Basics Flashcards
Types of altitudes
Indicated, pressure, density, true, absolute
Indicated altitude: uncorrected altitude read from dial when set to local pressure setting
Pressure altitude: altitude above standard 29.92 Hg plane
Density altitude: pressure altitude corrected for nonstandard temp
True altitude: actual height above MSL
Absolute altitude: height above airport elevation
Types of speeds
Indicated, calibrated, equivalent, true, MACH, ground speed
Indicated: read directly from ASI
Calibrated: IAS corrected for instrument and position errors
Equivalent: CAS corrected for compressibility errors
True: actual speed through air. EAS corrected for nonstandard temp/pres
MACH: ratio of TAS to local speed of sound
Ground Speed: actual speed over ground. TAS corrected for wind
Static port blockage effect on…
ASI, ALT, VSI
ASI: shows correct if you maintain alt where blockage occurred. At higher alt, indicated lower, at lower alt, indicated higher
ALT: freezes on alt where blockage occurred
VSI: freezes on 0
*after verifying a blockage, switch static sources or break VSI window (expect reverse indication on VSI)
When using alternate static source…
ASI: reads faster
ALT: reads higher
VSI: momentarily shows climb
Pilot blockage
ONLY the ASI is affected!
Ram air blocked and drain hole open: drops to 0
Ram air blocked and drain hole clogged: acts like altimeter, no longer reliable
Gyroscopic instruments
Attitude indicator: rigidity in space, pitch and bank info (may have small accelerate/decelerate and rollout errors)
Heading indicator: rigidity in space, reflects changes in heading, must calibrate with magnetic compass
Turn coordinator: principle of precision, rate of turn and roll
Magnetic compass errors
Deviation Variation Magnetic dip Oscillation North/south turning (UNOS) Acceleration/Deceleration (ANDS)
IFR taxi cockpit check
Magnetic compass: full of fluid, swings freely, known headings, deviation card installed
Airspeed: 0
Attitude: erect and correct +/- 5* within 5 min of engine start
Altimeter : set to local or field elevation, correct within 75ft of elevation
Turn coordinator: shows correct turn and ball swings opposite
Heading :set and indicates known headings and correct turns
Vertical: 0
Nav/comm: set
GPS: set
Enroute weather information sources
EFAS:enroute flight advisory service 122.0 “flight watch”
TWEB: Alaska only
HIWAS: hazardous inflight weather advisory service (select VORs)
ATIS
AWOS
ASOS
ATC weather advisories (airmet, sigmet)
Convective SIGMET
Valid how long?
Convective weather significant to all aircraft. Issued 55 min past every hour. Valid 2 hrs.
Surface winds equal or greater than 50kts
Hail at surface greater than 3/4 diameter
Tornadoes
Embedded thunderstorms
Line of thunderstorms 60 mi affecting 40% of length
Thunderstorms with heavy+ precipitation 40% of 3,000mi area
ALWAYS implies severe turbulence, icing, LLWS
SIGMET
Non connective potentially hazard weather affecting all aircraft
Icing
Clear air turbulence
Dust storms, sandstorms, vis less than 3 mi
Volcanic ash
AIRMET
T
Z
S
Significant weather phenomena of lower intensity that can affect all aircraft but potentially hazardous to aircraft with limited capability.
T turbulence with surface winds 30+ Kat
Z icing with freezing level heights
S mountain obscuration
Conditions necessary for formation of a thunderstorm…
Sufficient water vapor
Unstable temp lapse rate
Uplifting force (front passage, mountains, heating from below)
Thunderstorm hazards…
Limited visibility Severe Turbulence Wind shear Strong up drafts and down drafts Icing Hail Heavy rain Lightening Tornadoes
Life cycle of a thunderstorm…
Cumulus stage: 3-5 mi height, lifting action begins, 3000fpm
Mature: 5-10 mi height precipitation from cloud base, updraft 6000fpm, down drafts 2,500fpm, hazards most severe
Dissipating: 5-7 mi high, strong down drafts, cell is dying out
