B744F off the runway in YHZ

[STN Ramp Rat]

https://www.cbc.ca/news/canada/nova-scotia/halifax-airport-landing-747-1.4895103

Apparently its N908AR of Skylease Cargo, Great news no one is injured but the aircraft is clearly dead.

[India Four Two]

Try this:
https://www.cbc.ca/news/canada/nova-scotia/halifax-airport-landing-747-1.4895103

[Mudman]

Some clear photos here.
747 Runway Excursion YHZ

[AJW709]

https://twitter.com/natashapace/status/1060144723816525824?s=21

[gulliBell]

...but the aircraft is clearly dead.

Yep, clearly. It's back is broken, just behind the wings. It has a date with the wrecking ball and shredder.

[twochai]

Heheh! Should be cheap lobster in Toronto this weekend! There's always a silver lining in these things.

[TowerDog]

Take off or landing?
This may also break the back of the company, they are running on fumes financially.

[SigWit]

Take off or landing?
This may also break the back of the company, they are running on fumes financially.

Landing.

And yes, it probably ends the company as well...

[TylerMonkey]

Landed on rnwy 14.
2347 meters long.

[reverserunlocked]

Landing.

And yes, it probably ends the company as well...

Sad end to a Queen and even sadder for it spell the end of the whole airline. It must focus the mind somewhat if you’re flying for a carrier with only a couple of aircraft that even a minor prang rendering the aircraft U/S for a period of time might be enough to put the whole company under.

[The Ancient Geek]

Thats why you have insurance.

[TowerDog]

Sad end to a Queen and even sadder for it spell the end of the whole airline. It must focus the mind somewhat if you’re flying for a carrier with only a couple of aircraft that even a minor prang rendering the aircraft U/S for a period of time might be enough to put the whole company under.

They have already been under: Tradeiwnds Airlines went Tango Uniform in 2008 with all pilots furloughed.
Then from the ashes rose SkyLease 1 and only pilots who were not “Troublemakers” were recalled.
That would include those who were active in organization a union, including Yours Truly.
SkyLease have been struggling lately with pilot’s pay checks been missing in action or a few weeks late, as well as problems paying for fuel, cash only in some instances.
This incidence were unfortunate, but they all are.
Tailwind Landing.....What else, heavy rain, hydro planning, lost all brakes and all reverse, not on speed?

[Mudman]

View from the air...

View from the air

[Mudman]

A couple of recent pics I took of the aircraft departing YHZ in October.



https://cimg0.ibsrv.net/gimg/pprune.org-vbulletin/1200x800/drawsqdwkaam5ll_635398999866538fa1390ad06b74c21ca45ae93d.jpg

https://cimg7.ibsrv.net/gimg/pprune.org-vbulletin/1199x662/drawsqfwsaiojbx_f2c988394650ee79482692595adb744e9e3263c9.jpg

[SKORR4]

Anyone know why they chose the short runway at Halifax?

[hailstone]

why is it being reported as a "Chinese SkyLease Cargo 747", when it has an "N" Registration ? Are Skylease chinese owned ?

[Good Business Sense]

Landed on rnwy 14.
2347 meters long.

Short and worth paying good attention on a good day even if light ..... never mind with a good tailwind. 6000 and a bit feet after the touchdown zone !

[Airbubba]

ATC transcript and comments from JACDEC.com :

GG 4854: „Halifax Tower, ay.. good evening SkyCube 4854 heavy, for the ILS 14.“

Tower: „SkyCube 4854 heavy, Halifax Tower Good evening runway 14, wind 260 at 15 (knots), altimeter 2967 information Tango, number one.“

GG 4854: „Roger that, we have it..“

…

Tower: „SkyCube 4854, tailwind now 280 at 16 confirm gusting 21, confirm runway 14 still acceptable ?“

GG 4854: „Confirm..ah, still for 14.“

Tower: „SkyCube 4854 heavy, tower roger, wind 260 at 16 gusting 21 cleared to land on 14.“

GG 4854: „Cleared to land..ah.. affir..clear to land on 14, SkyCube 4854 heavy“

Tower: „Roger.“

…

Tower: „SkyCube 4854 do you read ?“

GG 4854: „Halifax Tower, SkyCube 5854 is off the runway. Requesting full emergency assistance.“

Tower: „SkyCube 4854 Roger, emergency has been activated.“

At about 04:40L, about 30 minutes before the accident landing, Cargojet B757F (CJT626) landed on runway 14.
At about 04:50L, about 25 minutes before the accident landing, Morningstar (FDX) B757F (MAL8062) landed on runway 23.
At about 04:52L, about 23 minutes before the accident landing, a Learjet 35A landed on runway 23.

2018-11-07 Sky Lease Cargo B747-400F overrun at Halifax Airport » JACDEC (http://www.jacdec.de/2018/11/07/2018-11-07-sky-lease-cargo-b747-400f-overrun-at-halifax-airport/)

[The Ancient Geek]

Is there a good reason for selecting runway 14 ?.
Do both runways have, for example, a working ILS ?

