First release · Nº 001

Preflight Kit.

iPhone · iOS 17 and later

Our first app. Twelve flight-computer tools for student pilots, each one on a single screen, and every one of them works with no signal.

Twelvemodules, one screen each

Fouraircraft types, checked against the POH

Zerobytes of your data leaving the phone

Coming to the App Store

Free for seven days. Then £6.99 once. No subscription, and nothing to cancel.

Preflight Kit showing a Piper PA-28-161 Warrior II: its tools, and the aeroplane drawn to its own span and length.

Why we built it

Most of learning to fly happens on the ground.

Preflight Kit is for the kitchen table the night before the lesson. Work a heading, a fuel figure or a crosswind as many times as it takes for it to stop being hard. No exercise sheet, no timer, no marking.

Change one number and the drawing changes with it. Swing the wind round the compass and the drift changes sides. Push the crosswind past the limit and the verdict turns red. That is the part a whizz-wheel cannot do: show you what a number means while you are still learning what it is.

Crosswind · try it

Within the limit

Headwind: 6 kt
Crosswind from left: 8 kt
Angle off the runway: 50°
Crosswind limit PA-28-161: 17 kt

Wind from · °220

Wind speed · kt10

Runway

Drag the wind on the drawing, or use the sliders. The app does this on the phone, with haptics on the verdict.

The kit

Twelve modules.

Every one is a single screen with the working shown, grouped the way a flight is: what you do at the table, what the wind is doing, and what you need with the aeroplane already moving. Nothing is buried in a menu, because in the air you have no spare hand for menus.

Plan at the table

PLOGHeadings, times and legs for the whole route.

FuelThe minimum you must carry, and the margin you actually have.

Takeoff & landingYour POH figure taken through the CAA safety factors, with a verdict against the runway you have.

Climb & descentTop of climb, top of descent, and the rate to fly.

Wind & air before you go

Wind StarDrift and groundspeed for every track, on one dial.

Wind FinderThe wind’s speed and direction, read back from the drift you are seeing.

CrosswindThe head and cross split, against the limit.

Air & altitudesPressure altitude, density altitude and TAS.

In the air on the kneeboard

Time · Speed · DistanceAny two of them give the third.

DiversionNew heading and new time, in seconds.

Back on trackThe 1-in-60 correction, drawn.

Holding patternEntry sector, drift headings and the outbound time.

And the small things

Kilograms to pounds, litres to gallons, feet to metres, knots, Celsius, hectopascals. Drag to scrub, no keyboard. Fuel reserve rules you set once, day and night. Haptics on every verdict.

The aeroplane

The aeroplane your school flies.

Pick the type and its book figures arrive already entered, checked against the POH. Add the registration and the empty weight off the school’s schedule, and it is ready before your next lesson.

Types carried

Figures from the POH

Type	MTOW	Demo. x-wind	V_r	V_y	V_ne	Usable fuel	Burn
Cessna 150M	1,600 lb	13 kt	53	68	141	85.2 L	22.3 L/hr
Cessna 152	1,670 lb	12 kt	50	67	149	92.7 L	23.1 L/hr
Cessna 172N	2,300 lb	15 kt	55	73	160	151.4 L	31.8 L/hr
Piper PA-28-161 Warrior II	2,440 lb	17 kt	55	79	160	181.7 L	32.2 L/hr

Weight & balance · PA-28-161

Empty weight1,467 lb87.0 in

Pilot & front passenger340 lb80.5 in

Rear passengers170 lb118.1 in

Baggage30 lb142.8 in

Fuel · 181.7 L, full tanks288 lb95.0 in

Take-off2,295 lb90.1 in

Inside the envelope 145 lb under MTOW

A worked example on the shipped Warrior II template, at a typical empty weight. Load it differently and the point moves.

What the type brings

V-speeds: The reference card for the type, from V_so to V_ne.
Weight & balance: Stations and their arms, the tanks, and the CG envelope drawn to the book.
The drawing: The aeroplane to its own span and length, so you can see you picked the right one.
Performance: The POH take-off and landing tables, read at the pressure altitude and temperature you have.
Compass card: For °M, steer °C — the deviation card off the panel.
Or enter it by hand: Every one of these can be typed in for an aeroplane we do not carry, envelope corner points included.

The screens

Every answer is drawn.

Nine screens · hover to hold

Crosswind: runway 27, wind 220 at 10 gusting 20, split into 6 knots of headwind and 8 knots of crosswind from the left. — CrosswindHead and cross, against the limit

Wind Star: drift and groundspeed for twelve tracks around one dial. — Wind StarDrift on every heading at once

Takeoff and landing: 800 metres required against 1,200 metres available, with the runway declared distances drawn. — Takeoff & landingTORA, TODA, ASDA, LDA, decoded

Fuel: minimum fuel required broken into taxi, trip, contingency, alternate and final reserve, with the margin left over. — FuelThe minimum, and the margin

Wind Finder: the wind worked back from a heading of 340, a track of 300 and a groundspeed of 95. — Wind FinderThe wind, from the drift you flew

Holding pattern: a teardrop entry drawn on the compass with the entry sectors marked. — Holding patternThe entry, before you need it

An aircraft: G-ABCD, a Piper PA-28-161 Warrior II, drawn to its own span and length. — Your aeroplaneDrawn to its own span and length

The hangar: a list of saved aircraft with registration, type, maximum take-off weight, usable fuel and burn rate. — The hangarEvery aeroplane you fly

Convert: litres to US gallons, imperial gallons, kilograms and pounds on parallel scrub scales. — ConvertDrag to scrub, no keyboard

Offline, always

It works with no signal.

There is no account to make and nothing to sign in to. It works in the club house, in the hangar and in the air, which is where a flight-computer has to work or it is not one.

No account

No password and no e-mail address. Open it and it is already yours.

No advertising

No analytics, no crash reporter, no third-party code of any kind.

Nothing leaves the phone

Not your route, not your aeroplane, not your figures. The only network traffic the app makes is the App Store’s own.

The promise

There is no licence check to fail. It will never lock you out mid-flight.

Seven days free

Then it is your call.

Every module is open from the first launch: your aeroplane, every diagram, the whole kit. Nothing is held back to sell you later. Fly a week of lessons on it and find out whether it is any good.

On day seven there is no automatic charge and nothing to cancel. If it has earned its place you buy it once, and it is yours on every iPhone signed in to your Apple Account.

£6.99 One paymentNo subscription

Trial: Seven days, everything open
After the trial: £6.99 once
Devices: Every iPhone on your Apple Account
Requires: iOS 17 or later

Coming to the App Store

Prices shown in your own storefront.
Terms of Use · Privacy notice

Tools, not authorities

Preflight Kit is an instructional tool for pilots. Its figures are yours to check against the POH, the AIP and the current charts. You remain in command.

The app has its own Terms of Use and Privacy notice, bundled in it and published here in full. The studio’s own are in the footer.