Skylease Cargo 747 Runway Overrun YHZ Nov 7, 2018

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pelmet
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Re: Skylease Cargo 747 Runway Overrun YHZ Nov 7, 2018

Post by pelmet »

It would be interesting to know what their landing weight was.

Some of these aircraft can be more difficult to land at light weights than at medium to heavy weights. There can be artificially high approach speeds due to VMC considerations leading to a tendency to float(although once down, stopping capability is very good). One might think that the light weight is a benefit until they float well down the runway. Have seen this sort of feature in more than one type. Add in a tailwind and it can get very interesting.
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Pavese
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Re: Skylease Cargo 747 Runway Overrun YHZ Nov 7, 2018

Post by Pavese »

pelmet wrote: Fri Nov 16, 2018 8:11 pm It would be interesting to know what their landing weight was.

SNIP!
I heard/read somewhere (local media?), that the timeline for getting the A/C removed depended on offloading the significant fuel load. They went on to say that they fueled in Chicago and had enough endurance for the next leg to Anchorage so I'm speculating that the A/C wouldn't be characterized as "light" for the YHZ landing. Take that with a grain of salt of course because I'm not an expert on the A/C we're discussing, my point of reference is a C-152 Heavy. :lol:

D 8)
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jschnurr
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Re: Skylease Cargo 747 Runway Overrun YHZ Nov 7, 2018

Post by jschnurr »

Here's a video I came across on facebook of the demolition. It was hard to watch the fate of such a marvelous piece of engineering and design.

https://www.facebook.com/chris.freeman. ... 046365831/

I'm surprised they didn't salvage the "good" parts, eg, windshields. Does the insurance decide if it is worth their while to send in a scavenger crew?
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tps8903
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Re: Skylease Cargo 747 Runway Overrun YHZ Nov 7, 2018

Post by tps8903 »

jschnurr wrote: Wed Nov 21, 2018 6:59 am Here's a video I came across on facebook of the demolition. It was hard to watch the fate of such a marvelous piece of engineering and design.

https://www.facebook.com/chris.freeman. ... 046365831/

I'm surprised they didn't salvage the "good" parts, eg, windshields. Does the insurance decide if it is worth their while to send in a scavenger crew?
Drove by a flatbed on the 102 southbound yesterday on my way home from the airport with the nose cone and part of the wing strapped on it. I did a double take, then realised what it was. Surprised they were going towards downtown Halifax with those parts.
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GRK2
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Re: Skylease Cargo 747 Runway Overrun YHZ Nov 7, 2018

Post by GRK2 »

pelmet wrote: Fri Nov 16, 2018 8:11 pm It would be interesting to know what their landing weight was.

Some of these aircraft can be more difficult to land at light weights than at medium to heavy weights. There can be artificially high approach speeds due to VMC considerations leading to a tendency to float(although once down, stopping capability is very good). One might think that the light weight is a benefit until they float well down the runway. Have seen this sort of feature in more than one type. Add in a tailwind and it can get very interesting.
If you float at ANY weight in this type (I have more than a dozen years as Capt on them) it's because you buggered up the flare. Floating means you held it off the try to get that smooth touchdown and floated. Dangerous move on a shorter or contaminated runway. Check your landing distance perf and if it's marginal, then either divert or pick a better runway. As for the "artificial" speeds you talk about for VMC? What, exactly, are you on about? VMCG applies for speed reductions in V1 due to contaminated runway surfaces for takeoff, so that covers VMCG. Are you perhaps referring to VMCA? Doesn't apply at all as the approach speeds will ALWAYS be more than VMCA. Even with an Engine Out SID. Back to school sonny! The performance speeds are to be flown as published for a reason. They are not artificial at all.
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pelmet
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Re: Skylease Cargo 747 Runway Overrun YHZ Nov 7, 2018

Post by pelmet »

GRK2 wrote: Thu Nov 22, 2018 5:55 am
pelmet wrote: Fri Nov 16, 2018 8:11 pm It would be interesting to know what their landing weight was.

