Vietnam B789 at Munich on Aug 15th 2026, late rotation, tailstrike, runway overrun, tyre damage

[BobDDuck]

So I've been out of the big-plane game for a while now (11+ years?!? That long?!? Oye!) but I guess most of the big jet operators don't have any sort of acceleration check or similar? Back in the day (apparently WAY back in the day) if Freddy was heavy enough (or runway short enough) and we had to do a standing take-off, we would calculate a acceleration check. Basically after XX seconds after brake release you needed to be at XXX airspeed or well, RTO.

This was used in addition to the normal V1/V2 and all, but a good way to make sure you were going fast enough. I know this was the way with the legacy (TF-39) jets but I don't remember if it carried over the the CF6s.

We don't have one as policy, other than the normal Airbus 100 knots callout (for verifying all three speed tapes are about the same). I've got a series of rough estimates in my head based on weight and FLEX temp for time to reach 80 knots.

 

[///AMG]

So I've been out of the big-plane game for a while now (11+ years?!? That long?!? Oye!) but I guess most of the big jet operators don't have any sort of acceleration check or similar? Back in the day (apparently WAY back in the day) if Freddy was heavy enough (or runway short enough) and we had to do a standing take-off, we would calculate a acceleration check. Basically after XX seconds after brake release you needed to be at XXX airspeed or well, RTO.

This was used in addition to the normal V1/V2 and all, but a good way to make sure you were going fast enough. I know this was the way with the legacy (TF-39) jets but I don't remember if it carried over the the CF6s.

Last time I remember doing an accel check was in the T-45 in flight school. I think it was a set distance, and the calculation was the speed you should be at the corresponding distance marker. Haven't seen it since though

 

[DE727UPS]

It's that something. Such a simple thing to check speed at a given point. Never heard of it before. Not a bad idea and not a hard thing to figure out.

 

[Cherokee_Cruiser]

On the 737 about 80% of the time you’ll hit 80 kts passing the 1000 ft white paint markers. Definitely by 1,500 ft marker.



General rule of thumb applies. 2/3 of rotation speed by half way down the runway. Eg, 165 knot rotation. You should be 110 knots at least by half way down the runway.

 

[MikeD]

Last time I remember doing an accel check was in the T-45 in flight school. I think it was a set distance, and the calculation was the speed you should be at the corresponding distance marker. Haven't seen it since though

It's that something. Such a simple thing to check speed at a given point. Never heard of it before. Not a bad idea and not a hard thing to figure out.

we had it in the T-38, A-10 and F-117. in the two former ones, it was a chart we manually ran during preflight planning prior to brief. in the latter, it was a computer program output.

In the takeoff data section of the card below. below, it shows as ACS, or Accel Check Speed. Along with rotation speed, takeoff/liftoff speed. single engine, T/O distance, and max abort speeds.

 

[///AMG]

we had it in the T-38, A-10 and F-117. in the two former ones, it was a chart we manually ran during preflight planning prior to brief. in the latter, it was a computer program output.

In the takeoff data section of the card below. below, it shows as ACS, or Accel Check Speed. Along with rotation speed, takeoff/liftoff speed. single engine, T/O distance, and max abort speeds.

View attachment 90591

Hah those are some legit rotation/TO numbers. Makes sense given the apparent aerodynamics of the airplane, or lack thereof Also I think a line speed check for us really wouldn't make sense, normal takeoff is like a 1800-2000' TOD/roll. Rather than almost 7000! I think maybe the longest I've seen it, with a bunch of bombs in Fallon at high elevation on a hot day, was perhaps 3500-4000'? But our low speed/high speed cutoff used to be 100 knots. It has more recently evolved to "airspeed alive" which is right around 50 knots. By then, you have traveled like 12 feet down the runway