Table of Contents
What is SMOH in aviation?
Overhauled (SMOH or SFOH) An engine that has been completely disassembled (the crank case is split and all the parts pulled out), extensively inspected, and reassembled to either service limits or new limits.
How is VMC calculated?
VMC increases with increased drag on the inoperative engine. VMC is highest, VMC is determined with the critical engine propeller windmilling in the takeoff position, unless the engine is equipped with an autofeather system.
How many times can an aircraft engine be overhauled?
Engines- in theory they can be overhauled indefinitely. In fact, overhauls are only a recommendation for non commercial ops. Real world- after 2-3 overhauls may as well exchange for a 0 time already overhauled or rebuilt engine.
What is the difference between overhauled and rebuilt?
A “rebuilt” engine should be put back into like-new condition, with all parts examined and replaced if they aren’t within new tolerances. An “overhauled” engine has new parts installed when they are worn beyond limits, but many are left in place because the wear limit hasn’t been exceeded.
What is 1.3 VSO?
1.3 Vso is 1.3 times the stalling speed, or the minimum steady flight speed, in the landing configuration with flaps down, engine at low or idle power as it would be just prior to touchdown.
What factors decrease VMC?
Anything increasing the amount of force the rudder can produce will decrease Vmc, and vice versa.
- MAXIMUM TAKEOFF POWER – BAD for Vmc.
- CRITICAL ENGINE INOPERATIVE – BAD for Vmc.
- INOPERATIVE ENGINE WINDMILLING – BAD for Vmc.
- SEA LEVEL CONDITIONS – BAD for Vmc.
- MOST UNFAVORABLE LEGAL WEIGHT (LIGHTEST WEIGHT) – BAD for Vmc.
What factors determine VMC?
Factors of Vmc
- Maximum take-off Power at Sea Level. (Density Altitude is at Sea Level) Increase.
- At Gross Weight. Decrease. Decrease.
- Most Adverse CG (usually Aft) Increase. Increase.
- Gear Up. Increase.
- Take-off Flaps. Increase.
- Take-off Trim. Decrease.
- Take-off Cowl Flaps. Decrease.
- Windmilling Propeller on Critical Engine. Increase.
Can I overhaul my own aircraft engine?
In a legal sense, there’s no difference between a new and rebuilt engine. In most cases, an FAA-certificated airframe and powerplant (A) technician can legally overhaul your piston aircraft engine and return it to service, providing it doesn’t need any major repairs.
When should an aircraft engine be overhauled?
Times typically run between 1,500 and 2,500 hours and there’s usually a calendar factor of about 12 years so the guidance is for whatever comes first. Piston aircraft engines are extremely reliable when properly maintained, when flown regularly and correctly.
Do all planes have a Hobbs meter?
Each engine on the aircraft must also have a corresponding oil pressure gauge, temperature gauge and tachometer as well as other basic equipment for the safe operation of the aircraft. General aviation aircraft are not required to have a Hobbs meter, but many aircraft used for hire and rental have them installed.
What is a 100 hour check on an aircraft engine?
Simply, how many hours has the engine been run. There is a gadget called a Hobbs Meter, attached to an engine, that functions as a stop watch, to tell anyone who looks at it how many hours the engine has been on. Aircraft engines are required to have a 100 hour check by a certified mechanic, or lose the legal certificate that allows it to fly.
What is flight time in aviation?
FAR 1.1 defines flight time as “Pilot time that commences when an aircraft moves under its own power for the purpose of flight and ends when the aircraft comes to rest after landing.” An oil pressure switch-activated Hobbs meter most closely approximates this.
How do you measure engine time on a plane?
There are two common ways to measure engine time. One is a recording tachometer that essentially counts the revolutions of the engine and reports the number of hours of engine operation. The other is a “Hobbs” meter that measures time when electric power is applied to it. Many planes have a Hobbs meter arranged to meas