Supply, Delivery, Installation & Testing of Meteorological System and Accessories

Mahavir Shree International Pvt. Ltd. successfully delivered Aviation Weather Observation System (AWOS/Meteorological Information System) across 18 domestic airports in Nepal for CAAN/CNAD. The project encompassed the complete design, supply, installation, integration, testing, and commissioning of met parks at runway thresholds and ATC tower displays, aligned with ICAO and WMO requirements. The system enables Aerodrome Flight Information Service (AFIS) operations with accurate, real-time display of wind, pressure (QNH/QFE), and temperature/humidity data, improving flight safety, decision support, and operational continuity.

Contract: CAAN/CNAD/NCB-01/076/77


Airports Covered (18)
- Rajbiraj Airport
- Doti Airport
- Balewa Airport
- Safebagar Airport
- Rumjatar Airport
- Rara Airport
- Chaurjahari Airport
- Meghauli Airport
- Salle Airport
- Nepalgunj Airport
- Bharatpur Airport
- Jumla Airport
- Chandragadhi Airport
- Dhangadhi Airport
- Biratnagar Airport
- Janakpur Airport
- Simara Airport
- Surkhet Airport

Project Objectives
- Provide AFIS-equipped domestic aerodromes with certified meteorological sensing and display systems.
- Ensure compliance with ICAO Annex 3 and WMO guidelines for measurement, averaging, and gust calculations.
- Deliver robust, solar-powered met parks at runway thresholds with protected data paths to tower consoles.
- Standardize ATC console met displays and operational workflows across multiple airports.
- Enable long-life, maintainable infrastructure with at least 10 years of post-commissioning support.

Standards & Compliance
- ICAO Annex 3: Meteorological Service for International Air Navigation
- ICAO Annex 14, Vol I, Ch. 6: Obstacle lighting (Type B, Low Intensity)
- WMO guidelines: Wind gust calculation, averaging periods, and sensor compliance
- ISO 16622: Ultrasonic anemometer compliance
- EMC EN/IEC 61326-1: Instruments and display electronics
- Sensors calibrated by accredited laboratories; calibration certificates delivered

Delivered Solution

1) Met Parks (Runway Threshold) – Civil & Structural
- Compound: 4 m x 4 m chain-link fenced met park with lockable gate, 0.5 m elevated platform, compacted and topped with 50 mm PCC for stability and drainage.
- Mast: 10 m frangible, self-supporting, tiltable rectangular truss aluminum mast (UV-protected, red/white), modular (≥3 sections), designed for ≥134 mph wind load.
- Equipment mounting: GI pole Ø2”, 3 m for weatherproof electronics enclosure; IP-rated housings installed per approved shop drawings.
- Obstruction light: ICAO Type B low-intensity red LED, 12 VDC, ≥30 cd, ≤5 W, IP68-rated, die-cast aluminum body, pipe-mounted.
- Earthing and lightning protection:
- Lightning arrester: ≥7 ft, 14 mm copper rod
- Copper strip: ≥20 mm x 3 mm; gas/chemical welded joints
- Copper plates: 680 x 680 x 3 mm (2 pcs)
- Ground resistance: <15 Ω; separate earths with adequate separation
- Executed per DWG-02 and approved earthing design

2) Sensors & Data Acquisition
- Wind (Ultrasonic with bird protection)
- Range: 0–65 m/s; resolution 0.01 m/s; accuracy ±0.1 m/s
- Direction: 0–360°; resolution ≤1°; accuracy ±2°
- Response: ≤260 ms; IP66/67; stainless-steel construction
- Calculations: 3 s, 2 min, 10 min averages; gusts per WMO (vector resolution)
- Compliance: ISO 16622; WMO/ICAO compliant
- Pressure
- Type: Capacitive/aneroid/silicon absolute
- Range: 500–1100 hPa; resolution ≤0.1 hPa; accuracy ±0.25 hPa
- Stability: ±0.1 hPa/year
- Calculations: QNH and QFE
- Interface: RS-232/RS-485/422/SDI/analog; 12 VDC nominal
- EMC: EN 61326; local display provided
- Temperature & Relative Humidity (combined with radiation shield)
- Temp: −10 to +60 °C; accuracy ±0.2 °C (or better)
- RH: 0–100%; accuracy ±2% RH (or better)
- Dewpoint computed; IP65 or better; 12 VDC nominal; EN 61326
- Data Logger
- Edge acquisition, processing, storage, and transmission from met park to tower
- Time-averaging and gust computations per WMO
- Surge protection
- SPD deployed to protect all sensitive electronics per OEM recommendations

3) ATC Tower Console – MET Display
- Single-screen, multicolor PC-based display; licensed software (no custom code) for maintainability
- Parameters shown with required averaging and min/max:
- Wind speed: instant (3 s), 2 min avg, 10 min avg, gusts
- Wind direction: instant (3 s), 2 min avg, 10 min avg, min/max with graphical rose
- Temperature, Relative Humidity, Dew Point
- Pressure: QNH and QFE
- Interfaces: Ethernet 10/100, RS-232/RS-485; power: 220 VAC ±10% and 24 VDC
- Mounting options: ATC console/desktop/wall; EN 61326-1 EMC compliance

