Tech Quiz Flashcards
Definition TORA?
T\O run available. ( the length of runway available as suitable for the ground run of a t/o).
Definition TODR?
T/O distance required.
- When flying from AKL to Perth on a great circle, what happens to heading? Does it slowly increase or decrease?
Heading will increase as great Circle is concave to equator on Mercator chart
- When flying from AKL to Perth on a great circle, is it a straight or curved line on a Lamberts chart?
Great circles are straight lines on Lamberts charts (in fact very slightly curved towards parallel of origin)
- With a constant IAS, what happens to Mach # and TAS during a climb?
Mach # and TAS will increase
- What is the temp at 39,000 ft in ISA?
From 36,090 feet temperature is constant at -56.5°C
- How do you work out the local speed of sound? What is LSS at sea level at ISA conditions?
LSS = 38.94√Temperature (where temperature is in Kelvin)
At sea level = √ (273+15) = 660.83 knots
- When flying EAST are the days longer or shorter?
Shorter as earth is rotating towards East
- What is MCRIT?
MCRIT is the critical Mach number. This is the speed at which the airflow over certain parts of the airframe (most likely the point of maximum camber of the aerofoil) reaches M1.0. MCRIT is increased through slimness and through the use of sweepback.
- Which part of a swept wing stalls first?
A raw swept wing will stall at the tips first. The total airflow over the swept wing includes a span wise vector. The flow of air outwards along the wing causes the boundary layer on a swept wing to drift outwards towards the tips resulting in an undesirably thick boundary layer in the region of the tips. The retardation of the air by the boundary layer is one of the major causes of the stall. A thick boundary layer will encourage the stall. The boundary layer is thicker at the wingtips therefore the tip is likely to stall before the root.
When a tapered wing is also swept, the tip stalling trend is enhanced by the span wise airflow towards the tip, particularly at low speed and high lift hence the need to avoid a grossly large taper ratio.
The degree of this trend is modified by the varying use of built-in wing twist; span wise aerofoil variation, vortex generators, in the gear/flap configuration, and leading edge and trailing edge devices. Reducing sweepback using crescent shaped wings may be a possibility
- Does a jet have a critical engine?
On a jet there is no critical engine in a nil wind situation. Its VMCA in the flight manual is a fixed speed and does not change with the effects of a crosswind (during certification VMCA tests are conducted in zero wind and no nose-wheel steering)
In a crosswind situation the preferred engine to lose would be the outboard downwind engine as the crosswind will aid in directional control opposing the yaw caused by the failed engine (due to weather cocking action of the cross wind against the vertical stabiliser). This effect will be exactly the same on the reverse side Thus on a 4 engine aircraft taking off with wind from right to left the No4 engine (right hand outboard) would be the critical engine (reference: Stanley Stewart – Flying the Big Jets)
In the cruise the outboard engines in a 4 engined aircraft are considered to be the critical engines
- How do you stop Dutch roll?
A yaw damper will prevent Dutch roll but if this fails use aileron.
A yaw damper is a gyro system sensitive to changes in yaw which feeds a signal into the rudder which then applies rudder to oppose the yaw. With this device, a Dutch roll will not develop because the yaw which triggers it all off is not allowed to develop. It applies the rudder in the correct direction and in the correct amount, thus preventing the slip starting or building up and stopping all rolling tendency Apart from the swept wing, the basic cause of Dutch rolling tendency is lack of effective fin and rudder area.
- What happens to TOD point with increased weight? Or … In a descent at a constant speed of 300 kts (which is > Vmin drag) the glide angle will be (shallower / steeper) at a higher weight?
TOD will be closer to point of origin in order to reduce angle of descent (forward component of weight greater at higher weights)
- What effect does an aft C of G have on range?
For maximum range it would be best to load it with an aft CoG as this would require an upward force from the tailplane (or less of a downward force required from the tailplane) which acts in the same direction as lift and hence opposes some of the aircraft’s weight. Less lift from the mainplanes means less drag therefore less thrust is required, less thrust means reduced fuel flow and hence more range can be obtained for the amount of fuel on board.
- How many satellites are required for RAIM detection? Number of satellites required for RAIM detection AND exclusion?
RAIM is a software algorithm that is available in some GPS receivers which gives an indication if the position solution given by the GPS receiver is OK to use.
It is OK to use if the position solutions (latitude, longitude and altitude), worked out from any four of at least five or more GPS satellites, all fall within a pre-defined tolerance. If the solution falls outside this tolerance then a RAIM warning is given which is indicated on the receiver. This means that the accuracy of the position on the receiver can not be guaranteed at that point in time and so it is advisable not to use the GPS for navigation until this warning disappears.
