A fly different 172 models and some of them are ambiguous with respect to using flaps for short field takeoffs. Some have no flaps in the checklist, but suggest you get better performance if you add 10° flaps for both the ground roll and 50ft obstacle.
In general, having 10° flaps, reduces the ground roll, but increases the takeoff distance over a 50ft obstacle. No flaps, increased ground roll, shorter takeoff dsitance over 50ft obstacle.
This is not always the case depending on the model, and sometimes, it's written in abiguous language.
172N I would use 10° flaps unless high density altitude. Ground roll and 50ft obstacle reduce. Weirdly, the actual procedure says to use flaps up?????
>Use of 10° flaps allows safe use of approximately 5 KIAS lower takeoff speeds than with flaps up. The lower speeds result in shortening takeoff distances up to approximately 10%. However, this advantage is lost if flaps up speeds are used, or in high altitude takeoffs at maximum weight where climb performance would be marginal with 10° flaps.
172L no flaps if obstacle. 10° if no obstacle. Ground roll reduced and 50ft obstacle increased. The Checklist says no flaps???
>The use of 10* flaps will shorten the ground run approximately 10%, but this advantage is lost in the climb to a 50-foot obstacle.
172P I would use 10°. Ground roll and 50ft obstacle reduced
>Using 10° wing flaps reduces the ground roll and total distance over an obstacle
172S I would use 10° flaps. Ground roll and 50ft obstacle reduced
>Using 10° wing flaps reduces
the ground roll and total distance over an obstacle by approximately 10 percent.
What do you guys do? Sometimes the checklist and the amplified procedure contradict each other where the amplified procedures suggests that you get better performance if you use flaps for both takeoff roll and 50ft obstacle. My school has multiple models. Do I just have the student learn short field flaps settings for each plane? That's way too much in my opinion for a student pilot!
