Fly with understanding.
The theory, the signals and the installation practice behind your instruments — written by the engineers who build them. Free, for every pilot.
The polar tells you everything.
One curve describes your glider completely — best glide, speed to fly, and what MacCready actually means. With an interactive polar.
How your computer knows the wind.
No wind vane, no probe — just vectors. The wind triangle, circling drift, and why a heading source changes everything. With a final glide tool.
FLARM antennas, installed properly.
Most range problems are installation problems. Placement, polarization, carbon fuselages, and how to verify your range with real flight logs.
The propeller is a gearbox.
Why one blade angle cannot serve takeoff and cruise, what a governor actually does, and how IAS mode makes it single-lever. With an interactive demo.
The runway does not get longer when it gets hot.
Density altitude, mass, surface, slope and wind multiply into a takeoff distance nobody planned for — for aeroplanes, self-launchers and aerotow. With an interactive performance calculator.
How FLARM actually works.
Not radar and not a transponder. What every aircraft broadcasts, how the collision prediction is built, what the three alarm levels really mean — and where it is blind. With an interactive encounter tool.
How GNSS receivers work.
Four satellites, one clock error, and centimetres from orbit. What your position solution is really made of — and what degrades it. With a sky you can drag.
Total energy compensation, explained.
Why a raw vario lies every time you touch the stick — and how a TE probe subtracts your own energy from the reading.
Fly heavy, climb light.
Water ballast does not change your glide ratio — it moves it to a faster speed. Wing loading, the √-scaling law, and when the water pays. With an interactive dual polar.
The final glide is a bet you can compute.
Arrival altitude is arithmetic: distance, wind, MacCready and a margin in metres. What degrades a glide and how to decide. With an interactive calculator.
Three holes in the fuselage run your instruments.
Pitot, static and the TE probe: which instrument drinks from which line, what position error is, and how one leak rewrites the panel. With a fault simulator.
Which altitude is the true one?
Altimeter, flight computer, GPS and IGC file each report a different altitude — and all of them are right. QNH, ISA, temperature error and the geoid. With an interactive tool.
Your vario is always telling you about the past.
Every variometer filters, and every filter costs time. Where the lag comes from, what the response setting chooses, and what netto and relative add. With an interactive thermal crossing.
How an AHRS knows which way is up.
Gyros drift, accelerometers lie in every turn, and yet the horizon holds. The sensor fusion inside an attitude reference — and why a circling glider is its hardest case. With an interactive turn demo.
12 volts is not 12 volts.
Batteries sag, wires eat volts, and the radio reboots the panel on the first call of the day. Lead vs LiFePO4, fusing and capacity planning. With an interactive discharge tool.
What makes a flight log official.
The IGC file is a plain text file the whole sport agrees to trust. B-records, the G-record signature, approval levels and engine noise — and how a claim actually gets made.
The thermal assistant is drawing your last turn.
It is not a thermal detector — it is a wind-corrected memory of the lift you already flew through. Read properly it is worth half a metre per second. With an interactive centring tool.
The airspace you cannot see is still there.
Classes, floors and ceilings written in three different altitude references — and how a flight computer turns a polygon file into a warning that arrives while you can still turn. With an interactive vertical-limits tool.
Who can actually see you.
FLARM, Mode S, ADS-B and TCAS are four conversations on four frequencies. Which of them carries your aircraft, which is deaf to you, and what a unified traffic display really merges. With an interactive visibility matrix.
One cable behind the panel.
Why modern instruments share two wires instead of a loom, what CAN really does with them, the 120 Ω rule that decides whether your panel is reliable, and where gigabit Ethernet takes over. With an interactive bus tool.
The six-pack did not disappear, it moved.
A glass panel is the same six instruments rearranged around one principle. Colour bands, trend vectors, failure flags — and what the stall speed does when you bank. With an interactive PFD.
The wing does not know how fast you are going.
A wing stalls at an angle, not at a speed. Why the placard number is true at exactly one weight and one bank angle — and what an angle-of-attack indication gives you instead. With an interactive gauge.
The engine is talking in numbers.
EGT is not a limit, it is a mixture indicator. CHT is the limit. What every engine parameter really tells you, and why a logged trend finds failures a red line never will. With an interactive leaning tool.
Thermals are only one of the ways up.
Ridge lift, mountain wave and convergence are three more engines, each with its own rules, its own hazards and its own signature on the instruments. With an interactive lee-wave cross-section.
Four airspeeds, and only one of them is on the dial.
Indicated, calibrated, true and ground speed are four different numbers, and every limit in the aircraft manual is written in exactly one of them. Which one, why, and the altitude trap in Vne. With an interactive tool.
The polar in your manual has never hit a bug.
Insects, rain and years of wear quietly rewrite the one curve your computer trusts. Slide the degradation on and watch a 42:1 glider become a 32:1 glider — and a final glide stop reaching.
An outlanding is a landing, not an emergency.
Field selection is a sequence of altitudes, each with one job. The interactive ladder shows how many minutes you really have between still soaring and committed — fewer than it feels.
The day is decided before you rig.
Two temperatures and a pencil sounding forecast cloudbase, thermal tops and start time. Warm the afternoon in the interactive sounding and watch the day switch on — or refuse to.
