Foreign investment in air transport services is limited to 49% of equity ownership.
"ANNEX I - SCHEDULE OF BRUNEI DARUSSALAM
Sector: Transport Services
Sub-sector: Specialty air services (flight training organisation)
Obligations Concerned: National Treatment (Article 9.4), Performance Requirements (Article 9.10), Senior Management and Boards of Directors (Article 9.11), 
Market Access (Article 10.5), Local Presence (Article 10.6)
Measures: Administrative Measures and Guidelines
Description: Investment
1. Foreign nationals and enterprises may not provide specialty air transport services (flight training) in Brunei Darussalam, unless:
(a) through an enterprise established in Brunei Darussalam that is a joint venture, where the foreign national or enterprise does not own more than 49 per cent equity shareholding in any such enterprise providing specialty air services (flight training); (b) they comply with any performance requirements imposed, including a requirement to transfer a particular technology or other proprietary knowledge as long as such requirement to transfer technology or other proprietary knowledge does not unreasonably prejudice the legitimate interests of the owner of technology and is not for the purpose of commercial exploitation by Brunei Darussalam; and (c) a  majority of the senior managers in any such enterprises established are Brunei nationals. 
2. The number of enterprises in Brunei Darussalam providing specialty air services (flight training) may be subject to needs-based quantitative limits.” (ANNEX I - SCHEDULE OF BRUNEI DARUSSALAM, Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP)) 
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"Interpretation. 3. In this Order, unless the context requires - [...]
"air transport enterprise" means an enterprise engaged in or offering to engage in scheduled or non-scheduled public transport by air; [...]
"citizen" means an individual who is a citizen of Brunei Darussalam, a person to whom a Residence Permit has been granted under regulations made under the Immigration Act (Chapter 17) or a body corporate incorporated or registered in Brunei Darussalam under the Companies Act (Chapter 39); 
[...]
PART VI - AIR TRANSPORT
Operating licence.
25. (1) Notwithstanding any international agreement, no air transport enterprise shall apply for an operating licence pursuant to any regulations relating to the licensing of commercial flying, before an air operator's certificate is issued.
(2) Without prejudice to any international agreement to which Brunei Darussalam is a party, no air transport enterprise shall be granted an operating licence unless it has its principal place of business in Brunei Darussalam, and is owned and controlled by Brunei Darussalam or by a citizen.
(3) The Director shall establish criteria and the procedure for obtaining an operating licence" (CIVIL AVIATION ORDER, 2006)
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"PART I - REGISTRATION AND MARKING OF AIRCRAFT
Aircraft to be registered and registration of aircraft in Brunei Darussalam. [...]
(4) Subject to the provisions of this regulation, an aircraft shall not be registered or continue to be registered in Brunei Darussalam if it appears to the Director that {a} the aircraft is registered outside Brunei Darussalam and that such registration does not cease by operation of law upon the aircraft being registered in Brunei Darussalam; {b) a person who is not qualified, as defined in sub-regulation (5), holds any legal or beneficial interest by way of ownership in the aircraft or any share therein; or {c) it would be detrimental to the public interest for the aircraft to be or to continue to be registered in Brunei Darussalam. 
(5) The following persons and no others shall be qualified to hold a legal or beneficial interest by way of ownership in an aircraft registered in Brunei Darussalam or a share therein {a} His Majesty the Sultan and Yang Di-Pertuan; {b) the Government; {c) citizens and such other persons as the Minister shall approve; and {d) partnerships and voluntary associations whose principal place of business or recreation is in Brunei Darussalam, or otherwise as the Minister shall approve. 
(6) If any unqualified person residing or having a place of business in Brunei Darussalam holds a legal or beneficial interest by way of ownership in an aircraft, or a share therein, the Minister, upon being satisfied that the aircraft may otherwise be properly so registered, may register the aircraft in Brunei Darussalam. That person shall not cause or permit the aircraft, while it is registered in pursuance of this sub-regulation, to be used for the purpose of public transport or aerial work. This restriction does not apply when a leasing agreement between a Brunei Darussalam operator holding a Brunei Darussalam air operator's certificate and the lessor of the aircraft is notified to the Director and the interest of the lessor is registered in the register of Brunei Darussalam aircraft. [...]"  (CIVIL AVIATION REGULATIONS, 2006)
ANNEX I - SCHEDULE OF BRUNEI DARUSSALAM, Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP)
CIVIL AVIATION ORDER, 2006
CIVIL AVIATION REGULATIONS, 2006
[<a href="https://www.mfat.govt.nz/assets/Trade-agreements/TPP/Annexes-ENGLISH/Annex-I.-Brunei.pdf">CPTPP</a>],[<a href="https://www.dca.gov.bn/AIC/Civil%20Aviation%20Order%202006.pdf">Order</a>],[<a href="https://www.agc.gov.bn/AGC%20Images/LAWS/Gazette_PDF/2006/EN/s069.pdf">Reg</a>]