[CanadianAirbusPilot]

Runway 14 and 23 have an ILS. Runway 23 however has been notamed u/s due construction. Ceiling and vis seemed okay for a NPA if they wanted to land into wind (if they had GPS). Without GPS there is no approach onto 32, only place I have circled in a transport category jet aircraft close to minimums.

[Airbubba]

Is there a good reason for selecting runway 14 ?.
Do both runways have, for example, a working ILS ?

ILS 14 was working until the plane took out the localizer on the upwind end.

ILS 23 was previously Notam'ed out of service:

YHZ 11/021 YHZ CYHZ ILS 23 U/S 1811062155-1811082100

[DaveReidUK]

why is it being reported as a "Chinese SkyLease Cargo 747", when it has an "N" Registration ? Are Skylease chinese owned ?

No obvious Chinese connection AFAIK.

[MELDreamer]

No obvious Chinese connection AFAIK.
Apparently from Sept2018 it had ""Having Fish Every Year" in large Chinese titles on its left side. Maybe that's where the impression of Chinese ownership came from.
Boeing 747-412F - Sky Lease Cargo Aviation Photo #5272303 Airliners.net (http://www.airliners.net/photo/Sky-Lease-Cargo/Boeing-747-412F/5272303/L)
According to FR24 in the last seven days it has operated twice from Halifax to Changsha via Anchorage and return via ANC and ORD. Maybe earlier history would indicate a longterm regular contract to Changsha perhaps carrying fish?

[no expert]

No obvious Chinese connection AFAIK.

From a Halifax Stanfield Airport press release dated August of this year:

"First Catch, a Chinese-owned seafood freight forwarding company based at Halifax Stanfield, is currently offering two flights per week from Halifax to Changsha, the capital of Hunan province. The flights are operated by SkyLease Cargo utilizing a Boeing 747-400 freighter aircraft, which has the capacity to carry up to 120 tonnes of Nova Scotia seafood to China."

[TowerDog]

Yeah, China contract but the airplanes and crews are based in MIA at the corrosion corner of the airport.
A lot of the experienced pilots have left causing a brain drain.

[Mudman]

Took some photos on the way home from work.
https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/2000x1081/img_8937_19fd9c3c40746ba9893f930b3a52f9119c140dbe.jpg
https://cimg7.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_8947_0122e251aec2f29b8c9d1424071d1e1aa7282ae3.jpg
https://cimg8.ibsrv.net/gimg/pprune.org-vbulletin/2000x1042/img_8934_d03c5b4fa6191ac0838a2ad62d0b9e15c797fbcb.jpg
https://cimg9.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_8998_8cf2b4c1d1e5ca6150f7f9040ffb57640b0a1b07.jpg
https://cimg0.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_8962_8352d76cee75cf282a9c2496525a51c667b52819.jpg
https://cimg2.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_8941_8a0e452d588886d4b3486071c1ad1beb5560f849.jpg
https://cimg3.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_8977_82068dac8fce5c881c7e8c55b8c6d04bb097ac66.jpg
https://cimg5.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_8955_1db39af1b14c2ca7ed86f0c3c4b6f52f3a7971f3.jpg
https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_8969_896bd08a7718e08da62b60ddd15a969720e50602.jpg
https://cimg7.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_8938_937decb6a78349593ff3200d36a50e37f70fd0d1.jpg

[TowerDog]

Sad ending to a great airplane.
Curious to why...

[Airbubba]

Took some photos on the way home from work.

Those weren't taken with an iPhone. Great pictures of a sad event.

Sad ending to a great airplane.
Curious to why...

I'm guessing that they didn't have GPS for the RNAV 23 as CanadianAirbusPilot said and thought they needed the ILS to get under the 500 broken layer on the 9Z weather. They were empty and viz was good but the runway was short, wet, not grooved and had a gusty tailwind.

But, that is just a guess...

[Mudman]

Those weren't taken with an iPhone. Great pictures of a sad event.
Thanks. Canon 70D Sigma 10-20mm and Canon 70-300mm

[McGinty]

Miracle that there was no fire, given that they must have had enough fuel for quite a diversion if needed.

[Airbubba]

Miracle that there was no fire, given that they must have had enough fuel for quite a diversion if needed.

There actually was a small fire on the tail according to the LiveATC recording linked in the JACDEC article cited above. I presume it was the APU or its fuel line. It flared up and was put out a couple of times by the ARFF crew according to the transmissions.

But yes, the outcome could have been much worse for the crew.

I notice that the spoilers are down, were they caught on the evac checklist? Or, do they quickly bleed down when the hydraulics are shut off?

[parabellum]

And yes, it probably ends the company as well...

Just possible the insurance money could save the day? Pay off a few bills, get another one out of the desert?

[Airbubba]

Allegedly the same PIC :confused: :

https://aviation-safety.net/wikibase/wiki.php?id=214704

[FBW390]

Tailwind and gusty wind? Wet runway? The shortest runway? The safety margin was strongly reduced! Not the best choice to go for rwy 14...
Let's talk seriously now...What about landing performance calculations? Were they really within limits with the usual 15% recommanded increment? The margin should have been so tight!
Now if the ceiling was 500 ft AGL or above, why not try GPS or NDB 23?

