@SLFY:
Not sure if you are interpreting this graph correctly. When I look at your graph I would get the impression that when I compare two approach configurations, let's say Flaps 35 and 25, then you see that at VREF the CL for Flaps 25 is around 1.4 ish and the one for F35 is maybe 1.55 while the L/D ratio decreases from almost 10.8 down to 7.8. Seems like a lot more drag to me...
During the good-ol' days hauling the 737-200s around, I remember that on a medium-heavy landing weight, the required fuel flow on approach for Flaps 40 was around 3500 lbs/h per engine compared to around 3000 lbs/h by using Flaps 30. The difference in VREF was only 3 knots. Just an example... (Sorry, I forgot about the EPR, use the fuel flow as an indicator how much Thrust is required to overcome drag
)
And like Mmmayday38 pointed out in his good post earlier:
“The action of reducing the flap setting was prompt and resulted in a reduction of the aerodynamic drag, with minimal effect on the aircraft stall speed; it moved the point of initial ground contact about 50m towards the runway threshold. Had the flaps remained at flap 30, the touchdown would have been just before the ILS antenna, but still within the airfield boundary. The effects of contact with the ILS antenna are unknown but such contact would probably have led to more substantial structural damage to the aircraft.”
I think that sums it up rather nicely
I say, well done Mmmayday38!
