Book Questions Flashcards
which statement is true regarding bearings used in high powered reciprocating aircraft engines?
There is less rolling friction when ball bearings are used than when roller bearings are employed.
a condition that can occur in Radial engines but is less likely to occur in horizontally opposed engines is…?
hydraulic lock
which condition would be least likely caused by failed or failed engine bearings?
Low oil temps
what is the principal advange of using propeller reduction gears?
to enable the engine RPM to be INCREASED with an accompanying INCREASE in power and allow the propeller to remain at a LOWER RPM
which will decrease volumetric efficiency in a reciprocating engine?
improper valve timing, sharp bends in the induction system and high carb air temps
which is a charastic of a thrust bearing used in most radial engines?
Deep-Groove Ball
which bearing is least likely to be a roller or ball bearing?
Master Rod Bearing (radial engine)
the operating temp valve clearance of a radial engine as compared to a cold valve clearance is?
Greater
a 9 cylinder engine with a bore of 5.5” and a stroke of 6” will have a total piston displacement of?
1,283 cubic inches
the distance that is known as one half of the diameter is ?
radius
there are 5 events in a 4 stroke cycle enginem the order of their occurrance is?
intake, compression, ignition, power, exhaust
the primary concern in establishing the firing order for an opposed engine is to?
provide for balance and eliminate vibration to the greatest extent possible
If fuel/air ratio is proper and ignition timing is correct, the combustion process should be completed?
Just after top (dead) centre at the beginning of the power stroke
Grinding the valves of a reciprocating engine to a feather edge is likely to result in?
Pre ignition and burnt valves
Which statement is correct regarding engine crankshafts?
Movable counterweights serve to reduce the torsion of vibrations in an aircraft Reciprocating engine
On which strokes are both valves on a four stroke cycle reciprocating aircraft engine open?
Exhaust and intake
Which type of roller bearings are generally used for connecting rods and camshafts?
plain
What is the actual power delivered to the propeller of an aircraft engine called?
brake horsepower
Turbo prop engines measure power produced with a torque meter, and it is proportional to what type of piston engine horsepower?
Brake horsepower
Cam-ground pistons are installed in some aircraft engines to?
Provide a better fit at operating temperatures
Some aircraft engine manufacturers equipped their product with choked or taper-ground cylinders in order to?
Provide a straight cylinder bore at operating temperatures
What tool is generally used to measure the crankshaft rotation in degrees?
timing disk
If an engine with a stroke of 6” inches operated at 2000 RPM, the piston movement within the cylinder will be?
At maximum velocity, 90 degrees after tdc
An aircraft reciprocating engine using hydraulic valve lifters is observed to have NO clearance in its valve operating mechanism after the minimum inlet oil and cylinder head temperatures for takeoff have been reached. When can this condition be expected?
During normal operation
Using the following information, determine how many degrees the crankshaft will rotate with both the intake and exhaust evolves seated(CLOSED)…
Intake valve opens at 15’ BTDC
Exhaust opens 70’ BBDC
Intake closes 45’ ABDC
Exhaust closes 10’ ATDC
245 degrees
If the intake valve is opened too early in the cycle of operation of a 4 stroke cycle engine, it may result in?
Backfiring into the induction system
Some cylinder barrels are hardened by?
Nitriding
Which statement is correct regarding a four stroke cycle aircraft engine?
The intake valve closes on the compression stroke
On which part of the cylinder walls of a normally operating engine with the greatest amount of wear occur?
Near the top of the cylinder
During overhaul reciprocating engine exhaust valves are checked for stretch with?
With a contour or radius gauge
When is the fuel/air mixture ignited in a conventional reciprocating engine?
Shortly before the piston reaches the top of the compression stroke
What is the purpose of a safety circlet (circlip) installed on some valve stems?
To prevent valves from falling into the combustion chamber
Valve overlap is defined as the number of degrees of crankshaft travel during?
During which both valves are off their seats
ingition occurs at 28’ BTDC on a certain 4 stroke cycle engine, and the intake valve opens at 15’ degrees BTDC. How many degrees of crankshaft travel after ignition does the intake valve open? Consider one cylinder only)
373 degrees
The valve clearance of an engine using hydraulic lifters when the lifters are completely flat, or empty, should not exceed?
A specified amount above 0
If the exhaust valve of a 4 stroke cycle engine is closed and the intake valve is just closing, the piston is on the?
Compression stroke
Which of the following are factors in establishing the maximum compression ratio limitations of an aircraft engine?
