Aircraft maintenance engineering

21/04/2026

What do we need to to prepare before study Aircraft maintenance mechanic? 🧰

21/04/2026

Krueger flaps are high lift devices that are fitted to all or part of the leading edge of the wings of some a ircraft types. The aerodynamic effect of Krueger flaps is similar to that of slats; however, they are deployed differently. Krueger flaps are mounted on the bottom surface of the wing and are hinged at their leading edges. Actuators extend the flap down and forwards from the under surface of the wing thus increasing the wing camber which, in turn, increases lift.

Krueger Flap

Early generation jet airliners such as the B707 Series utilized Krueger flaps as their sole leading edge high lift devices. Current generation aircraft use either all slats or a combination of slats and Krueger flaps. Examples of the latter configuration include the B747 and the BOEING 737-700.

21/04/2026

The Mechanics of Lift: Flap Actuation Systems ✈️
In aerospace design, reliability is driven by mechanical precision. The flap actuation system is a masterclass in motion transformation—converting high-speed rotational torque into high-load linear displacement.

Engineering Highlights:

Torque Conversion: Utilizing drive screws to overcome aerodynamic resistance.

Kinematic Flow: The bellcrank’s role in force direction and mechanical advantage.

Structural Integrity: Synchronized movement across the flap tracks for aerodynamic stability.

A critical look at the systems that make controlled, low-speed flight possible.

19/04/2026

✈️ Maximum Continuous Thrust (MCT)

Maximum Continuous Thrust (MCT) is the highest engine thrust setting that can be applied continuously without time limitation, while remaining within certified temperature and structural limits.
It is a manufacturer-defined and regulator-approved limit that ensures safe, sustained engine operation.

🔧 Definition of “Continuous”

At MCT, the engine can operate indefinitely without exceeding allowable thermal or mechanical stresses.
This contrasts with higher thrust settings such as takeoff thrust, which are time-limited due to increased engine loading.

⚙️ Operating Principle

Modern engines are managed by the FADEC (Full Authority Digital Engine Control), which governs thrust output and engine protection.

Operational sequence:

1️⃣ Thrust Selection
The pilot selects thrust via the thrust levers or predefined modes.

2️⃣ Limit Calculation
FADEC determines the maximum allowable thrust based on:
• Engine temperature (EGT)
• Ambient conditions (altitude, outside air temperature)
• Engine performance limits

3️⃣ MCT Limitation Applied
FADEC ensures thrust remains within the maximum continuous limit, preventing exceedance of safe parameters.

4️⃣ Stable Operation
The engine delivers steady, high thrust without overheating or excessive wear.

✈️ Operational Use

MCT is primarily used in non-normal or performance-critical conditions, including:

• Single-engine operation (engine failure scenarios)
• Extended climb requiring sustained high thrust
• Hot and high environments where engine performance is reduced

👉 On aircraft such as the Airbus A320, MCT is a key thrust setting during engine-out procedures.

⚖️ Comparison of Thrust Settings
Thrust Setting Description
TOGA (Takeoff/Go-Around) Maximum thrust, time-limited
CLB (Climb) Reduced thrust for efficiency
MCT Maximum continuous thrust, no time limit
Idle Minimum thrust
⚠️ Operational Significance

✔ Prevents engine overheating and overstress
✔ Enables sustained high-thrust operation
✔ Critical for emergency and abnormal procedures
✔ Preserves engine durability and reliability

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14/04/2026

🔹 Primary Control Surfaces
1️⃣ Aileron (Roll Control)

Located on the outer wings
• Moves one wing up and the other down
• Controls rolling motion (left/right)
• Essential for turning the aircraft

2️⃣ Elevator (Pitch Control)

Located on the horizontal stabilizer
• Moves the nose up or down
• Controls pitch (climb or descent)

3️⃣ Rudder (Yaw Control)

Located on the vertical stabilizer
• Moves the nose left or right
• Controls yaw (directional movement)

🔹 Three Axes of Movement

• Roll – Rotation around longitudinal axis
• Pitch – Rotation around lateral axis
• Yaw – Rotation around vertical axis

All three must work together for stable and controlled flight.

🔹 How It Works

When the pilot moves the control stick or pedals:
• Mechanical linkages or hydraulic systems move the control surfaces
• Airflow changes around the surfaces
• This creates forces that change aircraft direction

🔹 Importance

✔ Provides full control of aircraft movement
✔ Ensures flight stability and safety
✔ Allows smooth turning, climbing, and descending

📌 Short Khmer Caption

✈️ Flight Control System

ប្រព័ន្ធនេះអនុញ្ញាតឱ្យបញ្ជាយន្តហោះតាម 3 ចលនា៖
• Aileron – Roll
• Elevator – Pitch
• Rudder – Yaw

ជាផ្នែកសំខាន់សម្រាប់សុវត្ថិភាពនៃការហោះហើរ។

📘 Technical Aviation Series – By Chhoun Limeng

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06/04/2026

✈️ Thrust Reverser System in Jet Engines

How the Thrust Reverser works in a turbofan engine. This system is used mainly during landing to help the aircraft slow down by redirecting engine airflow forward instead of backward.

Thrust Reverser Operation
The Thrust Reverser is a critical system used after landing to help decelerate the aircraft. When deployed, internal blocker doors redirect the engine’s bypass airflow through cascade vanes, producing reverse thrust that opposes the aircraft’s forward motion.
This system significantly reduces landing distance, assists the braking system, and enhances safety during landing operations. It is commonly installed on modern airliners such as the Airbus A320 and Boeing 737
— Aviation Education by Chhoun Limeng ✈️

06/04/2026

I hope one day I can work with him .

06/04/2026

Why Engineering have to around check when landing?

05/04/2026

04/04/2026

what is Total Air Temperature ?

Total Air Temperature (TAT) is the highest temperature measured on an aircraft's skin, representing the true air temperature plus heating caused by high-speed compression and friction, known as "ram rise". It is crucial for jet engine efficiency, calculating true airspeed, and detecting icing conditions. TAT is always higher than the Static Air Temperature (SAT).

Total Air Temperature (TAT) គឺជាសីតុណ្ហភាពខ្យល់ដែលយន្តហោះទទួលបានពេលកំពុងហោះហើរ។ វារួមបញ្ចូលទាំង សីតុណ្ហភាពខ្យល់ធម្មតា (Static Air Temperature - SAT) និង សីតុណ្ហភាពដែលកើនឡើងដោយសារល្បឿនយន្តហោះ នៅពេលខ្យល់ត្រូវបានបង្ហាប់ពេលហោះ។

TAT មានសារៈសំខាន់សម្រាប់

ការគណនាប្រសិទ្ធភាពម៉ាស៊ីន
ការគណនាល្បឿនពិតរបស់យន្តហោះ
ការគ្រប់គ្រងប្រព័ន្ធហោះហើរ និងការគណនាផ្សេងៗក្នុងយន្តហោះ។

✈ Aviation Knowledge Series
Credit: Chhoun Limeng

01/04/2026

i'm new pilot 😇

01/04/2026

✈ What is Pilot Monitoring (PM)?

In modern aviation, safe flight operations rely on strong crew coordination. The Pilot Monitoring (PM) plays a vital role by supporting the Pilot Flying (PF) throughout all phases of flight.

While the PF controls the aircraft, the PM focuses on monitoring flight instruments, managing communication with Air Traffic Control (ATC), and verifying operational procedures. This teamwork helps maintain situational awareness, reduce human error, and ensure flight safety.

A well-coordinated cockpit is the foundation of safe and efficient flight operations.

📘 Aviation Knowledge Series

Prepared by: Chhoun Limeng

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