Compass Calibration Base Survey


The Compass Calibration Base survey team are located at Land Magnetic Range, Portland Bill, Dorset.

The team are Professional QinetiQ Engineers, providing a unique, unrivalled service. They have an international reputation; surveys in Germany, Canada, Cyprus and the 1etherlands show their flexibility and deployment capabilities.

QinetiQ’s magnetic survey work is recognised by the CAA and Air Accidents Investigation Branch (AAIB) - CompassBase accuracy is a significant factor in meeting British Civil Airworthiness requirements. This refers to overall compass accuracy, as well as other magnetic direction-finding equipment installed in aircraft.

The Aim

Compass Base surveys aim to establish an area of known magnetic characteristics, so that aircraft compasses and other magnetic direction-finding systems may be calibrated. It also ensures that deviations derived from a Compass Swing are only caused by aircraft magnetism.

The Standard

All aircraft require checks and calibrations on their on-board navigation systems. The survey is carried out using magnectic compasses that have been calibrated at the Compass Test Centre that is located at MOD Portland Bill.

The Requirement

Airport Operators must provide a calibrated, certified magnetically clean environment which has been calibrated and certified. This enables their customers to conduct regular Compass Swings, and other magnetic calibrations.


Once installed, the Compass Base may receive a Class 1 or Class 2 certification - depending on how many magnetic deviations there are across the base area, in accordance with CAA CAAIP, Book 2, Chapter34-10 V4.1 ơ dated 27 June 2016. For Military bases, the standard is set in the Manual of Aerodrome Design and Safeguarding (MADS), Chapter 5, Annex 5: Compass Calibration Base Issue, Issue 8 26 - dated October 2016.

Your Compass Base must also receive routine magnetic surveys according to its’ classification: Every 5 years for Class 1, and every 2 years for Class 2.


• Detailed magnetic survey, accurately
quantifying found magnetic
• Location and isolation of ferromagnetic material causing anomalies
within the Compass Base.
• Classificationcertification of limits
set out in relevant CAA and Military
• Conducted on a global basis, with
survey team travelling at short notice.
• In-life support, advice and regular
routine surveys of all Commercial and
Military Compass Bases.
• Permeability material and aggregate
testing, for use in Compass Base
construction and maintenance.