Title: De Havilland DH121 Trident

The DH121 Trident was designed by De Havilland in response to a specification from British European Airways (BEA) for a replacement aircraft for the Viscount. BEA subsequently changed the specification to tailor the aircraft to their particular needs, and the design was downsized. However once the first aircraft had been built, BEA realised it needed a larger aircraft, and more powerful engines, high-lift devices, and increased passenger capacity were progressively installed. The last series, the 3B, had a lengthened fuselage and could accommodate up to 180 passengers. However it needed a fourth engine for take-off, installed in a fairing beneath the rudder,
and had a much shorter range.

All Tridents suffered from poor take-off performance, BEA crews joking that it only left the ground due to the curvature of the earth. The Trident was notable as being the first passenger jet to be fitted with a fully automatic landing system. Only 117 Tridents were built in total, compared to 1700 Boeing 727s, an aircraft which fitted the original DH121 specification almost exactly.

This title contains the flight manual for the early Trident 1E along with two manufacturer’s brochures. The files have been scanned from the original flight manuals and retain any colour pages.



This title contains:

  • De Havilland manufacturers Crew’s Notes for the DH121 Trident series 1E, CM-121-1E-102, in three volumes:
    Volume 1 (approx 560 pages) – Decsription, Sections 1 to 10.
    Volume 2 (approx 486 pages) – Description, Sections 11 to 18. Limitations and Procedures.
    Volume 3 (approx 410 pages) – Flight Planning Data.
  • Manufacturer’s brochure for the Trident 2E, dated May 1971 with approx 20 pages.
  • Manufacturer’s brochure for the Trident 3B, dated Mar 1970 with approx 44 pages.