Departing Saudia Cargo 747 'departs' runway

[Plumb Bob]

Maastricht-Aachen Airport, late Saturday evening, approx. 22:25 UTC.

A Saudia Cargo 747-428F(ER) bound for Jeddah has somehow left the paved surfaces during line-up or the beginning of the take-off run, and is now standing "in the grass", according to media sources and Flightradar24 imagery.
Airplane is TC-ACR, operating as SV / SVA916.

The source below suggests thrust asymmetry due to engine ‘failure’.
https://www.transport-online.nl/site/85998/vrachtvliegtuig-van-baan-geraakt-op-maastricht-aachen-airport-foto/

"The aircraft suffered engine failure then rejected takeoff, leading some of the wheels into the grass." (https://twitter.com/airlivenet)

[parabellum]

Engine failure below eighty knots can be quite a handful.

[TowerDog]

Depends where you are from. :sad:

[shortly2]

Yup, closing the thrust levers is so difficult.

[Airbubba]

Was this a Turkish MyCargo (formerly ACT Airlines) crew?

Does the B-744 have the gotcha on a low speed (below 85 knots) reject where the throttles come back up if you don't click the disconnect?

[lomapaseo]

has somehow left the paved surfaces during line-up or the beginning of the take-off run

How does this relate to the 85 kts in the discussion above? isn't the nose wheel dominant during line up?

[Coastrider26]

The N-1 or 2 take off can be quite tricky on the 744 especially at low speeds when you can end up 90 degrees of runway heading in a matter less than a second with the tiller being unable to correct this.
Having said this knowing the operator was the one who had a crash in Russia couple of months ago because the crew was far above the 3 degree glide maybe something might be wrong with the cockpit culture or training?

Yes it was the Turks Airbubba

[Start Fore]

Yes, there's a reason we stand the trust levers up to 1.20 or 45% to stabilise the engines before selecting TOGA.

You'll end up off the side one day if you don't.

Off course, there's always going to be clowns that don't follow Boeing advice...

[RAT 5]

Has the airport a B747 tug? I doubt it, but then again if there nose wheel is near the grass so will the tug be. What is happening about opening the runway?

[Basil]

Fortunately, never had it happen to me but have been warned of the dangers of a low speed engine failure. It is a genuine hazard.

[GS-Alpha]

I have had a low speed No1 failure in the simulator and it is tricky. The nose wheel is sliding before you know it. Closing the thrust levers and disconnecting the auto throttle; the engines still take a while to spool down plus by the time they have, you already have rotational inertia so it will keep going even with the differential thrust removed, the nosewheel has already lost traction so is doing little to counteract the spin. Differential braking would help, but a normal RTO uses auto brakes which you would disengage by applying foot braking, so that is not your first immediate reaction. By the time you have processed what is happening and that you require manual braking, you are already headed for the side of the runway. If you were quick enough on the brakes and moving slowly enough when the problem first occurred, you will stop before leaving the paved surface, but I can imagine there is a 'sweet spot' where you would not stand a chance of avoiding it in the real world.

[Hotel Tango]

Just for the record, it was an engine failure at take off thrust. Nothing to do with the line-up.

Airport will be closed until tomorrow morning at the very least.

[Sailvi767]

Autobrakes are not generally a factor in a low speed abort since they have not armed. Differential braking is immediately available.

[LeadSled]

Folks,
Believe me ( I have quite a few thousand hours on them) a -744 engine failure with thrust set, and around 80/90 knots (way below Vmcg) is the hardest to keep off the grass.

Particularly a RR 524 powered, the thrust wind-down seems faster than GE in a flame out.

The moment your sense the failure, it is THRUST OFF, BRAKES ON in that order -- then speedbrakes etc. ---- and you will probably wind up using some differential brake at the expense of stopping distance, to stay on the runway. You have one, maybe two seconds to get the asymmetric thrust off.

FAA have a study ( probably more than one) of engine failures on takeoff, for you doubters, makes interesting reading. For an embarrassingly large number of aborts due to engine failure, runway length to stop is not a big issue, because the aircraft will go off the side due loss of directional control.

