I thought this might interest you. The U.S. Government Accountability Office (GAO) issued a report in November 2011 regarding the quality of spare parts used in U.S. military equipment. (Credit for the link goes to "The Boresight" blog, http://theboresight.blogspot.com/2009/09/some-thoughts-and-discussion.html
You can read through the report on your own, but I'll summarize it. The investigation is ongoing, but of the 7 parts they've tested, all 7 have failed to be authentic. All 7 were from China (pages 2-3).
This is not a trivial matter. Quoting directly from the report:
"An authentic part with this number is a voltage
regulator that may be commonly found in military systems such as the Air
Force’s KC-130 Hercules aircraft, the Navy’s F/A-18E Super Hornet
fighter plane, the Marine Corps’ V-22 Osprey aircraft, and the Navy’s
SSN-688 Los Angeles Class nuclear-powered attack submarine. If
authentic, these parts provide accurate power voltage to segments of the
system they serve. Failure can lead to unreliable operation of several
components (e.g., integrated circuits) in the system and poses risks to the
function of the system where the parts reside" (page 7).
"An authentic part with this part number is an operational amplifier that may be
commonly found in the Army and Air Force’s Joint Surveillance and
Target Attack Radar System (JSTARS); the Air Force’s F-15 Eagle fighter
plane; and the Air Force, Navy, and Marine Corps’ Maverick AGM-65A
missile. If authentic, this part converts input voltages into output voltages
that can be hundreds to thousands of times larger. Failure can lead to
unreliable operation of several components (e.g., integrated circuits) in
the system and poses risks to the function of the system where the parts
reside" (page 8). (<http://www.gao.gov/new.items/d12213t.pdf
Now, if this is the case for U.S. military equipment, I can only imagine what is happening with Chinese military equipment. The "Epoch Times" (March 18, 2010) has an informative article.
"AVICSAC former employee Ma Ming told The Epoch Times that beginning in the latter part of 2007, former plant manager Yang Yongying began subcontracting the production of parts for J-8 (Jian-8; NATO reporting name Finback) and J-8II, one of the most advanced all-weather interceptors in China, to eight private workshops to increase profits.
According to Ma, workers in those private workshops have no qualifications, training, or vocational certificates, or even basic technical knowledge. As a result, several serious accidents have occurred. However, workshop owners used payoffs to silence reports on those accidents, and Ma believes many aircraft equipped with such parts are in danger ….
Although there are several military representatives from the navy and air force who are supposed to oversee the management, Ma said that "they also took advantage of their military privileges to have their relatives run such workshops,” so in the end no one responded to Ma’s reports ….
After reporting the corruption to many levels of authorities without response, Ma posted the information on the Internet: "Yang is not alone. It is a bunch of corrupt officials. I want to teach them a lesson—at least I can constrain them from doing more bad things."
Yang has now stepped down from his position. Ma said it is probable that some higher authorities feared his case would lead to more trouble. To date, no media report has confirmed Yang’s removal." (<http://www.theepochtimes.com/n2/china-news/corruption-jet-fighter-j-8-j-8ii-military-industry-31665-print.html