49 CFR 1013.2 - The irrevocability of the trust.
(a) The trust and the nomination of the trustee during the term of the trust should be irrevocable.
(b) The trust should remain in effect until certain events, specified in the trust, occur. For example, the trust might remain in effect until (1) all the deposited stock is sold to a person not affiliated with the settlor or (2) the trustee receives a Board decision authorizing the settlor to acquire control of the carrier or authorizing the release of the securities for any reason.
(c) The settlor should not be able to control the events terminating the trust except by filing with this Board an application to control the carrier whose stock is held in trust.
(d) The trust agreement should contain provisions to ensure that no violations of 49 U.S.C. 11343 will result from termination of the trust.