PTS Area of Operation II: Technical Subject Areas- A Flashcards
Airspeed Indicator
differential pressure gauge that
measures and promptly indicates the difference between pitot
(impact/dynamic pressure) and static pressure. When the aircraft moves through the air, the
pressure on the pitot line becomes greater than the pressure
in the static lines. This difference in pressure is registered by
the airspeed pointer on the face of the instrument,
ASI uses both
pitot tube and static system. ASI introduces the static
pressure into the airspeed case while the pitot pressure
(dynamic) is introduced into the diaphragm. The dynamic
pressure expands or contracts one side of the diaphragm,
which is attached to an indicating system. The system drives
the mechanical linkage and the airspeed needle.
Pitot Tube
Ram Air- Impact air forced into the pitot tube by the relative wind which exerts pressure
Types of airspeed
Indicated Calibrated true Groundspeed
Indicated airspeed
the direct instrument
reading obtained from the ASI, uncorrected for
variations in atmospheric density, installation error,
or instrument error. Manufacturers use this airspeed
as the basis for determining aircraft performance.
Takeoff, landing, and stall speeds listed in the AFM/
POH are IAS and do not normally vary with altitude
or temperature.
Calibrated airspeed
IAS corrected for installation error and instrument error. Although manufacturers attempt to keep airspeed errors to a minimum, it is not possible to eliminate all errors throughout the airspeed operating range. At certain airspeeds and with certain flap settings, the installation and instrument errors may total several knots. This error is generally greatest at low airspeeds and nose high attitudes. In the cruising and higher airspeed ranges, IAS and CAS
are approximately the same. Refer to the airspeed calibration chart to correct for possible airspeed errors
True airspeed
corrected for altitude and nonstandard temperature. Because air density decreases with an increase in altitude, an aircraft has to be flown faster at higher altitudes to cause the same
pressure difference between pitot impact pressure and static pressure. Therefore, for a given CAS, TAS
increases as altitude increases; or for a given TAS, CAS decreases as altitude increases. A pilot can find TAS by two methods. The most accurate method is
to use a flight computer. With this method, the CAS is corrected for temperature and pressure variation by
using the airspeed correction scale on the computer. Extremely accurate electronic flight computers are
also available. Just enter the CAS, pressure altitude, and temperature, and the computer calculates the TAS.
A second method, which is a rule of thumb, provides the approximate TAS. Simply add 2 percent to the
CAS for each 1,000 feet of altitude. The TAS is the speed that is used for flight planning and is used when
filing a flight plan.
Groundspeed
actual speed over the ground
ASI color coding
Aircraft weighing 12,500 pounds or less, manufactured after
1945, and certificated by the FAA are required to have ASIs
marked in accordance with a standard color-coded marking
system
White arc
commonly referred to as the flap operating range since its lower limit represents the full flap stall speed and its upper limit provides the maximum flap speed. Approaches and landings are usually flown at speeds within the white arc
Lower limit of white arc
Lower limit of white arc (VS0)—the stalling speed
or the minimum steady flight speed in the landing
configuration. In small aircraft, this is the power-off
stall speed at the maximum landing weight in the
landing configuration (gear and flaps down).
Upper limit of white arc
Upper limit of the white arc (VFE)—the maximum
speed with the flaps extended.
Green arc
the normal operating range of the aircraft.
Most flying occurs within this range.
Lower limit of green arc
Lower limit of green arc (VS1)—the stalling speed
or the minimum steady flight speed obtained in a
specified configuration. For most aircraft, this is the
power-off stall speed at the maximum takeoff weight
in the clean configuration (gear up, if retractable, and
flaps up).
Upper limit of the green arc
Upper limit of green arc (VN0)—the maximum structural cruising speed. Do not exceed this speed except in smooth air.
Yellow arc
Yellow arc—caution range. Fly within this range only in smooth air and then only with caution.
Red Line
never exceed speed. Operating above
this speed is prohibited since it may result in damage or structural failure
S model V speeds
Vso 40
Vs 48
Vbg 68
Vx 62
Vy 74
Vfe flaps 10 110
Vfe flaps 20 30 85
Va Max 105
Vno 129
Vne 163
ASI Instruments check
Prior to takeoff, the ASI should read zero. However, if there
is a strong wind blowing directly into the pitot tube, the ASI
may read higher than zero. When beginning the takeoff,
make sure the airspeed is increasing at an appropriate rate.
