MDR Flashcards
(26 cards)
What is the equation for Track Error using the 1-in-60 rule?
Track error = (Distance off track x 60)/Distance along track
What is the equation for Max Drift?
Max drift = Wind speed (kts) / TAS (nm/min)
Draw the MDR clock
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What fraction of the max drift will be added in the wind angle is 60 degrees?
1/1
What fraction of the max drift will be added in the wind angle is 6 degrees?
1/10
What fraction of the max drift will be added in the wind angle is 10 degrees?
1/6
What fraction of the max drift will be added in the wind angle is 15 degrees?
1/4
What fraction of the max drift will be added in the wind angle is 20 degrees?
1/3
What fraction of the max drift will be added in the wind angle is 24 degrees?
2/5
What fraction of the max drift will be added in the wind angle is 30 degrees?
1/2
What fraction of the max drift will be added in the wind angle is 36 degrees?
3/5
What fraction of the max drift will be added in the wind angle is 40 degrees?
2/3
What fraction of the max drift will be added in the wind angle is 45 degrees?
3/4
What fraction of the max drift will be added in the wind angle is 50 degrees?
5/6
What fraction of the max drift will be added in the wind angle is 54 degrees?
9/10
What are the 4 steps to MDR?
1- Picture the situation (e.g. triangle of velocities)
2 - Heading
3 - Ground speed
4 - Time
How is heading calculated using MDR?
1 - Calculate max drift
2 - Calculate actual drift (max drift x clock fraction)
3 - Apply actual drift to track = Heading
How is groundspeed calculated using MDR?
1 - Wind speed x Clock fraction (90-wind angle) = Head/tail component
2 - Add/subtract head/tail component to TAS to get GS
How is time calculated using MDR?
Time = Distance/speed
How can distance be estimated on a map/chart?
Hand measurements (known distances from dimensions in glove, e.g. thumb width, max span, etc)
Map comparisons (compare with features of a known size on the map, e.g. sides of grid squares, MATZ dimensions, ATZ dimensions, etc).
Pre-flight map preparation includes distance-to-go markers or time marks.
Map scale
How can heading be estimated on a map/chart?
Visual inspection (bisect or trisect a right angle)
1-in-60 rule (can also be used in conjunction with latitude and longitude graticules)
Comparison with marked tracks/known directions on the map, e.g. drawn and measured tracks, airway centrelines, overprinted VOR radials.
Latitude and Longitude graticules
How is the angle for clock use calculated when using MDR to determine GS?
Angle for clock use = 90 - Wind angle
E.g. Wind angle = 35 degrees
Clock angle = 90-35 = 55 degrees
55 on clock = approx. 9/10 of the wind speed
What is the Standard Closing Angle (SCA) technique used for?
Regaining track when a position is fixed off-track, but no off-track feature is available to assist regaining track, or when it is impracticable to over-fly an on-track feature.
How is Standard Closing Angle (SCA) determined for any groundspeed?
SCA = 60/GS(nm/min)
Note:
For a GS of 3nm/min, SCA = 60/3 = 20 degrees