AVIA 222 Advanced Flight Operations Cont’d
Payload Review • First, before starting on the new stuff lets just do a quick review of payload calculation: Payload = ZFW – BOW ZFW = BOW + Payload (passengers and cargo) BOW = empty weight plus crew w/baggage and equipment EOW = Basic a/c empty weight with unusable fluids
Example, Find PAYLOAD: • Fuel = 3000lbs • Crew and baggage = 550lbs • Zero Fuel Weight = 14,000lbs • Empty Operating Weight = 7000lbs Payload = ZFW – BOW Payload = 14,000 – (7000lbs + 550lbs) Payload = 6,450lbs. – 3000lbs fuel = 3,450 (fuel, when added, reduces payload)
IATRA TOPICS • The following point form slides are topics that do appear in the course outline but are areas that are specified on the Transport Canada Aircraft Type Rating Study and Reference Guide….which if you have not reviewed I would highly recommend that you spend some time looking over the topics and the CARS references provided.
Canadian Runway Friction Index • The CRFI is the Canadian method of determining the equivalent braking available in conditions other than dry bare runways. • The CRFI is broadcast in the form of a notam or as part of a ATIS broadcast. Friction reading from 0.1 to 1.0 represent minimum to maximum braking for the surface condition. Water over 3mm, or ice can increase braking distances from 75% to 100% and would be rated very low (0.2 – 0.4) • The CRFI can be represented in a performance graph for braking or crosswinds.
Hydroplaning • Dynamic hydroplaning: is due to standing water • Viscous Hydroplaning: occurs on a smooth surface with a thin layer of water (most common on the rubber streaked surface at the touchdown zone). • Reverted Rubber Hydroplaning: is after a long skid when the hot tire boils the water on the runway surface under the tire and the steam prevents tire contact.
Hydroplaning Non-rotating tire: Hydroplaning speed = 7.7 x √PSI Rotating tire: Hydroplaning speed = 9 x √PSI
Visual Approach Systems • VASIS: Visual Approach Slope Indicating System • Visible for at least 4nm out • Indicates a 3 degrees slope to the threshold • Three bar systems work for both eye to wheel heights of up to 25’, and up to EWH of 45’ or widebody a/c. • Normal aircraft ignore the upper single indicator light • Widebody/EWH >45’ ignore the lower two lights. • In either case red upper and white lower indicates the correct approach path.
Clear Air Turbulence • CAT is any turbulence not related to convective activity. • CAT is most common in the area of the jet stream. • The jets streams are caused by strong horizontal temperature gradients (air mass boundaries). As a result: • If Cat is encountered in the jet stream region monitor the outside temp… • If temp is increasing, climb to clear the CAT ASAP • If temp is decreasing, descend to clear the CAT ASAP • If temp is constant climb or descend
CAT/Jet Stream Con’t • CAT can be expected when 30kt isotachs are spaced closer than 90nm on the 250mb upper air chart. • If flying in the jet stream core with a direct head or tailwind and you encounter a pride of CATs it is generally best to turn south to give them the shake!
CAT can often be seen in the contrails of jets high overhead when they are well defined for some areas, then in clear skies often break up suddenly into more blurred contrails.
Airframe Icing • Airframe icing occurs in cloud at temperatures between +2C and –40C • It is most severe at temps from 0C to –15C in cloud thickness of 5000’ to 8000’ • Clear Ice = large supercooled drops with a high catch rate just below freezing…is heavy and forms backwards along the airframe.
Rime Ice: small supercooled droplets that occur in stable clouds well below 0C • Low catch rate, moves foreword as it accumulates • Builds up on small sharp surfaces such as antennae • Thin wings on high speed a/c have the quickest catch rates.
De-Ice fluids • Type I deicing fluid is a glycol/water mixture of up to 50/50 for limited protection for a short period of ground time. • Type II are more viscous (reduced flow), and stay on the wings longer with some water absorbing abilities. Wind shear stress on takeoff reduces viscosity for flow off. • Type III a hybrid between type I and II with flow properties that will work on a/c with rotation speeds below 100kts. • Type IV, much the same as type II but with a longer hold over time (used on large a/c as visible by the green dye added to help with recognition and proper coverage. • When deicing surfaces start with the surfaces that can be seen from the cockpit so as to be aware of any buildup before takeoff.
Cruise Performance The cruise segment of a flight is from the top of the climb to the bottom of the descent. • Specific Air Range (SAR) SAR = True Airspeed Fuel Flow
Range • Specific Ground Range (SGR) SGR = Groundspeed Fuel Flow
Point of No Return • The PNR is the farthest point the a/c can travel under the given wind conditions and still return to the point of departure. PNR is also referred to as Radius of Action with a specific calculated fuel burn that would allow enough fuel to return to base. • The PNR is a fuel based problem related to endurance in hours, not to actual distance traveled.
Formula: Distance to PNR = End. X G/S out x G/S Home G/S Out + G/S Home *endurance is in hours of flight ***If in zero winds, then PNR will equal half of the endurance.
Time to PNR in a HEADWIND is longer • Time to PNR in a TAILWIND is Shorter. • PNR moves with the wind Time to PNR = Distance to PNR G/S Out
PNR Example: • Calculate the time and distance to the PNR given the following: • Track 220 true • Winds 170 true at 30kts • TAS 180 kts • Distance 1,240nm • Endurance of 8 hours ***A flight computer of some type is required to calculate the wind corrected groundspeed. ***Use the same wind but the reciprocal track for ground speed home Distance to PNR = 8 x 159 x 198 = 705.5 nm 159 + 198
Critical Point (CP) • The CP is the point along the planned track from which it will take the same amount of time to continue to the destination as it will to return to the starting point. • The CP is calculated to provide a pilot with quick decision if a power loss or system failure occurs.
Critical Point (CP) • The CP is strictly a distance calculation. • In zero winds the CP is at the half way point • With a headwind the CP moves closer to the destination. • With a tailwind the CP distance is closer… • CP “moves into the wind” CP Distance = D x Hr Or + Hr D = Total distance Hr = Reduced G/s home Or = Reduced G/s
Critical Point (CP) If…you want to find the time it takes to get to the critical point (CP) then use the following: Flight time to CP = Distance to CP Normal G/s out
Flight Calculator • Know how to do wind corrections and ground speed. Also, know how to calculate the winds from a known track, heading, TAS and groundspeed • For example: • If your heading was 170 true to maintain a track of 180 true, with a TAS of 150 and a groundspeed of 160 then what is the wind speed and direction?
To solve for the previous question: • Place your track at the true index mark at the top. • Set the groundspeed at the grommet hole • Calculate the wind correction angle (10 degrees) • Place a dot on the plastic at the TAS along the correction angle • Rotate the dot to the center line and read the wind direction at the top.
Question 1: Calculate the time and distance to the PNR given the following: • Track 355 true • Winds 250 true at 40kts • TAS 200 kts • Distance 1,440nm • Endurance of 9 hours • Time to PNR = ? • Distance to PNR = ?
Question 2: Calculate the time and distance to the PNR given the following: • Track 120 true • Winds 150 true at 20kts • TAS 160 kts • Distance 1,100nm • Endurance of 6 hours • Time to PNR = ? • Distance to PNR = ?
Question 3: Calculate the time and distance to the CP given the following: • Track 050 true • Winds 150 true at 20kts • TAS on 4 engines 330 kts • TAS on 3 engines 290 kts • Distance 1,100nm • Endurance of 6 hours • Time to CP = ? • Distance to CP = ?