Why New OLS?
The ICAO Annex 14 update has introduced a completely new concept for safeguarding airports: the transition from traditional Obstacle Limitation Surfaces (OLS) to a differentiated system of OLS, Obstacle Free Surfaces (OFS) and Obstacle Evaluation Surfaces (OES).
This change requires airports and civil aviation authorities worldwide to:
Adapt their safeguarding policies and procedures to the new standards,
Assess and re-map obstacles based on risk rather than simple geometry,
Ensure obstacle-free zones in critical runway areas.
For many stakeholders, this means new responsibilities, more complex analyses – and also opportunities for more flexible planning. With our unique combination of consulting expertise, project experience and ICAO training, airsight helps airports, ANSPs and authorities to understand, implement and maintain the new OLS system efficiently and in compliance.
airsight has developed a set of service offers – tailored packages that address the most common safeguarding needs. These offers are not „one-size-fits-all“ solutions: each aerodrome has its own environment, procedures and operational challenges. Our packages therefore serve as a flexible framework that can be combined and adapted to each case. Please contact our team to discuss your specific needs – together we define the right approach and assemble the most effective safeguarding solution.
Obstacle Free Surfaces (OFS)
We support you in ensuring obstacle-free runway protection zones
OFS Design
Obstacle Free Surfaces (OFS) are designed in accordance with the relevant Aeroplane Design Group (ADG) and the operational use of each runway. airsight prepares all required OFS as individual surfaces for each runway end, including:
- Approach surface
- Transitional surface
- Inner approach surface
- Inner transitional surface
- Balked landing surface
In addition, Visual Segment Surfaces (VSS) and Obstacle Clearance Surfaces (OCS) are created in accordance with the relevant instrument approach procedures.
The full set of surfaces can be delivered both individually and as a merged OFS template including all OFS, VSS and OCS. All surfaces are provided in standard aeronautical data formats — .shp, .kml/.kmz, .dgn, .dwg — together with a concise report outlining all surface parameters.
OFS Analysis
airsight conducts OFS analyses using a provided or agreed terrain and obstacle dataset (TOD). The analysis identifies all infringements of the individual OFS, VSS and OCS surfaces.
A comparison between OFS analysis and the legacy OLS analysis is provided, showing differences in obstacle impacts and protection volumes.
If required, legacy OLS can be re-created and analysed in addition to the OFS.
Obstacle Evaluation Surfaces (OES)
Risk-based obstacle evaluation tailored to your aerodrome
Obstacle Evaluation Surfaces (OES) are designed to reflect the operational role of each runway and enable a more accurate assessment of obstacles using real aerodrome procedures. airsight supports airports with both the design and analysis of OES in accordance with ICAO Annex 14.
airsight prepares individual standard OES in accordance with the relevant ADG and runway operations. Depending on the aerodrome, this includes:
- Take-off climb surface (for runways used for departures)
- Horizontal surface for VFR circuits / IFR circling
- Basic ILS surfaces for promulgated precision approaches
- Straight-in instrument approach surfaces for non-precision approaches
- Instrument departure surfaces for IFR departures
OES can be slightly modified to reflect specific operations, such as:
- adjusted take-off climb slopes
- adjusted approach or departure alignments
- circling protection only on one runway side
A comparison between the combined OES template and the legacy OLS (inner horizontal, conical, outer horizontal) is provided, including height differences.
airsight provides both individual surfaces and a merged OES template.
All OES datasets are delivered in .shp, .kml/.kmz, .dgn, .dwg, together with a concise surface-parameter report.
Using a provided terrain and obstacle dataset (TOD), or data collected through an obstacle survey, airsight analyses which obstacles might penetrate the individual OES surfaces.
The analysis includes:
- Obstacle surveys and obstacle data collection
- Review and validation of the provided obstacle survey data
- Identification of obstacle penetrations for each applicable OES surface
- Obstacle penetration tables including surface type and penetration extent
- Visualisation of obstacles and affected OES surfaces
Where required, legacy OLS can be recreated and analysed in addition to support transition studies and regulatory discussions. A direct comparison between OES and legacy OLS assessment results can be provided, highlighting differences in obstacle protection and obstacle penetration outcomes.
All assessment results are delivered in .shp, .kml/.kmz, .dgn and .dwg format together with a concise obstacle assessment report.
Customised OES Templates
We offer tailored OES templates based on published or foreseen Instrument Flight Procedures
For aerodromes with complex flight procedures or planned operational changes, a standard OES layout may not provide sufficient protection. airsight therefore develops tailored OES templates based on published or foreseen Instrument Flight Procedures (IFPs).
Tailored Design Adjustments
OES surfaces are adapted precisely to match the geometry of real procedures.
Examples include:
- adjusted slope and path of take-off climb surfaces for contingency procedures
- adjusted approach paths for curved visual or RNP AR procedures
- tailored ILS surfaces for precision approaches
Integration of IFR & PANS-OPS Criteria
The customised OES template incorporates surfaces that protect IFR approaches and departures in accordance with ICAO PANS-OPS Doc 8168 and operational requirements. By considering key IFR and PANS-OPS design criteria, the resulting OES provides a more comprehensive reflection of actual flight operations and obstacle clearance requirements. This supports a strategic approach to obstacle management that extends beyond traditional safeguarding concepts.
Future Procedure Protection
Additional surfaces can be included to protect future planned procedures and other types of operations such as VFR, helicopter or military procedures. This ensures that obstacle management considerations are incorporated early during the planning process and provides protection for anticipated operational requirements. The approach supports future aerodrome development while preserving the flexibility to implement new procedures.
Deliverables & Comparison
airsight provides the customised OES template as a merged dataset in .shp, .kml/.kmz, .dgn, .dwg, together with a concise report.
A comparison against the legacy OLS inner horizontal, conical and outer horizontal surfaces is included, highlighting height differences.
Interested in a customised OES Template?
Send us a message, we will review your request and get back to you!
Why airsight?
airsight combines technical expertise in ICAO Annex 14 with extensive experience in obstacle assessment and aerodrome operations.
airsight combines unique expertise in aerodrome safeguarding with decades of international project experience and ICAO-recognised training activities. Our clients benefit from a holistic approach:
ICAO Annex 14 experts – active in international working groups, training providers and advisors to authorities.
Extensive project experience worldwide – from major international airports to regional aerodromes in challenging environments.
Integrated services – combining training, consulting, obstacle surveys, and safeguarding assessments.
Trusted partner – supporting airports, ANSPs and civil aviation authorities in both regulatory compliance and practical implementation.
This combination enables airsight to deliver not just technical compliance, but also efficient, tailored solutions that work in real-world operational contexts.