Altimeter
The altimeter is an instrument that measures the height of
an aircraft above a given pressure level
altimeter works by
A stack of sealed aneroid wafers comprise the main
component of the altimeter. An aneroid wafer is a sealed wafer that is evacuated to an internal pressure of 29.92 inches of mercury (“Hg). These wafers are free to expand and contract with changes to the static pressure. A higher static pressure presses down on the wafers and causes them
to collapse. A lower static pressure (less than 29.92 “Hg)
allows the wafers to expand. A mechanical linkage connects
the wafer movement to the needles on the indicator face, which translates compression of the wafers into a decrease in altitude and translates an expansion of the wafers into an
increase in altitude
kollsman window
barometric pressure window is sometimes referred to as
the Kollsman window
GOING FROM A HIGH TO A LOW, LOOK OUT BELOW.”
For example, if an aircraft is
flown from a high pressure area to a low pressure area without adjusting the altimeter, a constant altitude will be displayed, but the actual heigh of the aircraft above the ground would
be lower then the indicated altitude. :
FROM HOT TO COLD, LOOK OUT
BELOW
Since cold air is denser than warm air, when operating in temperatures
that are colder than standard, the altitude is lower than the altimeter indication
Not changing altimeter setting example
The importance of properly setting the altimeter cannot
be overemphasized. Assume the pilot did not adjust the
altimeter at Abilene to the current setting and continued using
the Mineral Wells setting of 29.94 “Hg. When entering the
Abilene traffic pattern at an indicated altitude of 2,600 feet,
the aircraft would be approximately 250 feet below the proper
traffic pattern altitude. Upon landing, the altimeter would
indicate approximately 250 feet higher than the field elevation.
Not changing altimeter setting example
The following is another method of computing the altitude
deviation. Start by subtracting the current altimeter setting
from 29.94 “Hg. Always remember to place the original setting
as the top number. Then subtract the current altimeter setting.
Mineral Wells altimeter setting 29.94
Abilene altimeter setting 29.69
29.94 – 29.69 = Difference 0.25
(Since 1 inch of pressure is equal to approximately 1,000 feet
of altitude, 0.25 × 1,000 feet = 250 feet.) Always subtract
the number from the indicated altitude.
2,600 – 250 = 2,350
Now, try a lower pressure setting. Adjust from altimeter
setting 29.94 to 30.56 “Hg.
Mineral Wells altimeter setting 29.94
Altimeter setting 30.56
29.94 – 30.56 = Difference –0.62
(Since 1 inch of pressure is equal to approximately 1,000 feet
of altitude, 0.62 × 1,000 feet = 620 feet.) Always subtract
the number from the indicated altitude.
2,600 – (–620) = 3,220
The pilot will be 620 feet high.
Indicated altitude
read directly from the altimeter
(uncorrected) when it is set to the current altimeter
setting
True altitude
—the vertical distance of the aircraft
above sea level—the actual altitude. It is often expressed as feet above mean sea level (MSL). Airport, terrain, and obstacle elevations on aeronautical charts are true altitudes
Absolute altitude
the vertical distance of an aircraft
above the terrain, or above ground level (AGL).
Pressure altitude
the altitude indicated when
the altimeter setting window (barometric scale) is
adjusted to 29.92 “Hg. This is the altitude above the standard datum plane, which is a theoretical
plane where air pressure (corrected to 15 °C) equals 29.92 “Hg. Pressure altitude is used to compute density
altitude, true altitude, true airspeed (TAS), and other performance data.
Density altitude
pressure altitude corrected
for variations from standard temperature. When
conditions are standard, pressure altitude and density
altitude are the same. If the temperature is above standard, the density altitude is higher than pressure altitude. If the temperature is below standard, the density altitude is lower than pressure altitude. This is an important altitude because it is directly related to the aircraft’s performance.
Altimeter instrument check
set pressure altitude if off elevation more than 75 feet cant use
VSI displays what
- Trend information shows an immediate indication of an increase or decrease in the aircraft’s rate of climb or descent.
- Rate information shows a stabilized rate of change in altitude
VSI operation
static pressure decreases, and as it decreases immediately in the diaphragm. But the instrument casing is a different story. Since the calibrated leak lets air out slowly, it creates a higher pressure in the casing than the diaphragm. When that happens, it creates a pressure differential, the diaphragm is squeezed down, and the gears connected to the VSI needle make it move up or down
When you initially start climbing or descending, your VSI needle will start moving, but it can’t immediately indicate how fast you’re climbing. This is what’s called trend information. When you see the directing of the needle moving up, you know your climb rate is increasing, and when it moves down, you know your climb rate is decreasing. You just don’t know how much
After a second or two, the calibrated leak has a chance to catch up and reach equilibrium, and your VSI will stabilize at a certain climb or descent rate. When that happens, you have rate information.