[Airbubba]

With the gust I get a 16 knot tailwind component, does the B-744F even have numbers for this?

[extreme P]

My googlefu says max tailwind limit is 15 knots.

[Mudman]

https://cimg3.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_9032_590c6498b0119ae3aea1a4b89ba6766f402e8c2c.jpg
Some more photos...
Interesting to see the bits of the fan blades along the fence line.
https://cimg2.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_9128_b0c472f8bf25d3020f13e4a704337fb8337d5582.jpg
https://cimg8.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_9126_6facf1b70b2f165ec94430c2967cbb16e5538dc5.jpg
https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_9079_c16c7cfb25ad95c73f574c9aea8590555e7257a4.jpg
https://cimg5.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_9098_5e5c6aa184fbca059216a3af50a9e2fc77354d67.jpg
https://cimg5.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_9103_26e4f4ae221accab0b88f72d7c9f285ad9e8b4ef.jpg
https://cimg2.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_9088_90947b6810d546a49e630c9a0a517e8131e99a30.jpg
https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/2000x1124/20181109_072718_2131e4412073ef4485f28506e27e9b3f8ddaea4a.jpg
https://cimg2.ibsrv.net/gimg/pprune.org-vbulletin/2000x1124/20181109_071433_7e5e6648a15b66c6d014507d5bec47672eff2f2c.jpg
https://cimg3.ibsrv.net/gimg/pprune.org-vbulletin/2000x1124/20181109_071444_efbd51b2f9a01f426a2eab8d0531c7dc804dcaf6.jpg
https://cimg4.ibsrv.net/gimg/pprune.org-vbulletin/1120x2000/20181109_073013_a80fbf0f2caa672c3c88e9273e0e2fc344bc49c4.jpg

[giggitygiggity]

Allegedly the same PIC :confused: :

https://aviation-safety.net/wikibase/wiki.php?id=214704

If that is this case, i hope the pilot is reading this as he deserves to be told he should never be allowed near an aircraft for the rest of his days. He obviously doesn't know how to fly and only how to crash. Rejecting a takeoff above V1 with an engine failure on a 4 engine aircraft (not that it makes it any more acceptable than doing it on any aircraft with any number of engines after passing V1) followed by landing with a 21kt tailwind in the wet on a short runway. His license should have been torn up after the first un-deniable cockup. Thank god this guy wasn't flying passengers, only his unlucky colleagues. Ultimately, the airline here sounds responsible, allowing this plonker to sit in the cockpit of their nice aircraft.

Constructively, ATC were trying to help, perhaps they could be more clear and calculate the tailwind component and press their concerns by matter of factly asking again, 'are you sure you want to land with a 21kt tailwind?'

[Airbubba]

Thanks again for more great pictures Mudman. Do you shoot in RAW and edit in LR?

I hope the TSB finds those fan blades. Most probably not related to the cause of the mishap in this case, however. Part of a CF6 disk was found nearly 3000 feet from the plane in the AA383 abort at ORD a couple of years ago.

Constructively, ATC were trying to help, perhaps they could be more clear and calculate the tailwind component and press their concerns by matter of factly asking again, 'are you sure you want to land with a 21kt tailwind?'

I've never seen ATC calculate a tailwind component for me. I did have a couple of colleagues violated by the FAA years ago after an inspector in the cockpit of another aircraft observed them doing a tailwind takeoff in excess of the ten knot limit on that aircraft.

Just for clarity, while the quartering tailwind was gusting to 21 knots, the tailwind component was less due to the direction.

From the JACDEC transcript I posted earlier:

Tower: „SkyCube 4854, tailwind now 280 at 16 confirm gusting 21, confirm runway 14 still acceptable ?“

GG 4854: „Confirm..ah, still for 14.“

I get a 16 knot tailwind component for this wind gust on runway 14.

Tower: „SkyCube 4854 heavy, tower roger, wind 260 at 16 gusting 21 cleared to land on 14.“

GG 4854: „Cleared to land..ah.. affir..clear to land on 14, SkyCube 4854 heavy“

Tower: „Roger.“


With this final wind check the tailwind component is 10 knots in the gust as the reported direction swings more to a crosswind.

[giggitygiggity]

Tbh, i didn't calculate it precisely so you got me there, but either way, it is most of it when there is in fact a runway in the reciprocal direction (ceiling providing) and an alternate that I'm sure was just fine and dandy.

I'm sure they have never had to tell you that info and thankfully i've never been in that situation they've needed to tell me, but obviously the controller thought this was a bad idea. I don't fly the 747 but is a 2300m wet runway going to work in a tailwind at a reasonable weight, let alone a 16kt one? Whilst I know it isn't his job to try to persuade the guy not to take it, obviously he was concerned that it might be out of limits and that perhaps giving the tailwind to a pilot that doesn't seem to be internalising the information given (a bloody strong tailwind), stating the obvious might have been useful in this instance to snap him out of it. I'm not sure of the name of the CRM model but there is one that tries to empower individuals to basically bark cold hard information with as much clarity as possible to stop someone from doing something stupid (RAISE model?), although I don't know how this would fit in to a controllers role as a service provider. I cant remember the exact details but there was a similar case in florida (i think?!) recently with a light twin, the pilot was told about a tailwind in excess of 20kts, he was just given the direction and perhaps was overloaded at that time that he didn't have the capacity to calculate the component. Perhaps someone more familiar with the 747 would suggest what a sensible RLD/FLD for a 16kt tailwind?

