PA-34-220T Seneca III — Examination Notes

1. Aircraft General

The aircraft is powered by turbocharged six-cylinder Lycoming engines driving constant-speed feathering propellers. Engine controls consist of separate throttle, propeller and mixture controls for each engine located on the center quadrant.

2. Weight & Balance

CG Limits

Exam Memory: Rear CG remains constant at 94.6 in. Only the forward limit changes with weight.

3. Fuel System

Single Engine Operation

During single-engine operation:

• Operating engine fuel selector → X-FEED
• Inoperative engine fuel selector → OFF

Fuel Drain System

Fuel drains are installed for:

• Each fuel tank
• Each fuel filter
• Each crossfeed line

Fuel must be drained during preflight to remove water, sediment and contamination and to verify fuel grade.

Crossfeed drains are located on the underside of the fuselage near the trailing edge of the right wing flap.

4. Engine Induction & Alternate Air

The engine induction system uses a paper element air filter.

If the primary induction source becomes blocked by ice, snow or freezing rain, an automatic alternate air door opens.

Alternate air:

• Is heated
• Is unfiltered
• Bypasses the normal filter
• Prevents induction icing

Limitation

Alternate air should not be used during ground operations or takeoff because dust and debris may enter the engine.

5. Propeller System

Standard Propeller

Optional Propeller

Propeller Diameter

Feathering System

Propeller Overspeed

Usually caused by governor malfunction.

Correct action:

1. Reduce throttle.
2. Move propeller control to minimum RPM.
3. Do not feather unless required by emergency procedures.

6. Engine Operating Limits

Avoid Continuous Operation

Continuous operation above 32 in Hg manifold pressure should be avoided between:

2000–2200 RPM

Crosswind / Tailwind Ground Operation

Continuous ground operation should be avoided between:

1700–2100 RPM

when crosswind or tailwind exceeds 10 kt.

7. Oil System

Oil Temperature Limits

8. Fuel Flow Limits

9. Electrical System

10. Starting Limitations

High-Yield Memory Table

11. Airspeeds & Flight Limitations

The PA-34-220T airspeed indicator uses standard color coding. Questions from this section are frequently repeated and should be memorized exactly.

Airspeed Indicator Markings

Easy Memory

The three most important speeds:

Think:
66 → 82 → 92

12. Landing Gear System

The landing gear is a hydraulically actuated retractable tricycle-type landing gear system.

Gear Retraction

The gear is:

• Retracted hydraulically
• Extended hydraulically
• Locked mechanically

Gear Retraction Force

Nose Gear

Nose Wheel Steering

Steering is accomplished through rudder pedal linkage and differential braking.

Squat Switch

The squat switch prevents accidental landing gear retraction while the aircraft is on the ground.

Function

• Senses weight-on-wheels
• Prevents gear retraction
• Allows normal retraction after lift-off

13. Stall Characteristics

The Seneca III is designed to provide significant warning before a stall occurs.

Stall Warning

The stall warning system activates approximately:

5–10 knots before stall speed

Indications may include:

• Stall horn
• Airframe buffet
• Pitch changes
• Reduced control effectiveness

Recovery

1. Reduce angle of attack.
2. Apply power as required.
3. Level wings.
4. Establish positive climb.

14. Spin Characteristics

Intentional spins are prohibited.

If an inadvertent spin develops:

1. Throttles idle.
2. Full opposite rudder.
3. Control wheel forward as required.
4. Recover from dive after rotation stops.
5. Return smoothly to level flight.

15. Single Engine Operations

This is one of the highest-yield exam topics.

Critical Speed

VMC (66 KIAS)

Minimum speed at which directional control can be maintained following sudden failure of the critical engine.

Below VMC:

• Rudder becomes ineffective.
• Aircraft may yaw and roll uncontrollably toward the failed engine.

Best Single Engine Climb

VYSE (92 KIAS)

Provides:

• Maximum single-engine rate of climb.
• Identified by blue radial line.

Intentional OEI Practice

VSSE (82 KIAS)

Used as minimum safe speed for:

• Simulated engine failures.
• Training exercises.

Never intentionally reduce below VSSE during training.

Engine Failure Memory Flow

1. Maintain directional control.
2. Pitch for VYSE (92 KIAS).
3. Identify failed engine.
4. Verify failed engine.
5. Feather propeller if required.
6. Secure engine.

16. Cabin Heater System

The aircraft uses a combustion heater system for cabin heating.

Limitation

The combustion heater is:

Not approved above 25,000 ft

This is a favorite limitation question.

17. Induction Ice Protection

When primary induction air becomes restricted:

• Alternate air door opens automatically.
• Warm engine compartment air enters induction system.
• Induction ice is bypassed.

Characteristics

18. Common Exam Limitation Table

One-Page Revision Sheet

Most Frequently Asked Numbers

66, 82, 92, 129, 169, 205

(VMC → VSSE → VYSE → VLE/VFE → VNO → VNE)

These six numbers alone cover a large percentage of technical-specific examination questions on the PA-34-220T Seneca III.