Editing Lockheed L-1011 TriStar (section)

=== Other components and systems ===
The APU, which was the Pratt and Whitney [[Pratt & Whitney Canada PT6|ST6L]],<ref>{{Cite web |title=ST6L-73 Tristar Auxiliary Power Unit |url=https://gasturbineworld.co.uk/tristar-aircraft-apu/ |access-date=2025-01-31 |website=gas turbine world |language=en-US}}</ref> was capable of operating up to 30,000 feet; its two square-shaped inlet doors are situated on the bottom fuselage on the aircraft's centerline towards the rear of the plane.<ref name=":0" />{{Rp|28}}

Compared to the typical three-system of its era, the L-1011 had four independent 3,000-psi hydraulic systems, A through D.<ref name=":0" />{{Rp|29}}

Part of the production process also used a unique [[autoclave]] system for bonding fuselage panels together; this made the L-1011 extremely resistant to corrosion.