[Havingwings4ever]

Guess the ILS will be out of service a bit longer on 23, they took out (part) of the approach lights.

[By George]

Ex-Singapore Cargo (9V-SFF). Had many happy hours in that when it was fairly new. I know it is only a machine, supposedly with no sole, but what a way to treat a Lady. Always sad to see them sticking out of the mud like that. If I may venture a tiny criticism, to land on a strip of that length with that sort of tailwind is very unwise.
I remember one of it's sisters having a winglet 'removed' in SFO by a tail-stand being towed by a tractor. Its rego was non other than 9V-SFO. The 'Queen' deserves better.

[RufusXS]

Indeed, the Queens are coming off the flight lines at a greater rate than they're coming off the assembly lines it seems. Sad.

[flydog]

gigittygigitty whatever ....wise ass

you would do well to wait for the result of the investigation before you condemn anyone or criticize their flying or techniques, you do not know what happened any more than anyone else.
speculation ruins lives and families, leave the guys alone for now, first rule of aviation the pilots, they will be blamed if at all possible by all the agencies possible.....this is enough to cope with, without so called colleagues and fellow pilots condemning them without any evidence.

Did you stop to think for 1 minute if the aircraft systems all functioned properly, did the autobrake work, the gnd spoilers work the brakes work, reverse thrust?

leave them alone and concentrate and hope that you always make the correct decisions

[halfofrho]

Regardless of whether it was a malfunction with the jet of some kind, basic airmanship comes in to play here. Did they choose the correct landing runway for the conditions in hand?

[Mudman]

Update: Work has begun to remove the aircraft. TSB has released it and the site to the owners and the airport authority. So far cleaning up the debris and draining tanks.
Antenna array is almost replaced.

https://cimg2.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_9185_f0cc987e2219a72401ac6c53d4a91fef17a5ca88.jpg
https://cimg3.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_9192_7a1c361a6d504acd49394c7c52d08fd5e96a13df.jpg

https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_9209_ce8050dd13138e1c2b64f1a43286b41f28571b10.jpg

https://cimg0.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_9218_61da02ebf5c6baa7c9d51a991a23d9366de27914.jpg
https://cimg3.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_9204_d54f908180a761ff51485bb442eec3d2cb132ac7.jpg
https://cimg2.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_9182_a6612f56cf0cf97bb92c0f05b94530ed93319aa7.jpg




https://cimg2.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_9196_eaff8fe4568c39dbd260ae7545ebd7f3a19142e0.jpg

https://cimg5.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_9178_cb55f0bb20466e5091ac89edef3b466fce4092a4.jpg
https://cimg4.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_9200_984b736e017d7fd07c21b2d09bd581c07e17a302.jpg
https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_9202_a5a8b032ef8cb4167ebe6b3635a6bdef17bd8635.jpg
https://cimg7.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_9177_d83d4c973edaf4146e6fcb83a49237d041df3538.jpg
https://cimg8.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_9198_acf054f367e982001efb1dffda2d07fdaec868bf.jpg
https://cimg8.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_9211_62153e033babb1ead1b0b1d57b580d4afe841e7c.jpg

https://cimg2.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_9176_dc586f06e8cc29593539a9cbbb61406f4a02bbcc.jpg

https://cimg4.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/img_9193_bd2aaf940bf10b58611c435f5e14e94978939aec.jpg

[Derfred]

Australian control towers will always provide the maximum recent tailwind component with a takeoff or landing clearance. It seems to be SOP.

I don’t know if they calculate it manually or just read it off a console, but it’s very handy.

[oceancrosser]

Crosswind as well.

[RufusXS]

Mudman

Thanks for posting the pics. Question for those of you who know: when an airframe is written off but there are salvageable parts, what happens? Does the insurance company sell it to a salvage company, and they can pull parts that are "good?" Or does it not work that way because of certification requirements. Just curious.

[rationalfunctions]

TSB report was released a couple of days ago. https://www.bst-tsb.gc.ca/eng/rapports-reports/aviation/2018/a18a0085/a18a0085.pdf
A long list of contributing factors, but seems like the style and sequencing of NOTAMs added to confusion as they misinterpreted that Runway 23 was not available

[cossack]

Canada finally adopted ICAO standard NOTAM formatting in late 2019 IIRC. Some NOTAM writers still leave a lot to be desired.
Where I work only the 2 minute average wind and 10 minute gust (5kts above mean) are available to ATC. No instantaneous wind or cross/tail wind component readily available but I will preface a wind read out with " slight tailwind" etc to draw attention.

[Equivocal]

Which is almost exactly what the international SARPs specify - make the gusts 10kts or more above the mean and it would be fully compliant with the SARPs. IIRC, you have a UK background - the use of 'instantaneous' values continued in use in the UK many years after it was superseded by major, if not all, international airports in other states because the UK did not implement the averaging SARPs when they were published.

