Gear, Brakes, Cabin & CO

Tricycle gear places the center of gravity ahead of the mains, which makes the airplane stable on the ground and gives good forward visibility. Look at the nose gear and you'll find an oleo (air-over-oil) shock strut that absorbs shock, torque links that keep the wheel aligned with the strut as it extends and compresses, and a shimmy damper that stops the nosewheel from oscillating. What you won't find is a brake. And for all that hardware, the nose gear still isn't built to take the shock of a hard landing: touch down on the main wheels first and hold the nose off, because a nose-first arrival can bend the firewall or cause a propeller strike.

• What type of landing gear does your airplane have? Which wheels have brakes?
• What do the torque links and the shimmy damper on the nose gear do?
• Why do you touch down on the main wheels first?

Brakes convert energy to heat, and heat is their enemy. Riding or dragging the brakes — resting your toes on them during taxi — overheats them, causing brake fade (reduced effectiveness) and rapid wear, and in the worst case a brake fire. Control your taxi speed with power first: reduce the throttle, let the airplane slow to a walk, and use short, positive brake applications rather than continuous pressure.

• How do the brakes work in your airplane?
• What is differential braking, and when would you use it?

Think of it as two separate paths. Exhaust gas runs inside the muffler and goes overboard out the tailpipe. Your cabin air passes around the outside of that muffler, picks up heat, and goes to the vents — it should never touch the exhaust gas at all. The only thing keeping those two paths apart is the muffler wall. So a cracked muffler, a leaking exhaust joint, or a failed shroud lets exhaust gas — which contains carbon monoxide — cross into the cabin-heat air and ride it straight to you. That's why the exhaust system gets inspected, and it's exactly why carbon monoxide is the next thing we cover.

• Where does the cabin heat in your airplane come from?
• Why is a cracked exhaust a cabin-air concern?

CO poisoning is insidious: the early symptoms — headache, drowsiness, dizziness, nausea, blurred vision, and impaired judgment — come on gradually and are easily blamed on fatigue or airsickness, so pilots keep flying while getting worse. Protect yourself two ways. First, carry a working CO detector; an electronic detector that alarms is far better than a chemical spot card, which fades over time and is easy to overlook. Second, know the response: if you suspect CO, turn the cabin heat OFF, open the fresh-air vents and a window, use supplemental oxygen if you have it, and land as soon as practical — then get medical attention, because CO stays in your blood for hours.

• What are the sources and symptoms of carbon monoxide poisoning?
• What would you do if you suspected CO in the cabin?

Ice, water, or even an insect can block the pitot tube and corrupt your airspeed indication, so turn pitot heat on when flying in visible moisture or icing conditions, or whenever your POH calls for it — and remember it's a real electrical load. On the ground, use a pitot cover to keep bugs and water out, and know where the drain holes are. Some airplanes have an alternate static source for when the normal port blocks. Exactly how a blocked pitot or static changes each instrument's reading is its own topic — you'll cover that in Module 4.

• What instruments does the pitot-static system feed?
• When do you use pitot heat, and why?

Land on the mains and protect the nosewheel. Don't ride the brakes — control taxi speed with power. Suspect CO? Heat off, vents open, land. In visible moisture, pitot heat on before it ices. And when any question of limits or procedure comes up, the POH — not memory or habit — is the final word. That POH discipline is the whole subject of the next lesson.

• Walk me through the abnormal you'd watch for in each of these systems.
• Where do you find the limits and procedures for all of them?