sc13da11812.htm

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D/A

(Amendment No. 5)

Under the Securities Exchange Act of 1934

American Pacific Corporation

(Name of Issuer)

Common Stock, par value $0.10 per share

(Title of Class of Securities)

028740108

(CUSIP Number)

Cornwall Capital Management LP

One Rockefeller Plaza, 24th Floor

New York, New York 10020

Attention: Ian D. Haft

(917) 639-5438

With a copy to:

Richard J. Birns, Esq.

Boies, Schiller & Flexner LLP

575 Lexington Avenue, 7th Floor

New York, NY 10022

(212) 446-2300

(Name, Address and Telephone Number of Person

Authorized to Receive Notices and Communications)

November 8, 2012

(Date of Event which Requires Filing of this 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: o

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Rule 240.13d-7 for other parties to whom copies are to be sent.

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

SCHEDULE 13D

CUSIP No. 028740108
1	NAME OF REPORTING PERSON / I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Cornwall Master LP
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) ¨ (b) þ
3	SEC USE ONLY
4	SOURCE OF FUNDS (See Instructions) WC
5	CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) o
6	CITIZENSHIP OR PLACE OF ORGANIZATION Cayman Islands
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 1,141,481 shares of common stock
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 1,141,481 shares of common stock
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 1,141,481 shares of common stock
12	CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) (see Item 5) 14.975%
14	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) PN

CUSIP No. 028740108
1	NAME OF REPORTING PERSON / I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Cornwall Capital Management LP
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) ¨ (b) þ
3	SEC USE ONLY
4	SOURCE OF FUNDS (See Instructions) AF
5	CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) o
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 1,141,481 shares of common stock
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 1,141,481 shares of common stock
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 1,141,481 shares of common stock
12	CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) (see Item 5) 14.975%
14	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) IA, PN

CUSIP No. 028740108
1	NAME OF REPORTING PERSON / I.R.S. IDENTIFICATION NO. OF ABOVE PERSON. Cornwall GP, LLC
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) ¨ (b) þ
3	SEC USE ONLY
4	SOURCE OF FUNDS (See Instructions) AF
5	CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) o
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 1,141,481 shares of common stock
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 1,141,481 shares of common stock
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 1,141,481 shares of common stock
12	CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) (see Item 5) 14.975%
14	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) OO

CUSIP No. 028740108
1	NAME OF REPORTING PERSON / I.R.S. IDENTIFICATION NO. OF ABOVE PERSON. James Mai
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) ¨ (b) þ
3	SEC USE ONLY
4	SOURCE OF FUNDS (See Instructions) AF
5	CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) o
6	CITIZENSHIP OR PLACE OF ORGANIZATION United States of America
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 1,141,481 shares of common stock
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 1,141,481 shares of common stock
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 1,141,481 shares of common stock
12	CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) (see Item 5) 14.975%
14	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) IN

This Amendment No. 5 (this “Amendment”) amends the statement on Schedule 13D filed with the Securities and Exchange Commission (the “SEC”) on October 12, 2011 (as amended by Amendment No. 1 filed with the SEC on December 6, 2011, Amendment No. 2 filed with the SEC on June 6, 2012, Amendment No. 3 filed with the SEC on September 6, 2012 and Amendment No. 4 filed with the SEC on October 29, 2012 and hereby, the “Schedule 13D”), with respect to shares of common stock, par value $0.10 per share (the “Shares”), of American Pacific Corporation, a Delaware corporation (the “Company”). Capitalized terms used herein and not otherwise defined in this Amendment have the meanings set forth in the Schedule 13D. This Amendment amends Items 3 and 5 as set forth below.

Item 3.	Source and Amount of Funds or other Consideration
	Item 3 is amended and restated as follows as of the date hereof: Funds for the purchase of the Shares by Cornwall Master reported herein were derived from general working capital made in the ordinary course of business. A total of approximately $9,634,337 (excluding commissions) was paid to acquire the Shares reported herein.
Item 5.	Interest in Securities of the Company
	Item 5(a)-(c) is amended and supplemented to add the following information for updating as of the date hereof: (a) As of the date hereof, the Reporting Persons may be deemed the beneficial owner of an aggregate of 1,141,481 Shares directly held by Cornwall Master. The Shares beneficially owned by the Reporting Persons represent approximately 14.9750% of the Shares outstanding. Percentages of the Shares outstanding reported in this Schedule 13D are calculated based upon the 7,622,591 Shares outstanding as of July 31, 2012, as reported in the Company’s Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2012, filed by the Company with the SEC on August 13, 2012. Cornwall Master directly holds 1,141,481 Shares; none of the other Reporting Persons directly hold any Shares. (b) Due to the relationships described in Item 2, each of the Reporting Persons shares voting and dispositive power over the Shares held directly by Cornwall Master. (c) The trading dates, number of Shares purchased or sold, and the price per Share for all transactions by the Reporting Persons in Shares since the last filing on Schedule 13D, all of which were brokered transactions, are set forth below.

Name of Reporting Person	Date	Number of Shares Purchased (Sold)	Average Price per Share
Cornwall Master	11/08/2012	125,000	$12.2500

SIGNATURES

After reasonable inquiry and to the best of each of the undersigned’s knowledge and belief, each of the undersigned, severally and not jointly, certifies that the information set forth in this statement is true, complete and correct.

Dated: November 9, 2012

CORNWALL MASTER LP

By:	Cornwall GP, LLC, its general partner

	By:	/s/ James Mai
		Name: James Mai
		Title: Managing Member


CORNWALL CAPITAL MANAGEMENT LP

By:	CMGP, LLC, its general partner

	By:	/s/ James Mai
		Name: James Mai
		Title: Managing Member


CORNWALL GP, LLC

By:	/s/ James Mai
	Name: James Mai
	Title: Managing Member


/s/ James Mai
JAMES MAI, individually