Some of the posts suggest it is just a "walk in the park" but that is just where you might finish up --- out in the green stuff, any of you who think you are fireproof could not be on the actual aircraft --- except as self-loading freight.

[b1lanc]

Interesting that initial reports suggest deployment of thrust reversers.

[ironbutt57]

Yup, closing the thrust levers is so difficult.



try it in the sim sometime

[Liffy 1M]

Photo here: https://flic.kr/p/21nmAFE

[golfyankeesierra]

Folks,
Believe me ( I have quite a few thousand hours on them) a -744 engine failure with thrust set, and around 80/90 knots (way below Vmcg) is the hardest to keep off the grass
Absolutely, and that is at normal (high) gross weights already the case.

Then at low weights, full thrust and wet runway it is almost impossible to keep it on the runway even when thrustlevers are closed right away. Only heavy asymmetric braking might prevent an offroad excursion...
In this aspect 4 engined plane is more critical then 2 engined.
(of course this applies to outboard engine only)

So don't blame the Turkish this time..

[cappt]

Yup, closing the thrust levers is so difficult.

How many hours do you have in the Whale?

[gearlever]

In this aspect B747 is more critical then all other aircraft.
(of course this applies to outboard engine only)

Try an empty A300 or similar....

[Coastrider26]

Compared to an A330 which I guess is the closest you can get to an A300 is a ride in the park compared to a 744 under similair low speed condtions

[golfyankeesierra]

I flew both 744 and 330 and stand by my comment..

[fox niner]

I see all four thrust reversers deployed on the photograph above.

[procede]

Maybe an A380 could be more difficult as the outer engines are further away from the CoG?

[golfyankeesierra]

Sorry, could well be true, probably similarly (or more) challenging, have no idea and wasn't out for a contest.
Was a bit annoyed by the armchair pilots criticizing a crew without having any idea and thinking that just cutting the power is enough to keep it on the runway :ugh:

[Intruder]

I see all four thrust reversers deployed on the photograph above.
That could be a possible complexifier...

Thrust levers back and up to the reverse idle detent is one way to ensure the autothrottles are disengaged during a low-speed reject. HOWEVER, if all 4 throttles are brought to full reverse, they can take you off the runway almost as quickly! Been there, done that in the sim...

Our training center has enforced several different routines over the past 20 years. Currently, they want to see thumb squarely on the autothrottle disconnect lever until the "80 knots, thrust set" call. Personally, that takes my other fingers higher up on the thrust levers, with an increased probability of my pinkie slipping off #4. That could be a REAL problem when #1 fails...

[Plumb Bob]

Everybody thanks for your interesting contributions.

Based on two images on the AvHerald page Incident: MyCargo B744 at Maastricht on Nov 11th 2017, runway excursion on takeoff (http://avherald.com/h?article=4b0ed972) for this incident, one by Jan Severijns with a shallow peaked-roof hanger in the background and beyond it a very conspicuous antenna tower, and the image by Jeroen Stroes on that same page with the very dark brown ‘Koninklijke Marechaussee - Brigade Limburg Zuid’ office building visible under the side view of the tailplane (with the elevator hinge line pointing to the office complex), as well as an earlier nighttime photo in which the GS antenna for runway 21 is visible in the foreground https://pbs.twimg.com/media/DOY2K42W4AAJU03.jpg, my (plumb bob) finding on Google Earth is that the a/c heading is almost exactly 45 degrees veered to the right of the runway heading. And it looks as if the tail and the LH wingtip are still just over or just clear of the runway shoulder.

My resulting plot differs considerably (closer to the beginning of the runway) from Simon’s on AvHerald, but he came first, with a position, so he left the heading for me).

Been flying and seen flying close to runway edges more than once :-)

[mrdeux]

I've flown both the 747 and the 380, and the low speed failure of an outboard engine will have you on the grass in seconds. Not an easy failure by any means.

[gearlever]

Okay, so I correct my comment about twins like A300.
The largest 4holer I have flown was A340 but as we all know it has only 4 hair dryers :)

[suninmyeyes]

At least it looks repairable unlike their tarmac excursion with a 747 many years ago, see below

http://i66.tinypic.com/2z5j6mg.jpg

[TowerDog]

I've flown both the 747 and the 380, and the low speed failure of an outboard engine will have you on the grass in seconds. Not an easy failure by any means.

