AEROWAY TECHNICAL REFERENCE
STD: 29.92 inHg
AEROWAY.ORGREF-01
Aeronautical Reference Architecture
SOURCE HIERARCHY & MULTI-JURISDICTION INTEGRITY (FAA · EASA · ICAO)Published: Authority Registry Audited:

Governing Sources & Technical Standards

Aeroway enforces a strict rule: Source before coding. Every non-trivial calculation model references its governing authority. We explicitly document and separate requirements from the Federal Aviation Administration (FAA), the European Union Aviation Safety Agency (EASA), and the International Civil Aviation Organization (ICAO).

The Aeroway Technical Authority Hierarchy

  1. Current Official Regulation: Applicable national/regional civil aviation regulations (e.g. FAA 14 CFR Part 91, EASA Part-NCO / SERA) for legal operating minimums.
  2. Official Aviation Handbooks & Manuals: FAA-H-8083 series, FAA Orders, EASA Easy Access Rules, and ICAO manuals for standard procedures and aerodynamic concepts.
  3. Aircraft AFM / POH: Manufacturer-approved operating handbooks for aircraft-specific performance, weight & balance, and limitations.
  4. Standard Physical Specifications: International standards such as ICAO Document 7488 for Standard Atmosphere profiles and ASTM fuel specifications.
  5. Authoritative Engineering Derivations: Established aerodynamic and trigonometric principles for geometric relationships where no regulatory variant exists.

Multi-Jurisdiction Alignment: FAA (United States) vs EASA (Europe)

Aeroway does not universally apply U.S. rules worldwide. Where regulatory modes exist (such as VFR fuel reserves or cloud clearance minimums), the interface explicitly labels the jurisdiction:

United States (FAA 14 CFR)
  • Fuel reserves: § 91.151 (Day: +30 min, Night: +45 min)
  • Altimetry: Inches of Mercury (inHg) & QNH
  • Weather minimums: § 91.155 Airspace Class Matrix
  • PIC Responsibility: 14 CFR § 91.3
Europe (EASA Air Operations)
  • Fuel reserves: Part-NCO.OP.125 (+10 min local, +30 min VFR, +45 min IFR)
  • Altimetry: Hectopascals (hPa / mb) & QNH standard
  • Weather minimums: SERA.5001 & SERA.5005 VMC Criteria
  • PIC Responsibility: EASA NCO.GEN.105

Civil Aviation Regulations (FAA 14 CFR & EASA Regulations)

US14 CFR § 91.151

14 CFR § 91.151 — Fuel requirements for flight in VFR conditions

National Archives / FAA

U.S. Part 91 specific minimum fuel reserve requirement for airplanes.

Key Citations:
  • (a)(1) Day VFR: 30 minutes
  • (a)(2) Night VFR: 45 minutes
US14 CFR § 91.167

14 CFR § 91.167 — Fuel requirements for flight in IFR conditions

National Archives / FAA

U.S. Part 91 specific minimum IFR fuel reserve for civil airplanes.

Key Citations:
  • (a)(3) 45 minutes at normal cruising speed
US14 CFR § 91.155

14 CFR § 91.155 — Basic VFR weather minimums

National Archives / FAA

Establishes legal flight visibility and distance-from-cloud minimums for VFR operations.

Key Citations:
  • Cloud clearance and flight visibility by airspace class
US14 CFR § 91.121

14 CFR § 91.121 — Altimeter settings

National Archives / FAA

Mandates standard 29.92 inHg above 18,000 ft MSL and establishes lowest usable flight level table during low-pressure systems.

Key Citations:
  • (a) Operations below 18,000 ft MSL: current reported altimeter setting
  • (a)(2) Operations at or above 18,000 ft MSL: standard 29.92 inHg
  • (b) Table 1: Lowest usable flight level based on current altimeter setting
US14 CFR § 91.159

14 CFR § 91.159 — VFR cruising altitude or flight level

National Archives / FAA

Governs semicircular cruising altitudes above 3,000 ft AGL for VFR flights (IFR cruising altitudes are under 14 CFR § 91.179).

Key Citations:
  • (a) Semicircular rule: Magnetic course 000° to 179° (Odd thousands + 500 ft)
  • (b) Semicircular rule: Magnetic course 180° to 359° (Even thousands + 500 ft)
US14 CFR § 91.3

14 CFR § 91.3 — Responsibility and authority of the pilot in command

National Archives / FAA

Codifies that mathematical reference models do not relieve the PIC of direct operational responsibility.

Key Citations:
  • (a) Final authority as to the safe operation of that aircraft
EASARegulation (EU) No 965/2012(Current Easy Access Edition)

EASA Annex VII (Part-NCO) to Regulation (EU) No 965/2012 — Non-Commercial Air Operations

European Union Aviation Safety Agency (EASA)

European Union governing framework for non-commercial general aviation fuel planning, reserves, and PIC authority.