Some of these aircraft can be more difficult to land at light weights than at medium to heavy weights. There can be artificially high approach speeds due to VMC considerations leading to a tendency to float(although once down, stopping capability is very good). One might think that the light weight is a benefit until they float well down the runway. Have seen this sort of feature in more than one type. Add in a tailwind and it can get very interesting.
As for the "artificial" speeds you talk about for VMC? What, exactly, are you on about? VMCG applies for speed reductions in V1 due to contaminated runway surfaces for takeoff, so that covers VMCG. Are you perhaps referring to VMCA? Doesn't apply at all as the approach speeds will ALWAYS be more than VMCA. Even with an Engine Out SID. Back to school sonny! The performance speeds are to be flown as published for a reason. They are not artificial at all.
You will notice that I said that "some" of these aircraft can be more difficult to land at light weights due to floating. However, I didn't commit that specifically to the 747-400 freighter. However, you would be very correct in stating that this accident involved a 744 so perhaps we should stick to 744 info.

But....you do seem to be unaware of what I am talking about and suggest that I need to go back to school, so let's see if I do. First of all, you wondered what I was "on about" and guessed at VMCG or VMCA. I was on about neither but instead......VMCL, which is defined as:

"the minimum control speed during approach and landing with all engines operating, is the calibrated airspeed at which, when the critical engine is suddenly made inoperative, it is possible to maintain control of the aeroplane with that engine still inoperative, and maintain straight flight with an angle of bank of not more than 5º. VMCL must be established with: • The aeroplane in the most critical configuration (or, at the option of the applicant, each configuration) for approach and landing with all engines operating; • The most unfavourable centre of gravity; • The aeroplane trimmed for approach with all engines operating; • The most unfavourable weight, or, at the option of the applicant, as a function of weight. • Go-around thrust setting on the operating engines"

The aircraft's stall speed with a certain margin added is usually the limiting factor in determining the approach speed but if the VMCL is greater that the stall speed plus its added margin, then VMCL will be the limiting factor which results in an approach speed that is artificially higher than what it would be if VMC considerations did not have to be accounted for. Actually, there can be other reasons for artifially high approach speeds such as fuselage ground clearance(ie avoiding a tailstrike) although I am not sure if that affects the 747-400 as it does for some 'stretched' aircraft. The end result of these can be floating due to the higher than 'ideal' approach speed which is somewhere around 1.3 times the stall speed.

https://www.skybrary.aero/bookshelf/books/2263.pdf

I took a look through some FCTM's to give you an example of what I am talking about as it is interesting info of which to be aware. In the 777 FCTM it says that the VREF normally decreases as airplane gross weight decreases. However, in the shorter freighter version, VREF reaches a limit, or floor at low gross weights. This floor is based on directional controllability limitations. Further reductions in weight will not change VREF which remains constant. This information in the FCTM is no doubt due to the big GE-90 engine thrust versus shorter fuselage effect as compared to the longer versions such as the 300ER. One can see in the Vref speeds sections that the same speed is used for a wide range of weights at the lower end of the weight categories(ie. artificially high speeds at low weights which means more likely to float).

I found a 747-400 FCTM and there is no mention of this. I am sure you will correctly state that my earlier comment is therefore not applicable to this accident(although once again aft fuselage clearance in the flare could be a factor in its approach speeds although how weight affects this, I don't know). However, it has been my experience that at least some lightly loaded transport category aircraft seem to, at minimum, handle differently in the flare. It would be interesting to hear if anyone else feels that way or if I am the only one.

Two months later...Hello GRK2? Any response? You seem to have disappeared.
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Last edited by pelmet on Fri Feb 01, 2019 2:00 am, edited 9 times in total.
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telex
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Re: Skylease Cargo 747 Runway Overrun YHZ Nov 7, 2018

Post by telex »

B763. At heavy weights Vref 25 is LOWER than Vref 30.

There is a good reason for it. We don't always see what is going on behind the scenes.

