Question 1: What is the purpose of the 'actuating pipe' (or signal pipe) in some automatic brake systems?

• It provides a separate faster-propagating signal to trigger emergency brake applications ahead of the pressure wave (Correct answer)
• It equalizes pressure between the main and emergency reservoirs
• It supplies air to the locomotive's horn and bell systems
• It connects the independent brake to the train brake system during emergencies

Correct answer: It provides a separate faster-propagating signal to trigger emergency brake applications ahead of the pressure wave

The actuating pipe carries an emergency signal that propagates faster than the brake pipe pressure drop, allowing near-simultaneous brake application along the entire train length.

Question 2: How does risk management apply to daily practice in Heating, Ventilation & AC for Locomotive Engineer professionals?

• Through proactive identification of potential hazards and implementation of preventive measures (Correct answer)
• Only through responding to incidents after they occur
• By avoiding high-risk situations entirely
• Through annual safety audits exclusively

Correct answer: Through proactive identification of potential hazards and implementation of preventive measures

Effective risk management in Heating, Ventilation & AC requires proactive hazard identification and preventive measures, not just reactive responses. This approach reduces incidents, improves outcomes, and protects both professionals and clients.

Question 3: During a train handling situation with a long train on undulating terrain, 'power braking' refers to:

• Running the locomotive at Notch 8 against a fully set automatic brake
• Using dynamic braking simultaneously with the independent brake
• Activating the emergency brake override while maintaining throttle
• Applying brakes while in throttle to control speed and manage slack (Correct answer)

Correct answer: Applying brakes while in throttle to control speed and manage slack

Power braking involves applying the train brakes while maintaining throttle power, which stretches the train and controls slack to prevent dangerous run-ins on rolling terrain.

Question 4: During a pre-departure inspection, you notice one side of the locomotive body is visibly lower than the other. What is the most likely cause?

• Failed or collapsed suspension spring on the low side (Correct answer)
• Incorrect tire pressure
• Loose drawbar pin
• Asymmetric fuel load only

Correct answer: Failed or collapsed suspension spring on the low side

A broken or collapsed suspension spring on one side removes its load-bearing contribution, causing that corner of the locomotive body to sink lower.

Question 5: What is the role of the receiver-drier in a locomotive AC system?

• It stores liquid refrigerant and removes moisture to protect system components (Correct answer)
• It acts as a backup compressor when primary compressor capacity is insufficient
• It boosts refrigerant pressure between the evaporator and compressor
• It regulates airflow through the condenser based on ambient temperature

Correct answer: It stores liquid refrigerant and removes moisture to protect system components

The receiver-drier stores a reserve of liquid refrigerant and contains desiccant to absorb moisture that could damage the system.

Question 6: What is the PRIMARY purpose of continuing education requirements in Brake Systems & Safety for LEC professionals?

• Earning additional credentials for career advancement
• Networking with other professionals in the field
• Fulfilling mandatory regulatory requirements only
• Maintaining current knowledge and competency as the field evolves (Correct answer)

Correct answer: Maintaining current knowledge and competency as the field evolves

Continuing education in Brake Systems & Safety ensures professionals maintain current knowledge and skills as standards, technologies, and best practices evolve in the Locomotive Engineer field.

Question 7: What does a 'Slow Clear' signal aspect require the engineer to do?

• Proceed at the maximum authorized speed for the territory
• Stop and contact the dispatcher before proceeding
• Proceed through the turnout at or below the slow speed limit, then resume normal speed (Correct answer)
• Reduce to restricted speed and be prepared to stop short of any obstruction

Correct answer: Proceed through the turnout at or below the slow speed limit, then resume normal speed

A Slow Clear signal requires the engineer to reduce speed to the designated slow speed (typically 15 mph) through the turnout, after which normal authorized speed may resume.

Question 8: How does the load weight of a train affect its performance?

• It makes the train more stable.
• It increases fuel efficiency.
• It reduces the time needed to accelerate.
• It requires more power to move and increases stopping distances.

A heavier train requires significantly more power from the locomotive's engines to overcome inertia and friction, thus increasing the effort needed to accelerate and maintain speed. Additionally, greater mass means more momentum, which in turn requires a longer distance and more braking effort to bring the train to a complete stop safely.

Question 9: When should an engineer 'notch up' (increase throttle) after a speed restriction?