4) Power – Stand-alone Solar PV at Met Parks
- Solar panels: 12 V / 100 Wp mono-crystalline; TUV IEC 61215 & 61730; mounted on 2 m aluminum pole
- Battery: VRLA maintenance-free, 12 V, 100 Ah @ C10; ~1200 cycles at 60% DoD
- Charge controller: MPPT, 12 V system, 25 A ±5%; −5 to +55 °C; protections (SC/OL/RP/HVD/LVD, surge)
- DC cabling and accessories sized and installed per load and distance

5) Data Communication (Met Park <> Tower) – Fiber
- Media converters: Single-mode, SC; 1310 nm; up to 40 km; Tx ≥ −5 dBm; Rx ≤ −25 dBm; RJ-45 + fiber ports; 12–48 VDC input; UL/EN; reverse polarity and power line protections
- Optical fiber cable: SM G.652.D, ≥6 cores; OD ≥8.0 mm; crush 2000 N; bend radius ≥20D; attenuation ≤0.38 dB/km (1310 nm), ≤0.25 dB/km (1550 nm)
- Trenching and protection:
- 90 cm depth trenching with plastic protection mesh (9" width, 10 mm thick)
- Conduits: 1" PVC (trench) and ≥1.5" HDPE (handholes/ducts); occupancy ≤80%
- “Below fiber cable” cement slabs at ≥25 m intervals and at bends
- Hand holes and markers (per DWG-03):
- Hand holes: 600 x 600 mm; surface cover 400 x 400 mm concrete
- Concrete PEG markers: 2 ft above ground; placed ~100 cm from hand hole center; spacing ~100 m; metallic/concrete plates indicating OFC and distance (m/ft)
- 2 m fiber slack coiled within each hand hole
- Existing fiber re-use: Where feasible, integration with existing OFC was performed to optimize cost and minimize civil works

6) Transportation
- Road transportation from CAAN/CNAD to each project site, including handling and staging

Implementation Approach

- Site Surveys
- Joint MSI–CNAD surveys at all airports; siting of met parks near runway thresholds per CAAN/ICAO siting criteria
- Shop Drawings and Approvals
- Site-specific shop drawings for civil, structural, electrical, and fiber routes approved by CNAD prior to execution (referenced DWGs 01–03)
- Installation & Integration
- Works executed per ICAO Annex 3, OEM manuals, and CNAD instructions where standards are silent
- Full integration of sensors, power, data logging, fiber, and tower displays; re-use of existing OFC where directed
- Testing & Commissioning
- Test plans, procedures, and records submitted and approved at least one week prior to SAT
- Site Acceptance Testing (SAT) conducted with CNAD engineers; earthing resistance measurements recorded (<15 Ω); calibration certificates verified
- Documentation & Handover
- Delivered: System block diagrams, wiring diagrams, user/operational manuals, calibration certificates, as-built drawings, test reports, spares list
- Training & Knowledge Transfer
- 5 working days of local technical maintenance and operational training at CAAN/CNAD, led by the OEM’s technical specialist; all costs covered by MSIPL

Operations, Warranty & Support
- Warranty: 1 year on all system components following successful operational testing; software updates provided during warranty
- Long-term Support: MSIPL guarantees availability of maintenance support for a minimum of 10 years post-commissioning
- Spare parts and calibration support programs established per CAAN needs

Notable Technical Highlights
- 18 multi-site met parks standardized on 10 m frangible masts with ICAO-compliant obstruction lighting
- WMO/ICAO-compliant sensing with accredited calibration for wind, pressure (QNH/QFE), temperature, and humidity
- Redundant protections: lightning/earthing, surge suppression, and environmental enclosures for high availability
- Solar-powered operation ensures resilience and reduced OPEX at remote aerodromes
- Fiber backbone with protected trenching, signage, and maintainability provisions (slack coils, hand holes, markers)

Outcomes & Benefits
- Enhanced AFIS safety and decision-making with accurate, standardized MET data presented at tower consoles
- Improved continuity of operations via solar power, robust earthing, and surge protection
- Consistent user interfaces and maintenance practices across 18 airports, simplifying training and support
- Future-ready architecture leveraging licensed software and standard interfaces (Ethernet/serial), easing lifecycle management

Roles & Responsibilities (as executed)
- CAAN/CNAD: Site selection, land matters, field facilitation, and customs support
- MSI (Bidder/Contractor):
- Supply, installation, commissioning, and SAT
- 1-year warranty and software updates
- 10-year maintenance support guarantee
- Local training and full documentation (system diagrams, wiring, manuals)

Key Outcomes

- Meteorological systems successfully installed and operational across 18 domestic airports.

- Real-time data availability for AFIS operations, enhancing aviation safety and efficiency.

- Sustainable, solar-powered systems ensuring uninterrupted operation in remote airports.

- Robust fiber optic communication systems ensuring accurate and reliable data transmission.

- Skilled local technical personnel trained for long-term maintenance and operation.

Mahavir Shree International Pvt. Ltd. appreciates the opportunity to partner with CAAN/CNAD on this nationally significant safety infrastructure and remains committed to long-term operational excellence and support across Nepal’s domestic airports. By completing this project, Mahavir Shree International Pvt. Ltd. reaffirmed its commitment to strengthening Nepal’s aviation infrastructure with world-class solutions.

Through the integration of ICAO/WMO-compliant meteorological systems, domestic airports are now better equipped to support safe, efficient, and modern air navigation across the country.