Airplane Navigational Tools

Navigation:- Determination of position and velocity of a moving vehicle. Co-ordinates also gives direction.

Fix:- The point which is obtained with the help of co-ordinates.

Heading:- Direction of the nose of Aircraft is called heading.

Bearing:-  Its destination point.

Relative Bearing:- Difference Between heading and bearing. RB + MH = MB

Radial:- Guidance from beacon to aircraft.

Beacon:- It is an antenna which transfer radiation in all directions/ Source of Energy.

Controls:- Constant Feedback System.

Flag:- Indicator for equipment failure or not working properly.

Line-Of-Position:- Its a path/line which gives direction to destination, same as the terminology for Course.

Air Corridor:- Difference between two NDBs.

Omni Bearing Selector:- It helps in selecting right bearing for navigator, It is found in VOR.

Precision:- It gives you accuracy.

Procession:- Is a movement orthogonal to the applied force.

Transceiver:- It can transmit and receive when asked for.

Transponder:- It can transmit and respond when asked for, the phenomena is called trans-pondering and the device is called Transponder.

Moving Target Indicator:- Its a mode of Radar which discriminate a target against clutter.

Localize:-  Guides the aircraft in horizontal plane, localizes it to the center of runway,

Glide-scope:- Guides the aircraft in vertical plane to touch down point.

Decision Height:- It tells whether we have to land or take-off. 

Marker Beacons:- They helps to find final approach and is based on directional beams propagated from two transmitters.

All above terminologies are referred from North.

Forms of Navigation Include:-

• Celestial Navigation -  Using the Stars, Sun and Planets. Oldest form of Navigation.
• Pilot-age - Pilot uses landmarks to determine position.
• Dead Reckoning - Pilot determine position using speed, time, direction and destination.
• Radio Navigation - Use of high tech instruments to determine position by use of radio waves.

Magnetic Compass:-

• Everything that flies has a magnetic compass mounted to the windshield.
• It can be used almost anywhere in the world.
• Its the most reliable thing in the aircraft, uses no power or technology. 

VHF Omnidirectional Range (VOR):-

• Being used since 1950's
• Operated by FAA
• VOR signal displays aircraft's position relative to specific station
• Uses thousands of radio transmitters located throughout U.S and the world
• Aircraft must be within receiving range.
• mainly two types CVOR & DVOR.
• Conventional VOR works on conventions/rules.
• Doppler VOR works on Doppler effect. It transmits all waves of same frequency and has 52 antennas

Automatic Direction Finder (ADF):-

• Uses low frequency signals 
• When frequency is set to proper station, the needle will point exactly to the station
• Gives relative bearing from ground or ship to aircraft.
• It only gives Line-of-position (LOP).
• RBI is the 2nd name of ADF.
• Three types of ADF, Fixed Card ADF, Moving Card ADF and RMI
• Fix Card ADF gives Relative bearing.
• Moving Card ADF gives Magnetic Bearing
• Radio-Magnetic Indicator (RMI) gives relative bearing to or from the transmitting station.

Relative Bearing Indicator:-

• Displays bearing relative to vehicle carrying a detector.
• Commonly used in conjunction with an ADF and NDB aid.

Non-Directional Beacon:-

• Radio transmitter used in navigational aid.
• operated at 190 - 1750 KHz  (Standardized by ICAO).
• Distance can also be determined from NDB station.

to be continued...

Source:- 

• Lectures on Navigation and Guidance by Syed Najeeb Haider Jafri, Assitant Prof. & Deputy Director at PAF-Kiet, Pakistan
• Avionics Navigation Systems By Myron Kayton & Walter R.Fried, 2nd Edition

Aircraft Navigation System

The above system utilizes three types of sensors information:

1. Absolute position data from radio aids, radar checkpoints, and satellites (based on the range or differential range measurements.
2. Dead-reckoning data, obtained from inertial, Doppler, or air-data sensors, as a means of extrapolation present position. A heading reference is required in order to resolve the measured velocities into the computational coordinates.
3. Line-of-sight directions to stars, which measure a combination of position and attitude errors.

The navigation computer combines the sensor information to obtain an estimate of the aircraft's position, velocity and attitude. The best estimate of position is then combined with waypoint information to determine range and bearing to the destination. Bearing Angle is displayed and sent to the autopilot as a steering command. Range to go is the basis of calculations, executed in a navigation or flight-management system, that predict time of arrival at waypoints and that predict fuel consumption. Map displays, read from on-board compact discs(CD-ROM), are driven by calculated position.

Dead-reckoning:- Navigating the aircraft without external navigation/guidance.

