Mandatory Permit Directives (MPDs) are published by the Civil Aviation Authority in
accordance with British Civil Airworthiness Requirements (BCAR) Chapter A5-8. They
summarise the mandatory actions that are required to be complied with by UK owners and
Operators of Permit to Fly aircraft.
Owners and Operators must ensure that aircraft operating on Permits to Fly comply with
Modifications, Inspections and Service Bulletins that have been classified Mandatory by
the CAA. These MPDs have been compiled from publications such as CAP 476 –
Mandatory Aircraft Modifications and Inspections Summary, Type Acceptance Data
Sheets, Type Approval Data Sheets, Airworthiness Approval Notes, Manufacturers Service
Bulletins and Letters to Owners/Operators.
The design standard of a microlight is defined in either a Type Acceptance Data Sheet for
microlights meeting the intent of BCAR Section S or Type Approval Data Sheet for a
microlight constructed by a CAA Approved Organisation.
The MPDs for type accepted microlights make reference to the Type Acceptance Data
Sheet whereas for type approved microlights the specific subject matter is listed.
Enquires regarding MPDs should be made to the United Kingdom Civil Aviation Authority,
AD Unit, Airworthiness Strategy and Policy Department, Safety Regulation Group, Aviation
House, Gatwick Airport South, West Sussex RH6 0YR. Phone: +44 (0)1293 573150/3238
Fax: +44 (0)1293 573993 Email: [email protected].
Amendments to this document will usually be issued in January and July, incorporating all
new and revised MPDs with updated Alphabetical and Numerical Indices.
MPDs issued between these amendments are available at http://www.caa.co.uk/MPDS
and the latest version of this CAP at www.caa.co.uk/CAP661.
REG CAP 661-2008 history
2008REG CAP 661-2008 Mandatory Permit Directives For Aircraft Operating on a Permit to Fly
1995REG CAP 661-1995 Mandatory Permit Directives For Aircraft Operating on a Permit to Fly Reprinted July 2010 (incorporating revisions to date)