One thing I would love to test (just to see what happens).

 

Replace 747-8i engines with Quad GE90s

or Trent 900's lol.

Please give us a release date for the 747 v2!! It seems like we're waiting forever. I own the 737, 777 and J 41. Want add the 747 to my stable. ✈️

 

That won't happen until the release is imminent, like a week or so.  Hang in there Mike.

One thing I would love to test (just to see what happens).

 

Replace 747-8i engines with Quad GE90s

I bet she'd fly just fine on 2

Kinda' makes you wonder if someday in the future, all those 744's parked in the desert because they just can't compete with the fuel efficiency of a large twin, would have a new life if they re-engined them with dual GE90s.  That would HAVE to be cheaper than buying a new large twin off the assembly line.

 

I wonder if anyone ever seriously explored that?

I bet she'd fly just fine on 2

Kinda' makes you wonder if someday in the future, all those 744's parked in the desert because they just can't compete with the fuel efficiency of a large twin, would have a new life if they re-engined them with dual GE90s.  That would HAVE to be cheaper than buying a new large twin off the assembly line.

 

I wonder if anyone ever seriously explored that?

Good idea, Steve, but won't the airframe ticked off a good few hours and in a lawsuit, I guess shelling out for a new twin a/c is cheaper than multi-billion lawsuits?

GE90s are more powerful engines.

you learn something every day! Thanks for the lesson.

I think out of all the new things I've seen hit the sim community over the years, this is my fav. Looking forward to it!

Good idea, Steve, but won't the airframe ticked off a good few hours and in a lawsuit, I guess shelling out for a new twin a/c is cheaper than multi-billion lawsuits?

I'd agree Rick....but while the airframes may have alot of hours, I bet their cycles are low since they did long haul with much fewer cycles than a regional/domestic bird like a CRJ, 737, etc.  (except for those ANA domestics)

 

That is a bigger factor in airframe life, and I bet if you went shopping in Victorville, you could find a few late model, low hours/cycles 744 bought by an ambitious airline that had to park them when they over-stretched the budget and made some bad forecasting decisions , hehe.

 

Watch the 60 mins story here.  Its about a Qantas 767, but they mention all the 747s at the end as they are touring Victorville...a bucket list destination for me for sure. :smile:  https://www.youtube.com/watch?v=We7qdE4pMtk

The Qantas fleet was impeccability maintained, and I'd have no issue making my private jet a 747-GE90 retrofit.    

Commercial Member

 

3,804 posts

Posted Yesterday, 01:00 PM

Avantime, on 17 Jan 2016 - 03:05 AM, said:

 

 

 

Not an expert of the 747 by any means, but I did manage to cobble up some information on the internet as I'm rather bored with no new PMDG aircraft to buy. ;-)

 

1) What is it?

Landing gear control handle lock

 

2) There are two of them- what is the other one doing?

I can only find references for 1 lever, attached to a lock solenoid and a relay, which is connected to a proximity switch electronics unit or PSEU.

 

3) What electrical sources do each of them use?

28VDC from DC Bus 2

 

4) What signal are they getting from the air-ground circuit? (meaning: which gear signal unlocks each of them?")

Primary and alternate gear tilt sensor circuits (All body/wing gear tilted) and the body gear steering actuator lock circuits.

 

 

The reason I asked was due to a post I read on pprune, where the click sound was used to indicate that the aircraft is airborne. The 'latch' is probably referenced in relation to the 747 Classic, where AFAIK there's an actual latch.

 

 

Lian-

 

MOSTLY correct!  Well done!

 

The answer I was looking for was that it is a solenoid that you hear making that clicking noise.  There is a second one that you also hear at almost the same moment, and that one is blocking movement of the speedbrake handle beyond the flight detent with the air-ground system sensing air mode.

 

Since you went through the effort-  yes- it is modeled. 

 

 

Lian, Robert, great dialogue, very intriguing and stimulating!

 

-Jay B.

