Airhead ATPL question bank

Aircraft fuel systems can feel like a maze of tanks, pumps, valves and pipes. ⛽️✈️

That's why we've put together this handy infographic to show how it all works.

Save it for your next ATPL revision session and let us know — which topic would you like us to simplify next?

What is Fly-By-Wire? ✈️

Everything you need to know, simplified into one picture.

Save it for later, and see how modern aircraft turn pilot inputs into precise control movements.

✈️ Boeing 777 Variants Explained
777-200
The first production model of the family and still widely used by United Airlines as a high-density domestic aircraft. This variant was powered by the RR Trent 800 or the PW4000. British Airways, however, had a small number powered by GE90s as part of the GE90 certification programme.
777-200ER
An improved version of the -200 with additional fuel tanks located in the fuselage, increasing the overall range. This was the most popular -200 variant and was available with all three engine types.
777-200LR
Developed as a competitor to the A340-500 using the newer, more efficient GE90 engines. These did not sell particularly well, as they were designed for a relatively small market, and were only available with GE90s.
777-300
The longer and lesser-known variant of the 777 family, overshadowed by the -300ER. These were only powered by the RR Trent 800 and PW4000, and only around 60 were produced. Today, airlines such as Rossiya, Cathay Pacific, Korean Air, and ANA operate the -300. They were largely replaced by the -300ER due to poorer climb performance.
777-300ERSF
An in-development freighter conversion for the -300ER, currently in the late stages awaiting certification. Built by IAI in Israel and, like the -300ER, only available with GE90s.
777-200LRF
The freighter variant of the -200LR and extremely popular with cargo operators. It was designed as a replacement for the 747-400F and MD-11F. Available only with GE90s.
777-200LRMF
The first -200LR conversion kit. Being developed by Mammoth Aviation in partnership with STS Aviation. The first few aircraft will be ex-Delta 777-200LRs. GE90 only.
777-300ERMF
None have been built yet, which is why the picture shows a 777-300ERSF. However, they should be relatively similar as IAI will share its development work with Mammoth Aviation.
777-200QTD
The Quiet Technology Demonstrator, which used water injection and specially designed RR Trent 800 engine nozzles to reduce engine noise. This technology later contributed to the GEnx and LEAP-1B engines.
777-200SAF
The Sustainable Aviation Fuel variant used by Boeing, powered by PW4000s running on biofuel. These helped develop technology later

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