Cessna P210N Pressurized Centurion (1978-1985)

The 1978 Cessna P210N was the first pressurized single-engine piston aircraft certified for production in the United States. With a 3.35 psi cabin differential, the P210N maintains a sea-level-equivalent cabin altitude to 5,000 ft, and an 8,000 ft cabin altitude at FL230 -- enabling comfortable high-altitude cruise without oxygen masks. Approximately 834 examples were produced across the eight-year run.

The P210N is a specialist airplane: faster, more capable, and more demanding than any other piston single Cessna produced. Acquisition costs run $160,000-$310,000; annual operating costs $25,000-$45,000. The pressurization system adds significant complexity and cost, but unlocks routine FL200-FL230 cruise without crew oxygen.

For pilots whose mission demands routine high-altitude operation (transcontinental, over-the-top weather, terrain clearance, max speed) and who are willing to invest in maintenance, the P210N is the most capable single-engine piston ever produced. The Cirrus SR22T comes close on speed but lacks pressurization; the Beechcraft A36 lacks pressurization and turbo capability.

The TSIO-520-AF Engine

The P210N uses the Continental TSIO-520-AF -- a 310 HP twin-turbocharged variant specifically developed for the P210 application. The "twin-turbo" designation reflects the larger turbocharger setup needed to maintain manifold pressure at higher altitudes for pressurization air supply. TBO 1,400 hours.

Operating considerations:

• Cylinder management: Even more critical than other turbo Continentals. CHTs above 370°F shorten cylinder life rapidly.
• Cool-down time: Required 5-7 minute cool-down after high-power flight.
• Bleed air integrity: The engine drives the cabin pressurization compressor; bleed air leaks are common 5-7 years after engine installation.

The Pressurization System

The P210N uses an engine-driven compressor to supply cabin pressurization air. Key system features:

• 3.35 psi maximum differential
• Sea-level cabin to 5,000 ft (no climb)
• 8,000 ft cabin at FL230 (max altitude)
• Door seal: rubberized weather-strip with annual inspection
• Window seals: bonded glass-to-frame, lifetime barring damage
• Outflow valve: spring-loaded relief, simple design

Pressurization maintenance items:

• Door seal replacement: $2,000-$4,000 every 8-12 years
• Window seal repair (if leaks develop): $1,500-$3,000 per window
• Outflow valve overhaul: $1,500-$2,500 every 15-20 years
• Compressor inspection: annual during engine inspection

Pressurization leak symptoms:

• Cabin won't pressurize fully
• Unusual whistling sounds at altitude
• Higher than expected outflow valve cycling
• Cabin altitude doesn't match POH chart

200 KTAS cruise at FL200 (75% power), 930 FPM sea-level climb, 17.5 GPH at max cruise. Service ceiling 23,000 ft.

Real-world cross-country at FL230 with oxygen-free comfort:

• Two adults + 90 gal fuel: 900 NM range with 45-min reserves
• Four adults + 60 gal fuel: 600 NM range
• Six adults + 45 gal fuel: 450 NM range

The pressurization enables flat-out cruise at FL200-FL230 without oxygen workload -- a meaningful comfort and safety advantage on long legs.

P210N pricing is highly variable based on:

• Pressurization system condition (the dominant factor)
• Engine time and turbo condition
• Avionics tier
• Whether converted to Silver Eagle (Rolls-Royce turbine conversion)

Silver Eagle Conversion: O&N Aircraft's Silver Eagle replaces the TSIO-520-AF with a Rolls-Royce 250-B17F turboprop (450 SHP). Aircraft pricing $400,000-$800,000+. Different airplane operationally; not addressed in this article.

210 + T210 universal concerns apply. P210N-specific:

1. Pressurization test: Mandatory during pre-buy. Verify cabin holds rated differential, outflow valve operates correctly, door/window seals don't leak.
2. Bleed air system: Inspect compressor, ducting, regulators. Bleed air leaks reduce pressurization performance.
3. Door seal age and condition: 8-12 year replacement interval. Aged seals are a $2,000-$4,000 line item.
4. Engine cylinder condition: TSIO-520-AF runs hot. Borescope inspection of all six cylinders essential.
5. Specialist mechanic availability: P210s are not common; finding a mechanic with pressurization-system experience matters more than for other Centurions. Limited regional specialist pool.