Yeah that would work great in ATL on 26R or 8L which downlopes right in the middle and a Vapp of 150kts some days.

Thanks, it is true. There is also a safety aspect to the use of autobrakes. At cold temperatures the carbon brakes are like sheets of untreated glass, they slide right over each other. Heat helps the materials grip each other.

I try to remember to let the First Officers taxi on a cold morning, just to see how little braking force is available with cold brakes. On the 321 a pilot can pretty much go to the floor and get a smooth stop. It is good for a pilot to know and realize, especially when we want to taxi to, but not past, a hold short line.

I can't remember from my bus days, but are there no concerns with slow speed reverse wrt FOD? I guess going off the prepared surfaces causes more fod issues lol. We just got a notice about slow speed reverse causing tail stress issues. As we approach cold weather season, I'm reminded that I'll dang near come to a complete stop before making some turn offs with the 717, she's likes to slide a bit.



Notice a bunch of people on the 717 FB page talking about how they're actually liking them. It will be interesting to see if how the brake wear goes with this. I did one a few months ago as directed by a checklist. Didn't notice a big deal with them, got off at the same taxiway I expected and brakes temps were standard.

The 737 could save a lot of fuel if we just bolted the flight spoilers down.

When I fly to MEX, I pretend it’s all water underneath between JFK and MEX. So totally the same as BCN or MAD. Ha!

Then you would lose that additional 300 fpm LOL.

This is the latest emphasis item and a quick way to get hot brakes (on the ER at least.) We paid for autobrakes, use them.

I try to leave them on until we are close to the turn off. No hot brakes even with idle reverse.

I did my first flaps 25 landing in 717 a few days ago. Captain did his first on his leg as well. Both landings were some of the smoothest we had in some time. Maybe because we were trying so hard to not screw it up?

As for brake wear... VAPP is not much higher than flaps 40. There's not THAT much extra energy to dissapate before a turnoff. That said, I do think the biggest difference in braking required comes down to how much longer it takes to get the nosewheel down (thus reversers deployed). The higher pitch attitude does require an extra second or 2 before the nosewheel comes down without slamming it down.

140 knots at 90,000 lbs (making numbers up, feel free to insert real ones but convert to SI units) =
105,813,216 joules.

145 knots at 90,000 lbs = 113,562,811 joules

A 5 knot increase in speed in this example is a 7.3% increase in kinetic energy to dissipate. The speeds are the most important thing. Even assuming a mass of 1 kg, a 3.6% increase in speed increases energy 7.3%.

Can you run the numbers again using an additional 2 second delay to thrust reverser deployment over a set stopping distance? That's more to the the point I was trying to make.

Thrust reverser effectiveness increases at higher speeds. Deployment of TR in the 717 depends on nose-wheel touchdown, which takes longer at Flaps 25 vs Flaps 40. I think that the delay of TR deployment may have equal or greater impact on stopping distance than the higher approach speed.