The RAIM availability (or ability of a GPS receiver to provide a RAIM warning) is dependent on the number of satellites available or in view by the GPS receiver. Remembering we need a minimum of five satellites to provide a RAIM warning.
For RAIM detection and exclusion 6 satellites required.
So, if there are less than this number at any point in time at some location then this is identified as a ‘RAIM hole’ (or RAIM unavailability).
It is basically a function of the geometry of the GPS satellites overhead of the receiver. Additionally, some satellites may have been taken out for ‘maintenance’ by the owners of the GPS constellation - the U.S. Department of Defence (DoD). GPS NOTAMS or Notice Advisories to Navstar Users (NANUs as they are called) are disseminated by the DoD prior to any planned GPS satellite outage.
Baro-aiding may be used to improve RAIM availability since the additional altitude information provided by baro-aiding effectively acts as an additional satellite. Baro-aiding will be made mandatory for IFR GPS use and will be included in New Zealand Civil Aviation Rules Part 91.
IMPORTANT NOTE: GPS receivers that also provide RAIM prediction do not take into account GPS satellites which have been taken out of service for maintenance by the United States Department of Defence. Their RAIM predictions may not be accurate therefore. The RAIM Prediction Service takes both the satellite geometry and maintenance outages into account giving more accurate predictions.
The RAIM Prediction Service provides RAIM outage information for aerodromes with a published GPS approach and some additional aerodromes as a check of RAIM coverage.
RAIM outage data is computed once per day (at 1400 UTC) or when a satellite outage NOTAM has been received. The computation is for the following 72 hour period
Definition V1?
The speed on which from a balanced field takeoff it is possible to either reject the takeoff and stop within the available stopping distance or to continue after engine failure and clear a screen height of 35 feet at the end of the surface available. In effect V1 is a “go speed”.
Definition VMCA?
VMCA is the minimum airspeed at which, when sudden and complete failure of the critical engine occurs at that speed, at 50feet (takeoff flap and max power on live engine, failed engine not feathered) it is possible to recover the airplane and maintain it in straight flight at that speed, either with zero yaw or with an angle of bank not in excess of 5°. Must be greater than or equal to 1.2VS (with undercarriage retracted and flaps in takeoff position)
Definition V2?
V2 is the take-off safety speed or initial target climb speed. It is the speed to be attained at or before 35’ following an engine failure to ensure climb gradients are achieved and hence obstacles are cleared by the required margins.
Definition VMCG?
VMCG is the minimum speed on the ground during the take off run, at which it is possible to recover control of the aircraft with the use of primary aerodynamic controls and the takeoff can be continued safely, when the critical engine suddenly becomes inoperative, with the remaining engines at takeoff thrust. Usually VMCG is higher than VMCA as cannot use 5° bank.
Definition VA?
VA is the design manoeuvring speed, the maximum speed at which application of full available rudder, aileron or elevator will not overstress the aircraft.
Abbreviations, FG, BR, VA?
FG = Fog BR = Mist (Brume) VA = Volcanic Ash
Abbreviations
GR = Hail (GS = Small hail) SN = Snow SQ = Squall TS = Thunderstorm SG = Snow grains
Abbreviations, GR, SN, SQ, TS, SG?
GR = Hail (GS = Small hail) SN = Snow SQ = Squall TS = Thunderstorm SG = Snow grains
Abbreviations PRFG, PL, MIFG, FU, BCFG?
PRFG = Partial Fog (covering part of aerodrome) PL = Ice pellets MIFG = shallow fog FU = smoke BCFG = fog patches
- What is a katabatic wind?
A katabatic wind is a down-slope wind that develops as air cools in contact with cold ground and slips down the side of the hill
- Describe the parameters of CAVOK? General.
- Visibility better than 10km
- no cloud below 5’000 AGL or below minimum sector altitude whichever is the higher
- no CB’s, precipitation, drifting fog, dust devils etc
- What are Dangerous Goods (DGs) classes?
Class Type Includes 1 Explosives. Ammunition, explosives, fireworks 2 Gases. Aerosols, lighter refills, sparklet bulbs 3 Flammable liquids. Paint, paint thinners 4 Flammable solids. Calcium carbide 5 Oxidisers. Catalysts, pool chlorine 6 Toxic. Agricultural chemicals 7 Radioactive.
8 Corrosives. Caustic cleaners 9 Miscellaneous. Mercury, motor vehicles
- Centreline lighting becomes alternating red/white at what distance to the end of the runway? Centreline lighting becomes Red how much distance remains?
