King Air Engine Oil Systems & Diagnostic Testing
Explore the named components, make a prediction, then connect the supplied result to the system. This workshop adds coached practice alongside the course handbook and assessed lab.
King Air oil: supply, return, cooling and indication
Follow the PT6A-60A pressure supply and all four scavenge-pump elements. Locate the accessory gearbox (AGB) and reduction gearbox (RGB), then trace bearing-oil recovery and the heater's cold direct-to-tank and hotter cooler-bound returns. Keep the separate cooler valve, cooling air and cockpit indication circuits distinct.
Original functional map: pressure supply, liquid recovery and ventilation have different routes. Heater-return selection precedes the separate cooler core/bypass decision; the gauge and warning have independent reporting paths.
Recorded state: before the supplied change
Green outlines identify components named in the selected exercise record; they do not indicate a healthy component.
Named connections and what each arrow means
- Integral tank, pump and filtered supply → Lubricated areas and used-oil collectionPhysical relationship: Regulated, filtered pressure-oil delivery
- Lubricated areas and used-oil collection → Two double-element scavenge pumpsPhysical relationship: Used oil from distinct sumps / bearing areas
- Two double-element scavenge pumps → Oil-to-fuel heater and return selectorPhysical relationship: Rear internal element: accessory-gearbox return
- Two double-element scavenge pumps → Cooler core, bypass gallery and tank returnPhysical relationship: Rear external element: reduction-gearbox return
- Oil-to-fuel heater and return selector → Integral tank, pump and filtered supplyPhysical relationship: Cold heater oil: direct tank return outside de-aerator tray
- Oil-to-fuel heater and return selector → Cooler core, bypass gallery and tank returnPhysical relationship: Hot heater oil: all or part joins reduction-gearbox return to cooler
- Cooler core, bypass gallery and tank return → Integral tank, pump and filtered supplyPhysical relationship: Cooler outlet → top adapter → de-aerator tray → tank
- Cooling-air duct, shroud and core face → Cooler core, bypass gallery and tank returnPhysical relationship: Air-side heat-rejection prerequisite
- Lubricated areas and used-oil collection → Continuous pressure and temperature indicationInformation / signal: Local pressure / temperature sensing boundaries
- Lubricated areas and used-oil collection → Independent low-pressure switch and warningInformation / signal: Separate pressure-switch sensing boundary
- Integral tank, pump and filtered supply → Engine/tank air spaces and breather outletPhysical relationship: Tank air-space ventilation
- Lubricated areas and used-oil collection → Engine/tank air spaces and breather outletPhysical relationship: Engine air-space ventilation
Integral tank, pump and filtered supply
Store oil and deliver it through the engine's pressure system.
Supplied record: Actual supply pressure / flow unmeasured
How it works with the rest
The tank forms part of the compressor inlet case. An internal pressure pump at its bottom supplies the engine through pressure regulation, cold-pressure relief and the downstream filter/check/bypass arrangement. A bypass provision is part of the filter assembly; a pressure indication does not inspect filter condition or every downstream passage. The description's tank, usable and total-system capacities are different from the residual-aware addition in the servicing task.
What the evidence must show
Identify quantity, pump/regulation/filter condition and the actual pressure-sensing boundary separately. Do not infer individual bearing delivery or return-flow availability from one gauge reading.
Selected: Integral tank, pump and filtered supply
Follow the change through the system.
Fictional B300/B300C PT6A-60A concept trainer: the rear external reduction-gearbox return and rear internal accessory/heater return begin as separately available paths. Apply introduces a complete interruption only in the external pump's downstream gearbox-to-cooler segment, upstream of the junction where diverted heater-return oil joins the cooler-bound route. The supplied pressure-gauge observation remains unchanged. This is a path-availability comparison, not a running engine simulation; no circulation rate, oil accumulation or safe continued-operation period is calculated.
Before the recorded change
Available-return record: both named scavenge routes are supplied available. A separate pressure-gauge observation is retained; actual pressure and individual bearing delivery are unmeasured.
Next observation
Choose your prediction before revealing the supplied result.
Reference: MM130-590031-11: 79-00-00 p. 1 and Figure 2 Sheets 1-2, pp. 3-4 (Apr 1/2018); 79-30-00 p. 1 (Apr 1/2018).
Course applicability and study references
Formative supplement to TM-072 Rev B using the supplied B300/B300C MM130-590031-11 Chapter 79, LEP November 1, 2024. Internal engine routing is also explained from the retained P&WC 3034342 Revision 43 study edition (October 7, 2013), 79-00-00 and Figure 1, with oil pages dated November 5, 1999. Covers the described PT6A-60A installation and indicating arrangements; modified sensors and displays require their own effective data. These fictional concept-trainer records supply qualitative conditions and observations. They calculate no oil pressure, circulation rate, temperature or heat-rejection capacity, and give no aircraft running or maintenance procedure. The source's 160°F statement describes cooler routing, not an operating limit. Existing assessed work and completion requirements remain separate.
- Supply, return and ventilation architecture
B300/B300C MM130-590031-11 Chapter 79, supplied LEP November 1, 2024: 79-00-00 p. 1 and Figure 2 Sheets 1–2, pp. 3–4 (April 1, 2018). Internal bearing, four-element scavenge and direct-versus-cooler heater returns also use P&WC 3034342, retained Revision 43 (October 7, 2013), 79-00-00 pp. 2–3/4 and Figure 1 p. 5/6, dated November 5, 1999. The two front elements collect bearing oil into the AGB; internal rear feeds the heater and external rear recovers RGB-sump oil toward the cooler. Current aircraft-effective instructions govern physical work.
- Two thermal decisions and external cooler inspection
B300/B300C 79-00-00 p. 1 and Figure 2 sheet 2, p. 4 (April 1, 2018), pp. 601–602, and 79-10-01 pp. 401–402 (April 15, 2023). The cooler figure identifies OPEN as divided core/bypass flow and CLOSED as core-only flow. P&WC 3034342 study-edition 79-00-00 p. 3/4 and Figure 1 p. 5/6 identify cold heater return outside the de-aerator tray and hot all-or-part diversion into the cooler circuit. Oil routing, cooling air, attachment and sealing require separate observations.
- Separate indicating and warning circuits
79-30-00 p. 1 and p. 101, 79-30-01 p. 101 and 79-30-07 p. 501 (Apr 1/2018). The pressure transducer/gauge, resistance bulb/gauge and low-pressure switch/warning have different sensing and reporting boundaries. The original circuit/installation applies only where effective.
- Component evidence and task limits
79-30-03 pp. 501-502/Table 501 (Apr 1/2018); 79-30-01 pp. 501-503/Figure 502 (Apr 15/2023). Transducer points/directions and actual-temperature bulb resistance remain separate component tests. No harness substitution, circulation calculation, engine operating limit or physical running procedure is introduced by this workshop.
Original learning diagrams and supplied training records explain the stated relationships. Current aircraft-effective instructions and authorization govern actual maintenance.