Flying a twin-engine aircraft isn't just flying a single with a spare engine. It's a different category of operation — with new procedures, new aerodynamics, and new failure modes to manage. The multi-engine rating prepares you for all of it.
Rating Requirements
Unlike most certificates, the multi-engine add-on rating has no minimum flight hour requirement. The standard is simple: demonstrate proficiency to an FAA Designated Pilot Examiner. How many hours that takes depends on your aptitude and the quality of your instruction — typically 10–20 hours for a well-prepared commercial pilot.
Key Concepts
Vmc — Minimum Controllable Airspeed
Vmc is the minimum airspeed at which directional control can be maintained with the critical engine inoperative and the remaining engine at full power. Below Vmc, the aircraft will yaw uncontrollably toward the dead engine. Understanding the factors that affect Vmc — and staying above it at all times — is the foundation of multi-engine safety.
Factors that raise Vmc: high density altitude decreases Vmc. Factors that lower Vmc: feathering the prop, reducing power on good engine, banking into good engine (up to 5°).
Engine-Out Memory Items: PARE
- P — Power: throttle up both engines, then identify
- A — Ailerons/Aircraft: maintain directional control, bank 5° toward good engine
- R — Rudder: apply rudder toward good engine, identify dead engine ("dead foot = dead engine")
- E — Engine: verify failure, feather prop on dead engine, secure failed engine systems
Critical Engine
On conventional (non-centerline-thrust) twins, one engine — typically the left — is more critical than the other. This is because of P-factor: at high angles of attack, the descending propeller blade on the left engine is further from centerline and produces more thrust, meaning its loss creates greater yaw. Identifying the critical engine and understanding its impact is tested on every multi-engine checkride.
Performance Planning
Multi-engine performance planning introduces concepts not found in single-engine training:
- Accelerate-stop distance — runway needed to accelerate to decision speed and stop if an engine fails
- Accelerate-go distance — runway needed to continue takeoff on one engine after engine failure
- Single-engine service ceiling — maximum altitude where the aircraft can maintain 50 fpm climb on one engine
- Vyse (Blue Line) — best single-engine rate of climb speed, marked in blue on the airspeed indicator
Training at Parrish Aviation
Parrish Aviation uses the Piper Twin Comanche for multi-engine training — a classic, capable twin that provides excellent systems complexity for learning multi-engine operations. After earning your multi-engine rating, you can add the MEI (Multi-Engine Instructor) certificate to teach multi-engine students and increase your hourly earning rate as a CFI.
Career Value
The multi-engine rating is required for the ATP certificate, most regional airline positions, and many corporate and charter operations. Adding it to your commercial certificate meaningfully expands the jobs available to you.
Ready to Start Your Aviation Journey?
Parrish Aviation — FAA Part 141 Flight School at Dallas Executive Airport (KRBD)