[kgbbristol]

Confusing NOTAMs led overrun 747 crew to believe longer runway was unavailable Investigators probing the overrun that destroyed a Boeing 747-400F at Halifax have highlighted the contribution of poorly-presented NOTAM information to the accident


See Flight Global article #144397 "confusing-notams-led-overrun-747-crew-to-believe-longer-runway-was-unavailable"

[Big Pistons Forever]

ANS providers use NOTAMS for the same purpose a drunk leans on a lamppost. In both cases it is for support not illumination :rolleyes:

[FlyingStone]

Luckily during this period of reduced flying, the amount of NOTAMs have reduced significantly as well, so it most certainly doesn't take 60 pages of reading to do a simple short haul flight across Europe. :*

[Chris2303]

https://www.flightglobal.com/safety/sky-lease-747-wrecked-after-minor-factors-conspired-to-cause-halifax-overrun/144390.article?utm_campaign=FG-INTERNATIONAL-DUBAI-SHOW-BAE-06072021-DE&utm_medium=email&utm_source=newsletter&utm_content=FG-INTERNATIONAL-DUBAI-SHOW-BAE-06072021-DE&fbclid=IwAR3xxPyoMfZtt5Ne7HykK5jQg-80zXXPyK2GOiVsJAzegslXwmjTCI9jRz4
Sky Lease 747 wrecked after minor factors conspired to cause Halifax overrun

[Zionstrat2]

Hello all, I'm an infrequent ga type trying to understand how one throttle could be missed. I may have missed something in the report, but do you guys have any ideas or stories that might help me understand what happened?

I've always imagined that 4 throttles would feel a lot like 2... With one or two fingers per throttle it seems like just retarding three throttles would feel weird. So it's hard for me to imagine the PF pulling four almost to idle and then letting one of them go. And I'm assuming the PF is handling throttles with this model?

Same thing with thrust reversers. Once again I have no experience but I imagine pulling three to the stops feels quite different than four.

Or are there other scenarios that come to mind? If this wasn't a heated pressurized cabin, I could imagine the first officer, wearing a parka, reaching across the pedestal and somehow catching an outside throttle with a sleeve...but that would have been number four instead of number one.

Appreciate any and all thoughts!

[vascodegama]

Go Around and get the sums right I would say.

[tdracer]

It's rare, but it's happened before - twice that I know of. Scenario is the pilot misses one outboard thrust lever, then in the process of lifting the reverse piggyback levers somehow nudges the remaining thrust lever forward. Both cases that I'm aware of happened interestingly in Korea - the first a passenger 747 at the old Seoul airport (Gimpo), I'm thinking in the 1990s, the second a freighter 747 at the new Incheon about 10 years ago. In both cases the aircraft went off the side and did a half spin in the grass. No serious injuries. Memory says the first one was Korean Airlines, the second a middle east freight outfit.

[Zionstrat2]

Much thanks! Looking forward to reading the cases.

[punkalouver]

This was definitely a landing where margins were tight. According to the report, despite all the notams, the longer runway(runway 23), which was into wind, actually did have an available approach for landing(NDB and LNAV). Being nighttime with the weather at non-precision minima and a wet surface, this would seem ideal except for one thing, the threshold was displaced by 1767 feet, something that would seem unusual for any large aircraft to land on, especially a 747. That being said, a 757 did land on the long runway earlier in the night.

With the decision to land on the 7700’ runway 14 with a 20 knot crosswind having been made, there was little room for error. But an accumulation of errors was made, starting with a belief that there was a reasonable margin for this landing, a landing that was not at a particularly light weight. It seems surprising that the captain would choose a flaps 25 landing versus flaps 30. While new on type, the report states that he “had more than 1000 hours PIC experience flying large aircraft worldwide” leading one to think that he would recognize that this was a short runway for an aircraft like the 747. The choice of flaps 25 instead of flaps 30 added 6 knots to the approach speed.

Unlike the other two 747’s in the fleet, this aircraft had performance charts that showed unfactored landing distances, meaning that there was no 15% safety margin added to the actual landing distance values. This information was mentioned on the performance chart but only in the fine print below the calculation table. In addition, the fine print mentions an air time of only 4.22 seconds from crossing the threshold to touchdown, something that’s unlikely to happen in the real world and is for Boeing test pilots(I believe this allowance was removed when TALPA came into effect). It is a good example of how valuable it can be to read the fine print which frequently has critical information that is not obvious.

The crew calculated a landing distance of 6000’ while the TSB calculated 6375’. What adjustment that was missed by the crew is not entirely known. There was an error that catches some pilots, an unnecessary wind additive to the approach speed. There was no headwind component, only a crosswind at 90° when the landing performance calculation was made. Yet the crew added another 5 extra knots to the approach making the Unfactored landing distance 6735’. Even when a 5 knot gust was reported later on, it need not have been considered as the crosswind had become a tailwind and gusts do not affect approach speed calculation with a tailwind. Therefore, with the flap 25 choice and the adjustment for the winds, there were eleven extra, unnecessary knots on the calculated approach speed.

