Wears 'Flight Research' titles. Used to test radio equipment and safety features. Later painted white and red. Ended up in Mexico. Photo by: Carl Mydans / Life

In flight over San Francisco. The 1939-1940 Golden Gate International Expo is under construction on Treasure Island, with the Pan Am flying boat terminal on the right side. As N16070 this DC-3 is preserved in the Evergreen museum in McMinnville, Oregon. Photo by: Carl Mydans / Life

Here on delivery and it flew with United until sold to Sterling in 1972 as OY-SBV. In 1974 it went to the Mauritania government and scrapped as 5T-RIM at Dakar (GOOY) in 1992. (Note the three ramp workers seemingly embarrassed while a 'suit' gets into the act and gives the departing jet the thumbs-up.)

Here on delivery and it flew with United until 1972 when it was sold to Sterling as OY-SAP, but leased/sold as PI-C970/RP-C970 instead until 1976 then restored to OY-SAP and scrapped at Copenhagen (EKCH) in 1977.

Here on delivery and operated by UAL until 1971. Acquired by Goodyear Aerospace as here in 1973. Donated to the Pima Air and Space Museum in 1990 and put on display.

Photographer: Unknown photographer.

Built in 1936. Name reported to be Mainliner Sacramento. N16062 served with Northeast Airlines from 1953. To North Cay Airways of Puerto Rico as N16060. Deregistered as 'destroyed' in 2009. Photo by: Carl Mydans / Life

Leaving the gate area at EWR in June, 1967. Later became VP-HCM with Belize Airways.

United Jet Freighter

A freak accident on 9 February 1937 killed the eleven souls on board. On approach to SFO, the co-pilot dropped his microphone which jammed the elevator controls. Photo by: Melvin Kevie / San Francisco Examiner / Berkeley University

Aircraft delivered earlier that same year in April and still wearing the original gold pin-striping and squared-off natural metal underbelly of United's early 727s.

Used as a Boeing demonstrator on a world tour. Was also a systems test airframe. In basic UAL colours but never operated by them. Re-reg as N68650, for various operators. Sadly, destroyed in mid-air collision with Cessna 310, N3121S, near Hendersonville NC 19 Jul 1967. The second N7003U (c/n 18791) was first registered in 1965. Photo most probably taken on 22 Oct1963 when the 727 visited AMS for the first time. KLM selected the smaller Douglas DC-9, which did not fly until 1965. The only Dutch airline ever to operate the 727 was Air Holland in the 1980s, but Lufthansa, Olympic, Air France, Iberia and Alitalia 727s visited AMS very frequently. Photo from: Amsterdam City Archives

There was another Convair, ex KLM, registered N73155 that was converted to a 580. The aircraft in the photo became N8786 and remained a 340. Chuck Boie photo.

Scrapped. Chuck Boie photo.