This is a great analysis of choppers that could be a proxy for the offshore drilling boom. According to the May 12th edition of Fortune Magazine, the offshore drilling boom combined along with increased usage of choppers for private travel has lead to a shortage of helicopters and their parts.

According to SinLetter, the earnings forecast of offshore drillers like Transocean (RIG), Diamond Offshore Drilling (DO) and Noble (NE), the offshore oil drilling boom is likely to continue for years to come. Four popular chopper models were mentioned in the sidebar accompanying the Fortune article. The Sikorsky S92 and S76 used for executive travel and by offshore drillers, the smaller AW119 Ke used by traffic reporters and the larger Boeing Chinook used to transport civilian cargo.

Below is a list of some of public helicopter plays:

1. Sikorsky Aircraft is a division of United Technologies (UTX) and makes the famous Black Hawk chopper as well as nearly half the maritime choppers used by armed forces around the world.

2. The Boeing Chinook made by Boeing (BA).

3. The AW119 Ke is made by AgustaWestland, a division of Italian company Finmeccanica. Finmeccanica is quoted on various exchanges such as London (FNA.L), Milan (FNC.ML), Berlin (FMNB.BE) as well as over-the-counter (OTC) in the “grey market” (FINMF.PK). Finmeccanica is said to be in talks to acquire New Jersey based defense company DRS Technologies (DRS). They are not a pure play and derives a majority of its revenue from defense electronics. Helicopters are the second biggest division of the company representing 22% of 2007 revenues.

4. Kaman (KAMN) is a pure play helicopter and industrial distribution company.

5. Bell helicopter, a subsidiary of aerospace giant Textron (TXT). As an added bonus, investing in Textron also gives you exposure to the red hot light jet segment as the company also makes the Cessna line of jets.

6. European aviation giant EADS (EAD.PA), more commonly known as the parent of Airbus, also has a helicopter division called Eurocopter that makes various models of both civil and military choppers.

There is a great table comparing the public companies in this article on SinLetters site.

Asif would invest in Textron (TXT) and Kaman (KAMN) based on their current valuation, estimated 2008 revenue growth rates and because they seem to be the closest to pure plays.