C172 Performance

Aim To determine take-off and landing distances using flight manual data for the Cessna 172SP

Objectives Calculate Take Off Distance Required for C172SP Calculate Landing Distance Required for C172SP Practice problems State TEM, Airmanship, and Human Factors considerations

1. Calculate TODR – 172SP TODR - C172SP These tables can be found in the aircraft flight manual. We use these tables to work out take-off distances for the C172SP This data is only true when the aircraft is flown to the prescribed conditions

1. Calculate TODR – 172SP TODR - C172SP Calculate TODR given the following information: Aerodrome: YBAS ATIS: YBAS H 042322 RWY: 30 WIND: 330/18 VIS: WX: CAVOK + CLD: TMP: 29 QNH: 1005 Weight: 1157 Kg (2550 lbs)

1. Calculate TODR – 172SP TODR - C172SP We can start by gathering the relevant information from the ERSA Elevation: 1789ft

1. Calculate TODR – 172SP TODR - C172SP We can start by gathering the relevant information from the ERSA Elevation: 1789ft TODA: 8983ft (2738m) Slope: 0.3% up

1. Calculate TODR – 172SP TODR - C172SP Fill out the W&B + Performance form with the known data YBAS 30 To determine pressure height: Determine pressure variation from ISA 1013 hPa – 1005 hPa = +8hPa Multiply variation by the pressure lapse rate, 30ft per 1 hPa +8 hPa x 30ft = +240ft Apply the variation to the aerodrome altitude Since QNH is less than ISA, pressure altitude will be higher 1789ft + 240ft = 2029ft 1005 hPa 2029ft 29⁰C 330/18 Bitumen 0.3% up 2550 lbs 8983ft

1. Calculate TODR – 172SP TODR - C172SP Determine Wind Components: YBAS Headwind Component = 17kts 30 1005 hPa 2029ft 29⁰C 330/18 H17/X09 Crosswind Component = 9kts Bitumen 0.3% up 2550 lbs 8983ft

1. Calculate TODR – 172SP TODR - C172SP Take-off Distance - Tables Once we have gathered all the relevant data we can then go to the performance charts to determine our TODR Our pressure height was 2029ft, temperature 29⁰C, so we must interpolate between 2000ft and 3000ft for 20⁰C and 30⁰C 2240ft – 2035ft = 205ft 205ft / 1000 = 0.205 0.205 x 29 = 6ft 2035ft + 6ft = 2041ft 2420ft – 2190ft = 230ft 230ft / 1000 = 0.23 0.23 x 29 = 7ft 2190ft + 7ft = 2197ft

1. Calculate TODR – 172SP TODR - C172SP Take-off Distance - Tables Our pressure temperature was 29⁰C so we must interpolate between 2197ft and 2041ft 2197ft – 2041ft = 156 156ft / 10 = 15.6 15.6 x 9 = 140ft 2041ft + 140ft = 2181ft

1. Calculate TODR – 172SP TODR - C172SP Take-off Distance - Tables Our headwind wind component was 17KTS so we must decrease our TODR 17 / 9 = 1.9 Therefore we can decrease our TODR by 19% 2181ft x 0.81 = 1767ft

1. Calculate TODR – 172SP TODR - C172SP This chart does not factor in CAO 20.7.4 so we must increase this value by 15% 1767 x 1.15 = 2032ft We then enter the TODR into the W&B + Performance form and compare it to our TODA YBAS 30 1005 hPa 2029ft 29⁰C 330/18 Bitumen 0.3% up 2550 lbs 2032ft (619m) 8983ft

2. Calculate LDR – 172SP LDR - C172SP These tables can be found in the aircraft flight manual. We use these tables to work out landing distances for the C172SP This data is only true when the aircraft is flown to the prescribed conditions

2. Calculate LDR – 172SP LDR - C172SP YBAS For this example we will use the same data that we used for the TODR tables 30 1005 hPa 2029ft 29⁰C 330/18 H17/X09 Bitumen 0.3% up 2550 lbs 1767ft 8983ft

2. Calculate LDR – 172SP LDR - C172SP YBAS We start by filling out the W&B + Performance form LDA is 7999ft 30 1005 hPa 2029ft 29⁰C 2550 lbs 7999ft

2. Calculate LDR – 172SP LDR - C172SP Landing Distance - Tables We can now use the performance charts to determine our LDR Our pressure height was 2029ft, temperature 29⁰C, so we must interpolate between 2000ft and 3000ft for 20⁰C and 30⁰C 1460ft – 1420ft = 40ft 40ft / 1000 = 0.04 0.04 x 29 = 1ft 1420ft + 1ft = 1420ft 1495ft – 1455 = 40ft 40ft / 1000 = 0.04 0.04 x 29 = 1ft 1455ft + 1ft = 1456ft

2. Calculate LDR – 172SP LDR - C172SP Landing Distance - Tables Our pressure temperature was 29 ⁰C so we must interpolate between 1456ft and 1420ft 1456ft – 1420 = 36 36 / 10 = 3.6 3.6 x 9 = 32ft 1420ft + 32ft = 1452ft

2. Calculate LDR – 172SP LDR - C172SP Landing Distance - Tables Our headwind wind component was 17KTS so we must decrease our LDR 17 / 9 = 1.9 Therefore we can decrease our LDR by 19% 1452ft x 0.81 = 1176ft NOTE: When calculating landing distance prior to departure we assume nil wind.

2. Calculate LDR – 172SP LDR - C172SP Landing Distance - Tables This chart does not factor in CAO 20.7.4 so we must increase this value by 15% 1176ft x 1.15 = 1352ft (412m)

2. Calculate LDR – 172SP LDR - C172SP Landing Distance - Tables YBAS We then enter the LDR into the W&B + Performance form and compare it to our LDA 30 1005 hPa 2029ft 29⁰C 2550 lbs 1352ft 7999ft

2. Practice C172SP Calculate TODR and LDR given the following information: Aerodrome: YPPF ATIS: YPPF C 180245 RWY: 03L WIND: 020/20 VIS: WX: CAVOK + CLD: TMP: 15 QNH: 1013 Weight: 1157 Kg (2550 lbs)

2. Practice C172SP Calculate TODR and LDR given the following information: Aerodrome: YPPF ATIS: YPPF E 200015 RWY: 21L WIND: 150/15 VIS: WX: CAVOK + CLD: TMP: 30 QNH: 998 Weight: 1157 Kg (2550 lbs)

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