Don't Fly This Route

[nhagag 26]

This is true story

I saw the news about DAL128 flight from Beijing to Seattle that was diverted to the Island of Shemya (PASY) this Christmas eve due to engine problems.

I liked the route and planned to emulate it in the PMDG 747-8i..

I spent considerable amount of time making the flight plan and executed it around the same TO and ARR times of the actual flight.

Eight hours into the flight, the Autothrottles disconnects, Autopilot disconnects and engine 1 and 4 failed, pumps failed the Aircraft lost speed <170 knots and altitude rapidly (from 370 to 230)

I could not save the flight. There was no time to react or divert.

Random failures is off in setting.

There was plenty of fuel plus reserve.

I was not too happy.

 

Bill Hagag

[LNGAB 3]

Sounds like the crossfeed valves weren’t open, and fuel tank 1&4 got empty .  

 

Gert Barring

Edited December 27, 2018 by LNGAB

[sloppysmusic 194]

If you had fsuipc then you would have auto saves going back before the incident.. Truly a virtual life saver for these kind of issues! 

[scandinavian13 5,192]

1 hour ago, nhagag said:

There was plenty of fuel plus reserve.

I was not too happy.

I can imagine, but I will also press back on you a bit here, as I saw a very similar thread only a few days ago.

The tough thing about making the products we make is that they are necessarily complex - what the real plane does, our planes do too. For the average simmer, and even pilots (specifically those not typed), this can be a lot of info, and if you're not paying attention, you can get yourself into a lot of (simulated) trouble very quickly.

A loss of a single engine is a rare enough event. The loss of two engines is statistically even rarer. The loss of specifically both outboard engines is likely statistically the same, but when it comes to coincidental stuff like that, you have to look a bit deeper. Specifically, in this case, the loss of the outboards sounds a lot like a case of forgetting to re-open the crossfeeds for the upcoming flight. The tank size for the inboards is a lot larger than the outboards (due to wing shape, etc.), which is why you operate on the inboards using the override pumps prior to switching to that TANK/ENG config. On their own, those tanks can handle a decent amount of flying, but if it's a longer flight, you're going to need to store (and use) more from the inboards.

Mistakes happen. The lovely bit of the sim is that the mistakes don't have dire consequences.

In this case, I'd be willing to bet that it was a mistake versus an error with the plane. If it were the latter, we'd see a lot more of this behavior from other people (and likely on random engines, and not just the outboards).

Looking at my stats on PMDG Global Flight Operations (in the test environment), I have 318.8 hours in the 744 and 748 (149 and 169.8, respectively), not including any test flights I've done outside of that environment, with an average segment length of 10-12 hours (with max segments around 14-15 - I like that LAX-SYD leg). It's very likely that I would've run across this if it were the plane, but I haven't.

[Ephedrin 418]

4 hours ago, scandinavian13 said:

Looking at my stats on PMDG Global Flight Operations (in the test environment), I have 318.8 hours in the 744 and 748 (149 and 169.8, respectively),

Plenty! 

😇

[nhagag 26]

I agree 100% with Kyle

I did forget to reopen the cross feed valves.

It was a lesson for future long haul flights

 

Bill

[downscc 1,327]

Wow, diversion to Shemya is hard core diversion.  I'm surprised they didn't continue to Cold Bay or even Anchorage.  Was the Delta flight a B744 or more likely a B77L?  Shemya is an Air Force early warning radar site and the 80 or so Airmen spending an isolated year there probably were thrilled at their unexpected visitors.  There is nothing else on that rock. Wow.

[skelsey 765]

1 hour ago, downscc said:

Wow, diversion to Shemya is hard core diversion.  I'm surprised they didn't continue to Cold Bay or even Anchorage.  Was the Delta flight a B744 or more likely a B77L?  Shemya is an Air Force early warning radar site and the 80 or so Airmen spending an isolated year there probably were thrilled at their unexpected visitors.  There is nothing else on that rock. Wow.

B763 as far as I recall.

The problem with twins.... engine problem = ,Land At Nearest Suitable Airport -- which may be somewhere very out of the way as in this case! 😂

[Captain Kevin 586]

4 hours ago, downscc said:

Was the Delta flight a B744 or more likely a B77L?

Don't think it could have been the 747-400 since Delta retired them last year. In any event, I'm pretty sure it was the 767-300ER.

[captainsazzman 83]

On 12/27/2018 at 7:21 PM, scandinavian13 said:

I can imagine, but I will also press back on you a bit here, as I saw a very similar thread only a few days ago.

The tough thing about making the products we make is that they are necessarily complex - what the real plane does, our planes do too. For the average simmer, and even pilots (specifically those not typed), this can be a lot of info, and if you're not paying attention, you can get yourself into a lot of (simulated) trouble very quickly.

A loss of a single engine is a rare enough event. The loss of two engines is statistically even rarer. The loss of specifically both outboard engines is likely statistically the same, but when it comes to coincidental stuff like that, you have to look a bit deeper. Specifically, in this case, the loss of the outboards sounds a lot like a case of forgetting to re-open the crossfeeds for the upcoming flight. The tank size for the inboards is a lot larger than the outboards (due to wing shape, etc.), which is why you operate on the inboards using the override pumps prior to switching to that TANK/ENG config. On their own, those tanks can handle a decent amount of flying, but if it's a longer flight, you're going to need to store (and use) more from the inboards.

Mistakes happen. The lovely bit of the sim is that the mistakes don't have dire consequences.