Detonation characteristics of the fuel, design limitations of the engine, and the degree of supercharging
Full floating piston pins are those which allow motion between the pin and what?
Both the piston and the small end of the connecting rod
The primary purpose in setting proper valve timing and overlap is to?
Obtain the best volumetric efficiency and lower cylinder operating temperatures
If the hot clearance is used to set the valves when the engine is cold, what will occur during operation of the engine?
The valves will open late and close early
What is the purpose of installing two or more springs on each valve in an aircraft engine?
To eliminate valve spring vibration or surging
During overhaul, the disassembled parts of an engine are usually degreased with some form of a mineral spirit solvent rather than water-mixed degreasers primarily because?
Water-mixed degreaser residues may cause engine oil contamination in the overhauled engine
Why does the smoothness of operation of an engine increase with the greater number of cylinders?
The power impulses are spaced closer together
Compression ratio is the ratio between?
Cylinder volume with piston at bottom dead centre and at top dead center
If the crankshaft runout readings on the dial indicator are plus 0.002 inch and minus 0.003 inch the runout is?
0.005 inch
(1) Cast iron piston rings may be used in chrome plated cylinders.
(2) Chrome plated rings may be used in plain steel cylinders.
Both 1 and 2 are true
How is proper edge clearance on new pistons ring assured during the overhaul of an engine?
By placing the rings in the cylinder and measuring the end gap with a feeler gauge
When cleaning aluminium and magnesium engine parts, it is inadvisable to soak them in solutions containing soap because?
Some of the soap will become impregnated in the surface of the material, and subsequently cause engine oil contamination and foaming
What is the purpose of a power check on a reciprocating engine?
To determine satisfactory performance
What will be the likely result if the piston ring gaps happen to be aligned when forming a differential pressure compression check on a cylinder?
a worn or defective ring(s) indication
The volume of a cylinder equals 70 cubic inches when the piston is at bottom dead centre. When the piston is at top of the cylinder, the volume equals 10 cubic inches.
What is the compression ratio?
7:1
Which of the following will be caused by excessive valve clearance of a cylinder on a reciprocating aircraft engine?
Reduced valve overlap period
The floating control thermostat used on some reciprocating engine installations helps regulate oil temperature by?
Control the air flow through the oil cooler
Which of the following would indicate a general weak engine condition when operated with a fixed-pitch propeller or test club.
Lower the normal static RPM, full throttle operation
What is required by 14 CFR (FAR) Part 43 Appendix D when performing an annual 100 hour inspection on a reciprocating engine?
cylinder compression check
During a 100 hour inspection, what must be checked/performed?
Oil screen check
During a 100 hour inspection of a starter generator, what is NOT an inspection item?
Shaft bearing condition
During a 100 hour inspection for starter generators, what are two inspection requirements?
1. Oil leakage
2. Shaft bearing condition
3. Commutator wear and pitting
- Oil leakage
& - Commutator wear and pitting
After spark plugs from an opposing engine have been serviced, in what position should they be reinstalled?
Next in firing order to the one from which they were removed and swapped bottom to top.
as the pressure is applied during a reciprocating engine compresson check using a differential pressure tester, what would the movement of the propeller in the direction of engine rotation indicate?
The pistion was positioned past top dead center.
excessive valve clearance results in the valves opening?
late and closing early
during routine inspection of a reciprocating engine, a deposit of small, bright metallic particles which do not cling to the magnetic drain plus is discovered in the oil sump and on the surface of the oil filter. this condition….
may be a result of abnormal plain type bearing wear and is cause for further investigation.
a characteristic of dyna-focal engine mounts as applied to an aircraft reciprocating engines is that the…?
the shock mounts point towards the engines center of gravity
if metallic particals are found in the oil filter during inspection…?
the cause should be identified and corrected before the aircraft is released for flight.
if the oil pressure gauge fluctuated over a wide range from zero to normal operating pressure, the most likely cause is….?
low oil supply
what special procedure must be followed when adjusting the valves of an engine equipped with a floating cam ring?
eliminate cam bearing clearance when making a valve adjustment
which of the following is most likely to occur if an overhead valve engine is operated with inadequate valve clearances?
the valves will not seat positively during start and engine warm up
excessive valve clearances will cause the duration of the valve opening to…?
decrease for both intake and exhaust valves
what does valve overlap promote?
better scavenging and cooling characteristics
what speed must a crankshaft turn if each cylinder of a 4 stroke cycle engine is to be fire 200 time a minute?
