Editing Lockheed L-1011 TriStar (section)

=== Electrical system and avionics ===
[[File:Lockheed L-1011 Tristar simulator cockpit RAF museum.jpg|thumb|The L-1011 TriStar's three-crew flight deck]]
The L-1011 was the first jetliner to have an [[integrated drive generator]] (IDG).<ref name=":0" />{{Rp|34}}

The FMS on the L-1011, certified by the FAA in September 1977, offered many features that have since become common. The features were aimed at greatly reducing crew workload and improving [[fuel efficiency]]. Of those are a Mach/IAS cruise control, an automatic Rough Air Mode that detects turbulence and adjusts the engine power setting accordingly, and a descent mode that figures out the optimum location to start a descent by "back computing" from a preselected point, allowing "on-altitude and on-speed" arrival.<ref name=":0" />{{Rp|36–38}}

The L-1011 also featured a highly advanced [[autopilot]] system and was the first widebody to receive [[FAA]] certification for [[Instrument Landing System#ILS categories|Cat-IIIc]] [[autoland]]ing, which approved the TriStar for completely [[instrument meteorological conditions|blind]] landings performed by the aircraft's autopilot in zero-[[visibility]] weather.<ref>{{cite news |last= Young |first= David |url= https://pqasb.pqarchiver.com/chicagotribune/access/614749782.html?dids=614749782:614749782&FMT=ABS&FMTS=ABS:AI&type=historic&date=Sep+18%2C+1977&author=&pub=Chicago+Tribune&desc=Look+Ma%2C+no+hands--learning+how+to+land+a+jumbo+jet&pqatl=google |title= Look Ma, no hands—learning how to land a jumbo jet |work= Chicago Tribune |date= September 18, 1977 |access-date= July 6, 2017 |archive-date= November 5, 2012 |archive-url= https://web.archive.org/web/20121105083907/http://pqasb.pqarchiver.com/chicagotribune/access/614749782.html?dids=614749782:614749782&FMT=ABS&FMTS=ABS:AI&type=historic&date=Sep+18,+1977&author=&pub=Chicago+Tribune&desc=Look+Ma,+no+hands--learning+how+to+land+a+jumbo+jet&pqatl=google |url-status= dead }}</ref> The L-1011 used an inertial navigation system to navigate;<ref>{{cite web |url= http://www.es.northropgrumman.com/solutions/ltn92/assets/LTN-92_Ring_Laser_Gyro_Inertia.pdf |title= LTN-92 Laser Gyro INS |archive-url= https://web.archive.org/web/20110927145118/http://www.es.northropgrumman.com/solutions/ltn92/assets/LTN-92_Ring_Laser_Gyro_Inertia.pdf |archive-date= September 27, 2011 |publisher= Northrop Grumman |access-date= July 16, 2011}}</ref><ref>{{cite book |url= http://www.tristar500.net/articles/cstmp_stansted.pdf |title= Report: Lockheed L1011-500 Tristar, CS-TMP |archive-url= https://web.archive.org/web/20091222142615/http://www.tristar500.net/articles/cstmp_stansted.pdf |archive-date= December 22, 2009 |publisher= Air Accidents Investigation Branch |access-date= July 16, 2011}}</ref> this included aligning the navigation system by entering current coordinates of longitude and latitude.<ref name="ReferenceA" />

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.<ref>{{cite report |url= http://www.aaib.gov.uk/cms_resources.cfm?file=/dft_avsafety_pdf_501051.pdf |title= Report: Lockheed L1011-385-1-14, G-BBAF |page= 5 |publisher= Air Accidents Investigation Branch |access-date= July 16, 2011}}</ref><ref>{{cite magazine |last= Kocivar |first= Ben |url= https://books.google.com/books?id=-AAAAAAAMBAJ&q=l1011&pg=PA50 |title= Giant Tri-Jets Are Coming |magazine= Popular Science |volume= 197 |issue= 6 |date= December 1970 |pages= 50–52 |issn= 0161-7370}}</ref> DLC helps maintain the aircraft on the glideslope during 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.