Attitude:- Orientation of the aircraft relative to Earth's horizon. / Vertical Navigation to aircraft.

Waypoint:- are the positions and marks in a way.

Bearing Angle:- Its the angle between forward direction of aircraft and a line towards the destination/object in question with respect to north.

Flight Management System:- Its a system which provides workload-reducing automation on flight deck with true multi-sensor navigation capabilities.

Map Displays:- Also known as Moving Map Displays are a type of moving electronic display typically used in GPS navigation devices.

C.E.P:- Circular Error Probable is an indicator to the weapon system which delivers accuracy as factor in determining the probable damage to a target. Its the radius of circle within which half of a missile's projectiles are expected to fall.

Source:- 

• Syed Najeeb Haider Jafri, Assistant Prof. & Deputy Director at PAF-KIET, Pakistan
• Avionics Navigation Systems by Myron Kayton & Walter R.Fried, 2nd Edition

The Copilot !

I am the copilot. I sit on the right

Its's up to me to be quick and bright;

I never talk back to remember what the Captain forgets.

I make out of the Flight plan and study the weather,

Pull up the gear, stand by feather;

Make out the mail forms and do the reporting,

And fly the old crate while the Captain is courting.

I take the reading, Adjust the power,

Put on the heaters when we're in the shower;

Tell him where we are on the darkest night,

And do all the book-work without any light.

I call for my Captain and buy him cokes,

I always laugh at his corny jokes;

And once in while when his landings are rusty,

I always come through with "By god  it's gusty !"

All in all I'm  a general stooge,

As I sit on the right of the man called "scrooge";

I guess you think that is past understanding,

But maybe someday he will give me a landing.

--Keith Murray

Source: Aviation Humor 

Pitot Tubes !

Pilots must keep track of a lot of data when they're in the cockpit of an airplane. Airspeed the velocity of an aircraft relative to the air mass through which it's flying, is one of the most important things they monitor. For a specific flight configuration, be it landing or economy cruising, a plane's speed must remain within  a fairly narrow range of values. If it flies too slowly, it can suffer an aerodynamic stall, when there's insufficient lift to overcome the downward force of gravity. If it flies too rapidly, it can suffer structural damage, such as the loss of flaps.

On commercial airliners, Pitot tube bear the burden of measuring airspeed. The devices get their names from Henri Pitot, a Frenchman who needed a tool to measure the speed of water flowing in rivers and canals. His solution was a slender tube with two holes, one in front and one on the side. Pitot oriented his device so that the front hole faced upstream, allowing water to flow through the tube. By measuring pressure differential at the front and side holes, he could calculate the speed of moving water.

Airplane Engineers realized they could accomplish the same thing by mounting pitot tubes on the edges of the wings or jutting up from the fuselage. In that position, the moving air-stream flows through the tubes and allows for an accurate measurement of the aircraft's speed.

Source: Aviation Innovations

Airfoil !

Birds have them. So that bats and butterflies. Daedalus and Icarus donned them to escape Minos, king of Crete. We're talking about wings, of course, or airfoils, which function to give an aircraft lift. Airfoils typically have a slight teardrop shape, with a curved upper surface and a flatter lower surface. As a result, air flowing over a wing creates an area of higher pressure beneath the wing, leading to the upward force that gets a plane off the ground.

Interestingly, some science books invoke Bernoulli's Principle to explain the uplifting story of airfoils. According to this logic, air moving over a wing's upper surface must travel-farther and therefore must travel faster, to arrive at the edge at the same time as air moving along the wing's lower surface. The difference in speed creates a pressure differential, leading to lift. Other books dismiss this as hogwash, preferring instead to rely on Newton's tried-and-true laws of motion. The wing pushes the air down, so the air pushes the wing up.

Source: Circumnavigation/feel-air 

Stipa-Coproni: One of the Smallest and Most Strangely Shaped Aircraft.

Technical Characteristics of Stipa-Coproni

General Characteristics:

Crew: 1 or 2

length: 5.88 m (19 ft 4 in)

Wingspan: 14.28 m (46 ft 10 in)

Height: 3 m (9 ft 10 in)

Loaded Weight: 800 kg (1,760 lb)

Power-plant: 1 x de Havilland Gipsy III inline piston engine, 120 hp (90 kw)

Propellers: 1 Propeller, 1 per engine

Performance: 

Maximum Speed: 131 km/h (81 mph)

Landing Speed:  68 km/h (42 mph)T

Source: Vintage Aviation

Every Aviator's Dream Bedroom

Source: Aviation at best