• Only after the entire train has cleared the end of the restriction zone (Correct answer)
• When the speedometer shows the train is 5 mph below maximum authorized speed
• At the engineer's discretion regardless of train position
• As soon as the locomotive clears the end of the restriction zone

Correct answer: Only after the entire train has cleared the end of the restriction zone

Speed restrictions apply to the entire train, so throttle increase is permissible only after the last car clears the end of the restricted zone.

Question 10: What train handling adjustment is required when operating with a loaded train on a segment where the grade changes from descending to ascending?

• Coast through the grade change with throttle and brakes both released
• Increase throttle early so the locomotive is pulling before rear cars reach the sag (Correct answer)
• Apply brakes on the descent to have speed below the ascending grade's limit before transitioning
• Release all brakes and increase throttle just before the grade change

Correct answer: Increase throttle early so the locomotive is pulling before rear cars reach the sag

Increasing throttle before the sag prevents the locomotive from pulling forward while the rear of the train is still being pushed downhill, which would cause severe run-in.

Question 11: On a six-axle diesel-electric locomotive, how are traction motors typically connected electrically during starting operations?

• All six motors in parallel for maximum speed
• All six motors in series for maximum voltage
• Motors grouped in series-parallel combinations for high starting torque (Correct answer)
• Motors switched off alternately to reduce heat buildup

Correct answer: Motors grouped in series-parallel combinations for high starting torque

Series-parallel groupings allow high torque at low speed by limiting current through individual motors while maintaining adequate voltage.

Question 12: An engine overspeed trip activates during a downhill grade with dynamic brakes applied. What is the most likely cause?

• Excessive fuel delivery from a stuck injector
• Cooling system failure causing thermal runaway
• The dynamic brake grids have failed open, removing the load from the engine (Correct answer)
• High altitude reducing air density and combustion efficiency

Correct answer: The dynamic brake grids have failed open, removing the load from the engine

If dynamic brake grids fail open, the generator load is removed from the engine, which can accelerate to overspeed if throttle is not immediately reduced.

Question 13: If an engineer experiences a sudden, complete loss of automatic brake system control while operating at track speed, the FIRST action is to:

• Notify the dispatcher and reduce to Restricted Speed
• Apply the independent brake and reduce throttle
• Sound the horn and continue to the next siding
• Immediately apply the emergency brake valve (Correct answer)

Correct answer: Immediately apply the emergency brake valve

Complete loss of automatic brake control is an emergency requiring immediate application of the emergency brake to stop the train as quickly as possible.

Question 14: What documentation practice is considered essential in Brake Systems & Safety within the Locomotive Engineer field?

• Recording actions, observations, and outcomes in real-time or as close to the event as possible (Correct answer)
• Completing all documentation at the end of the workday
• Using shorthand notes that can be expanded later if needed
• Only documenting unusual events or complications

Correct answer: Recording actions, observations, and outcomes in real-time or as close to the event as possible

Real-time or near-real-time documentation in Brake Systems & Safety ensures accuracy, provides a contemporaneous record, and is considered the gold standard for professional accountability and legal defensibility.

Question 15: When must a locomotive engineer conduct a 'set and release' brake test after switching operations?

• Only when operating on main track with speeds above 40 mph
• Only when the train has traveled more than 10 miles since the last inspection
• Every 4 hours regardless of switching activity
• Before departing if cars have been added, removed, or brake hoses reconnected (Correct answer)

Correct answer: Before departing if cars have been added, removed, or brake hoses reconnected

FRA rules require a brake test whenever the train consist is modified or brake connections are disturbed to ensure all connected brakes are operative.

Question 16: What condition is indicated when a locomotive's brake cylinder pressure fails to build above 15 psi during an emergency brake application?

• Normal operation — emergency applications are intentionally limited to 15 psi
• A defect such as a stuck control valve, kinked hose, or brake cylinder leak (Correct answer)
• The brake pipe is fully charged, preventing emergency reservoir use
• Wheel slide protection is actively reducing pressure to prevent skidding

Correct answer: A defect such as a stuck control valve, kinked hose, or brake cylinder leak

Emergency applications should produce brake cylinder pressures of 50 psi or more; failure to build pressure indicates a mechanical defect in the brake system.

Question 17: Under FRA regulations, what minimum off-duty rest period is required for a freight train engineer after reaching the 12-hour service limit?

