Lockheed L-1011 TriStar - Design

Design

The L-1011 featured a highly advanced autopilot system and was the first widebody to receive FAA certification for Cat-IIIc autolanding, which approved the TriStar for completely blind landings in zero-visibility weather performed by the aircraft's autopilot. The L-1011 used an Inertial Navigation System (INS) to navigate; this included aligning the navigation system by entering current coordinates of longitude and latitude.

It also had a unique Direct Lift Control (DLC) system, which allowed for smooth approaches when landing, without having to use significant pitch changes while on the approach path. DLC helps maintain the descending glideslope on final approach by automatically deploying spoiler panels on the wings. Thus, rather than maintaining the descent by adjusting pitch, DLC helps control the descent while maintaining a more consistent pitch angle, using four redundant hydraulic systems. Production also utilized a unique "autoclave" system for bonding fuselage panels together; this made the L-1011 extremely resistant to corrosion.

The earlier versions of the L-1011, such as the -1, -100, and -150 can be distinguished from the later models by the design of the middle engine nacelles. The earlier version nacelle has a round intake, whereas the later models have a small vertical fin between the bottom of the middle engine intake and the top of the fuselage.

The two L-1011 aircraft delivered to Pacific Southwest Airlines were configured with internal airstair doors that led into an entry hall in what was normally the forward lower baggage hold. This was to allow operations from airfields that did not have terminal buildings with jet bridges. These two aircraft were later in service with Aeroperú and Worldways Canada.