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pelmet
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Re: Skylease Cargo 747 Runway Overrun YHZ Nov 7, 2018

Post by pelmet »

Thanks Telex....another example of artificially high approach speeds. Do you find the 767 a bit more difficult to land in the desired touchdown spot at light weights which sometimes leads to floating?
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Last edited by pelmet on Fri Feb 01, 2019 2:01 am, edited 1 time in total.
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telex
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Re: Skylease Cargo 747 Runway Overrun YHZ Nov 7, 2018

Post by telex »

pelmet wrote: Thu Nov 22, 2018 9:10 pm Thanks Telex....another example of artificially high approach speeds. Do you find the aircraft a bit more difficult to land in the desired touchdown spot at light weights which sometimes leads to floating?
It's not a difficult airplane to fly. However, landing at light weight probably won't produce the best landing you have ever had.
Fly it by the numbers and leave the finesse for another day. Put it on the runway and park it.
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Re: Skylease Cargo 747 Runway Overrun YHZ Nov 7, 2018

Post by linecrew »

Has the 747 been completely removed? The weather cam at CYHZ for that direction is offline.
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Re: Skylease Cargo 747 Runway Overrun YHZ Nov 7, 2018

Post by tps8903 »

linecrew wrote: Sun Nov 25, 2018 10:04 am Has the 747 been completely removed? The weather cam at CYHZ for that direction is offline.
Looked pretty much removed 3 days ago. I'm sure they are digging through the paint shed looking for touch up paint for the ILS system and approach lights now.
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pelmet
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Re: Skylease Cargo 747 Runway Overrun YHZ Nov 7, 2018

Post by pelmet »

rookiepilot wrote: Mon Nov 12, 2018 8:24 pm
Eric Janson wrote: Mon Nov 12, 2018 6:04 pm
HiFlyChick wrote: Sun Nov 11, 2018 3:41 pm

Why would they spend all of that money on an ILS on 32, when the RNAV gets you down to 200 AGL?

In terms of extending the length, they just spent a bunch increasing the length of 23....
Since they already have the installation - moving the installation can be done at a fraction of the cost of a new ILS system. Perhaps even upgrade it to a Cat II/III installation.

Perhaps they can attract more operators with both runways the same length.
Funny how this is such a hard concept. Improve the product and actually attract more business!

A foreign concept in Canada.
According to an article I am reading, since 2010, over 500 million dollars have been spent gradually increasing the runway lengths to 7700 and 10,500 feet respectively. Sounds like these Canadians have embraced the concept of improving the product to attract more business. Talk is cheap(and frequently misleading)...half a billion dollars is expensive.
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pelmet
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Re: Skylease Cargo 747 Runway Overrun YHZ Nov 7, 2018

Post by pelmet »

pelmet wrote: Fri Nov 16, 2018 8:11 pm It would be interesting to know what their landing weight was.
Discovered that they had no cargo on board according to Flight International magazine. If it turns out that they landed long, the TSB might end up asking them if if they figured that they could get stopped quite quickly at a light weight.
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LETUN
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Re: Skylease Cargo 747 Runway Overrun YHZ Nov 7, 2018

Post by LETUN »

No cargo does not equal light weight. Coming from the States, they probably tankered up to MLW. Fuel is cheaper over there.
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pelmet
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Re: Skylease Cargo 747 Runway Overrun YHZ Nov 7, 2018

Post by pelmet »

LETUN wrote: Wed Jan 30, 2019 7:26 am No cargo does not equal light weight. Coming from the States, they probably tankered up to MLW. Fuel is cheaper over there.
Thanks,

Tankering is a possibility. It has to be at least 2.5 hours from Chicago to YHZ. Not too long a flight.

Will have to wait for further info.
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Skylease Cargo 747 Runway Overrun YHZ Nov 7 2018

Post by TimothysAr »

Speaking about fuel capacity, I wonder what the runway length at Lae was, and the "usuable" runway length at Howland? Coud she have refueled at Howland, and with the weight, taken off?
Tom
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Re: Skylease Cargo 747 Runway Overrun YHZ Nov 7 2018

Post by Blakey »

TimothysAr wrote: Thu Jan 31, 2019 8:22 am Speaking about fuel capacity, I wonder what the runway length at Lae was, and the "usuable" runway length at Howland? Coud she have refueled at Howland, and with the weight, taken off?
Tom
You might want to tell them that you are now talking about Amelia Earhart. Quite a jump from Halifax to Howland Island!
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Re: Skylease Cargo 747 Runway Overrun YHZ Nov 7, 2018

Post by JL »

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