Airhead ATPL question bank

The Semi-Circular Rule made simple. ✈️

One of those topics every pilot student needs to know — and one that often appears in exams.

Here's everything you need to know at a glance.

📊✈️ V-Speeds – Know Your Numbers!

V-speeds are fundamental reference points for every pilot. They’re not only important for exams but also define how your aircraft performs, how safely it flies, and how you make critical decisions in the air. 👨‍✈️📘

🔹 Va – Design manoeuvring speed. The maximum speed at which full control inputs can be made without overstressing the airframe.
🔹 Vs / Vso / Vs1 – Stall speeds in clean, landing, or specific configurations. Knowing these helps define your safe operating envelope during all phases of flight.
🔹 Vf – Design flap speed. Never extend your flaps above this speed.
🔹 Vle – Max speed with landing gear extended.
🔹 Vfe – Max flap extended speed. Exceeding it risks structural damage.
🔹 Vno – Maximum structural cruising speed. Don’t exceed this in turbulent conditions.
🔹 Vne – Never exceed speed. A structural red line.
🔹 Vx – Speed for best angle of climb. Useful for clearing obstacles.
🔹 Vy – Speed for best rate of climb. Ideal for efficient altitude gain. Quickest way to climb.
🔹 Vg – Best glide speed. Crucial during engine failure or emergencies.
🔹 Vref – Reference landing speed. Calculated based on weight, configuration, and approach. It’s used for final approach control and safety margins.

📌 Save this for your studies and your future flight bag!

Everything you need to know about a Dutch roll — all in one place.

We've broken down the essentials into simple, easy-to-follow cards.

Save this post for revision later and share it with a fellow pilot student. ✈️

One of the most common causes of fatal airline accidents before the 1970s was Controlled Flight Into Terrain (CFIT), in which a fully functioning aircraft, under the control of the pilot, is unintentionally flown into the ground, mountains, or other obstacles.

Many crews had little warning of rapidly approaching terrain, especially at night, in poor weather, or during high-workload phases of flight.

This resulted in the development of the Ground Proximity Warning System (GPWS), which monitored aircraft parameters such as radio altitude, descent rate, configuration, and terrain closure rate to provide aural warnings such as "PULL UP" or "TOO LOW TERRAIN".

The GPWS was revolutionary but only reacted to terrain directly underneath the aircraft, limiting warning time.

The next step was the Enhanced Ground Proximity Warning System (EGPWS).

EGPWS can predict conflicts with terrain ahead of the aircraft, rather than below it, by combining GPS position data, aircraft performance information, and an onboard terrain database.

It provides crews with those few extra seconds — or even minutes — to see what's happening and do something about it.

Today, EGPWS is standard safety equipment on modern transport aircraft and is credited with dramatically reducing CFIT accidents worldwide.

It also helps avoid flying into terrain and improves pilot situational awareness when approaching and departing airports, and when operating around mountainous terrain, especially in poor weather or low visibility.

📚 For exams, remember:
✈️ EGPWS = Predictive
✈️ GPWS = Reactive

Not all wings are created equal. ✈️

Different aircraft use different wing designs to improve performance, efficiency, and handling.

Swipe through to explore the main types of aeroplane wings.

Longest-range helicopters in the world 🚁
Swipe to see them all.

P.S. Practising for your ATPL(H)? Airhead Question Bank has you covered.
Link in bio.

🚀 Jet Propulsion — the big picture (and why Newton still runs the show) ✈️

Jet propulsion highlights the importance of Newton’s 3rd law. It simply embodies the principle that if you accelerate air (or gas) backwards, the aircraft moves forward.

The shown engines differ in spools and general architecture. Throughout the years, we have learned to package that “power” in more efficient ways — however, the world of propulsion is much bigger! How that energy is produced is what defines each engine type. Below are a couple of different examples explained 👇

🔹 Turbojet
The original gas turbine concept (Whittle, 1930). Efficient at high speeds, but less so at lower Mach numbers due to very high exhaust velocity. Best suited for fast aircraft.

🔹 Turbofan / Bypass Engines
Move a large mass of air at lower velocity, improving propulsive efficiency and reducing noise. This is why modern transport aircraft rely on them.

🔹 Turboprop
Most efficient at lower speeds. Uses the same gas turbine core, but thrust mainly comes from the propeller, not the jet.

🔹 Ramjet
No compressor, no turbine. Relies entirely on forward speed to compress air — meaning zero thrust at standstill. Excellent at high Mach numbers, useless for takeoff.

🔹 Pulsejet
Uses intermittent combustion. Can run statically but suffers from very high fuel consumption and vibration → historically interesting, operationally limited.

🔹 Rocket
Carries its own oxygen, so it works outside the atmosphere. Extremely powerful, extremely inefficient for sustained flight.

🔹 Turbo-Ramjet / Turbo-Rocket
Hybrid engines designed for very high Mach numbers, switching operating modes as speed increases.

📚 Exam tip: For a given thrust, it’s more efficient to accelerate a large mass of air slightly than a small mass of air a lot — this principle explains why bypass ratio matters so much.

💡 Save this, share it with your aviation mates, and thank Newton later.

A Radio Altimeter (RA) failure means more than just losing height indication below 2,500 ft AGL on your PFD.

Unlike the barometric altimeter, the RA measures true height above terrain using radio waves, making it critical during the approach and landing phase — especially in IMC. ✈️

An RA failure can affect multiple aircraft systems:

⚠️ Incorrect or lost automatic callouts and DH/MDH references

⚠️ Autothrust and autoflight degradation, especially during CAT II/III operations

⚠️ GPWS/EGPWS warnings becoming unreliable or inhibited

⚠️ TCAS logic and terrain awareness functions potentially affected, depending on aircraft type

Remember: RA is primarily used for low-altitude precision and system automation, while barometric altitude remains the primary reference for en-route flight and ATC separation.