A blood chit is a document carried by military personnel and addressed to any civilians who may come across an armed-services member – such as a shot-down pilot – in difficulties. As well as identifying the force to which the bearer belongs as friendly, the notice displays a message requesting that the service member be rendered every assistance.
The idea of blood chit originates from 1793 when French balloonist Jean-Pierre Blanchard demonstrated his hot air balloon in the United States. Because he could not control the direction of the balloon, no one knew where he would land. Because Blanchard did not speak English, George Washington gave him a letter that said that all U.S. citizens were obliged to assist him to return to Philadelphia.
In World War I, British Royal Flying Corps pilots in 1842 in India, Afghanistan and Mesopotamia carried a "goolie chit" printed in four local languages that promised a reward to anyone who would bring an unharmed British aviator back to British lines. The British officer John Masters recorded in his autobiography that Pathan women in the North-West Frontier Province (1901–1955) of British India (now modern day Pakistan) during the Anglo-Afghan Wars would behead and castrate non Muslim soldiers who were captured, like British and Sikhs.
In the Second Sino-Japanese War prior to World War II, foreign volunteer pilots of Flying Tigers carried notices printed in Chinese that informed the locals that this foreign pilot was fighting for China and they were obliged to help them. A text from one such blood chit translates as follows:
"I am an American airman. My plane is destroyed. I cannot speak your language. I am an enemy of the Japanese. Please give me food and take me to the nearest Allied military post. You will be rewarded."
United States Armed Forces
When the U.S. officially entered World War II in December 1941, flight crew survival kits included blood chits printed in 50 different languages that sported an American flag and promised a reward for a safe return of a pilot. The kit might also include gifts like gold coins, maps or sewing needles.
Many U.S. flight crews that flew over Asia had their "blood chit" sewn to the back of their flight jackets. Some units added the blood chit to the crew's flight suits while other units gave the blood chit out only for specific flights.
Currently, blood chits are a product of the Joint Personnel Recovery Agency. They are a small sheet of Tyvek material with an American flag and a statement in several languages indicating that the U.S. will reward anyone assisting the bearer to safety. They represent a written promise or obligation of the US Government.
There is a risk in wide spread knowledge of their use. History has shown that once any of our enemies who became knowledgeable of the successful return of an American with the assistance of an indigenous person(s) resulted in the torture and death of the helpers. In some cases the death of their entire family and even an entire village resulted in this information becoming open source."