• 6 consecutive hours
• 12 consecutive hours
• 10 consecutive hours (Correct answer)
• 8 consecutive hours

Correct answer: 10 consecutive hours

After reaching the 12-hour on-duty limit, freight train employees must receive at least 10 consecutive hours off duty before returning to service.

Question 18: When operating through a zone with restricted speed, a locomotive engineer is required to:

• Stop at the beginning of the zone and radio the dispatcher for clearance
• Operate at track speed but apply service brakes every 2 miles
• Operate at no more than 20 mph and be prepared to stop within half the range of vision (Correct answer)
• Reduce to 10 mph and sound the horn continuously

Correct answer: Operate at no more than 20 mph and be prepared to stop within half the range of vision

Restricted speed requires operating at no more than 20 mph while being prepared to stop within half the range of clear vision, watching for obstructions.

Question 19: What does an Absolute Block system ensure in railroad operations?

• That only one train occupies a block section at any given time (Correct answer)
• That all trains operate at the same speed within a division
• That PTC overrides the engineer whenever a rule violation is detected
• That all signals automatically reset to Stop when power fails

Correct answer: That only one train occupies a block section at any given time

An Absolute Block system ensures that only one train is permitted within a designated block section at any time, providing the most fundamental form of train separation.

Question 20: What is the minimum cetane number typically required for diesel fuel used in locomotive engines?

• 25
• 55
• 70
• 40 (Correct answer)

Correct answer: 40

A cetane number of at least 40 is required for reliable ignition in locomotive diesel engines; higher cetane improves cold-start performance and reduces combustion noise.

Question 21: What is 'dark territory' in the context of railroad signal systems?

• Track segments that are temporarily closed for maintenance after sunset
• A section of railroad where no wayside signals or PTC exist, requiring train order or track warrant authority (Correct answer)
• Areas where cab signals are required because wayside signals are not visible
• Track rated for slow speeds due to insufficient lighting at grade crossings

Correct answer: A section of railroad where no wayside signals or PTC exist, requiring train order or track warrant authority

Dark territory refers to sections of track that have no automatic block signals, cab signals, or PTC, requiring dispatchers to issue track warrants or train orders to authorize train movements.

Question 22: Why is the electrical system in a locomotive important for its operation?

• To monitor engine temperature.
• To charge the onboard electronics.
• To power essential systems like lights and communication.
• To power the train's entertainment systems.

Beyond powering the traction motors, the electrical system in a locomotive is crucial for operating numerous auxiliary and essential systems. This includes lighting for visibility, communication radios for dispatch and crew coordination, control systems, and safety devices, all of which are vital for safe and efficient train operation.

Question 23: What is the correct action when a locomotive's wheel slides during dynamic braking?

• Increase throttle briefly to spin wheels and clear ice
• Apply the independent brake to stop the slide immediately
• Sound the horn to warn of reduced braking capacity
• Reduce dynamic brake effort to allow wheels to recover traction (Correct answer)

Correct answer: Reduce dynamic brake effort to allow wheels to recover traction

Reducing dynamic brake effort decreases the retarding force, allowing slipping wheels to recover traction before increasing braking again.

Question 24: What is the purpose of maintaining positive cab pressure in a locomotive HVAC system?

• To increase air conditioning efficiency by compressing cab air
• To ensure adequate airflow to the engineer's breathing zone at all times
• To assist in opening heavy cab doors against wind resistance
• To prevent diesel exhaust, dust, and other contaminants from infiltrating the cab through gaps (Correct answer)

Correct answer: To prevent diesel exhaust, dust, and other contaminants from infiltrating the cab through gaps

Positive cab pressure ensures that air leaks outward rather than inward, preventing diesel exhaust and contaminants from entering the cab.

Question 25: What is 'truck warp' (or truck lozenging) and why is it a concern?

• Vertical displacement of the truck bolster
• Torsional wind-up in the drive shaft
• Diagonal distortion of the truck frame causing unequal wheel loading (Correct answer)
• Lateral offset of the axles

Correct answer: Diagonal distortion of the truck frame causing unequal wheel loading

Truck warp is a diagonal racking of the truck frame that causes two diagonally opposite wheels to be lighter on the rail, risking derailment.

