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Bob Scott

Is stable accelerated flight a PMDG 777 design criteria?

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Given the extremely long legs on a B777, it's hard for me to imagine most simmers taking on a 15+ hour flight in real time. For many add-ons, accelerated flight is a nice-to-have...seems that with this type of aircraft it's a must-have. I do note that the NGX is rock stable in 4x and 8x accelerated flight--not sure if that's by design or just a happy accident.

 

Is stable accelerated flight a PMDG design criteria for the 777?

 

Regards


Bob Scott | President and CEO, AVSIM Inc
ATP Gulfstream II-III-IV-V

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If the PMDG B777 indeed uses the coding architecture and systems logic of the PMDG B737, I would assume so, but would personally prefer real-time short-haul flights of less than two hours.

 

I agree, though, that there are times when time acceleration and deceleration are desirable. I found out the hard way that the PMDG B747 does not respond well to time deceleration (autopilot-induced stall and unresponsive elevators leading to a crash at a speed faster than the speed of sound). . . .

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taking on a 15+ hour flight in real time

 

Bring on ATL-JNB.

 

Is stable accelerated flight a PMDG design criteria for the 777?

 

I think that if the fuel and autopilot systems on the MD-11 and 744 can maintain themselves at x8, then I don't see why the 777 can't.


Kenny Lee
"Keep climbing"
pmdg_trijet.jpg

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I'd hope so. Even though I don't usually have time for a full real-time ULH, I don't want to be restricted to unrealistic Short hops, hence, 4x accel.

 

I haven't even completed a full flight yet in a certain well-publicised A320 because of the same thing. The most I've done is a 20 minute hop which had a CTD on finals

 

The less-publicised, often criticised 'prologue' Bus has no issues, and is silky smooth at 4x

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I don't want to be restricted to unrealistic Short hops, hence, 4x accel.

 

I haven't even completed a full flight yet in a certain well-publicised A320 because of the same thing.

But there are numerous real-world short-haul B777 flights, perhaps not frequently with the B777-200ER/LR, but certainly compatible. Take a look in Asia or perhaps Europe. In any case, using an A330, A340, B747, or B777 for an appropriate, properly managed short-haul flight is more realistic than using time acceleration.

 

The same is even more relevant to the A320. There seems to be little need of using time acceleration on the vast majority of A320 flights.

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If the PMDG B777 indeed uses the coding architecture and systems logic of the PMDG B737, I would assume so, but would personally prefer real-time short-haul flights of less than two hours.

 

I agree, though, that there are times when time acceleration and deceleration are desirable. I found out the hard way that the PMDG B747 does not respond well to time deceleration (autopilot-induced stall and unresponsive elevators leading to a crash at a speed faster than the speed of sound). . . .

 

Try putting the sim on pause, then switch back to 1X, then unpause. The 747X does fine if you work it that way.

 

I, too, would suspect that the 777 might be fine at 8X...was just wondering if it was something the design team is intentionally baking into the cake.

 

In any case, using an A330, A340, B747, or B777 for an appropriate, properly managed short-haul flight is more realistic than using time acceleration.

 

w/r/t realism...a 777 on a short-haul flight doesn't behave like a 777 loaded to the gills taking to the air for a 17 hour flight. I do that with the MD-11, for example...take it into the air heavy, do the boring overwater cruise at 8x, and then work the descent and landing in real time again. An entire day of droning isn't an acceptable price for the realistic feel of a heavy departure, IMHO. I have thousands of hours of r/w experience cruising in a heavy jet over the ocean. It's not part of the flying experience I care to re-live all that much. Both the short-haul in real time and long-haul with acceleration scenarios have a legit place in the simmer's quiver.

 

Regards


Bob Scott | President and CEO, AVSIM Inc
ATP Gulfstream II-III-IV-V

System1 (P3Dv5/v4): i9-13900KS @ 6.0GHz, water 2x360mm, ASUS Z790 Hero, 32GB GSkill 7800MHz CAS36, ASUS RTX4090
Samsung 55" JS8500 4K TV@30Hz,
3x 2TB WD SN850X 1x 4TB Crucial P3 M.2 NVME SSD, EVGA 1600T2 PSU, 1.2Gbps internet
Fiber link to Yamaha RX-V467 Home Theater Receiver, Polk/Klipsch 6" bookshelf speakers, Polk 12" subwoofer, 12.9" iPad Pro
PFC yoke/throttle quad/pedals with custom Hall sensor retrofit, Thermaltake View 71 case, Stream Deck XL button box

Sys2 (MSFS/XPlane): i9-10900K @ 5.1GHz, 32GB 3600/15, nVidia RTX4090FE, Alienware AW3821DW 38" 21:9 GSync, EVGA 1000P2
Thrustmaster TCA Boeing Yoke, TCA Airbus Sidestick, 2x TCA Airbus Throttle quads, PFC Cirrus Pedals, Coolermaster HAF932 case

