GPS & Modern Navigation
A typical training helicopter today carries a panel-mount GPS, an ADS-B Out installation, and an iPad running ForeFlight or Garmin Pilot. Modern nav reduces workload and increases situational awareness — when used right. Used wrong (head-down, single-source dependency, no cross-check) it has caused more accidents than it prevents. The PPL standard is to navigate through GPS while still being competent without it. Reference: AIM Chapter 1-1 for GPS, and AC 90-100A for IFR RNAV.
What GPS gives you
- Position — latitude, longitude, altitude. Accurate to ~5 m horizontal, worse vertical.
- Groundspeed — instant. Cross-check against your planned GS for wind verification.
- Track — your actual ground path. Compare to your magnetic course on the HSI/CDI to read drift.
- ETE / fuel-to-destination — auto-computed once you've entered the route.
- Nearest airport / NRST function — single-button list of nearby airports with distance and bearing. The single most useful emergency feature in a panel-mount.
- Direct-To — instant course to any waypoint. Often misused; see below.
WAAS, RAIM & signal integrity
- WAAS (Wide Area Augmentation System) — geostationary satellites that broadcast correction data, improving GPS accuracy enough for vertical guidance on IFR approaches (LPV, LNAV/VNAV).
- RAIM (Receiver Autonomous Integrity Monitoring) — the GPS verifies its own signal by comparing redundant satellites. Required for non-WAAS IFR GPS approaches; check RAIM availability in pre-flight via the receiver or FAA SAPT (Service Availability Prediction Tool).
- GPS jamming / interference — military testing produces NOTAMs. Read them. Loss of GPS in a non-WAAS system can mean instant approach unavailability.
- For a deeper dive on receivers and certification levels, see IFR Instruments — GPS & modern nav.
ADS-B In & FIS-B weather
- ADS-B Out (required per § 91.225) — broadcasts your position to ATC and other ADS-B aircraft.
- ADS-B In (not required, but valuable) — receives:
- TIS-B — traffic information from ATC radar. Other aircraft on your iPad screen.
- FIS-B — Flight Information Services Broadcast. Free in-flight weather: NEXRAD, METAR, TAF, AIRMET/SIGMET, NOTAMs.
- NEXRAD age stamp — the radar mosaic on your tablet can be 5–20 minutes old. Never use FIS-B NEXRAD as a tactical weather avoidance tool — only strategic. Cells build faster than the picture refreshes.
- Common ADS-B In hardware: Stratus (Appareo / ForeFlight), Garmin GDL series, Sentry. Talks to ForeFlight or Garmin Pilot via Wi-Fi or Bluetooth.
Panel-mount vs portable
- Panel-mount (Garmin GTN 650/750, GNS 430W/530W, Avidyne IFD): IFR-certified, integrated with autopilot and CDI/HSI, cleared for IFR navigation. The official navigation source under IFR.
- Portable / iPad (ForeFlight, Garmin Pilot, FltPlan Go): VFR situational awareness only. Not a primary IFR navigation source. Excellent for charts, flight plans, weather, ADS-B traffic, and as a cross-check.
- Practical setup in a Robinson R-22/R-44: ForeFlight on the iPad mounted on the yoke or center console, paired with a Sentry or Stratus for ADS-B In, plus the panel GPS (if equipped) for primary navigation.
- Carry a backup battery — the iPad will overheat or die at the wrong time.
How to use GPS without becoming dependent
- Brief the route before departure, not in the air. Programming a multi-leg flight plan while taxiing or at altitude is heads-down time you don't have.
- Always carry a paper or PDF sectional. Tablets fail, batteries die, software crashes. The chart is the backup.
- Cross-check GPS groundspeed against E6B-calculated GS. If they disagree, the wind is not what was forecast — adjust fuel and ETE.
- Don't blindly Direct-To across unknown terrain. The straight-line course may cross restricted airspace, mountains beyond your service ceiling, or a fuel-shortage region.
- Practice with the panel covered. Many DPE checkrides cover the GPS screen and require pilotage/dead reckoning to demonstrate the underlying skill.
- Know your single point of failure. If your only nav source is the iPad and it dies, what's your plan? Brief that backup before you launch.
Helicopter-specific GPS notes
- Helicopter Route Charts — special FAA charts for major metropolitan areas (LA, NYC, Houston, Boston, etc.) showing helicopter-specific routes, reporting points, and operating altitudes. Available at FAA AeroNav.
- Heliport identifiers in the GPS database typically start with the prefix that matches the regional convention — many heliports are private and not listed; use lat/long entry as a fallback.
- Confined-area approaches — Direct-To a heliport gets you to the airport reference point but not to the actual landing spot. Visual is final.
- EMS GPS approaches — Helicopter Point-in-Space (PinS) approaches are RNAV procedures designed for helicopter access to hospitals; require IFR rating and proper equipment. AC 90-95B.