Upon reaching the final approach, the wind had changed direction to become a quartering tailwind, adding close to another 500’ to the landing distance. In reality, they had an approach that had almost no room for error for what were certification test performance landing numbers. They confirmed that they were unaware of the small performance margin as they did discuss the new tailwind but appeared satisfied to continue on.

According to the report, there was ‘heightened anxiety’ in the comments made by the crew on short final but that was related to the crosswind. Unfortunately, their indicated speed was 9 knots faster than even the planned, unnecessarily high approach speed and also were slightly high by the time they crossed the threshold. That being said, they were able to touch down at 1350’ past the threshold which maybe could have somehow allowed a stop just by the end of the runway.

However, despite only a 15 knot crosswind(perhaps the wind did pick up with reports averaging it out), the landing was obviously not handled well and they touched down ‘firmly’, crabbed almost 5° and likely struck one of the nacelles. Although Boeing allows a crabbed touchdown, there appears to have been enough of a lateral displacement after touchdown that the report states ‘preventing a runway side excursion became their priority’. Perhaps the aircraft was drifting to the right upon touchdown due to a corrective action after being blown downwind of the centerline.

The control difficulties on landing led to other events on the rollout resulting in decelerating devices not being activated promptly. The No. 1 thrust lever which had been closed, was advanced forward of idle. One wonders if this was due to the pilot accidentally knocking with his hand in a rush for reverse while trying to control the aircraft. Because of this, no reverse was initially activated on the No. 1 engine and the speedbrakes retracted. The air-ground logic switches in the landing gear changed momentarily to Air Mode during this time period. The No. 1 thrust lever was brought to idle which allowed the speedbrakes to deploy and its reverser to be deployed but then the autobrakes disengaged for reasons unexplained, although large rudder pedal displacements were being used. Maximum reverse was selected but the captain was initially unaware of the autobrake disengagement. Manual brake application began 8 seconds after touchdown, but maximum braking effort did not occur until 15 seconds later, when the aircraft was 800 feet from the end of the runway.

Perhaps in the end, one needs to recognize when an approach has little margin for error, which may only be detailed in the fine print. Once that is recognized, one needs to ensure that in such situations, if any factor moves to a negative performance result, the approach is abandoned. In this case, a new tailwind with the approach speed faster than planned while slightly high on approach should have been enough to trigger a go-around. As for the touchdown and rollout, that is a pilot skill requirement. In this case, it needed a better level of proficiency, something that 110 hours of long haul flying on type may not give you.

[FlightDetent]

Much appreciated. A tale of many swiss-cheese holes.

There doesn't seem to be any single master error of the type you would not get away with on a normal day.

More like a snow-ball of stinky choices. Those where the TRE plucks his hair but cannot really fail a candidate for any single one of them.

Or? Myself not a checker...

[punkalouver]

I would be curious to know if any 747 drivers out there have an opinion on the flying the other approach to runway 23 with an almost 2000 foot displaced threshold.

Would you have chosen that approach that night based on the conditions at that time(500 foot ceiling at minimums at night and possibly raining).

[double_barrel]

Being nighttime with the weather at non-precision minima and a wet surface, this would seem ideal except for one thing, the threshold was displaced by 1767 feet, something that would seem unusual for any large aircraft to land on, especially a 747. That being said, a 757 did land on the long runway earlier in the night.

..........I would be curious to know if any 747 drivers out there have an opinion on the flying the other approach to runway 23 with an almost 2000 foot displaced threshold.


Could someone explain the significance of the displaced threshold in this discussion ? Are you saying it's OK to land before the displaced threshold under such circumstances? If so that seems odd, presumably the threshold is displaced for a reason. If not, how does the fact that the threshold is displaced affect the discussion - the landing distance available is the landing distance available.

[wiggy]

Could someone explain the significance of the displaced threshold in this discussion ? .

Well you can’t land short…:eek: I don’t think anybody here is suggesting that.

I think the real significance of the “displaced threshold” comment is in the context of the NOTAMS (3 pages just for that runway) - it may well have been one of the several factors that led to the crew constructing a seemingly unshakeable mental model :ooh: that 23 was simply not available…

From the performances POV even taking the displaced threshold into account there was just over 8700 feet of landing distance available on 23..verses the 7700 feet on the accident runway…and of course 23 would have had them landing into wind albeit having flown a non-precision approach, if I may use that term…

Rules regarding hindsight of course apply…:(

ETA, having worked back up the thread…re F25 vs. F30…we know that use of F30 should have been a given because of performance even before the wind turned out to be not as forecast. With that in mind from a human factors POV it would be very interesting to know what the company culture was, if there was any, to landing flap setting?

For flap life reasons F25 was pretty much the routine setting at the company I worked at and we only used F30 when conditions demanded it. I wonder how often the accident PF, 1000 hours on type, had performed a F30 landing?

[punkalouver]

Could someone explain the significance of the displaced threshold in this discussion ?

In one way, the displacement is irrelevant because the crew thought the runway was unavailable.

