work with nothing more than flight logs and oil-sample results, while full condition monitoring engages wherever HUMS or a retrofit unit is present.
Ground crew record usage, a guided regime questionnaire, oil-sample results and NDT findings — structured data that would otherwise live only on paper.
A small, non-intrusive DAU with a few accelerometers and a chip-detector tap presents the same internal record as HUMS — no downstream change.
With little failure history, physics and usage models lead; data-driven models earn trust as evidence accumulates, and uncertainty tightens over time.
Data management
Predictive maintenance lives or dies on data. RPMP treats every signal, sample and record as a controlled asset with an owner, a lifecycle and a retention rule — so the analytics are reproducible and the evidence holds up at airworthiness review.
Tail, component, configuration and limits as master data with a single owner — type-agnostic, effectivity-resolved, never duplicated.
High-rate vibration and feature streams are tiered and down-sampled by age, balancing query speed against decades of retention.
Schema-on-write validation, quarantine for bad records, and immutable provenance from every feature back to its source file and algorithm version.
Safety-relevant data is retained for the life of the aircraft plus the statutory margin, under a tamper-evident, policy-driven schedule.
Every data domain is classified (including SCOMET-controlled data) with role- and attribute-based access; no data leaves the enclave.
Exchanges align to the S-Series ILS specifications and the MIMOSA asset model, so RPMP plugs into enterprise logistics rather than walling it off.
The Application · Built for the hangar
The interface favours clarity over density: a small number of well-signposted screens, plain-language status, evidence one click away, and no action that cannot be undone or audited. Three capabilities anchor it.
Availability is computed from open items and life-limit margins — never hand-set — so the board can’t drift from reality.
An incident is a case with one owner, a status lifecycle and an append-only follow-up thread — nothing in the history can be silently edited.
Follow-up · oil sample requested · assigned to MRO planner · SLA 48h
Rotables and consumables are tracked against forecast demand from advisories, so a shortfall is flagged before it grounds a tail.
Incident workflow · tracked like a board
Every flagged anomaly becomes a card that moves across a board — reported, analysed, assigned, discussed, followed up and resolved — with an append-only message thread that survives audit. Several cases sit on the board; the lifecycle below plays out on one of them.
Beyond the aircraft · Fleet & logistics
The same asset model and the same predictive signals run the sustainment loop — every aircraft, every part, every order and every sortie. A predicted failure becomes a planned part, a reserved hangar slot and a re-tasked aircraft, instead of a surprise grounding.
Every tail, base, configuration and life-margin in one registry — with basing, transfers and modification state tracked.
RCM · FMECA · Weibull
A rotable pool and multi-echelon stock sized to a fleet-availability target — not blanket stock levels.
METRIC / VARI-METRIC · (s,S) · lateral resupply
Auto requisitions from reorder points and forecast shortfalls; a full, audited PO lifecycle with AOG escalation.
requisition → PO → received · repair orders
Tail assignment and maintenance-slot scheduling as one optimisation; predicted life enters as a soft due-date.
tail assignment · time-space network · multi-criteria
Delivery Approach · Sequenced in steps
Each capability is taken through three maturity stages — a walking skeleton that runs end-to-end on stubs, then real algorithms and screens, then hardening for performance, safety and security. Nine phases run against explicit exit gates; the skeleton gate is the one that matters early.
Charter, environments, standards and the definition of done.
Fleet, maintenance cycle, physics and regulatory model.
A walking skeleton through all six layers on synthetic data.
Modern HUMS + legacy hybrid capture, validated and lineage-tracked.
Feature extraction, state detection and health assessment live.
Physics + data-driven remaining-life with uncertainty.
Dashboard, incident follow-up workspace and availability board.
Evidence package, then airgapped rollout, training and sustainment.
Built to recognised condition-monitoring & airworthiness standards
Atmanirbhar Bharat · Sovereign sustainment
A full technical dossier — the activity & phase breakdown and the technical design — is available under briefing. Request access to discuss a deployment.