400RPM
engine crankshaft runout is usually checked…?
during engine overhaul and after a ‘prop strike’ or sudden engine stoppage
before attempting to start a radial engine, that has been stut down for 30 mins…?
turn the propeller by hand 3 - 4 revolutions in the normal direction of rotation to check for fluid lock.
an engine misses in both right and left positions of the magneto switch. the quickest method for locating the trouble is to…?
check for one or more cold cylinders
a hissing from the exhaust stacks when the propleer is being pulled through manually indicates?
Exhaust valve blow-by
if the oil pressure of a cold engine is higher than at normal operating temps, the…?
engines lubrication is probably not operating normally
if an engine operates with low oil pressure and high oil temps, the problem meay be caused by a…?
leaking oil dilution valve
which fuel/air mixture will result in the highest engine temp (all other factors constant)?
a mixture leaner than a manual mixture of 0.060
If an engine cylinder is to be removed, at what position in the cylinder should the piston be?
Top Dead Center TDC
the horsepower developed in the cylinders of a reciprocating engine is known as ?
indicated horsepower
the theoretical horsepower a reciprocating engine develops is?
IHP indicated horsepower
engine operating flexability is the ability of the engine to..?
run smoothly and give the desired performance at all speeds
Standard aircraft cylinder oversizes usually range from 0.010” to 0.030”. oversizes on automobile engine cylinders may range up to 0.100”. this is because the aircraft engine cylinders …?
have relatively thin walls and may be nitrided
if the ingition switch is moved from BOTH to either LEFT or RIGHT during an engine ground check, normal operation is usually indicated by a slight…?
drop in torque meter pressure indication
during ground check an engine is found to be running rough, the magneto drop is normal, and the manifulf pressure is higher than normal for any given RPM. The trouble may be caused by…?
a dead cylinder
what is the best indication of worn valve guides?
high oil consumption
by use of a differencial pressure tester, it is determined that cylinder 3 of a 9 cylinder radial engine will not hold pressure after the crankshaft has been rotated by 260 degrees from top dead center compression stroke cylinder 1. how can this indication usually be interpreted?
by a normal indication
when does valve overlap occur in the operation of an aircraft reciprocating engine?
at the end of the exhaust stroke and at the beginning of the intake stroke
what is the advantage of metalic-sodium filled exhaust valves in aircraft reciprocating engines
reduce valve operating temps
valve clearance changes on opposed type engines using hydraulic lifters are accomplished by?
push rod replacement
what is likely to occur if a reciprocting engine is operated at high power settings before it is properly warmed up?
Oil starvation of bearings and other parts
An INCREASE of manifold pressure with a constant RPM will cause the bearing load in an engine to…?
INCREASE
direct mechanical push pull carb heat control linkages should normally be adjusted so that the stop located on the diverter valve will be contacted…?
before the stop at the control lever is reached in both HOT and COLD positions
reduced air density at high altitude has a decided effect on carburetion, resulting in a reduction of engine power by?
excessively enriching the fuel/air mixture
increased water vapor (higher relative humidity) in the incoming air to a reciprocating engine will normally result in which of the following…?
decreased engine power at a constant RPM and manifold pressure
which of the following engine servicing comditions generally requires engine pre-oilling prior to starting the engine?
engine installion
during the inspection of the engine control system in which push-pull control rods are used, the threaded rod ends should…?
be checked for the amount of thread engagement by means of inspection holes
which of the following conditions would most likely lead to detonation?
use of fuel with too LOW octane rating
an unsupercharged aircraft reciprocating engine, operated at full throttle from sea level, to 10,000ft, provided the RPM is unchanged, will…?
lose power due to reduced density of the air drawn into the cylinders
which of the following would most likely cause a reciprocating engine to backfire through the induction system at low RPM operation?
lean mixture
how may it be determined that a reciprocating engine with a dry sump is pre-oiled sufficiently?
oil will flow from the engine return line or indicator port
what is the basic operating sequence for reducing the power output of an engine equipped with a constant speed propeller?
reduce the manifold pressure then the RPM
(1) preignition is caused by improper ignition timing
(2) detonation occurs when an area of a combustion chamber becomes incandescent and ignites the fuel/air mixture in advance of normal times ignition
NEITHER 1 Nor 2 is true
which statement pertaining to fuel/air ratios is true?
the mixture ratio which gives the best power is richer than the mixture ratio which gives max economy
what is meant by 1:15 air/fuel ratio?
too rich to fly
a reciprocating engine with a fuel/air ratio at more than 15 parts air to 1 part fuel by weight is…?
too lean to fly
what is the best fuel/air ratio for creating power?
