Stock code: 688563 Stock abbreviation: Aviation Materials Co., Ltd. Announcement No.: 2024-042

Beijing Institute of Aeronautical Materials Co., Ltd

Announcement on the Change of Accounting Firm

The board of directors and all directors of the company guarantee that there is no false record, misleading statement or material omission in the content of this announcement, and assume legal responsibility for the authenticity, accuracy and completeness of its content.

Important Content Notes:

Name of the accounting firm to be hired: Grant Thornton Certified Public Accountants (Special General Partnership) (hereinafter referred to as

"Grant Thornton").

The name of the accounting firm originally employed: Zhongshen Zhonghuan Certified Public Accountants (Special General Partnership) (hereinafter referred to as

Referred to as "Zhongshen Zhonghuan" or "Zhongshen Zhonghuan Certified Public Accountants").

The change of accounting firm is mainly based on the company's demand for audit services, according to the Ministry of Finance, the State Council

The relevant regulations of the State-owned Assets Supervision and Administration Commission of the State Council and the China Securities Regulatory Commission on the selection and appointment of accounting firms, after the relevant procedures have been performed,

According to the selection results, the company intends to engage Grant Thornton Certified Public Accountants for the company's 2024 financial report and internal control

system of audit institutions. The company has fully discussed the change of accounting firm with the former and former accounting firms

communication, all parties have been clearly aware of the matter and confirmed that there is no objection. The former and former accounting firms will follow the "Medium

CPA Auditing Standard No. 1153 - Communication between Former CPAs and Subsequent CPAs

and other relevant requirements, actively communicate and cooperate with the work.

This proposal still needs to be reviewed and approved by the company's general meeting of shareholders.

1. The basic information of the accounting firm to be employed

(1) Institutional information

1. Basic Information

Name of Accounting Firm: Grant Thornton Certified Public Accountants (Special General Partnership)

Date of Establishment: December 22, 2011

Form of organization: special general partnership

Registered address: 5th Floor, Scitech Plaza, No. 22, Jianguomenwai Street, Chaoyang District, Beijing

Senior Partner: Li Huiqi

As of the end of 2023, Grant Thornton has nearly 6,000 employees, including 225 partners, 1,364 certified public accountants, and more than 400 certified public accountants who have signed audit reports on securities service business.

Grant Thornton's business income in 2023 is 2.703 billion yuan, including 2.205 billion yuan from audit business and 502 million yuan from securities business. In the 2023 annual report, 257 listed companies were audited by clients, including manufacturing, information transmission, software and information technology services, wholesale and retail, electricity, heat, gas and water production and supply, transportation, warehousing and postal services, etc., with a total fee of 355 million yuan. The company has 6 audit clients of listed companies in the same industry.

2. Investor protection capabilities

Grant Thornton has purchased occupational insurance, with a cumulative compensation limit of 900 million yuan, and the purchase of occupational insurance complies with relevant regulations. At the end of 2023, the occupational risk fund will be 8.1509 million yuan.

Grant Thornton is not required to bear civil liability for civil lawsuits related to professional conduct that have been concluded in the past three years.

3. Integrity record

In the past three years, Grant Thornton has been subject to 0 criminal penalties, 1 administrative punishment and supervision for its professional behavior

11 management measures, 5 self-regulatory measures and 1 disciplinary action. 41 practitioners have been practicing in the past three years

He received 0 criminal penalties, 10 administrative punishments, 11 supervision and management measures, and 5 self-discipline and supervision measures

1 disciplinary sanction.

(2) Project information

1. Basic Information

Project Partner: Yang Zhi, became a certified public accountant in 2008, began to engage in the audit of listed companies in 2008, began to practice in Grant Thornton Certified Public Accountants in 2008, and signed 6 audit reports of listed companies in the past three years.

Project Signing Certified Public Accountant: Li Chunxu, became a certified public accountant in 2015, began to engage in the audit of listed companies in 2013, and began to practice in Grant Thornton Certified Public Accountants in 2007; In the past three years, 3 audit reports of listed companies have been signed.

Project Quality Review Partner: Bai Jing, became a certified public accountant in 2007, began to engage in the audit of listed companies in 2005, and began to practice in Grant Thornton Certified Public Accountants in 2005; In the past three years, 5 audit reports of listed companies have been signed, and 1 audit report of listed companies has been reviewed.