Yeah, one has to be on one’s toes to say the least. :sad:
Back in my 747-200 Days we practiced numerous low speed engine failures as part of the 3 engine ferry simulator training. With 2 out on the same side things got interesting really fast when slow.
To Hell in a hand basket as the Yanks would say..:ooh:

[Anilv]

That Saudia 743 with its nose in the drain was not during take-off or landing. It was being taxied out of a engine run pen and IIRC they did not have hydraulics fully on line, hence no steering or brakes.

[Hotel Tango]

The aircraft (from the MST incident) was recovered last night. Airport back to normal ops since 11:00 UTC today.

[zerozero]

Nothing to add, except what an FE told me as a new hire FO on the 747, 13 years ago: The nose wheel is basically there for decoration. All the weight is borne by the main gear, so they act like a pivot during low speed engine failure.

[suninmyeyes]

When I did my 747 classic course in a previous century I was taught that the typical weight on the 747 nosewheels was between 5 and 12 tonnes. When the 747-400 came out they had considered moving it to have a bit more weight on it but that would have made it a new aircraft design and certification would have taken for ever.

So here's a question for you. if the designers wanted more weight on the nosewheel would they move it backwards or forwards? A lot of people think the answer is forwards....

[The Ancient Geek]

Consider a simple [1] child's seesaw.
The balance point is the main gear axle, the nosewheel is balanced by the weight of the tail. Moving the nosewheel forward will give it more leverage and therefore lighter.

[1] The seesaw not the child.

[Flingwing47]

That Saudia 743 with its nose in the drain was not during take-off or landing. It was being taxied out of a engine run pen and IIRC they did not have hydraulics fully on line, hence no steering or brakes.

Yep, maintenance guy taxied it out of the gate with unqualified helper in FE seat.
Declined help of tech crew sitting in the upper deck.
Taxied at warp speed - without Hyd for brakes/steering.
Sad end to a great aircraft just out of overhaul AIO

[H Peacock]

Now if you did move the nose-leg rearward you would indeed get a greater vertical load going through it, but at the same time you are increasing the sideways load from the assymetric engine thrust and so it would be more likely to skid sideways allowing the aircraft to yaw!

[G-CPTN]

So here's a question for you. if the designers wanted more weight on the nosewheel would they move it backwards or forwards? A lot of people think the answer is forwards....

Neither - either move the main undercarriage or redistribute the weight / CofG so that more weight is loaded onto the nosewheel.

[Chu Chu]

Lots of current cars have stability control systems that automatically apply differential braking to prevent excessive "yaw." It doesn't seem like it would be technically difficult to install a version of that on an aircraft, perhaps set to be active only if there's an uncommanded thrust reduction on an outboard engine below 80 knots (or something like that). But I guess it's late in the 747 lifecycle.

[TowerDog]

I had the nosewheel on the 747-100/200 slide sideways across dry pavement many times, a lot less than 5-12 tons weight on it. Try 500 kilos if empty.
(Yes, we used center tank ballast fuel when flying empty but the nose still seemed very light, steering was best done with brakes and power.)

[B2N2]

Lots of current cars have stability control systems that automatically apply differential braking to prevent excessive "yaw." It doesn't seem like it would be technically difficult to install a version of that on an aircraft, perhaps set to be active only if there's an uncommanded thrust reduction on an outboard engine below 80 knots (or something like that). But I guess it's late in the 747 lifecycle.

You’re forgetting the closeness of the braked wheels to the centerline and the distance of the engines from same centerline.
74 engines produce in excess of 60,000lbs of thrust each.
That can not be corrected with differential braking.

[RatherBeFlying]

https://www.ntsb.gov/investigations/AccidentReports/Pages/AAR7212.aspx

[LeadSled]

Folks,
Various comments about the nose gear.
Believe me, in the situation under discussion, the ONLY contribution of the nose gear is to keep the nose off the ground. Nose gear steering is not going to contribute anything of significance to staying on the runway.
Indeed, depending on the weight and CofG, just doing a turn on a surface of normal friction, dead slow speed, can get interesting, with the usual muck and a bit of rain, work it out for yourself.
Use of differential brake, and a bit of thrust on the outboard, read Boeing's "recommendations" carefully, all is permitted that is not specifically prohibited.
Bottom line, "in the event", how fast you get the thrust levers hard back on the stops will determine the tenor of the discussion, when you next have a chat with the CP.