Question 26: Which of the following best describes 'dynamic braking capacity' limits related to engine diagnostics?

• Dynamic braking is limited by maximum generator field current
• Dynamic braking is limited by maximum safe exhaust temperature
• Dynamic braking output is limited by fuel delivery rate to the engine
• Dynamic braking capacity is limited by traction motor cooling capacity and grid resistor temperature (Correct answer)

Correct answer: Dynamic braking capacity is limited by traction motor cooling capacity and grid resistor temperature

Dynamic braking capacity is thermally limited by the ability of grid resistors and traction motors to dissipate the heat generated during braking.

Question 27: Why is it important to follow safety protocols when approaching railway crossings?

• To optimize train speed.
• To ensure the train remains on schedule.
• To reduce the train's fuel consumption.
• To avoid accidents and collisions at crossings.

Railway crossings are high-risk areas where trains and vehicles or pedestrians intersect. Following safety protocols, such as sounding the horn, reducing speed, and being prepared to stop, is crucial to prevent devastating accidents and collisions, ensuring the safety of everyone involved. These measures minimize the potential for fatalities, injuries, and property damage.

Question 28: What is the function of the load regulator on a diesel-electric locomotive?

• Regulates brake pipe pressure
• Adjusts cab temperature automatically
• Monitors axle bearing temperatures
• Controls fuel delivery to maintain constant engine RPM under varying loads (Correct answer)

Correct answer: Controls fuel delivery to maintain constant engine RPM under varying loads

The load regulator adjusts the electrical load on the main alternator to maintain constant engine RPM regardless of traction power demands.

Question 29: What is the minimum brake pipe pressure reduction required to initiate a service brake application under AAR rules?

• 2 psi
• 26 psi
• 12 psi
• 6 psi (Correct answer)

Correct answer: 6 psi

A minimum 6 psi reduction in brake pipe pressure is required to initiate a service brake application according to AAR standards.

Question 30: What is 'train line pressure equalization' and why does it matter before a brake test?

• Allowing brake pipe pressure to stabilize after charging so test reductions reflect true brake response (Correct answer)
• Balancing the locomotive's main reservoir with the brake pipe pressure
• The process of ensuring all brake cylinder pressures are equal before movement
• Resetting all triple valves to the release position simultaneously

Correct answer: Allowing brake pipe pressure to stabilize after charging so test reductions reflect true brake response

Equalization allows the brake pipe pressure to stabilize at full charge so that a subsequent reduction produces accurate, consistent brake response throughout the train.

Question 31: What action should an engineer take if the fuel level gauge shows empty but the locomotive is still running?

• Stop the locomotive safely and report the gauge as potentially faulty or tank as critically low (Correct answer)
• Switch to the reserve fuel system immediately without stopping
• Continue operating until the engine stops naturally
• Increase throttle to draw remaining fuel faster

Correct answer: Stop the locomotive safely and report the gauge as potentially faulty or tank as critically low

An empty fuel gauge requires the engineer to treat the condition as critical — stop safely, report it, and do not risk running dry, which can damage injection components.

Question 32: What does the term 'transition' refer to in the context of diesel-electric locomotive operation?

• Switching from diesel to battery power
• Activating dynamic braking from motoring mode
• Changing traction motor electrical connections to optimize power at different speeds (Correct answer)
• Transferring load between two prime movers

Correct answer: Changing traction motor electrical connections to optimize power at different speeds

Transition changes traction motor connections (series to parallel or changes in field strength) to deliver optimum tractive effort across different speed ranges.

Question 33: Why is it important for locomotive engineers to conduct pre-operational inspections?

• To ensure that the train is operating safely.
• To verify the number of passengers.
• To ensure the train is clean.
• To avoid delays in train schedules.

Pre-operational inspections are critical for locomotive engineers to identify any mechanical issues, defects, or unsafe conditions before the train departs. This thorough check ensures that all components, such as brakes, lights, and communication systems, are functioning correctly. By proactively addressing potential problems, engineers significantly reduce the risk of breakdowns or accidents during operation, prioritizing safety.

Question 34: What is the role of an oxidation catalyst in an after-treatment system when the exhaust temperature is below its light-off temperature?

• It injects extra DEF to compensate
• Its conversion efficiency is significantly reduced (Correct answer)
• It operates at full efficiency
• It switches to passive DPF mode

Correct answer: Its conversion efficiency is significantly reduced

Catalytic converters require minimum light-off temperatures (typically 200–300°C) to activate; below this threshold, conversion efficiency drops sharply.