Key Citations:
  • NCO.OP.125: Fuel and oil supply — aeroplanes (VFR / IFR reserve criteria)
  • NCO.GEN.105: Pilot-in-command responsibilities and authority
  • NCO.OP.110: Aerodrome operating minima
  • NCO.POL.100: Weighing and loading
EASARegulation (EU) No 923/2012(Current Easy Access Edition)

Standardised European Rules of the Air (SERA) — Regulation (EU) No 923/2012

European Union Aviation Safety Agency (EASA) / European Commission

Harmonized European airspace classification, VMC cloud clearances, and altimeter setting conventions (hPa / QNH).

Key Citations:
  • SERA.5001: VMC visibility and distance from cloud minima
  • SERA.5005: Visual flight rules
  • SERA.5015: Instrument flight rules (IFR)
  • SERA.8015: Air traffic control clearances & altimeter setting procedures
EASARegulation (EU) No 1178/2011(Current Easy Access Edition)

EASA Annex I (Part-FCL) to Regulation (EU) No 1178/2011 — Flight Crew Licensing

European Union Aviation Safety Agency (EASA)

European flight training hours, cross-country flight planning, and theoretical navigation knowledge standards.

Key Citations:
  • Subpart B: Light Aircraft Pilot Licence (LAPL)
  • Subpart C: Private Pilot Licence (PPL)
  • Subpart G: Instrument Rating (IR)
  • Theoretical knowledge: Navigation, Meteorology, Flight Performance & Planning
US14 CFR § 25.121(Current Edition)

14 CFR § 25.121 — Climb: One-engine-inoperative (Transport Category Airplanes)

Federal Aviation Administration (FAA) / e-CFR

Governs statutory multi-engine transport category transport climb gradients across all takeoff segments.

Key Citations:
  • § 25.121(a): Takeoff; landing gear extended (1st Segment)
  • § 25.121(b): Takeoff; landing gear retracted (2nd Segment: 2.4% / 2.7% / 3.0%)
  • § 25.121(c): Final takeoff segment
  • § 25.121(d): Approach climb
US14 CFR § 23.2110(2023)

Title 14 CFR Part 23 — Airworthiness Standards: Normal Category Airplanes, Section 23.2110: Ground and climb capabilities

Federal Aviation Administration (FAA) / US Government

Federal airworthiness standard governing stall speed, climb margins, and certified aircraft performance envelopes.

Key Citations:
  • Section 23.2110: Ground and climb capabilities
  • Section 23.2115: Takeoff and landing performance
  • Historical Section 23.49: Stalling speed and wing loading envelopes

Official Aviation Handbooks & Orders (FAA & ICAO)

USFAA-H-8083-25C(2023)

Pilot's Handbook of Aeronautical Knowledge

Federal Aviation Administration (FAA)

Primary FAA baseline for pilot navigation, altimetry, density altitude, and airspeed definitions.

Key Citations:
  • Chapter 4: Principles of Flight
  • Chapter 8: Flight Instruments
  • Chapter 11: Aircraft Performance
  • Chapter 16: Navigation
USFAA-H-8083-28B(2026)

Aviation Weather Handbook

Federal Aviation Administration (FAA)

Current 2026 FAA reference baseline for atmospheric moisture, lapse rates, and cloud base estimation.

Key Citations:
  • Chapter 2: Earth Atmosphere & Heat
  • Chapter 4: Moisture, Clouds & Precipitation
  • Chapter 19: Standard Atmosphere & Altimetry
USFAA-H-8083-3C(2021)

Airplane Flying Handbook

Federal Aviation Administration (FAA)
Key Citations:
  • Chapter 3: Basic Flight Maneuvers
  • Chapter 8: Approaches and Landings (Crosswind procedures)
USFAA-H-8083-1B(2016)

Aircraft Weight and Balance Handbook

Federal Aviation Administration (FAA)

Authoritative guidance for moment arms, datum references, and fuel weight nominal constants.

Key Citations:
  • Chapter 2: Weight and Balance Theory
  • Chapter 3: Weight and Balance Computations
  • Chapter 4: Center of Gravity Envelopes
USFAA-H-8083-16B(2017)

Instrument Procedures Handbook

Federal Aviation Administration (FAA)

Authoritative handbook covering practical pilot application of climb gradients and obstacle clearance.

Key Citations:
  • Chapter 1: IFR Takeoffs and Departures
  • Climb Gradient vs Rate of Climb Conversion
  • Obstacle Departure Procedures (ODP) & SIDs
USAdvisory Circular 91-79A (with Change 1)(2016)

Aircraft Landing Performance and Runway Surface Condition Assessment

Federal Aviation Administration (FAA)

Authoritative FAA TALPA baseline for surface condition derating factors on wet and contaminated runways.

