On-device transcription
A US-ATC fine-tuned Whisper model transcribes live radio at ~12.5× real-time on an M-class device — with no internet and nothing to phone home to.
An Obelisk Aerospace product
The whole flight deck, in one app.
Obelisk is an on-device ATC transcription engine wrapped in a full Electronic Flight Bag — charts, procedures, traffic, weather and planning, built to fly with no signal. Here’s everything it does.
12.5×
faster than real-time, on-device
9.1%
word error rate
~9,000
georeferenced approach plates
100%
on-device — audio never leaves
Transcription & ATC awareness
The whole pipeline — capture, squelch, a fine-tuned Whisper model, diarization and two-tier correction — runs on the Apple Neural Engine with no server.
Two-tier correction
A fast deterministic vocabulary pass, then an optional on-device LLM context-fixer that cleans misheard callsigns, phraseology and stray words — grounded in real ATC context. Every edit is shown from → to; the raw is always kept.
Skip-when-confident
Conservative / Balanced / Aggressive gates run the AI fixer only on suspicious transmissions — low confidence, callsign near-miss, repetition — to save CPU and battery.
Speaker labelling
One fused label per line: ATC (with a controller → aircraft arrow) or the pilot's callsign chip, split at push-to-talk breaks. Honest 'unknown' when it can't tell.
Callsign linking
Every transmission is tagged with a tappable callsign — tap to filter the transcript to just that aircraft. A green ✈ means they're in range on live ADS-B.
Voice-driven clearance loader
Hears a clearance addressed to your tail — 'cleared direct BOSOX', 'cleared the CIVET arrival' — and offers a one-tap chip to load it. Ownship-aware; never fires on another aircraft.
Any audio source
Internet live feed (LiveATC or any stream), a Stratux receiver over Wi-Fi, the device mic, USB audio, or an offline replay demo — monitored out the speakers so you know audio's arriving.
Per-line confidence
An always-visible 🟢🟡🔴 dot rates the grounding and cleanliness of each line, next to a live AI-fixer status with the real-time cost on screen.
A moving map that's the home screen
A GPU chart engine renders FAA charts, your route, airspace, airways, navaids, traffic, TFRs and plates entirely on-device — the transcript, plan and GPS float over it as cards you arrange.
Offline GPU chart engine
MapLibre renders everything on-device with no internet, built to sip power — with a classic MapKit engine one toggle away and an automatic fallback if the GPU map ever fails to draw.
Five base layersincl. night chart
VFR sectional, IFR low, IFR high, Satellite, and Dark (minimal) — a near-black night/IMC chart decluttered to just the route, fixes and restrictions.
Coded procedures (CIFP)
FAA-coded approaches, SIDs and STARs draw as georeferenced overlays and load into your plan — Y/Z approaches told apart, published holds drawn as real racetracks with the correct entry for your arrival.
Georeferenced plates
Send an approach plate to the map and it snaps to exact place, scale and orientation from FAA-embedded georeferencing — roughly 9,000 approaches, nearly every US instrument approach.
Tap-to-identify
Tap any airport, navaid, fix, airspace, airway, traffic contact, hazard or TFR to identify it — airports open a ForeFlight-style card with Info, Weather, Runway, Procedure and NOTAM tabs.
Live TFRs & airspace
FAA TFRs drawn in red with altitudes, the reason parsed from the NOTAM, and effective/expiry times; Class B/C/D and Restricted/Prohibited/Warning/MOA nationwide with plain-English explanations.
Build a route on the map
From any point: add, insert-in-order, Direct-To from your GPS position, set departure/destination. Search any airport or fix by name and drop a pulsing marker even if that layer is off.
Experimental globeexperimental
Zoom out and the flat chart curves onto a rotatable sphere, flattening seamlessly on zoom-in — a from-scratch globe projection for MapLibre.
Flight planning & the EFB
Paste a route and it becomes a color-coded plan on real charts, packs your callsign and waypoints into the corrector, and hands off to ForeFlight — offline, app-to-app.
Live route strip
A free-form route field — 'KMSP GEP KAMMA KORD' — recognizes each entity live into color-coded chips. Edits commit live; there's no Save button, so what you send is exactly what's on screen.
Trip numbers
Live DIST / ETE / ETA / FUEL / WIND under the route, with a stale-plan warning after a week.
Aircraft profiles
Save callsign, type, cruise speed, fuel burn, glide ratio and best-glide speed — feeding the trip math, the ownship clearance gate and the engine-out ranking.
ForeFlight hand-off
Accept an amended clearance ➔ ForeFlight, or send the whole plan; also export a Garmin .fpl. Import a route via 'Open in Obelisk' from ForeFlight's share sheet.
Pack the bag
Download the filed route's plates, the current airport's, or whole region bundles — with the 28-day chart cycle validity and an auto-pack-when-I-file toggle.