Question 35: What is the recommended procedure when a locomotive engineer suspects a 'hanging brake' (brake not fully releasing) on a car in the train?

• Apply the emergency brake to cycle the control valves and force a full release
• Stop the train, inspect the suspected car, and tag it out of service if the brake cannot be released (Correct answer)
• Increase brake pipe pressure above normal charge to force release
• Continue operating at reduced speed to burn off the heat from the dragging brake

Correct answer: Stop the train, inspect the suspected car, and tag it out of service if the brake cannot be released

A hanging brake generates excessive heat and can cause wheel damage or fire; the train must be stopped and the car inspected and tagged out if the defect cannot be corrected.

Question 36: What is the primary purpose of track geometry measurement cars operated by railroads and the FRA?

• To photograph rail head surface conditions for documentation and insurance purposes
• To measure track parameters such as gauge, alignment, and surface to detect defects before failure (Correct answer)
• To calculate ballast depth requirements for new track construction projects
• To test locomotive performance under revenue service conditions

Correct answer: To measure track parameters such as gauge, alignment, and surface to detect defects before failure

Track geometry cars use sensors and measurement systems to continuously record rail gauge, cross-level, alignment, surface, and curvature, allowing railroads to identify and prioritize track defects before they cause derailments.

Question 37: When a conflict arises between standard procedures and a unique situation in Brake Systems & Safety, what should a LEC professional prioritize?

• The preference of the client or stakeholder
• Safety and ethical obligations while seeking expert consultation (Correct answer)
• Strict adherence to written procedures without exception
• The most cost-effective solution available

Correct answer: Safety and ethical obligations while seeking expert consultation

Safety and ethics always take priority in Brake Systems & Safety. When standard procedures don't adequately address a unique situation, consulting with experienced colleagues or supervisors ensures both safety and professional standards are maintained.

Question 38: What is the purpose of the high-pressure cutout switch in a locomotive AC system?

• It limits the maximum cab temperature by cutting out the heating system
• It controls the speed of the condenser fan based on discharge pressure
• It disconnects power to the evaporator blower if cab temperature drops too low
• It shuts down the AC compressor if refrigerant pressure exceeds a safe limit to prevent component damage (Correct answer)

Correct answer: It shuts down the AC compressor if refrigerant pressure exceeds a safe limit to prevent component damage

The high-pressure cutout switch protects the compressor and system components from damage by shutting down the AC if discharge pressure becomes dangerously high.

Question 39: What should a locomotive engineer do when approaching a signal indicating stop?

• Speed up to avoid a delay.
• Apply the brakes and stop the train.
• Continue at the same speed.
• Switch to another track.

When a locomotive engineer approaches a signal indicating "stop," their immediate and non-negotiable action is to apply the brakes and bring the train to a complete stop before passing the signal. This is a fundamental safety rule in rail operations, designed to prevent collisions, derailments, and other hazardous incidents. Disregarding a stop signal is a severe violation with potentially catastrophic consequences.

Question 40: What is the primary function of the air brake system on a locomotive?

• To monitor fuel efficiency.
• To prevent overheating of the engine.
• To apply braking force and control the train's speed.
• To control the train's acceleration.

The air brake system is a critical safety and operational component on a locomotive and throughout the entire train. Its primary function is to apply braking force to the wheels of all cars simultaneously by releasing compressed air, which actuates brake cylinders. This system allows the engineer to control the train's speed, bring it to a stop, and maintain a controlled descent on grades, ensuring safe operation.

Question 41: What action should a locomotive engineer take when a train experiences a 'dynamiting' (emergency) brake application due to a break-in-two?

• Release the independent brake and allow the train to coast to a stop
• Place the automatic brake valve in emergency and protect the rear of the train (Correct answer)
• Apply only the independent brake to slow the locomotive consist
• Immediately apply full throttle to keep the train together

Correct answer: Place the automatic brake valve in emergency and protect the rear of the train

When a break-in-two occurs, the engineer must place the brake valve in emergency and follow rules to protect the rear section of the train from following traffic.

Question 42: Which standard of practice is MOST important for ensuring quality in Brake Systems & Safety?

