While they are predominantly associated with covers that were in an aircraft wreck, crash covers can also come from train, ship or other mode of mail transport.
Perhaps the most famous and costly crash covers are those that resulted from the fiery destruction of the zeppelin Hindenburg, at Lakehurst, N.J. on May 6, 1937, resulting in 367 crash mail covers.
Flights related to crash covers have even found their way into popular entertainment. The film The Aviator with Christopher Reeve playing a downed pilot, is from aviation writer Ernest Gann's novel of the same name. The plot is based on an actual crash along the Elko-Pasco CAM (Contract Air Mail) route.
CAMs Popular with Air Mail Collectors
In the Twenties when CAM flights covered the nation, no one was immune from crashing a mail plane, including Charles Lindbergh, who, some time before his history making transatlantic solo flight to Paris, was forced to bail out when his plane ran out of gas as Lindy flew the CAM 2 route. Mail recovered, it was sent on to its destination, Chicago, by train.
As Don Holmes in Airmail -- an illustrated history 1793-1981 writes "On November 3, 1926...Lindbergh had to bail out for a second time...It was generally agreed that Lindbergh had been overly aggressive in trying to get the mail through..." and the powers that be nearly grounded him.
Identifying and Recording Crash Covers
While the most dramatic pieces of crash mail have charring or water damage, some have no signs that they survived a crash at all. It is then up to the postmark and a bit of research to identify the cover as from a crash.
The American Air Mail Society has listed crash covers in their air mail catalog for many years -- it is a fairly definitive listing of known crash covers from the early days of the air mail to more current times.
Some collectors take issue with the collection of crash covers, especially those that are connected to loss of life. But most aerophilatelists feel that the souvenirs of disaster are part of the aviation record and are more than worthy to collect.
Collectors interested in crash covers should not be fooled by items of a commemorative nature, like those issued by private cachet makers to mark the crashes of the dirigibles Macon and Akron. There was no mail recovered from the wrecks of these airships. Perhaps not as dramatic as the Hindenburg wreck, these crashes were quite noteworthy at the time, with loss of life involved. Commemorative covers continue to be traded in the philatelic marketplace today, and a catalog listing the cachet varieties was published about 70 years after the crash events.
In fact there is a great deal of literature relating to crash covers, a few of the best available from the American Air Mail Society.
Crash Covers From Behemoths of the Air and Sea
In March 2012 the Smithsonian Institute's National Postal Museum mounted an exhibit called Fire and Ice. It features mail related to the ship Titanic and the Hindenburg. The zeppelin Hindenburg provided the fastest transatlantic airmail service at the time. While that service was taken advantage of by some mailers, it was mostly collectors who sent souvenir flight covers that helped finance the zeppelin's historic flights.
Although there was no mail recovered from the Titanic, what is known, thanks to the Wreck and Crash Mail Society's Kendall Sanford's recording efforts, are twenty three examples of mail facing slips. While these are not items of postal history per se, as they are without stamps or routing markings, they are much sought after by collectors as collateral items to their postal history collections of crash and wreck covers.