But the report does discuss that runway 23 with its 1787' displacement was available for landing as if it was an obvious option for the crew. However, there is no discussion about whether it was realistic to expect a 747 to be landed on a runway like this. The weather was at minimums and it was nighttime. If this approach(LNAV or NDB) was to be flown, I would assume the crew would use VNAV with a 3° descent angle, which would put them in position for landing as if there was no displaced threshold. At 500' above the airport, the crew would have to disconnect the autopilot and then do some sort of level off or reduced descent rate maneuver to land further down the runway.

Perhaps no big deal, but I am just wondering if anybody in the larger aircraft types has done this sort of thing.........or if they were going into Halifax that night would they have chosen runway 14 even if they knew 23 was available.

[FlightDetent]

Although my type fits inside the 74F,

Standard circle-to-land / Canarsie / KaiTak requires rolling out on the centre line around 500.

Performance wise, nominal touchdown point is typically 1500 ft past the threshold. Especially with heavies, observation shows around 2000' is the daily bread.

To compensate for the displacement discussed, adjusted profile is 130 ft i.s.o. 50 over the fence.

Does not sound too much of an issue, really.

[wiggy]

“ I would assume the crew would use VNAV with a 3° descent angle, which would put them in position for landing as if there was no displaced threshold. At 500' above the airport, the crew would have to disconnect the autopilot and then do some sort of level off or reduced descent rate maneuver to land further down the runway”

Given the NOTAMS I wouldn’t assume they would use VNAV….

It would LNAV and probably some other vertical mode such as V/S to fly a continuous descent…

I have not looked at the plates for what was available for 23 on the night but agree with FlightDetent’s thoughts..

BTW going back to my previous thoughts/comments re F25 vs F30 - whilst F30 almost certainly wouldn’t have saved things on the night it’s perhaps worth considering the choice of F25 and not F30 on a limiting”ish runway was a major source of comment in the report published post the Qantas 744 Bangkok gardening exercise about 20 years ago.

[SaulGoodman]

As they have flown the freighter close to MLW before I am sure they have experience using F30. F30 or F25 wouldn’t make a huge difference anyhow. A couple of kts and a hardly noticeable change in attitude compared to types with bigger differences in landing flaps. Maybe they opted for F25 due to x-wind of 15 kts, who knows…

[wiggy]

Ultimately who knows, there was a lot suboptimal that night…still a F30 with a resultant 6 knot drop in Vref might have been worth having if the crew had really been aware edgy things were but they didn’t ( though the pre-departure landing check must have rung bells).

As you say there’s not much attitude difference between the two settings, must admit never had an issue with F30 in crosswinds…

FWIW as I mentioned upthread the whole subject of F25/F30 got a bit of a wringing out in this…though mostly in the context of contaminated runways.

BKK overrun report (https://www.atsb.gov.au/media/24447/aair199904538_001.pdf)

Page 33 onwards and a whole annex to itself as well, Annex H…

[punkalouver]

F30 or F25 wouldn’t make a huge difference anyhow. A couple of kts and a hardly noticeable change in attitude compared to types with bigger differences in landing flaps. Maybe they opted for F25 due to x-wind of 15 kts, who knows…

The difference was 6 knots, which is significant in a situation like this, even if the crew was unaware of this.

According to the report, flaps 25 was used due to the belief that they had sufficient margin, not due to crosswind considerations. 15 knots at flaps 30 is not an issue.

[SaulGoodman]

The difference was 6 knots, which is significant in a situation like this, even if the crew was unaware of this.

According to the report, flaps 25 was used due to the belief that they had sufficient margin, not due to crosswind considerations. 15 knots at flaps 30 is not an issue.

I reacted to a previous post were it was mentioned that they might have opted for F25 as they might not have been familiar with F30. These 6 kts are insignificant handling wise is what I meant. In this case it extended the landing roll with a mere 500 feet, which is significant distant wise obviously.

[punkalouver]

“ I would assume the crew would use VNAV with a 3° descent angle, which would put them in position for landing as if there was no displaced threshold. At 500' above the airport, the crew would have to disconnect the autopilot and then do some sort of level off or reduced descent rate maneuver to land further down the runway”

Given the NOTAMS I wouldn’t assume they would use VNAV….

It would LNAV and probably some other vertical mode such as V/S to fly a continuous descent…


You are correct that the notam states that VNAV cannot be used with the LNAV. So what is available? When the safety board mentions that that runway 23 was open and could have been used I wonder if they really expect the 747 pilots to do an old fashioned 'dive and drive' NDB approach some sort of level off and descent again below minimums. I suppose it could be done. That is why I am curious what some 747 pilots might have done that night. I wonder if most would also have chosen runway 14.

Would anybody build their own VNAV descent complying with all crossing altitudes and perhaps that 130' threshold crossing altitude that Flight Detent mentioned.

[wiggy]

SaulG …Agreed.

punkalouver - I’d be pretty sure the availability of approaches played into this but what the incident crew were faced with wasn’t that unusual. I suspect many of us here have looked at NOTAMs and seen situations at destinations or alternates where due WIP you’ve potentially got no ILS, reduced landing distance and either no PAPIs or a temporary set..:bored:

At the end of the day a traditional non-precision approach is flyable in the 74 and routinely demonstrated on recurrent checks…In many instances LNAV can be used to assist the lateral tracking leaving a bit more capacity to handle the vertical profile using e.g. V/S.