I'd agree Rick....but while the airframes may have alot of hours, I bet their cycles are low since they did long haul with much fewer cycles than a regional/domestic bird like a CRJ, 737, etc.  (except for those ANA domestics)

 

That is a bigger factor in airframe life, and I bet if you went shopping in Victorville, you could find a few late model, low hours/cycles 744 bought by an ambitious airline that had to park them when they over-stretched the budget and made some bad forecasting decisions , hehe.

 

Watch the 60 mins story here.  Its about a Qantas 767, but they mention all the 747s at the end as they are touring Victorville...a bucket list destination for me for sure. :smile:  https://www.youtube.com/watch?v=We7qdE4pMtk

The Qantas fleet was impeccability maintained, and I'd have no issue making my private jet a 747-GE90 retrofit.    

Aah, clean forgot the cyclic life argument. Good points there, Steve, and thanks for the brilliant link. All-women crew. Wow, a new one for me Yes, QF are one of the better maintenance-wise operators.

 

 

I used to fly the PMDG 747-400 version 1 until the NGX and 777 came on the market. But then, you took an arrow to the knee

 

Kashif Eizdi

"along with a bunch of other prep work to ensure the engine does not rotate during the flight.  The lack of lubrication under pressure would be heck on the bearings, and would obviate the whole point of hauling the engine along"

 

I understand in layman's terms why this would be the case; the question it raised in my mind is if the same is true for an engine that is shut down in flight some hours prior to arrival (ie: the BA 744 that continued onwards from LAX on 3). Is a shut-down engine still protected by other active systems/connections while it windmills in flight, or is similar damage inflicted by said windmilling at cruise (of course in addition to whatever caused the shutdown)?

The spinning N2 Rotor by windmilling it "Should" produce oil pressure, but it is very low pressure compared to what is normally produced by a running engine and there is no way to monitor it to ensure you have positive oil pressure the entire flight.  Also the spinning fan would actually increase the drag that the spare engine would produce so removing the N1 Fan "streamlines" the engine a bit.  Locking the core rotor allows the engine to bearing to remain preserved and ensures you have a serviceable engine when you arrive. 

 

Windmilling in flight after a shutdown requires that the crew monitor and record the oil pressure on the shutdown engine and if positive oil pressure cannot be maintained, the engine comes off regardless of the failure mode.

the question it raised in my mind is if the same is true for an engine that is shut down in flight some hours prior to arrival (ie: the BA 744 that continued onwards from LAX on 3). Is a shut-down engine still protected by other active systems/connections while it windmills in flight, or is similar damage inflicted by said windmilling at cruise (of course in addition to whatever caused the shutdown)?

The inflight shutdown case compared to the fifth pod case are different. The difference is the fifth pod case is pre planned to cause minimal wear, and no damage as a result of it being slugged to the wing. That means adding all the hoo haa that you see (deflectors etc), and also removing the ting tang that you don't see (fan blades etc).

 

An engine IFSD obviously doesn't have all the ting tang removed or the hoo haa attached. Additional wear from this non-normal config would HAVE to be accepted as their is little choice. Unlike the fifth pod case, where you can act proactively to prevent additional wear or damage.

The inflight shutdown case compared to the fifth pod case are different. The difference is the fifth pod case is pre planned to cause minimal wear, and no damage as a result of it being slugged to the wing. That means adding all the hoo haa that you see (deflectors etc), and also removing the ting tang that you don't see (fan blades etc).

 

An engine IFSD obviously doesn't have all the ting tang removed or the hoo haa attached. Additional wear from this non-normal config would HAVE to be accepted as their is little choice. Unlike the fifth pod case, where you can act proactively to prevent additional wear or damage.

"Ting tang" and "hoo haa"  I take it those are Boeing in-house technical terms?  Are you sure that they should not be hyphenated?  I just can imagine how they would look on the checklists:  "Amplified ting-tang disconnect procedure" and "prior to hoo-haa insertion, please insure that adequate lubrication is present."  Goodness, now that sounds downright naughty

 

Andrew Jones

I wrote that as a young nephew of mine was playing with a toy truck using those words in it's song. A little too cheesy, but the point got across.