VSI Instrument check
VSI must be established. Make sure the VSI indicates a near zero
reading prior to leaving the ramp area and again just before
takeoff. If the VSI indicates anything other than zero, that
indication can be referenced as the zero mark.
Blocked Pitot tube
ASI- zero
Altimeter- works
VSI- works
Blocked Pitot tube and Drain Hole. Open static
ASI- High climb, Low descent
Altimeter-works
VSI- works
Blocked Static, Open pitot
ASI- Low Climb, High descent
Altimeter- Frozen
VSI- Frozen
Using alternate static air
ASI- reads high
Altimeter- reads high
VSI- momentarily shows climb
Broken VSI Glass
ASI- reads high
Altimeter- reads high
VSI-reverses
Precession
Precession is the tilting or turning of a gyro in response to a
deflective force. The reaction to this force does not occur at
the point at which it was applied; rather, it occurs at a point
that is 90° later in the direction of rotation. This principle
allows the gyro to determine a rate of turn by sensing the
amount of pressure created by a change in direction. The rate
at which the gyro precesses is inversely proportional to the
speed of the rotor and proportional to the deflective force
Attitude indicator
shows pitch and bank. the gyro in the attitude indicator is mounted in a horizontal plane, and depends upon rigidity in space for its operation. The horizon bar is fixed to the gyro and remains in a horizontal plane as the aircraft is pitched or banked about its lateral or longitudinal axis, indicating the attitude of the aircraft relative to the true horizon. The gyro spins in the horizontal plane and resists deflection
of the rotational path. Since the gyro relies on rigidity in space, the aircraft actually rotates around the spinning gyro.
Rigidity in Space
a gyroscope remains in a fixed position in the plane in which it is spinning.
An example of rigidity in space is that of a bicycle wheel. As the bicycle wheels increase speed, they become more stable in their plane of rotation. This is why a bicycle is unstable and
maneuverable at low speeds and stable and less maneuverable
at higher speeds. By mounting this wheel, or gyroscope, on a set of gimbal
rings, the gyro is able to rotate freely in any direction. Thus, if the gimbal rings are tilted, twisted, or otherwise moved,
the gyro remains in the plane in which it was originally spinning.
Gyros powered by
Vacuums or electronic
Attitude instrument Check
up and erect after 5 minutes within 5 degrees
attitude indicator error
Cannot pitch more than 70 degrees and bank 110 degrees would cause tumbling.
Heading indicator
shows changes in heading but cant measure heading, must set it based on mag compass. operates on riggity in space and has a vertically mounted gyro so only the horizontal axis is used to drive the display. Airplane spins around the gyro itself, when the aircraft turns the gyro and main drive gear stays in place and the. the main drive gear spins in the horizontal axis and then drives the compass card gear to indicated heading change.
Heading indicator error
precession or friction, must re align
Turn indicators
turn coordinator and turn and slip indicator
Turn coordinator
electric. used while banking. shows rate and quality of turn. shows straight and level and standard rate turns. also has inclinometer, shows slips or skids. gyro rotates vertivcally from a motor in the center angled at 30 degrees so it can remain upright in a turn
slip
needs more rudder, ball inside the turn
skid
needs less rudder, ball outside the turn
S model electrical system
28 volt DC system
Alternator with 60 amps
24 volt battery
4 volt discrepancy To charge the battery
Standby battery
Standby battery test for 10 seconds to make sure the green light stays on and shows a trend of constant power. Located between the firewall and instrument panel. Power essential bus if alternator and main battery fail. ARM-OFF-TEST. IF not armed does not charge and cannot be used if failures occur.
Standby battery annunciation shows -.5 volts are being drawn for more than 10 seconds
Busses
Electrical 1 &2
Avionics 1 & 2
Cross Feed Bus
Essential Bus
Electrical 1- Fuel Pump, Beacon Light, landing lights, overhead cabin lights and 12v power outlet, avionics 1,
Avionics 1- PFD and PFD cooling fans, ADC/AHRS, NAV 1 and engine airframe unit, FLight information system, DME, ADF
Cross Feed- ALt master switch, Warnings such as stall warning, AP warning, ELT warning, Main bus voltmeter, Stand by battery, Hourmeter, starter relay
Electrical Bus 2- Avionics 2, Pitot Heat, Nav and control wheel map lights, Taxi lights, strobes, panel lights
Avionics 2- MFD, transponder, nav 2, Avionics cooling fan, COM 2, Audio panel, AP
Essential Bus- PFD, ADC,AHRS, Nav 1 GIA Essential Bus voltmeter, Comm1 Standby indicator lights, standby battery.