As for VNAV - as I recall it on the likes of the 744/777 you weren’t allowed to build your own VNAV procedure, amending preprogrammed altitude constraints was not allowed.

[Uplinker]

Notwithstanding that there may have been some catastrophic failure of one or several retardation systems: would it be reasonable to assume that this crew had had ample time during the cruise to read the NOTAMS* and calculate their LDR in the conditions at Halifax - especially given that their desired runway, (with an ILS), was not the longest available?

Would it also be reasonable to assume they had EFBs, giving them a pretty accurate LDR and margin.? **

I ask because the decision of the Captain to continue to use the out-of wind runway - right on the limits - and use less than maximum landing flap, rather than an NPA onto a more into-wind runway, seems very questionable to me.

Tailwinds are very insiduous - even a few knots may sound insignificant, but as we know can have a large effect on the LDR.

*NOTAMS are often criticised for their number, relevance and awkward presentation: Perhaps ICAO should consider reviewing the format to present clearer information, more easily assimilated. For example, on runway related NOTAMS, add a simple statement at the beginning of each to state that "RWY XX is open but subject to the following restrictions":............

** Maybe EFBs could be modified to calculate a maximum wind acceptable in the given landing conditions; so a crew would instantly have a displayed go/no-go wind figure for when ATC gives the final wind with the landing clearance. Maybe some EFBs do, but the ones I used, (in three airlines) did not AFAIK.

[FlightDetent]

punkalouver There is a lot of confusion about what VNAV and LNAV actually are and what are they not.

The VNAV declared not available by ANSP is the result of the profile not taking you to the touchdown point. That invalidates the Instrument Approach Procedure, which for VNAV by definition must bring you with a constant slope to 50' over the threshold.

During VNAV+LNAV I.A.P you don't need(*) to check ALT-DIST as the sensor-instrument-autoflight-database combo is certified to be trusted. Just like an ILS approach (with its own set of pre-conditions). On the day the VNAV would still work fine only bring them to the original threshold.

With LNAV you rely on lateral guidance from the FMC but the vertical profile becomes your task to solve, that's what the ALT-DIST table is for. Then you fly a target 3° profile along the charted values same as any other 2D IAP. Think of LOC-only approach.

The ILS v.s. LOC analogy is helpful since, in a similar fashion,
- the 2 separate (VNAV+LNAV) and (LNAV) procedures are printed on the same sheet of paper
- the 2 separate (VNAV+LNAV) and (LNAV) procedures are completely identical laterally and vertically - trajectory wise
- the 2 separate (VNAV+LNAV) and (LNAV) procedures have different minima (DA/DDA/MDA+buffer/MDA)
- the 2 separate (VNAV+LNAV) and (LNAV) procedures require different authorisation (crew training, on-board installation, quality assurance of the database)

There's a small catch about the vertical guidance provided on the flight deck. For a LOC-only approach you would not the GP (most cases). Since the lateral and vertical profiles are both generated by the FMC onboard a VNAV+LNAV capable ship, when you fly LNAV-only, none of the displays, data and automation modes normally associated with VNAV is degraded in any way. Here the difference between
- flying the certified computer-generated profile and trusting it without cross-check (VNAV) and
- flying the ALT-DIST table with your own brainwork, using the FMC distance information to assure obstacle clearance (LNAV) - while the verical profile for VNAV remains visible and accurate
gets very very thin. But it is there! Yes, unless we talk low temperatures outside the IAP envelope, flying LNAV on a VNAV+LNAV capable aeroplane is pretty much only a state of mind. :ok:

This comes BEFORE we discuss which automation modes are available for each of the two options. Their overlap is brutal and the confusion is made worse by the fact that the most advanced vertical guidance mode of AP/FD is also called 'VNAV'.

(*)+(**) any explanation on this probably deserves a standalone thread.

- - - - - - - part 2- - - - - - - - - - - - - - - - - - - - - - - - - -

What wiggy explains about the no-modification rule for VNAV is a certification/authorisation requirement, breach of system integrity.

The easiest, most straightforward ways of flying an LNAV approach to a displaced threshold are to
a) Use the VNAV autopilot mode to drive the aeroplane's vertical trajectory along the self-generated profile, while the brain is manually checking the ALT-DIST table (LNAV rules!!), as if nothing was amiss. Once visual, disconnect and manually deviate 80' above the profile, then fly the airplane towards the desired touchdown point.
b) Use the V/S autopilot and while manually checking the ALT-DIST table (LNAV rules) deliberately stay 80' above the checkpoint altitudes. This takes you down the perfect profile for the displaced landing.

Obviously, had there been a TEMPO LNAV procedure with officially published corrected altitudes, the 'A' above would be illegal.


https://cimg8.ibsrv.net/gimg/pprune.org-vbulletin/590x575/snippet_vnav_a955329c36af09aabda491d1309be25087b5b360.png