DHL B737 Rochester, NY

[bafanguy]

Need a bit more detail on this one:

"...it rolled off the runway as it was preparing to take off."

https://www.whec.com/rochester-new-york-news/fire-crews-737-off-the-runway-at-rochester-airport/5751801/?cat=565

[Banana Joe]

I would not be surprised if the engines were not stabilised before pressing TOGA. I've seen some huge stagger and very different spool up times on the Classic in the last two years.

[Airbubba]

On the tower tape one of the pilots seems to say something like 'when we put full power on it, it veered to the left, we tried to stop it but we couldn't.'

Later Connie 822 asks if they want the engines shut down when the fire crew approaches. :confused:

The tower asks what happened at about 13:23 into this LiveATC.net clip:

http://archive-server.liveatc.net/kroc/KROC-Twr-Jun-05-2020-1300Z.mp3

As always, the time scale on these .mp3 clips sometimes seems to be different on other browsers and devices.

[Pistonprop]

A similar kind of incident. Not saying this is what happened here though.

https://aviation-safety.net/database/record.php?id=20171111-0

[lederhosen]

A very instructive sim exercise I remember involved low speed engine failure. Particularly with a slippery runway the lack of rudder effectiveness could make it tricky. But my company had at least one example of someone experienced pressing TOGA while still turning to line up and ending up on the grass. Some of our 737s also had a noticeable lag on one engine in the early spool up. It is a bit like ground looping a taildragger. You can't imagine it happening but once you get beyond a certain point you are just along for the ride. This one has either sunk in a long way or done some serious damage to the gear.

[Herod]

My guess is Banana Joe is right. I've seen it done more than once, thankfully without the dramatic exit. Apply a chunk of power gradually, then when it's plain both engines are spooling up, select TOGA.

[safetypee]

The link below covers some of the safety issues re setting takeoff thrust.

Although not Boeing specific, much of aviation knowledge is generic, to be interpreted, remembered, and recalled. Yet many reoccurring incidents suggest that this is not happening; why, why don't we learn.
Waiting for the SOP, no time for reading, lazy, someone else will remind you, complacent, no safety app, …

…https://www.airbus.com/content/dam/corporate-topics/publications/safety-first/Airbus-Safety-first-magazine-27.pdf Page 8

An SOP for learning ?

[DOVES]

It's as simple as that: 'Below Vmcg ther's no way to maintain directional control. Only reducing thrust on the symmetric engine, or simpler "STOP TAKE OFF"!

[B2N2]

I’ve been yelled at (more then once ) for using asymmetric power when turning onto the runway especially in combination of already being cleared for (immediate) take off.
Uneven spool up after TOGA.
Rochester NY is a right turn to line up on RWY22 if they came from the cargo apron.


https://cimg5.ibsrv.net/gimg/pprune.org-vbulletin/805x1237/image_7c8c2f183e435e6484d81498dc437a1f72a2a730.png

[Airbubba]

Excellent video from the ROC Firefighters Association with ATC and ARFF audio and pictures of the aircraft in the weeds. :ok:

Kalitta Charters II, radio callsign 'Dragster 822'. Connie Kalitta raced NHRA Top Fuel dragsters for over four decades and lost his son Scott to the sport in 2008.

https://youtu.be/q1WvtG3jFus

[OldLurker]

If you'll forgive an ignorant question from an amateur: as Airbubba mentions up there, the pilots apparently didn't shut down engines until several minutes after they stopped in the mud (in the video they talk about that at about 4 minutes in, and the video starts only after the incident has happened and someone's run out to the fence with camera). Why would that be? I'd have thought that after the "oh sh*t" moment, since they weren't about to go anywhere under engine power, they'd have shut down right away, leaving only the APU running (or starting it) if they needed it, which they also talk about on the radio. Or might they have been sitting there thinking "maybe we can power back onto the concrete"?

[lomapaseo]

It's as simple as that: 'Below Vmcg ther's no way to maintain directional control. Only reducing thrust on the symmetric engine, or simpler "STOP TAKE OFF"!

Yea and if the problem is that the engine on the other side is stuck at high power, lots of luck unless you chop the fuel quick enough. (very rare event)

[Australopithecus]

The picture of the nosegear in Airbubba’s linked video shows it at full right deflection, although it was plowing up dirt instead of influencing the trajectory much. I seem to recall the classic 737s defining feature was throttle stagger and different spool up times-but my airline used to replace one brand new engine with a high time one on aircraft as they were delivered.