Magnetic Compass Errors
MONAVD
Acceleration errors and why?
ANDS
The magnetic dip and the forces of inertia cause magnetic
compass errors when accelerating and decelerating on
easterly and westerly headings. Because of the penduloustype mounting, the aft end of the compass card is tilted
upward when accelerating and downward when decelerating
during changes of airspeed. When accelerating on either
an easterly or westerly heading, the error appears as a
turn indication toward north. When decelerating on either
of these headings, the compass indicates a turn toward
south.
Turning errors
UNOS
Magnetic compass
Self-contained that uses magnets suspended in fluid and align with the earths magnetic field.
tumble limits for attitude indicator
Some attitude indicators
have limits in the banking plane from 100° to 110°, and the pitch
limits can be from 60° to 70°. For those attitude indicators that
display only pitch information of +/- 25° vertically, the
instrument could “peg” (stop) and remain at this pitch indication
until the pitch no longer exceeds limitation or “tumble” and
provide erroneous pitch and bank indications when the aircraft
exceeds these limits.
VOR
Very High omni directional Range. Line of site reception
VOR frequencies
108-117.95mhz excluding 108.1-111.95 odd tenths
VOR full scale deflection
10 degrees
Must ID VORs?
yes
VOR service volumes
T (Terminal)
From 1,000 feet ATH up to and including 12,000 feet ATH at radial distances out to 25 NM.
L (Low Altitude)
From 1,000 feet ATH up to and including 18,000 feet ATH at radial distances out to 40 NM.
H (High Altitude)
From 1,000 feet ATH up to and including 14,500 feet ATH at radial distances out to 40 NM. From 14,500 ATH up to and including 60,000 feet at radial distances out to 100 NM. From 18,000 feet ATH up to and including 45,000 feet ATH at radial distances out to 130 NM.
VL (VOR Low)
From 1,000 feet ATH up to but not including 5,000 feet ATH at radial distances out to 40 NM. From 5,000 feet ATH up to but not including 18,000 feet ATH at radial distances out to 70 NM.
VH (VOR High)
From 1,000 feet ATH up to but not including 5,000 feet ATH at radial distances out to 40 NM. From 5,000 feet ATH up to but not including 14,500 feet ATH at radial distances out to 70 NM. From 14,500 ATH up to and including 60,000 feet at radial distances out to 100 NM. From 18,000 feet ATH up to and including 45,000 feet ATH at radial distances out to 130 NM.
VOR errors
Errors-
Line of sight- nothing can be in the way
Cone of confusion- short time over VOR it doesn’t know if to/from and cdi gets sensitive
Night effect- does not reflect vhs
Terrain- ground waves, magnetic radiation from sun bounced of terrain to cause false signals
VOR operation
Signal Transmission
a/c equipment measures a phase difference between two signals
reference signal-omni bearing
phase signal- electronic rotating
both of these are on the station
receiver know the difference between the two signals and gives location
VOR receiver checks are done
Every 30 days
DEPS
VOT
A VOT is coded to emit the 360 Radial in all directions around the facility.
This means the airplane’s VOR Receiver should read either: 360 FROM or 180 TO, regardless of the aircraft’s location in relation to the VOR.
How the check is done:
Tune and Identify the VOT.
center the CDI Needle.
Check for proper TO/FROM Indication.
The radial selected must be within: +/- 4 degrees of 360 or 180.
VOR ground Checkpoint
Many airports have VOR checkpoint signs that are located near a taxiway, ramp or runup area. These signs indicate the exact point on the airport where there is sufficient signal strength from a VOR to check the aircraft’s VOR receiver against the radial designated on the sign. To use a VOR checkpoint, simply follow the instructions on the sign.
The maximum indicated bearing error is plus or minus 4 degrees
Dual VOR Check
With a Dual VOR check, the airplane must be equipped with 2 VOR Receivers.
How the check is done:
The pilot tunes both VOR Receivers to the same VOR.
The pilot centers both CDI Needles.
Check for proper TO/FROM Indications.
With both CDI Needles Centered:
The Selected Radials should be within 4 degrees of each other.
