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UK Civil Aviation Regulations

These are published by the CAA on our UK Regulations pages. EU Regulations and EASA Access Guides published by EASA no longer apply in the UK. Our website and publications are being reviewed to update all references. Any references to EU law and EASA Access guides should be disregarded and where applicable the equivalent UK versions referred to instead.

UK Part 21 aircraft that do not have a valid Certificate of Airworthiness (CofA) or Restricted CofA (RCofA) but are capable of safe flight under defined conditions may be eligible for a Permit to Fly (PtF) under UK Regulation (EU) No 748/2012 UK Part 21 Subpart P.

A PtF is generally required when the aircraft is capable of performing safe flight but its CofA (or RCofA) cannot be issued or is temporarily invalid.

The PtF can be issued by the UK Civil Aviation Authority (CAA), or a UK CAA approved Design, Production or Continuing Airworthiness Management Organisation (Part M subpart G, Part-CAMO or Part-CAO) with appropriate competence and privilege. Permits to Fly provides further guidance and PtF applications. For a PtF to be issued, the safe condition of the aircraft must first be established. We may put in place restrictions on a permit to maintain an acceptable level of safety.

The configuration(s) for which the Permit to Fly is requested, any conditions or restrictions necessary for safe operation of the aircraft, their substantiation and the method for controlling the aircraft configuration in order to remain within the established conditions are termed 'Flight Conditions'.

The establishment and approval of Flight Conditions on a UK registered aircraft is done either by the UK CAA or a UK CAA approved design organisation with appropriate competence and privilege. When approved by the CAA, we will complete a CAA Form 18B to confirm the approval of safety design-related Flight Conditions.

The approval of Flight Conditions is related to the safety of the design when:

  • The aircraft does not conform to an approved design, such as when compliance with airworthiness requirements has yet to be demonstrated.
  • The result of damage to the aircraft beyond applicable limits.
  • When the aircraft does not comply with the essential requirements for airworthiness (for example non-compliance with any or a combination of the following):
    • an Airworthiness Directive (AD)
    • a Mandatory Service Bulletin (SB)
    • An Airworthiness Limitations, Airworthiness Limitation Items (ALIs).
    • A Certification Maintenance Requirement (CMR)
    • A Critical Design Configuration Control Limitation item (CDCCL)
    • The expiry of a life limited part.
    • A Master Minimum Equipment List (MMEL) item is affected.
  • The intended flight(s) is (are) outside of the approved envelope.
  • The Permit to Fly is issued for the purpose of 21.A.701(a)(15) (note that only the aircraft owner can apply for this PtF purpose).

Permits to Fly offers further guidance when the approval of Flight Conditions is not related to the safety of the design.


Anyone may apply for our approval of safety of design-related Flight Conditions.

How to apply

When the approval of Flight Conditions is related to the safety of the design, an application is made using CAA Form SRG1767 and completion of CAA Form 18B.

When the approval of Flight Conditions is not related to the safety of the design, the application for approval of non-design related Flight Conditions can be made using the online application form.

Approval process


Submit an application on CAA Form SRG1767 and a CAA Form 18B with Blocks 1 through to 12 completed.

Block 6 of the CAA Form 18B will detail the aircraft configuration, including in what way(s) the aircraft does not comply with the applicable airworthiness requirements.

Block 7 of the CAA Form 18B will detail the substantiation that the aircraft can fly safely and Block 8 will detail any conditions or restrictions

x x

CAA will review the data presented on the CAA Form 18B and consider the conditions for safe flight, particularly the detail in Blocks 7 and 8

CAA may require the Applicant to re-submit the Form 18B if amendments to substantiation or conditions/restrictions are required.

  x CAA will complete Block 13 of the CAA Form 18B and return to the Applicant. This constitutes the approval of the Flight Conditions.
x   Applicant uses the completed CAA Form 18B to support its application for a PtF.

Additional information

  • A PtF is issued in accordance with UK Part 21 Subpart P. Any natural or legal person can apply (no nationality restrictions) for the approval of Flight Conditions (FC) or the issuance of a PtF:
  • In accordance with UK Part 21, only the UK CAA or UK 21J approved design organisations can approve FC for UK registered aircraft.
  • UK approved 21J organisations cannot use their privileges to approve FC on non-UK registered aircraft.
  • The PtF holder should be the one operating the aircraft under the PtF.
  • A PtF issued under UK Part 21 does not allows flights outside UK airspace unless permission is granted by the State in which the aircraft intends to fly.