Live route progress
Time remaining to the next waypoint and to destination, plus clock arrival time in the destination's local zone, on the GPS bar.
Weather, winds & interference
A full NOAA aviation-weather briefing, NASA climate and hazard data, and a GPS-integrity monitor that tells jamming from spoofing — every chart cached for offline re-open.
NOAA weather gallery
GOES satellite, GFA cloud & surface, WPC prog charts, convective outlooks, precipitation, winds aloft, icing and turbulence — each viewed chart cached on disk and stamped with NOAA's release time.
METAR / TAF, decoded
Live METAR with a color-coded flight-category chip, TAF with plain-English decoded periods, and a trend that projects category now / +1 hr / +2 hr and flags fast deterioration.
Airport climate (NASA POWER)
A 16-sector windrose, best-time-of-day heatmap, density-altitude percentiles and favored-runway / crosswind-exceedance stats — decades of normals, ~2 MB once, then offline.
Radar & animated winds aloft
Translucent precipitation with a past→now→forecast scrubber, and Windy-style drifting wind streaks colored by speed with a 10-level altitude slider from the surface to FL390.
NASA natural hazards
Active wildfires, severe storms and volcanic activity from NASA EONET drawn on the map, with a heads-up when one sits near your route or ownship.
GPS integrity & AGL
A quiet advisory that warns when accuracy degrades, hides ownship rather than show a position it doesn't trust, and distinguishes jamming from possible spoofing — plus height above ground from a bundled terrain grid.
Airports & engine-out glide
A ForeFlight-style airport directory over nearly 10,000 US fields — and when it matters, a glide-range ranking that sweeps terrain along every path.
Airports directory
Rows with a diagram thumbnail, flight-category chip, latest weather, key frequencies and approaches — grouped into Favorites, Recent, On-route and GPS-driven Nearby.
Airport cards
Info, Weather (METAR/TAF/7-day/history), Runway (CIFP pairs with true headings and lengths), Procedure (plates with send-to-map and Activate approach) and NOTAM.
Engine-out glide rankingNRST
Takes your altitude and the aircraft's glide ratio, computes every airport inside the glide cone, then sweeps the terrain grid along each path — a field behind a ridge is shown blocked, not offered.
One-tap, fully reversible
DIRECT engages instantly with no confirmation — because one tap on 'Restore plan' puts your filed route and armed approach back exactly as they were.
Themes, widgets & logbook
Three cockpit themes, a windowing system for the map, PencilKit notes, plate binders and a full flight recorder — tuned for iPad in the cockpit.
Three cockpit themes
Cockpit (pure-black, avionics-style), Day (flat-white for bright sun) and Night (true red night-vision — plates open pre-inverted, essentially no blue or green light). The map recolors in place.
Floating widgets & docking
Transcript, traffic, GPS, performance and more float over the map with adjustable opacity — drag one to an edge to dock it as a resizable side pane. Layouts persist.
Notes (PencilKit)
Hand-write with finger or Apple Pencil on a full-page canvas with the system tool palette, and a thumbnail library of saved notes — black page, white pen, dark-adaptation safe.
Plate binders
One binder per airport, opening to large thumbnails grouped by category (approaches split by runway) sized to each plate's own aspect ratio, with a zoom slider that trades columns for size.
Logbook & flight recorder
Leave a breadcrumb trail, then replay the whole flight on a scrubber — position, altitude, ground speed and track — with metrics, stops and an editable aircraft and notes.
Live GPS bar
Signal quality, source (Stratux-preferred, on-device fallback), MSL, AGL, ground speed, track and live ETE/ETA — app-wide, just above the tab bar.
Downloads, diagnostics & privacy
Models and charts download once, then it flies fully offline. Nothing about your audio leaves the aircraft.
Offline charts & plates
FAA raster chart packs (VFR / IFR low / IFR high, 56-day cycle) and approach plates by region (28-day cycle) — per-pack or all, with storage readouts and protected storage that survives low-storage purges.
Speech-model management
Download the US-ATC fine-tuned model once over Wi-Fi; live picker with progress, thermal state, mid-load switching and watchdog recovery so it never wedges on 'Loading…'.
Satellites page
A predicted sky plot, usable-satellite counts against the 4/5 thresholds, predicted PDOP/HDOP/VDOP, and a predicted-vs-measured cross-check whose disagreement is the interference signature.
Battery diagnostics
Opt-in per-minute telemetry tagged by activity — CPU load, the map's real frame rate, transcription duty — a true discharge rate you can share as a file.
Data currency
App-wide badges stay quiet while current and speak up when procedures, plates or charts fall out of cycle — AIRAC cycles install without an app update, verified before anything is replaced.
Private by design
Capture, transcription and correction all run on-device; the optional transcript log stays on the device and is never uploaded; ADS-B and any cloud fixer are explicit opt-ins.
Put the tower on your side.
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