In this case, I'd be willing to bet that it was a mistake versus an error with the plane. If it were the latter, we'd see a lot more of this behavior from other people (and likely on random engines, and not just the outboards).

Looking at my stats on PMDG Global Flight Operations (in the test environment), I have 318.8 hours in the 744 and 748 (149 and 169.8, respectively), not including any test flights I've done outside of that environment, with an average segment length of 10-12 hours (with max segments around 14-15 - I like that LAX-SYD leg). It's very likely that I would've run across this if it were the plane, but I haven't.

Forgot to reopen the crossfeeds once, never made that mistake again haha!

[hohum 14]

On 12/27/2018 at 1:21 PM, scandinavian13 said:

what the real plane does, our planes do too.

If this were true, I'd be able to do RF legs in the 737, 777 and the 748.  It's 2019 now and I still can't fly approaches with RNP arcs in your planes.    I don't know how you can sit there with a straight face and make this claim because it's patently absurd.

 

Edited January 3, 2019 by hohum

[scandinavian13 5,192]

1 hour ago, hohum said:

If this were true, I'd be able to do RF legs in the 737, 777 and the 748.  It's 2019 now and I still can't fly approaches with RNP arcs in your planes.    I don't know how you can sit there with a straight face and make this claim because it's patently absurd.

 

I get that you're frustrated by this - I am too. All the same, the overarching concept holds true, and was the intent of my post, as I'm sure anyone with a rational and logical approach to the post could pick up: the software mimics the real world aircraft closely enough that it takes some time to learn how to properly operate the aircraft.

I will be in no way unclear that this post is a bit hyperbolic, however. It's one thing to vent a frustration. It's quite another to take a shot at someone by taking their post out of context, cherry picking a single issue, and labeling the whole thing "patently absurd." By and large, my post holds true. Labeling the whole post as absurd, and calling the simulation into question in its entirely (ignoring, as well, the fact that not all aircraft are RNP capable, and/or RNP certified), is itself absurd. There's no reason for it. The hyperbole only really undermines the argument.

Edited January 3, 2019 by scandinavian13

[hohum 14]

2 minutes ago, scandinavian13 said:

Labeling the whole post as absurd

Who's making a mountain out of a molehill now?   Did I label your entire post as absurd?  No.   As usual, you're being intentionally obtuse and rather rude towards someone who has some negative feedback about an otherwise awesome product. 

6 minutes ago, scandinavian13 said:

ignoring, as well, the fact that not all aircraft are RNP capable, and/or RNP certified)

The NG has been RNP-capable as a factory option for a really long time.   As is the 777 and the 747-8.  More and more airports are receiving RNP approaches so having a certified flight crew and an RNP capable aircraft is slowly becoming less optional and more of a requirement.  

ILS will soon be going the way of conventional radio navigation.   That is to say, the airline industry is walking it back on a large scale.   ILS systems are expensive and maintenance heavy.   They also don't work in all types of terrain.   Since RNAV is satellite based, it works everywhere.   

ILS systems have some benefits.   Like lower minimums and autoland.   Which is why I don't think it will disappear from major airports completely.   But carrying certification to fly RNP is soon going to be a requirement for an airline job.  

 

[scandinavian13 5,192]

1 minute ago, hohum said:

Who's making a mountain out of a molehill now?   Did I label your entire post as absurd?  No.   As usual, you're being intentionally obtuse and rather rude towards someone who has some negative feedback about an otherwise awesome product. 

You didn't? One moment...

1 hour ago, hohum said:

I don't know how you can sit there with a straight face and make this claim because it's patently absurd.

I rest my case.

2 minutes ago, hohum said:

The NG has been RNP-capable as a factory option for a really long time.   As is the 777 and the 747-8.  More and more airports are receiving RNP approaches so having a certified flight crew and an RNP capable aircraft is slowly becoming less optional and more of a requirement.  

ILS will soon be going the way of conventional radio navigation.   That is to say, the airline industry is walking it back on a large scale.   ILS systems are expensive and maintenance heavy.   They also don't work in all types of terrain.   Since RNAV is satellite based, it works everywhere.   

ILS systems have some benefits.   Like lower minimums and autoland.   Which is why I don't think it will disappear from major airports completely.   But carrying certification to fly RNP is soon going to be a requirement for an airline job.  

Yes, I know all of this. I was on a committee considering the concept where those with RNP equipage would get priority service at certain airports where RNP procedures would alleviate issues caused by ILS. This is why I agreed with you, as I noted in my very first sentence. I added the note that not all aircraft are actually equipped with that option, and further still, many operators haven't chosen to either equip, or maintain certification. With this in mind, my earlier statement is actually correct and not "patently absurd." Correct in 100% of cases? No. Patently absurd? Hardly.

So...more facts, fewer emotions, and borderline ad hom attacks. Your points will stand up on their own merits. Taking shots at what I said does not...

[Ephedrin 418]

I somehow doubt that ILS systems will vanish in the nearer future. Nor I think that aircraft will depend on GPS solely. That‘s just my thought and I don‘t have backup information on this but since GPS is still the property of the US military and has actually already been turned off for the public in the past during war times it seems a bit too risky to me to relate on it alone. Thinking about certain presidents I wouldn‘t trust on a system that can be used as a blackmail that easily. ILS means an airport and an airplane. GPS (and GNSS in general) means a third someone in charge. If one of it is gone there‘s no landing anymore in IMC? Hardly to imagine. Never make yourself 100% dependent on one nation/person. 

Again, only a thought now.