Portable Sys3 (P3Dv4/FSX/DCS): i9-9900K @ 5.0 Ghz, Noctua NH-D15, 32GB 3200/16, EVGA RTX3090, Dell S2417DG 24" GSync
Corsair RM850x PSU, TM TCA Officer Pack, Saitek combat pedals, TM Warthog HOTAS, Coolermaster HAF XB case

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Man up! LOL! I've only done 12 hours on the sim before, it was pretty fun and enjoyable. OMDB to the West Coast will be one of my first flights I'm the 777! I haven't done long haul since I bought the NGX last summer )-:

 

But then not everyone has my free time, neither will I from September/October )-:

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My first flight will probably be ORD-MIA or down to DFW, after that I'll be flying my usual routes with a pond hop maybe once every month or so.

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I've done DFW-NRT and LAX-HKG numerous times at 1x. Sometimes I find it fun, but I treat it like a real flight and let the other crews; otto1 and otto2 fly.

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Disregard lol.

Edited by EGLL77W

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I can't imagine using time acceleration!

 

I like to simulate real world aviation, you guys could try a combat sim; you get to fly aircraft really fast there


Alex Ridge

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any "acceleration" must mess up your weather anyway ... realtime or historic.. though you can resequence historic if you use ASE / AS2012.

 

for example, you won't arrive to dawn fogs if your many hours early !!!!!


for now, cheers

john martin

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I'd feel extremely guilty for speeding up my flights.

I usually fly on VATSIM as well which is a major no-no, these things help immerse me in realism.

One thing I do, is Take 30min breaks throughout the flight, which is perfectly acceptable while connected to VATSIM, once reported.


Regards,
Jamaljé Bassue

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If you work from home mostly, doing a 16 hour flight is a great way of getting work done :lol:

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Time compression is a bit of a lol for me. I fly on Vatsim most of the time, so I'd rather stick it out in 1x. Real world weather (AS2012) etc.

 

For me a long haul is about 2 hours of high intensity planning (about 1 hour before pushback, and then the first hour of flight) followed by periodic monitoring (pre-planned periods with alarms set for each action) till approaching top of decent (which keeps me at the cockpit for the next ~40 mins till the engines are shut down.)

 

Planning includes inserting Forecast Winds into the FMS after established at initial cruise altitude. With this information, the FMS predictions regarding waypoint crossing times and fuel burn are more accurate. This in turn means the time till step climb is more accurate from the FMC, and fuel burn to waypoints is more accurate. From fuel burn to waypoints, you can build a good picture for when fuel pumps and tanks need to be managed (MD11 doesn't need to be managed. Just stick it in "Auto" and forget. 747 needs lots of management.)

 

Once you have this sorted out you just need to set an alarm for the next "action"

 

Actions are Fuel burn, time, FIR boundary based and include: Timing FIR Boundary crossings (Useful if on Vatsim to check for ATC), fuel configuration changes & Step climbs, and generally being "within earshot" of the aircraft lets you deal with any unforseens. (TCAS alarms, autopilot disconnects, sudden extreme changes in engine thrust etc are things you can hear from a few rooms away).

 

It takes about 7 or 8 hours to cross the Atlantic (Eastern USA to Western Europe via NAT's).

10 to 15 across the Pacific (USA to Australia or Asia)

About 10 to 13 from Europe to East or Southeast Asia.

 

At best I usually can manage 2 a week (usually done on Vatsim at the beginning of a weekend ie Friday Night, Saturday night equivelent, leave Sunday for short haul or doing something out of the house.), sometimes I will only do one longhaul a month or less even depending on my mood/what needs doing.

 

Once you pass the 2 hour mark after takeoff, the only ongoing requirements at the aircraft are ATC related. This is why I prefer oceans, where Position reporting comes into effect (Procedural non-radar airspace) and ATC is less likley to randomly call you. Being passed into SELCAL watch turns ATC requests into an alarm too. Turn the ATC radio down, and only turn it up again when ATC wants to talk to you (SELCAL recieved or in response to your outgoing position report, which you obviously set an alarm for the last time you did a position report.)

 

The good ol' watch alarm. Sleep and sim. (or do housework and sim, or watch TV and sim, or browse the internet on a second screen and sim).

 

By sticking to the timetable (set an alarm, respond to it.) and doing all the tasks you need to do on time, you will reach your Top of Decent with the FMS all programmed, MCP set for decent, alarm set so you are back in the pilot seat, and then you can spend the last 30 or 40 minutes of the flight getting ready to land the thing.

 

The things that need to be done are: Checking your FS time matches your "watch time" (or phone time if using that kind of alarm).

Checking the waypoint you want to do something at in LEGS (or equivelent) page and see what time you pass that waypoint.

Set an alarm for that time (+ or - a minute or 2).

 

The hardest one to work out is the Fuel Tank-Engine feed for the 747-400. It may include making a fuel-burn chart which is time based then setting alarm for T-10 minutes or whatever before you approach 52 tonnes.

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