Damn, they almost made it. Not sure if flight was sustainable, but they were off the ground. When the former MD-11 pilot that Mentour Pilot interviewed yesterday said that V1 at MTOW would be approaching 180 kt, I thought no way. But looking at it from this angle, they were flying. It would be good to know if the flaps and slats remained deployed on the left wing, but can’t tell in the video.
Juan Browne talks about signs of compressor stalls to the center engine, in this video.
It sure looks like it’s being affected.
And if so, they never stood a chance…
Flaps/slats won’t run back due to hydraulic failure or a engine loss. They are on spindles that can be moved by hydraulic motors or by electric motors depending on control mode and aircraft design.
Sorry but that is very unlikely. V2, yes, perfectly plausible. For those who may not know (not you @chipwich), a primer:
V1 = Decision speed. Beyond this speed the Captain is committed to go. V1 is always =/<…
…Vr = Rotation speed.
V2 = Safety speed. This is the minimum climb speed after an engine failure. Usually 15-20 below maneuvering speed for the takeoff flap setting.
Even for a given weight, V1 varies wildly depending on runway condition (length/wet/dry) and airline policy. It isn’t unusual for it to be 30 knots below rotation. But also not unusual for it to be = to rotation.
I just watched the NTSB second briefing and they saidmthe ADB data said max speed achieved was 184.
So I can see VR at 180
You’re right. I went back and listened to the video. Petter asked the question about VR and I thought that they were talking about decision speed.
"I have never noticed any particular issues in terms of trying to maintain directional control during takeoff as long as of course you had your air speed you know in the V V2 region if you start getting slow just like any airplane it starts creating problems.
Yeah. Yeah. So the obviously we don’t know any air speed data so far. Um the apply radar24 is mentioning 186 knots of ground speed and we don’t know what the the winds are. But what what was a typical um a typical rotation speed um on this thing when it’s fully loaded?
It’s well in this case it’s going to be pretty heavy. So you’re looking at you know something over you know I’m just trying to go by memory. It’s been a been a while. I remember the approach speed and that you know max landing weight is 167 knots. Okay. So, you’re looking at uh pretty high speeds. Um, and I don’t have a number on top of my head because I’ve been flying the flew the trip 7 most recently, which has a different set of numbers, of course, but it’s it’s high. It’s on the higher end of u, you know, approaching 200 knots, but does not exceed 204 because that is your tire limitation speed. So, it’s up there around 180ish for sure, depending on what’s going on."
I know I am belaboring the point. But a Vr of 180 is simply too fast to be plausible. To most people, the difference between 165 and 180 may seem like parsing digits to the right of a decimal. But it is important. When you rotate at, say, 165 it is true that you might hit 180 when you achieve the target pitch, depending on how aggressive is your pull. But that settled-on actual Vr speed isn’t going to be 180. The max tire speed is 205. And that is ground-speed. Think Denver on a hot day. So generally, the manufacturers shoot for something south of 170 at max gross.
I’ll add a little story to paint a better picture. When I was young a lifetime ago I was a FO flying A320s out of Manchester. Several of our Captains were Bulgarian. These guys trained in the Soviet system. My favorite of them was Stefan Vlachkov. He learned to fly MiG-21s in Russia and later was president of Bul-ALPA, the Bulgarian airline pilot’s union. He was a traditional 50-something Soviet-bloc god-Captain who did his level best to be a western CRM-lovin’ teammate. But some things he simply could not abide. One was slow rotations. Me, a smooth 25yo FO showing off for his drop-dead lovely Irish gf in the back, would rotate so slowly that I’d hit 15-17° doing V2+30. Finally Stefan couldn’t take it anymore. “Ear-rick, why ees eet you rotate so sloowly theeyat you eat all you-ore fee-yerst segment climb eenergy? I want no more thee-yan V2+20.” That was more than 30 years ago and it is still my target. Unless I am super-light, if I hit target pitch doing more than V2+20, I consider myself to have screwed up.
Excellent post. Thank you. That was an informative read.
I can’t breathe!!
Stefan had a great point though.
Any aircraft will scoot through V2 on all engines.
But that doesn’t mean you should waste it on vanity.
Teaching practical performance is fun!
We so need a funny flying stories topic/thread.
Done!
NTSB briefing states aural alarm in the cockpit, 37s from take off thrust was called.
This may indicate that there was an engine fire warning and that the fire started in the engine, before the pylon sheared off the wing.
Couldn’t the fire warning be BECAUSE of the detachment? There are loops in the core and pylon (usually). So if that loop is destroyed its last act might be to trigger the warning.
Not sure how the fire detect loops work on that type. Maybe @TheAlmightySnark can chime in here?
But as I understand it it’s either electrical by measuring resistance that decreases when heated. Not sure what happens if resistance is suddenly zero, as in ripped off…?
The other is pneumatic. Gas in a tube is heated and expands, triggering a switch. Again, what happens when the loop is broken? We get a loop fault indication. But again, how it works on other types probably varies.
It should just throw a LOOP A/B fault, depends a little on how MD implemented this but it’s pretty standard on all modern aircraft. The Loop Overheat/Fire Detection boxes are smart enough to recognize when it has lost all contact with the loops and channels. I don’t know how MD implements their stuff though but it is a semi-modern airliner for all it’s worth.
The fire warning could have come from heat/fire ingress into the pylon on detachment if it was on fire at that point, they also tend to have overheat/fire detection loops(anywhere where there’s a chance of combustibles or fire sources really).
So the FAA has released a Emergency Airworthiness Directive, but it doesn’t say much at all honestly. It’s 2025-23-51 in the EAD docket -
https://drs.faa.gov/browse/excelExternalWindow/DRSDOCID188588539020251108211920.0001
I seem to recall both the 73 and 320 would give you a fire warning if both loops failed within a certain time span, for very fast burning fires.
The MD’s are older of course.
It will be interesting to hear where this started…
You mean infinite. Otherwise it would be a superconductor 
Resistance to infinity or signal to zero, then.