2

Do Flaps 10 really do anything performance-wise other than reducing ground roll and distance over a 50-foot obstacle? If not worried about clearing an obstacle, does a Flaps UP-normal takeoff make more sense (Better climb performance since no drag from Flaps) in the C172S?

Jacob Doore
  • 113
  • 1
  • 6
  • I think it was because of the power increase in the SP gave flaps 10 climb performance as good as or better than flaps up in the 160 hp version, so make that the standard TO setting and benefit from the shorter run. Not sure tho. – John K May 03 '21 at 18:11
  • "Why does the say" I think you're missing a word or two there... Please [edit] to clarify – FreeMan May 03 '21 at 18:15
  • Related – Pondlife May 04 '21 at 01:09

1 Answers1

4

The Cessna 172S has more power (180hp vs 160hp for 172R) and higher MTOW (2550lb vs 2400lb for 172R).

This means that folks used to rotating at 55 knots IAS in earlier models would be closer to stall if taking off "clean". Another way of doing it would be to add 5 knots and rotate clean at 60 knots.

Vx is also a bit higher in the 172S at 62 knots IAS.

Vy is at 74 knots and Vbg is still at 65 knots, indicating few changes aerodynamicly, just a bit more weight requiring more airspeed to generate adequate lift, or flaps can be added to increase lift coefficient at a lower airspeed.

Robert DiGiovanni
  • 20,216
  • 2
  • 24
  • 73