Key Citations:
  • Appendix 1: Runway Condition Assessment Matrix (RCAM)
  • Section 7: Landing Distance Assessment & Crosswind Considerations on Contaminated Runways
USFAA-H-8083-15B(2012)

Instrument Flying Handbook

Federal Aviation Administration (FAA)

Authoritative FAA handbook defining the Standard Rate Turn (3°/s, 2-minute 360° turn) and cockpit rule-of-thumb bank estimations.

Key Citations:
  • Chapter 5: Flight Instruments (Turn Indicators)
  • Chapter 7: Instrument Flight Maneuvers (Standard Rate Turns)

Engineering Standards & Certification Specifications (ICAO Doc 7488 & EASA CS-23)

USFAA Order 8260.3G(Current)

United States Standard for Terminal Instrument Procedures (TERPS)

Federal Aviation Administration (FAA)

Governs departure climb gradient specifications (ft/NM vs %) in U.S. procedure design.

Key Citations:
  • Volume 1, Chapter 2: General Criteria & Climb Gradients
  • Section 2-9: Departure Procedures and Minimum Climb Gradients
ICAODoc 7488/3(1993 (reaffirmed))

Manual of the ICAO Standard Atmosphere (extended to 80 kilometres / 262,500 feet)

International Civil Aviation Organization (ICAO)

International standard for pressure, temperature, density, speed of sound, and viscosity across flight levels.

Key Citations:
  • Part 1: Standard Atmosphere to 32 km
UniversalNASA-TM-X-74335 / NOAA-S/T 76-1562(1976)

U.S. Standard Atmosphere, 1976

NOAA, NASA, USAF

Thermodynamic model equations for barometric lapse, geopotential altitude, and speed of sound.

UniversalNASA Reference Publication 1046(1980)

Measurement of Aircraft Speed and Altitude

National Aeronautics and Space Administration (NASA)

Authoritative engineering reference for compressible pitot-static impact pressure and Mach-airspeed relations.

Key Citations:
  • Section 2: Airspeed Equations & Definitions (IAS, CAS, EAS, TAS)
  • Section 3: Compressible Impact Pressure (Saint-Venant / Rayleigh Relations)
EASACS-23 Amendment 6 / AMC & GM Issue 5, May 2026(May 2026)

Certification Specifications for Normal-Category Aeroplanes (CS-23)

European Union Aviation Safety Agency (EASA)

European airworthiness standards governing stall speed, climb gradients, demonstrated crosswinds, and AFM limitations.

Key Citations:
  • CS 23.2110: Ground and water stall speed
  • CS 23.2115: Take-off performance & climb gradients
  • CS 23.2120: Climb requirements
  • CS 23.2135: Controllability (Crosswind demonstrated limits)
  • CS 23.2600: Flight manual (AFM) requirements
USFAA Order 8260.3F(2023)

United States Standard for Terminal Instrument Procedures (TERPS)

Federal Aviation Administration (FAA)

Primary FAA standard governing standard 200 ft/NM climb gradients, 40:1 OCS, and diverse departure procedure criteria.

Key Citations:
  • Volume 1, Chapter 2: General Criteria & Climb Gradients
  • Volume 4, Chapter 1: Departure Procedure Construction
  • Section 2-6: Obstacle Clearance Surface (40:1 / 152 ft/NM)
UniversalMonthly Weather Review 108(7): 1046–1053(1980)

The Computation of Equivalent Potential Temperature

American Meteorological Society (AMS)

Authoritative aerodynamic and meteorological standard for thermodynamic parcel condensation height.

Key Citations:
  • Section 2: Formula for the Lifted Condensation Level (LCL)
  • Empirical temperature at condensation level
ICAOAnnex 14 Vol I(9th Edition)

Annex 14 to the Convention on International Civil Aviation — Aerodromes, Volume I: Aerodrome Design and Operations

International Civil Aviation Organization (ICAO)

Global ICAO standard defining runway magnetic orientation, usability factor, and crosswind calculation conventions.

Key Citations:
  • Chapter 3: Physical Characteristics (Runway Orientation & Wind Coverage)
  • Section 3.1: Runway Designators & Crosswind Usability Criteria (95% rule)
ICAODoc 8168 Vol I(6th Edition)

Procedures for Air Navigation Services — Aircraft Operations (PANS-OPS), Volume I: Flight Procedures

International Civil Aviation Organization (ICAO)

International standard for terminal procedure design, specifying holding pattern turn parameters (25° bank or 3°/s, whichever is lesser).

Key Citations:
  • Section 3: Departure and Arrival Procedures
  • Section 4: Holding Criteria (25° bank or 3°/s rate limit)