Airborne VOR
Airborne VOR Check: VOR equipment can also be checked for accuracy in flight. To accomplish an airborne VOR check:
Select a VOR radial that lies along the centerline of an established VOR airway.
Select a prominent ground point along the selected radial preferably more than 20 nautical miles from the VOR ground facility and maneuver the aircraft directly over the point at a reasonably low altitude.
Note the VOR bearing indicated by the receiver when over the ground point.
The maximum indicated bearing error is plus or minus 6 degrees
VOR MON
s flight procedures and route structure based on VORs are gradually being replaced with Performance-Based Navigation (PBN) procedures, the FAA is removing selected VORs from service. PBN procedures are primarily enabled by GPS and its augmentation systems, collectively referred to as Global Navigation Satellite System (GNSS). Aircraft that carry DME/DME equipment can also use RNAV which provides a backup to continue flying PBN during a GNSS disruption. For those aircraft that do not carry DME/DME, the FAA is retaining a limited network of VORs, called the VOR MON, to provide a basic conventional navigation service for operators to use if GNSS becomes unavailable. During a GNSS disruption, the MON will enable aircraft to navigate through the affected area or to a safe landing at a MON airport without reliance on GNSS. Navigation using the MON will not be as efficient as the new PBN route structure, but use of the MON will provide nearly continuous VOR signal coverage at 5,000 feet AGL across the NAS, outside of the Western U.S. Mountainous Area (WUSMA).
DME frequencys
UHF 962-1213MHz
DME
Normally tuned with VOR or LOC.
The airborne DME unit transmits interogation signal and the ground facility replies, calculates slant range on reply time,
DME Errors
be one mile away or further for every 1000 feet of altitide
DME service volumes
DL (DME Low)
For altitudes up to 12,900 feet ATH at a radial distance corresponding to the LOS to the NAVAID. From 12,900 feet ATH up to but not including 18,000 feet ATH at radial distances out to 130 NM
DH (DME High)
For altitudes up to 12,900 feet ATH at a radial distance corresponding to the LOS to the NAVAID. From 12,900 ATH up to and including 60,000 feet at radial distances out to 100 NM. From 12,900 feet ATH up to and including 45,000 feet ATH at radial distances out to 130 NM
ILS components
loc
gs
markers
approaching lighting
Localizer
lateral guidance. width between 3-6 degrees, so at threshold the width is 700 feet but depends on runway length 4 times more sensitive than a VOR, 2.5 degrees full deflection. 4 letter idents starting with an I must b tuned and Idenified
On departure end of the runway
Loc Frequencies
108.1-111.95 odd tenths
90 and 150 Hz frequencies carried over the VHF used to show lateral guidance
Localizer coverage
35 degrees each side of center line for 10 miles, 10 degrees out to 18 miles
LDA
The LDA is of comparable use and accuracy to a localizer but is not part of a complete ILS. The LDA course usually provides a more precise approach course than the similar Simplified Directional Facility (SDF) installation, which may have a course width of 6 or 12 degrees.
The LDA is not aligned with the runway. Straight-in minimums may be published where alignment does not exceed 30 degrees between the course and runway. Circling minimums only are published where this alignment exceeds 30 degrees.
GlideSlope
provides vertical guidance
3 degrees glideslope (standard) sometimes adjusted for obstacles or terrain
Sensitiviety of .7 degrees up or down 1.4 degress full deflection
Antenna found side of runway 250-500 from centerline 750-1250 feet down the runway
Provides 55 feet at threshold crossing height
Opposite of localizer 2 signals 90 hertz on right 150 hertz on left side
False glideslope
150 hz side 6,9 12.5 degrees due to being bounced off the ground so always intercept slope from underneath.
Don’t have to tune or ident glideslope
Seervice Volume can be used up to 10 miles out
Glideslope frequencies
UHF 40 channels 329.3mhz -335mhz and pairs with LOC
Outer marker
is blue in cockpit (sometimes associated with final approach fix on nonprecison approaches )
4-7 miles from the airport
400 hertz 2 dashes per second
Must have outer marker (doesn’t have to be the actual outer marker must be something to cross and identify
Received glideslope before outer marker
Middle marker
No longer needed
is amber in cockpit
3000-6000 from threshold 1300hz faster blinks than outer marker
200ft above touchdown (DA)
Marker beacons
The ILS was originally developed before DME was widely accessible. Because of that, marker beacons are sometimes included in an ILS approach. Each beacon designates a specific position on the approach, with an audible tone and/or visual light that illuminates in the cockpit.
