Crowne Plaza Hotel, London

Introduction

Green Shield Group proposed a rooftop solar development located on the Crowne Plaza Hotel, London Docklands. The development is located close to London City Airport and a glint and glare assessment was required to support the planning application.

In accordance with the associated Federal Aviation Administration (FAA) guidance and Pager Power’s Glint and Glare Guidance document, the potential impact of solar reflections upon pilots of approaching aircraft and the Digital Air Traffic Control (ATC) Tower personnel was assessed. It was therefore Pager Power’s role to assess if the proposals would not pose a significant risk to aviation safety and thus be acceptable to the airport.

Background

Glint and glare is a key issue for aviation safety in the UK. If a solar development is to be located in the vicinity of an aerodrome then a glint and glare assessment is likely to be requested. For licensed airports, the typical range is within 10km and for unlicensed airfields this reduces to 5km.

The proposed rooftop solar development located on the Crowne Plaza Hotel is located just over 1.65km west of the runway 09 threshold.

The Challenge

Pager Power was engaged initially to investigate the effects of glint and glare by undertaking geometric solar reflection calculations. The assessed layout is predicted to cause an acceptable level of solar glare to aircraft on the approach path because the solar reflections would be of intensity that would have a ‘low potential to produce a temporary after-image’. This intensity of glare is deemed acceptable based on FAA solar glint and glare guidance. The UK Civil Aviation Authority (CAA) is yet to produce detailed glint and glare guidance and therefore many aviation stakeholders in the UK have adopted the FAA guidance.

Solar reflections of intensity of ‘low potential to produce a temporary after-image’ were geometrically possible towards the Digital ATC Tower. Glare of any kind towards an ATC tower was formerly not permissible under the interim guidance provided by the FAA in the USA for on-airfield solar. Pager Power recommends a pragmatic approach to consider glare towards an ATC Tower in an operational context. Where solar reflections are of an intensity no greater than ‘low potential for temporary after-image’ (green glare), expert assessment of the glare scenario and mitigating factors is recommended.

The Solution

Pager Power reviewed the available imagery to determine whether visible line of sight was possible to the reflecting panel area. This review indicated that the Novotel building would significantly screen the reflecting panels such that no visible reflection would be possible in practice.

The Result

Following the submission of the analysis to London City Airport, no objection was received. The rooftop solar development located on the Crowne Plaza Hotel subsequently obtained planning permission and has now been built.