1:15
backfiring through the carb generally results from the use of…?
an excessively lean mixture
which of these conditions will cause an engine to have an increased tendency to detonate?
High manifold pressure or high intake air temps
OR
Engine overheated
when will small induction air leaks have the most noticable effect on engine operation?
at low RPM
one of the best indicators of a reciprocating engine combustion chamber problem is…?
spark plug condition
to reduce the power output of an engine equipped with a constant speed propeller and operating near maximum BMEP, the…?
Manifold pressure is reduced with the throttle control before the RPM is reduced with the propeller control.
what would cause excessive pressure build up in the crankcase in a reciprocating engine?
Plugged crankcase breather
excessive valve clearance in a piston engine …?
decreases valve overlap
to what alitiude will a turbo charged engine maintain sea level pressure…?
critical altitude
if air is heard coming from the crankcase breather or oil filler during a differencial pressure check, what is this an indication of?
pistion ring leakage
one cause of afterfiring in an aircraft engine is?
an excessively rich mixture
afterfiring in aircraft engine may be caused by…
1. overly rich fuel mixture.
2. faulty spark plugs.
3.
4. defective fuel-injection nozzels
5. incorrect valve clearance
1, 2, 4, 5
On a reciprocating engine aircraft using a shrouded exhaust muffler system as a source for cabin heat, the exhaust system should be?
Visually inspected for any indication of cracks or an operational carbon monoxide detection test should be done
What is the result of an exhaust muffler internal failure in a small reciprocating engine?
Partial or total blockage of flow of exhaust gases resulting in engine failure.
- Airworthiness directives are federal aviation regulations and must be complied with unless specific exemption is granted.
- Airworthiness directives of an emergency nature may require Immediate compliance upon reciept.
BOTH 1 and 2 are true
Which of the following contains a minimum checklist for 100-hour inspection of engines?
14 CFR (FAR) Part43 Appendix D
When must an airworthiness directive (AD) be completed after it becomes effective?
As specified in the AD
Which of the following contains a table that lists the engines to which a given propeller is adaptable?
Propeller type certificate data sheet
Which of the following component inspections is to be accomplished on a 100 hour inspection?
Check Cylinder Compression
You are performing a 100 hour inspection on a R985-22 aircraft engine. What does ‘985’ indicate?
Total piston displacement of the engine
Straightening nitrided crankshafts is?
NOT recommended
The breaking loose of small pieces of metal from coated surfaces, usually caused by defective plating or excessive loads, is called?
Flaking
Each powerplant installed on an airplane with a standard airworthiness certificate must have been?
Type Certificated
A Severe condition of chafing or fretting in which a transfer of metal from one part to another occurs is called… what?
Galling
Indentations on bearing races caused by high static loads are known as
Brinelling
Where would you find type design information for an R1830-92 engine certificated under the Civil Air Regulation (CAR) and installed on a DC-3?
The Aircraft Engine Specifications
When inspecting an aircraft reciprocating engine what document is used to determine if the proper magnetos are installed?
Aircraft engine specifications or type certificate data sheet
Which of the following can inspect and approve an engine MAJOR repair for its return to service?
Certified mechanic with inspection authorisation
What publication is used for guidance to determine whether a powerplant repair is major or minor?
14 CFR Part 43
During a 100 hour inspection on a wooden propeller, you find it is necessary to replace the laminate, this is a…?
Minor maintenance
The airworthiness standards for the issue of type certificates for small airplanes with nine or less passenger seats in the normal, utility, and acrobatic categories may be found in the?
14 CFR Part 23
Which of the following contains approved data for performing major repair to an aircraft engine?
The manufacturer’s maintenance instructions when FAA approved
What maintenance records are required following a major repair of an aircraft engine?
Entries in the engine maintenance record and FAA Form 337
A ground incident that results in propeller sudden stoppage would require a crankshaft runout inspection. What publication would be used to obtain crankshaft runout tolerance?
Current manufacture maintenance instructions
Sudden stoppage occurs when one or more of the propeller blades strike an object in such a way that the revolutions per minute RPM?
Drops to zero in less than one revolution
The fuel flow meter used with the continuous fuel injection system installed on an aircraft horizontally opposed reciprocating engine measures the fuel pressure drop across the??
fuel nozzles