Inner marker
white light in cockpit
Used for Category 2 or 3 ILS with no published radio altitude
100 feet above the touchdown
3000hz faster than middle marker
Blinks six dots per second
Compass Locator
Compass locator transmitters are often situated at the MM and OM sites. The transmitters have a power of less than 25 watts, a range of at least 15 miles and operate between 190 and 535 kHz. At some locations, higher powered radio beacons, up to 400 watts, are used as OM compass locators.
Compass locators transmit two letter identification groups. The outer locator transmits the first two letters of the localizer identification group, and the middle locator transmits the last two letters of the localizer identification group
Marker beacon frequencies
Marker beacons (MB) use a carrier frequency of 75 MHz with an amplitude modulation (AM) depth of 95%. The frequency of the marker is configured using the Marker Frequency field, which can be 400 Hz for the outer marker, 1300 Hz for the middle marker, and 3000 Hz for the inner marker
back course marker
White, 3000Hz indicates FAF on selected back course approaches and where a descent is commenced. Not apart of the ILS system
Cat 1 ILS mins
Decision Height (DH) 200 feet and Runway Visual Range (RVR) 2,400 feet (with touchdown zone and centerline lighting, RVR 1,800 feet), or (with Autopilot or FD or HUD, RVR 1,800 feet);
INOP Localizer on ILS
Inoperative localizer. When the localizer fails, an ILS approach is not authorized.
INOP glideslope on ILS
Inoperative glide slope. When the glide slope fails, the ILS reverts to a non-precision localizer approach.
NAVAID Identifier Removal During Maintenance
During periods of routine or emergency maintenance, coded identification (or code and voice, where applicable) is removed from certain FAA NAVAIDs. Removal of identification serves as a warning to pilots that the facility is officially off the air for tune-up or repair and may be unreliable even though intermittent or constant signals are received.
Kinds of approach lights
ALS with Sequenced Flashers (ALSF-1)
Medium Intensity Approach Lighting System (MALS)
Medium Intensity Approach Lighting System with Sequenced Flashers (MALSF)
Medium Intensity Approach Lighting System with Runway Alignment Indicator Lights (MALSR)
Omnidirectional Approach Lighting System (ODALS)
Visual Approach Slope Indicator(VASI)
Precision Approach Path Indicator(PAPI)
ALS purpose
provies visible means to transition from instruments to visual approach. Help estimate flight visibility
Precison approach lights distance
Landing threshold to approach area
2400-3000 feet long
Non-precision approach light distance
Landing threshold to approach area
1400-1500 feet long
What is GNSS
Global Navigations Satellite System
What GNSS so we use
GPS Global positioning system
3 components of GNSS
SPACE: 31 Navigation System using time and range Satellites- NAVSTAR
Arranged in 6 orbital planes spaced 60 degrees apart, altitude of 11,000 feet. Orbit earth every 12 hours (move fast)
At least 6 satellites in view at all times
Mask Angle= satellite within 10 degrees of the horizon signal is weak
Satellites equipped w/ atomic clock for precise timing
Control: Operated by the US air force 50th space wing
Ground based monitoring stations to
16 monitor stations , 11 ground Antennas, 1 master station, and 1 alternate station (WAAS)
User Segment:
Antenna and receiver on the aircraft
Receiver will display position, velocity and time to destination.
Must ensure satellite coverage and NOTAMS
Handheld GPS is not IFR certified
How GPS works in plane
Satellite sends signal to airplane and calculates time and knows distance from the satellite. This is a time solution. your location can be anywhere, so we need time solutions from multiple satellites to pinpoint location 3 satellites for 2D 4 satellites for 3D positioning. GPS receivers have RAIM to monitor the reliability of each satellite being used for position. This needs 5 satellites. A 6th is needed for fault detection and correction
What is Baro Aiding
Barometric aiding is an integrity augmentation that allows a GPS system to use a non-satellite input
source (e.g. the aircraft pitot-static system) to provide vertical reference and reduces the number of
required satellites from five to four. Baro-aiding requires four satellites and a barometric altimeter input
to detect an integrity anomaly. The current altimeter setting may need to be entered into the receiver as
described in the operating manual. Baro-aiding satisfies the Receiver Autonomous Integrity Monitoring
(RAIM) requirement in lieu of a fifth satellite.