[fabvirgil]

I’m sorry, but there is so much rubbish being spoken here. Yes the classic B747 does have similarities to the B744, they both have a hump! But it’s the automatics the auto throttle system which needs to be understood.
Forget all the rubbish about nose wheel steering etc. Ignore the slippery runway, it was damp, possibly wet.

I have around 15000 hours on the B747, most of it as a skipper on the B744.

Yes this is a ‘rumour’ network, but come on. This is why Pprune is akin to the U.K. Daily Mail.

A low speed reject in a B744 is tricky, but we train for it.....every 6 months. If you can’t do it....don’t fly it.

But at the end of the day SOPs cover it, don’t have a go at Boeing, don’t insinuate design flaws. Don’t compare it to other aircraft, when you obviously don’t understand the systems. It’s nothing like the ‘classic’, I know I flew the classic for five years......twenty more on the 400 variant.

FACT 90 degrees off centreline at low speed, in the grass, is gross pilot error. Regardless of any report. Here ends the lesson.

[LeadSled]

fabvirgil,
You are not the only one posting here with a long and intimate acquaintance with the B747, all models. I don't really believe anybody was suggesting that Boeing got it wrong, just stating a few facts of life. There is nothing in any of my comments that is inconsistent with the AFM for any model.
Did you ever have a low speed abort with the thrust set?? In the real world, as opposed to the simulator?
Indeed, differing only in degree, the same thing could be said about any of the four-engine jets. One night in Tokyo, many years ago, I saw the results of a mishandled abort in a DC-8 --- the aircraft was a write-off.
Perhaps, despite your experience, reading the FAA study on real world aborts, or the Boeing studies on same, would be of real value.

[Meikleour]

I experienced an outer engine failure on a TOGA A340 departure at about 60 kts. It did indeed require differential braking to counter the very rapid and large swing away from the centreline of the runway. In my experience this scenario is not nearly carried out often enough in the sim.

[Start Fore]

I've been flying the 747-200/400/-8 for a legacy airline for two decades and I've NEVER practiced the above scenario in the sim.

I'll be asking to give it a go next time though...

[JammedStab]

Saw it once in the sim. Partial runway excursion. I suppose crosswind can make a big difference.

[ACJDriver]

I've been flying the 747-200/400/-8 for a legacy airline for two decades and I've NEVER practiced the above scenario in the sim.

I'll be asking to give it a go next time though...

I am surprised and you work for a legacy carrier in Hong Kong? For your next recurrent training, try a -400/-800 eng 1 or 4 low speed abort on a contaminated runway. Fun stuff...in the sim.

[parabellum]

Start Fore - Do you operate Cat2/3? If you do, once you have done a few 'ordinary' rejects get the SIM instructor to give you the failure using Reduced Visibility procedures so that you are monitoring the black and white 'barbers pole' on the coaming, it can become even more interesting!

[Start Fore]

I'll be giving that a go on the next sim session for sure.

[LeadSled]

Start Fore,
What you say does surprise me, because Boeing training material on the subject is quite extensive.

As parabellum quite rightly says, in 100M viz., it can get quite exciting.

In my company, which has also been around for quite a time, it makes regular random appearances in the cyclic training program.

Indeed, we always made the point that you don't get a "practice go" before an engine failure on takeoff on the line, so why should base or simulator training be any different.

I don't know what your company is like with "staff suggestions", but is does suggest a gap in the training that needs to be filled.

[Maisk Rotum]

Whilst the low speed RTO with an outboard engine failure would arguably be one of the most difficult manoeuvres in the -400, the other being an outer engine failure on the upwind side in a strong crosswind just as the gear is lifting off, nevertheless as long as the appropriate thrust for the weight and not some macho thrust has been set, it is easily done (with correct training) at just 30 or 40 kts and in RVRs where you can only count a few centerline lights. There may be a bigger issue here I suspect. They were not very succesful at completing an ILS with a servicable aircraft at Bishkek in January.