Coming home early is the expensive mistake.
Racing tasks and AATs score the same clock differently. The interactive scorer shows what ten minutes under time really costs — and how deep into the last area the arithmetic says to fly.
Your compass points down more than north.
At our latitudes nine-tenths of the magnetic field points into the ground, and every degree of bank invites it into the heading. The interactive rose shows the northerly turning error — and what tilt compensation buys.
The first thing hypoxia takes is your opinion of it.
Saturation, time of useful consciousness and cylinder endurance as functions of altitude. Slide the wave climb upward and watch the margins shrink — and what a pulse-demand system does to the bottle arithmetic.
Airspace moves. Your SD card does not.
Airspace, turnpoints, obstacles and firmware age at different speeds, all against a 28-day clock. The interactive calendar shows the odds that something you rely on changed while you were not looking.
The panel has room for everything except everything.
Cutout spacing, scan ergonomics and the current budget in one interactive panel builder — stack instruments into a 57-millimetre world and watch the amp meter and the battery clock react.
There is a correct speed for being impatient.
Power required, best endurance, best range and Carson's compromise on one interactive curve — with wind and fuel sliders pricing every knot of hurry in litres and kilometres.
Loading is aerodynamics you do on the ground.
Two schematic aircraft — a trainer and a two-seat glider — with live CG arithmetic. Slide pilots, fuel and ballast across the envelope and see exactly where the minimum-cockpit-load placard comes from.
Fuel is measured in minutes, not litres.
Usable fuel, honest flow, reserves and the error bars of every gauge in one interactive endurance bar. Watch a 120-litre tank become three and a half hours — and how fast a headwind and a lazy lean eat it.
Carburettor ice does not check the calendar.
A carburettor cools itself twenty degrees below the day, so icing peaks in warm, humid air. The interactive envelope shows the risk for your temperature, dew point and throttle — and why descent power is the trap.
You get to keep a third of the cable.
A winch trades a kilometre of cable for four hundred metres of height in forty seconds. The interactive profile shows what the wind and the winch driver add to your release height — and rehearses the cable-break ladder at every height.
Slowing down is structural engineering.
A vertical gust multiplies load in proportion to your airspeed, and the wing cannot tell turbulence from a pull-up. The interactive V-n envelope shows the gust arithmetic, what manoeuvring speed actually promises — and why ballast makes rough air smoother.
The battery is the first fuel gauge that tells the truth.
Watt-hours are litres you can actually measure. Climb costs mgh, level flight costs drag times speed, and the reserve is a number, not a hope — an interactive energy planner for FES, sustainer and electric self-launch gliders.
Instruments age in the hangar, not in the air.
Tubing hardens, baro sensors drift, batteries fade and the compass swings — all while the glider sleeps. The annual instrument check, item by item, with an interactive leak-test bench.
One glider, five polars.
A flapped wing is a different glider at every notch, and the polar you fly is a family of curves rather than one. Flap schedules, negative flap in the cruise, the placards on the lever — and what a flap sensor lets the computer correct. With an interactive polar family.
Speed is altitude you have not cashed yet.
Your computer counts the speed you are carrying as height, assumes a finish crossing at 97 km/h and a pull-up, and calls the sum arrival. The flight recorder writes down only the altimeter — and the badge rule is written against the file. With an interactive finish-line energy tool.
Your instruments speak in sentences.
Every computer, vario and traffic box on the panel shares one dialect from 1983: a dollar sign, comma-separated fields and two hex digits of checksum. What a sentence carries, why the baud rate is a budget, and what a tablet actually reads. With an interactive sentence builder.
The vario you fly by is the one you hear.
Pitch for climb, a chirp rate for confirmation and a band of silence for the air you do not need to know about. How a variometer turns lift into sound, why the ear beats the eye, and what changes in the cruise. With an interactive vario you can listen to.
Certified is a sentence about paperwork.
An approved article, an approved installation and an aircraft that requires either are three different questions, and only one of them is answered on a product page. What the words mean, who signs which document, and why the same instrument is routine on one airfield and a project on the next. With an interactive paperwork sorter.
The hum in your headset is a wiring diagram.
Two grounds a metre apart are never at quite the same potential, and every millivolt between them arrives in the audio, the GPS and the traffic receiver. Ground loops, star grounds, which end of a shield to tie, and the switching regulator nobody suspects. With an interactive noise-budget tool.
The impossible turn is a sum.
An engine failure on climb-out leaves you with two hundred and forty degrees of turning, a pause while you refuse to believe it, and a glide back to a runway you will land on downwind. Bank angle, reaction time, wind and glide ratio decide it before you do. With an interactive turn-back calculator.
Petrol boils sooner than you think.
Winter petrol on a summer apron, a hot cowl at idle and a climb to three thousand metres all close the gap between the pressure in the line and the pressure at which the fuel boils, and a bubble in the line stops an engine as surely as an empty tank. Volatility, ethanol, temperature and altitude in one margin. With an interactive vapour-lock tool.
Written where the instruments are built.
Every article comes from the same desks in Celje where we design variometers, AHRS units and FLARM installations — fifty years of them. No marketing filter.
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