Optimum flaps for takeoff
 

Hey all

Wondering what individual airlines like southwest/ Ryanair/ Turkish etc are using for take off flaps. Fixed or optimum?

Virtually every airline would use optimum as an SOP now, The performance data for most companies is set to exclude F1 for -800/900.

The vast majority of our take offs are flaps 1, on the -800. That's what "Optimum" often spits out. On shorter runways in suggests higher settings to allow higher ATM.

Application calculates the best scenario, and optimum flaps are being used in most of the cases, even though , if compare fuel used Flaps1 nad Flaps 5 TKOF on NG the difference reaches 80kg accordingly. For specific scenarios or airport you can choose fixed flaps ....

Optimum flaps often requires higher takeoff speeds; therefore higher tyre speeds. Higher VR speeds than necessary increase the chances of tyre failure. High speed tyre failure on limiting runway length increase the chances of an over-run if the pilot decides for whatever the reason to abort the take of run. Especially as loss of braking efficiency will occur with tyre failure. No brainer for the safety conscious pilot especially if runway wet

Incident: Alitalia Cityliner E175 at Rome on Sep 15th 2018, burst both right main tyres on departure

what happened to these tyres?

Fair enough question. The answer is not off the top of my head. The evidence comes from my recollection of reading numerous incident and accident reports over the many years I have been flying aeroplanes big and small. Some of these included tyre failure incidents. One recommendation by McDonnell Douglas does stick in my mind, however.
That is, do not abort for a tyre failure if the failure occurs at speeds more than V1 minus 20 knots. Loss of braking efficiency means V1 as a decision speed becomes invalid. MD would not have issued that warning unless there was evidence that tyre failures at high speed have happened. MD did not supply individual details.

MD could've issued the warning as it is proven much safer to continue a departure and land (normally) with a tyre missing instead of a executing a (rare) high speed RTO. Crew familiarisation comes into play here as well as recognition and non-eventful execution of an RTO.

My company has dabbled with the fixed versus Optimum Flap for A330/340 fleet for some time. Tail strike avoidance was one reason given by the fixed flap fans. At the end of the day, it's all just silly really. The manufacturer wouldn't have called it optimum if it wasn't that. Train your pilots properly and use Optimum Flap. In the 2 yrs since moving back to Opt Flap, we haven't seen any tail strikes, or increased tire failures for that matter.