[RAT 5]

Not ever flown a 4-pot, is it more likely to have a bird strike in the outboard engines than the inners? If that is so, then surely practicing the more difficult and likely event is the proper use of simulators. Assuming you have performed the mandatory RTO training due to engine failure, that would suggest that many operators must choice the inboard engines. My question is why? Why not choose any engine and therefore cover all possibilities? Equally, why not train the difference a/c reaction to inboard/outboard engine failures and with left/right x-winds, and wet runways. There has to be a significant difference; having read the posts from the experienced crews. Surely the company has a strong interest in training its crews not to bend its high value assets when the poo hits the fan. Ticking boxes is not training. We've seen the consequence of that philosophy in real-life events.

Come on XAA's, review your remit over airline training.

[gearlever]

Engine failure?
Only Saudi says so in the aftermath of the incident.

Saudia Cargo's parent Company Saudi Arabian Airlines reported the aircraft suffered an engine problem causing the runway excursion while attempting to takeoff. There were no injuries and no damage.

The Dutch DSB reported they opened an investigation into the runway excursion of a cargo aircraft at Maastricht Airport.

On Nov 16th 2017 the DSB reported that the aircraft of ACT Airlines was accelerating for takeoff when the aircraft suddenly pulled to the right, the crew could not correct, the aircraft exited the runway and came to a stop in the grass. The 4 crew remained uninjured, the aircraft sustained damage. The cargo and fuel were unloaded, then the aircraft was recovered and moved back onto paved surface. The investigation is ongoing with the assistance from Turkish, American and British accident investigation authorities.
AvHerald

[Meikleour]

RAT 5 (http://www.pprune.org/members/17662-rat-5): 4 engine check rides in the sim and on the aircraft (when we used to do it) always require the most limiting condition to be used ie. an outer engine.

The whole point of this thread is to highlight the condition where directional authority is poor prior to Vmcg and to point out how nasty a seemingly low speed event can be.

[Hotel Tango]

Engine failure?
Only Saudi says so in the aftermath of the incident.

:= No, it was reported as such on the r/t to ATC. I have no idea what the nationalities of the crew were (they are quite mixed at ACT) but quite likely not Saudi.

[Dan Winterland]

If it happened over 20 knots, then the body gear steering would not be operative on the 744. In slippery conditions, the nose-wheel does very little to help you steer.

[JammedStab]

Maybe that's why its starts to skid if turning too quickly into the gate more often than the triple.

[Callsign Kilo]

People without 4 holer time should probably lay off the analysis. Even a two engined jet, below VMCG will bite. Think aft CG, wet runway, high thrust rating, crosswind then engine failure. Add in startle factor and the potential to mishandle = grass. It’s been done before. Probably a manoeuvre not practiced enough in the simulator.

[Hotel Tango]

The latest info is that the a/c has been declared as not airworthy and will be in need of repair sur place.

[golfyankeesierra]

What Kilo says, the whole point of a low speed RTO is the startle and surprise effect. If you know it’s coming, it’s no big deal. Once in a while when you don’t expect it the instructor should throw in one and you’ll never forget.
Asking for one in your next session is nice but won’t be the same.

[Start Fore]

I'll be asking for one in my next sim session.

As I mentioned earlier, I've been flying the 747 for two decades and now a Captain, and have NEVER been given this scenario in the sim, bizarrely.

As an added bonus I'll be putting the clipboard over the upper EICAS before I start the take off roll so I can't cheat like I usually do, by watching which engine rolls back.

Also, I'll delay my RTO for about 3 seconds to simulate the startle/identification factor..

All in 100m viz.

Wish me luck!

[zerozero]

Good for you!
But it will all be over in less than 3 secs.
;)

[Hotel Tango]

Marking indicating the damaged area of the aircraft concerned.

http://imagizer.imageshack.us/v2/xq90/924/5M5pjN.jpg (https://imageshack.com/i/po5M5pjNj)

[Hotel Tango]

Aircraft still at Maastricht and now undergoing repairs.

https://imagizer.imageshack.com/v2/640x480q90/924/pOAl8Y.jpg (https://imageshack.com/i/popOAl8Yj)