What is Satellite Based Augmentation System (SBAS)
IN the U.S. we use WAAS. Wide area augmentation system uses ground stations( Wide area refrence stations (38 of them) and wide area master stations (3 of them)) to measure error and produce correction signals. The GPS satellites send a signal to a Wide area refrence station, which is a known location and compares it to the gps computed position. Then these signals are sent to a master station. Gives a message to uplink dishes and then are sent back to Geostationary satellites in space (different from the 24 GPS satellites) then to the GPS in the plane that has WAAS receiver along with the GPS satellites. This geostationary signal augments the signal so it improves accuracy, integrity, and availability monitoring. Accuracy can be 1 meter or less,non WAAS can be 5 meters
CHECK RAIM BEFORE EVERY FLIGHT
UNLESS WAAS EQUIPPED
Baro V-NAV
uses barometric altitude information from the aircraft’s pitot-static system and air data computer to compute vertical guidance for the pilot. The specified vertical path is typically computed between two waypoints or an angle from a single way point. When using baro-VNAV guidance, the pilots should check for any published temperature limitations on the approach chart which may result in approach restrictions.
What is RAIM
Receiver Autonomous Integrity Monitoring allows your airplane’s GPS navigator to confirm that it’s receiving a sufficient number of valid satellite signals to correctly determine its location and altitude, while rejecting any faulty signals from malfunctioning satellites. This assurance of positional integrity requires at least five functioning satellites in view. Various websites and applications confirm RAIM availability for our intended flight path and time. If RAIM is, or becomes unavailable, then GPS cannot be used for navigation
WAAS enables
different approaches that can use lower minimums
LNAV Approach
(GPS LOC)
lateranl navigation only
non waas
GPS approach mode is .3nm
MDA and fly forward to MAP
LNAV + V approach
Lateral navigation with advisory glideslope(get glidepath but its not approved to go below MDA)
GPS approach mode is .3nm
nonWAAS BUT WAAS created the glidepath
So if you have WAAS it can create an advisory glidepath on an LNAV to create LNAV + V but its still on precision and have to meet step downs and the MDA and fly forward to the MAP
NOT published on plates, the GPS tells you if vertical advisory is being used
LP approach
Localizer performance
WAAS approach
approach mode .1nm (more precise)
Has an MDA, fly down to then forward to MAP then go miss
not a fall back from an LPV approach. LP approaches are only made when a glidepath isn’t possible due to obstacles
LP+V
Localizer performance with advisory glidepath(not approved just created by the WAAS receiver)
approach mode .1nm
SO it has MDA, fly down to then forward to MAP then go miss
glidepath shouldnt be flown use stepdowns
LP+V Danger
not obstacle clear to the runway
if on advisory glidepath below the MDA can run into obstacles
LPV appraoch
WAAS
approved glidepath
Has a DA
GO missed at DA
Fallback is LNAV/VNAV
then Lnav, not LP approach
LNAV/VNAV
Non WAAS
LNAV/VNAV approaches don’t have increasing angular guidance as you approach the runway. Instead, they’re just like an LNAV only approach, decreasing to 0.3 NM sensitivity when you’re within 2 miles of the final approach fix, all the way to the missed approach point
They have approved vertical guidance
SO they have a DA
Vertical Navigation (VNAV) utilizes an internally generated glideslope based on the Wide Area Augmentation System (WAAS)
OR
baro-VNAV systems EXTERNAL FROM THE GPS. uses change in pressure to create a glide path
What is RNAV
Area navigation
types are:
GPS
VOR/DME RNAV
DME/DME RNAV
INertial Refrence Unit/System(IRU/IRS)
GPS is a type of rnav system that is whyn GPS approaches say
“RNAV(GPS)”
Simply navigate through an area without going to actual stations like VORs
PBN
Performance-Based Navigation (PBN) is comprised of Area Navigation (RNAV) and Required Navigation Performance (RNP) and describes an aircraft’s capability to navigate using performance standards
Performance-Based Navigation (PBN) is a specification for describing how accurately an aircraft can navigate. Three components define an aircraft’s PBN code.
Crew alerting capabilities-RNAV or RNP?
Sensor accuracy-PBN equipment must ensure the aircraft can navigate within some maximum width at least 95% of the time.
Sensor type-what type of RNAV is it? (GPS,DME/DME, etc?
IN an ICAO flight plan based on the
PBN is an umbrella for everything RNAV
RNP
RNP is a PBN system that includes autonomous onboard performance monitoring and crew alerting capability if the performance isn’t accurate(EX. RAIM) . Aircraft needs to meet requirements of PBN, a specified RNAV or RNP accuracy 95% of flight time.