Lighting will be coded to show white from the threshold to a point 914m from the runway end; alternating red and white from 914m to 300m from end; and red between 300m and runway end.
What is a sector 1 entry to a holding pattern?
Parallel entry = Sector 1
Turn onto outbound heading and fly to DME limiting outbound distance then turn onto holding side to intercept inbound heading.
What is a sector 2 entry to holding pattern?
Offset entry = Sector 2
Having reached fix aircraft is turned to fly track of 30° from reciprocal of inbound track (on side of pattern). Fly outbound for appropriate distance or time, then turned to intercept inbound track.
What is sector 3 entry to holding pattern?
Sector 3 = direct.
What times are used for holds above and below FL140?
Standard leg 1 minute below FL140 or 1 ½ minutes above FL140
Pilot may allow for wind if timed legs otherwise DME always limiting distance
Speeds
Max hold speed 14000ft and below, standard and turbulent?
230kts unless 1st segment of approach is above 230kts.
(170kts cat b.)
Turbulent 280kts (170kts.catB)
Max hold speeds 14000ft to 20000ft? Normal turbulent
240kts
Turbulent =lessor of 240kts or m.80
Max hold speeds 20000ft -34000ft? Normal and turbulent
265kts.
Turbulent =lessor of 265kts and m.80
Max hold above 34000ft? Normal turbulent
M.83 for both.
- Hydroplaning speed of rotating wheel 100psi?
Theoretical minimum hydroplaning speeds = 9 x √tyre pressure
So 90 knots
How do you work out headwind and crosswind?
Headwind component = surface wind x cos Ө
Crosswind component = surface wind x sin Ө
- Flying Wellington to Chathams ETP of 1hr 50min, you are 10min ahead of flight plan (tail wind) what effect on ETP? Will it be closer to Wellington or Chathams?
Closer to Wellington
- What does sweepback do for stability and critical mach
• The primary purpose of sweepback is to increase the value of MCRIT for a given aircraft. Since only the component of the relative airflow across the wing which is parallel with the chord line can be considered as producing/creating lift, only the vector speed of this chordwise component is significant when considering MCRIT. In effect, the wing is persuaded to believe that it is flying slower than it really is; this means that the airspeed can be increased before the effective chordwise component becomes sonic and thus the critical Mach # is raised. This is why a high speed a/c has a swept wing. As the thickness/chord ratio defines the amount of acceleration imposed on the upper surface stream it follows that the thinner the wing, the lower the acceleration, and the higher will be the airspeed before, for this reason alone, the upper flow becomes sonic. This is why a high speed a/c has a thin swept wing.
:
• Lateral stability (about the longitudinal axis) is reduced. If a straight wing aircraft is yawing it also rolls; this tendency is increased in a swept wing aircraft because the effective spans on both wings are altered. With yaw, both values of V and CL are increased on the outer wing and reduced on the inner wing posing a very marked tendency to roll the aircraft.
• Longitudinal stability (about the lateral axis) is also reduced due to the effects of mach tuck
- Dihedral provides what stability about what axis? Why do we use dihedral?
Dihedral is the angle between the mainplanes (or tailplane) and the horizontal. If the planes are inclined upwards towards the wingtips this is positive and is called dihedral, if downwards this is negative and called anhedral. Anhedral is used for dynamic stability.
Dihedral is an aid to lateral stability (about the aircraft longitudinal axis).
- Static vent blocked effect on altimeter in climb (over read/under read)?
Altimeter will read at altitude where it became blocked as it only reads static pressure – therefore under-read.
- At what cabin alt does crew require supplemental O2? What are the oxygen rules?
With reference to Part 91
Pressurised Aircraft when cabin exceeds 10,000ft
• Crew supplemental oxygen to be used
• Crew supplemental and portable oxygen to be used if away from station
Pressurised aircraft between FL350-410
• 1 pilot at controls must be wearing mask whenever cabin is above FL130
• Or if 2 pilots at controls must have access to masks in 5 seconds
Pressurised aircraft above FL410
• I pilot at controls wearing mask at all times
Pressurised aircraft in event of pressurisation failure
• Unless aircraft can descend below FL140 in 4 minutes then supplemental oxygen for each passenger to be used whenever cabin is above FL140
Unpressurised Aircraft
• When above FL130 continuous oxygen for pax and crew
• Between 10,000 and FL130 for more than 30 minutes continuous oxygen for crew and supplemental for passengers
- At 36000 ft and wanting to climb, the SAT is -42. What ISA chart would you refer to for climb performance? ISA -5, ISA, ISA+5, ISA+10, ISA+15, ISA+20 etc…
ISA @ 36,000 = -56.5 so ISA +15
