13D Filing: Caledonia Investments PLC Buys More Shares of Struggling Bristow Group Inc (BRS) After They Hit 10-Year Low

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 1)*

Bristow Group
Inc.

(Name of Issuer)

Common Stock ($0.01 par value)

(Title of Class of Securities)

676255 10 2

(CUSIP
Number)

Mr. Graeme P. Denison, Caledonia Investments plc, 2^nd Floor, Stratton
House, 5 Stratton Street,

London, England W1J 8LA (44-20-7802-8080)

(Name, Address and Telephone Number of Person Authorized to Receive Notice and Communications)

February 12, 2016

(Date
of Event which Requires Filing of Statement)

If the filing
person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following
box  ¨.

NOTE: Schedules filed in paper format shall include a signed original and five copies of the Schedule, including all exhibits. See §
240.13d-7(b) for other parties to whom copies are to be sent.

*	The remainder of this cover page shall be filled out for a reporting persons initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

The information required on the remainder of this cover
page shall not be deemed to be filed for the purpose of Section 18 of the Securities Exchange Act of 1934 (Act) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions
of the Act (however, see the Notes).