The Boeing 377 Stratocruiser (first flight: Jul, 1947) was a large, long-range airliner developed from the C-97 Stratofreighter military transport, itself a derivative of the B-29 Superfortress.  Boeing’s 377 design was advanced for its day as it featured two passenger decks and a pressurized cabin, however reliability was poor due to problems with the four 28-cylinder Pratt & Whitney R-4360 Wasp Major radial engines and control problems with the engine propellers. Only 55 Model 377s were built for airlines, along with a single prototype. 

Boeing 377 in flight.

Cockpit Procedures Trainers were used as a less expensive and a more efficient method to train and test flight crews.  They were ground based devices which had no ‘motion’ to simulate flight, however the cost to operate a procedures trainer was about 5% as much as the actual aircraft (CPT’s were frequently made from old aircraft cockpits).  

Boeing 377, Pilot (Left front seat), Co-pilot (Right front seat), and Flight Engineer (Right side seat, called the “Side Saddle” seat) duty positions

Cockpit Procedure Trainers were necessary for large, long-distance aircraft in the 1940’s and 50’s, because:

• Flight crews were large; consisting of the Pilot, Co-pilot, Flight Engineer and Navigator,
• The aircraft of the day had little, or no, systems automation,  
• Correct operation of aircraft primary systems (engines, fuel, navigation, communication, electrical, hydraulic, oil, etc.), alternate systems, backup systems and emergency systems required manual manipulation of 100 to 200 switches and buttons, and monitoring of multiple gages by the flight deck crew. 
• Flight deck crews had to complete multiple (and complex) normal, abnormal, and emergency checklists rapidly and efficiently.  

377 varients were converted into the famous "Guppy" series of cargo aircraft.

With Cockpit Procedures Trainers, entire flight deck crews could be trained and tested on flight deck familiarity; normal, abnormal, and emergency procedures; checklist flows, crew coordination and crew proficiency.

Boeing 377 Stratocruiser Cockpit Procedures Trainer. Attached to B-747 engine inlet to show size comparison.

The Museums Cockpit Procedures Trainer is owned by David Lane, a friend of the San Diego Air & Space Museum.