• Minimizing documentation to focus on practical work
• Following evidence-based protocols while adapting to specific circumstances (Correct answer)
• Using the most advanced technology available regardless of need
• Strictly adhering to the same procedure in every situation

Correct answer: Following evidence-based protocols while adapting to specific circumstances

Evidence-based protocols provide a foundation of proven practices, but effective Locomotive Engineer professionals must also adapt their approach based on specific circumstances and individual case needs within Brake Systems & Safety.

Question 43: Which type of brake shoe provides a higher friction coefficient at low speeds but tends to overheat on long downgrades?

• Low-friction synthetic shoes
• High-friction composition (HFC) shoes
• Cast iron shoes (Correct answer)
• Ceramic-composite shoes

Correct answer: Cast iron shoes

Cast iron brake shoes provide excellent friction at low speeds but are prone to overheating on sustained downgrades, which can cause wheel damage.

Question 44: When calculating a train's stopping distance, which variable does NOT directly factor into the calculation?

• Train speed at the point of brake application
• Locomotive cab color and visibility markings (Correct answer)
• Grade of the track in the stopping zone
• Total train weight (gross rail load)

Correct answer: Locomotive cab color and visibility markings

Stopping distance is determined by physics—speed, weight, brake force, and grade—not by the visual markings on the locomotive.

Question 45: What is the correct procedure for a 'set and release' brake test after picking up cars from a yard?

• Reduce brake pipe to zero, confirm all brakes apply, then recharge
• Make a 26-pound reduction and verify brakes apply within 60 seconds
• Make a 6-pound brake pipe reduction, observe brake application, then release and observe release throughout the train (Correct answer)
• Apply the independent brake on the locomotive only and confirm rear crew observes it

Correct answer: Make a 6-pound brake pipe reduction, observe brake application, then release and observe release throughout the train

A set-and-release test uses a 6-pound reduction to verify brakes apply and release properly after a pick-up before proceeding.

Question 46: What condition is indicated when a locomotive's exhaust appears black and sooty during operation?

• Lean fuel mixture with too little fuel
• Rich fuel mixture with incomplete combustion (Correct answer)
• Normal combustion at full throttle
• Water contamination in the fuel system

Correct answer: Rich fuel mixture with incomplete combustion

Black exhaust indicates a rich mixture where excess fuel is not fully burned, often caused by clogged injectors, restricted air intake, or over-fueling.

Question 47: What does the differential pressure indicator on a fuel filter housing signal when it activates?

• The fuel tank is nearly empty
• Injection pressure has exceeded the maximum limit
• Fuel temperature is too high
• The filter element is loaded and requires replacement (Correct answer)

Correct answer: The filter element is loaded and requires replacement

A differential pressure indicator trips when the pressure drop across the filter exceeds a set limit, indicating the element is clogged and needs changing.

Question 48: What is the function of the NOx sensor located downstream of the SCR catalyst?

• It activates the diesel particulate filter
• It monitors SCR conversion efficiency and detects catalyst degradation (Correct answer)
• It controls the EGR valve position
• It measures intake air NOx levels

Correct answer: It monitors SCR conversion efficiency and detects catalyst degradation

A downstream NOx sensor measures residual NOx after the SCR catalyst, allowing the engine control unit to calculate conversion efficiency and detect catalyst failure.

Question 49: When operating with an empty train on a descending grade, how does required brake effort compare to a loaded train on the same grade?

• Empty trains require less brake effort because gravitational force is lower (Correct answer)
• Empty trains require more brake effort because lighter wheels have less adhesion
• Empty trains require more brake effort due to higher center of gravity
• Empty trains and loaded trains require identical brake effort per car

Correct answer: Empty trains require less brake effort because gravitational force is lower

Lighter empty trains have less gravitational force pulling them downhill, so less retarding force is needed to maintain or reduce speed on a given grade.

Question 50: Which condition would cause a locomotive diesel engine to 'hunt' or surge at a steady throttle notch?

• Faulty or unstable governor unable to maintain constant engine speed (Correct answer)
• Excessive traction motor field shunting
• Stuck-open coolant thermostat
• High ambient temperature reducing air density

Correct answer: Faulty or unstable governor unable to maintain constant engine speed

Engine hunting or surging at a fixed throttle position is a classic symptom of a faulty governor that cannot maintain stable speed control.