2. Integrity record

The project partner, the signing certified public accountant, and the project quality review partner have not been affected by their professional conduct in the past three years

As for criminal punishment, it has not been subject to administrative punishment and supervision by the China Securities Regulatory Commission, its dispatched agencies, industry authorities, etc

The self-regulatory measures and self-regulatory measures have not been subject to the self-regulatory measures of self-regulatory organizations such as stock exchanges and industry associations

Impose, disciplinary action.

3. Independence

Grant Thornton Certified Public Accountants and project partners, signatory certified public accountants, and project quality review partners are not

There are circumstances that may affect independence.

4. Audit fees

The audit fee is mainly determined based on the responsibility of the professional service and the degree of professional expertise required, taking into account the experience and level of the employees involved, the corresponding fee rate and the working hours invested.

After comprehensive assessment, the company's audit fee in 2024 is expected to be 950,000 yuan, which is the same as the audit fee in 2023, including 700,000 yuan for financial report audit and 250,000 yuan for internal control audit.

2. A description of the proposed change of accounting firm

(1) The situation of the former accounting firm and the audit opinion of the previous year

The accounting firm originally hired by the company is Zhongshen Zhonghuan Certified Public Accountants (Special General Partnership), which has provided audit services for the company for 4 consecutive years, and issued a standard unqualified audit report for the company in 2023. The company does not have the situation that the former accounting firm has been entrusted to carry out part of the audit work and then dismissed the former accounting firm.

(2) The reason for the proposed change of the new accounting firm

According to the relevant regulations of the Ministry of Finance, the State-owned Assets Supervision and Administration Commission of the State Council and the China Securities Regulatory Commission on the selection and appointment of accounting firms, after performing the relevant procedures, according to the selection results, the company intends to hire Grant Thornton Certified Public Accountants as the company's 2024 financial report and internal control audit institution. At the same time, the board of directors of the company expressed its heartfelt thanks to Zhongshen Zhonghuan Certified Public Accountants (Special General Partnership) for providing professional, rigorous and responsible audit services during its tenure as the company's audit institution.

(3) The communication between the company and the former accounting firms

The Company has fully communicated with the former and former accounting firms regarding the change of accounting firms, and all parties have clearly understood the matter and confirmed that there is no objection. The former and former accounting firms will actively communicate and cooperate with each other in accordance with the Chinese Certified Public Accountants Auditing Standard No. 1153 - Communication between Former Certified Public Accountants and Subsequent Certified Public Accountants and other relevant requirements.

3. The procedures to be performed by the accounting firm are to be changed

(1) The deliberations of the Audit Committee

The 18th meeting of the Audit Committee of the first board of directors of the company deliberated and passed the "Proposal on Changing the Accounting Firm". The Audit Committee of the Board of Directors of the Company has fully understood and reviewed the professional competence, investor protection ability, independence and integrity of Grant Thornton Certified Public Accountants, and the Audit Committee believes that Grant Thornton Certified Public Accountants has the experience and ability to provide audit services for listed companies and can meet the requirements of the Company's annual audit work, and agrees that the Company will hire Grant Thornton Certified Public Accountants as the Company's 2024 annual audit institution, responsible for financial audit and internal control audit, and submit it to the Board of Directors of the Company for deliberation.

(2) The deliberations of the Board of Directors

On December 11, 2024, the company held the 20th meeting of the first board of directors, deliberated and passed the "Proposal on Changing the Accounting Firm", agreed to hire Grant Thornton Certified Public Accountants as the company's 2024 audit institution, and submitted the proposal to the company's general meeting of shareholders for deliberation.

(3) The deliberations of the board of supervisors

The board of supervisors believes that the change of accounting firm is in line with the relevant regulations of the Ministry of Finance, the State-owned Assets Supervision and Administration Commission of the State Council and the China Securities Regulatory Commission on the selection and appointment of accounting firms, in line with the company's business development and demand for audit services, and can ensure the independence and objectivity of the company's audit work. The company intends to hire Grant Thornton Certified Public Accountants (Special General Partnership) with the qualifications of accounting firms to perform and engage in securities and futures related business, and has the corresponding conditions and competence to undertake the company's audit business, and can meet the company's requirements for annual financial reports and internal control audits.

(4) Effective date

The change of accounting firm still needs to be submitted to the general meeting of shareholders of the company for deliberation, and will take effect from the date of approval of the general meeting of shareholders of the company.

The announcement is hereby made.

Board of Directors of Beijing Institute of Aeronautical Materials Co., Ltd

December 12, 2024