US Approaches with RNP in tittle
cannot fly dont have equipment and/or authorization from the FAA on crew or plane
RNAV GPS approaches are rnp approaches, the faa makes it confusing. our equipment still needs to make sure that it is accurate for 95% of time fore whatever equipment it is using
ADS-B out works by
broadcasting information about an aircraft’s GPS location, altitude, ground speed and other data to ground stations and other aircraft, once per second. Air traffic controllers and properly equipped aircraft can immediately receive this information
ADS-B in
ADS-B In provides operators of properly equipped aircraft with weather and traffic position information delivered directly to the cockpit. ADS-B In-equipped aircraft have access to the graphical weather displays in the cockpit as well as text-based advisories, including Notices to Airmen and significant weather activity.
Mode C transponder
Mode C is the most widely used transponder mode.
Mode C provides information on the aircraft’s pressure altitude. Combined with mode A, ATC and other aircraft can receive an aircraft’s unique squawk code, position, and altitude.
This combination of mode A and mode C is normally just referred to as mode C
Mode S transponder
Mode S, short for “Mode Select,” is a type of transponder that offers more advanced communication capabilities than mode A or mode C transponders.
When you use a mode S transponder, it transmits a variety of valuable information to ATC and other aircraft.
Here’s a rundown of the critical data transmitted by a mode S transponder:
Unique ICAO Address: Every aircraft has a unique ICAO (International Civil Aviation Organization) address assigned to it. Mode S transponders send this address, which helps ATC and other aircraft identify your specific aircraft.
Squawk Code: Just like mode A, mode S transponders also transmit the four-digit squawk code assigned by ATC.
Altitude: Similar to mode C, mode S transponders provide your aircraft’s altitude.
Position, Speed, and Heading: Mode S transponders can also send your aircraft’s GPS-based position, speed, and heading, which helps ATC and nearby aircraft know your location and direction of travel.
Additional Flight-Related Data: Depending on the transponder’s capabilities, it can transmit other flight-related information, such as intent data, which provides ATC with a better understanding of your planned flight maneuvers. For example, some mode S transponders can transmit the selected heading on your autopilot. If ATC notices that you have the wrong heading set, they may be able to warn you.
But there are two more systems that make mode S transponders incredibly valuable.
They’re called Traffic Collision Avoidance Systems (TCAS) and Automatic Dependent Surveillance-Broadcast (ADS-B).
These systems improve situational awareness and help prevent mid-air collisions by allowing aircraft to share their positions and other relevant information with each other. This way, pilots can get warnings if aircraft get too close to each other, even if ATC doesn’t notice.
Chart Supplement
is a pilot’s manual that provides detailed information on airports. More info that isn’t on the sectional. frequncies, hours, notes, navaids, etc.
WAAS Sensitivity
ENROUTE- +- 2 nmiles
Terminal +- 1 nmiles
Approach (2nm from the FAF) +-.3 nm
Non WAAS sensitivity
CDI sensitivity with gps with no WAAS
ENROUTE- +- 5 nmiles
Terminal +- 1 nmiles
Approach (2nm from the FAF) +-.3 nm,
Missed Approach +- 1 nm
Raim failure
With no RAIM Pilot has no reassurance of GPS accuracy. NO RAIM= NO APPROACH
If RAIM failure happens before FAF or before approach mode we know not to proceed approach go miss
Failure after FAF can proceed for up to 5 minutes
Yellow LOI on G1000
Since You have WAAS it means you can
skip raim check, use GPS as primary means of navigation
WAAS and RAIM, Same thing?
They do the same thing but not the same. own things.
With WAAS alternate considerations
Can use a GPS only airport
WAAS lets you shoot was precision gps appraoch
LPV. The GPS appraoch you select in the HSI it will show you what to show. Purple LPV in the HSI
WAAS enroute accurate to in different phases of flight
2 miles. HSI says ENR
1 Mile HSI says TERM
.3 miles. HSI says APP(2nm from FAF)
RNAV vs RNP
just a RNAV system does not have the capability to verify its accuracy or tell you if it isnt. WAAS or RAIM is RNP because it shows messages if accuracy is bad. Old airliners with ring laser gyros are just RNAV because over time the accuracy degreades but the system doesn’t detect it or have a way to tell you.
When loading an approach into the gps what does the receiver do
It looks at what RNP value it can do, the most accurate one based on what it can do and what satellites it has.
