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PostPosted: Fri Nov 14, 2008 12:00 am
by Adamski
Just to make a change from buzzing the Sky tower, I thought I'd try my first long-haul trip ... across the Tasman ... from Auckland to Brisbane (about 1250 nm).

I've got full realism on, so I have to manage the fuel and engine correctly ... and for an extra challenge, I thought I'd load up the NZ Dak to maximum passengers/cargo.

Has the Dak got the legs for it? I've tried all sorts of combinations of prop/mixture/throttle settings and usually cruise at 10k, but I can only get about 2/3 of the way there (maximum) blink.gif

Should I dial in a 150k tailwind? Get the passengers to flap their arms? tongue.gif

How did they do it in the old days?

Aaaah ... I think I answered my own question:
http://www.airliners.net/aircraft-data/stats.main?id=188

"Max speed 346km/h (187kt), economical cruising speed 266km/h (143kt). Initial rate of climb 1130ft/min. Range with max fuel 2420km (1307nm), range with max payload 563km (305nm)."

I always have maximum fuel, so to get the maximum range do I have to throw the passengers out? laugh.gif

PostPosted: Fri Nov 14, 2008 7:28 am
by Charl
Yes, but best do that before takeoff...
Stands to reason it'll go further with less payload innit?
Most aircraft go over MTOW if you fuel 'em + load 'em in any case.

PostPosted: Fri Nov 14, 2008 10:21 am
by Ian Warren
I bumped into a session in flight planning years ago , transit the Pionair DC-3 to Australia , I recall Norfolk Island as a stop of / divert , .. I do believe they had ferry tanks and the flight was to be 8.5 hours , this is due to the Tasman slipstream and winds of the season coming to NZ's winter , a strong headwind .

PostPosted: Fri Nov 14, 2008 10:22 am
by Chairman
The documentation for the MAAM dc-3 says at 100% payload you'll max out with 50% fuel. However there's max and there's Max ...

What are you using for a MTOW ? The MAAM DC-3's use 26,900 while the default fs9 dc-3 uses 26,200. RNZAF wartime MTOW was 29,000, and after the war the UK government set a civil MTOW of 28,000.

Based on the MAAM bird - Fuel weighs 6 lbs / gallon, and the main tanks between them hold 404 gallons, so that's 404 * 6 = 2424 lbs. 29,000 - 2424 = 26,576, so based on the civil MTOW you're probably using you could carry enough extra fuel to fill both main tanks again just by loading to a military MTOW.

So how do you carry it ? Well there's an old trick called DIY ferry tanks ... Squeeze as much fuel in as you can, then as much payload as you can up to your high MTOW. When fuel starts to get low just "transfer some fuel from the ferry tanks into the main tanks" by reducing the payload by 1200 lbs and increasing the fuel by 200 gallons.

Another thing that may be handy, although it's definitely cheating - I edited my aircraft.cfg so that all the fuel is carried in the main tanks. I didn't increase the capacity, just changed where it was carried. The result is that I don't have to get up in the middle of the night to change from aux tanks to main tanks halfway through a long flight, and as an added bonus I don't get any of those nasty moments caused by the main tanks running dry while the fuel gauge selectors are still set to look at the aux tanks.

Code: Select all
[fuel]
LeftMain=   0.0, -9.7,  0.0,  402.0,  0.0
Center1=    0.0,  0.0,  0.0,  001.0,  0.0
RightMain=  0.0,  9.7,  0.0,  402.0,  0.0
Center2=    0.0,  0.0,  0.0,  001.0 , 0.0
//LeftMain=   0.0, -9.7,  0.0,  202.0,  0.0
//Center1=    0.0,  0.0,  0.0,  200.0,  0.0
//RightMain=  0.0,  9.7,  0.0,  202.0,  0.0
//Center2=    0.0,  0.0,  0.0,  200.0 , 0.0
fuel_type=1.0
number_of_tank_selectors=2
electric_pump=1


Or you could just go via Norfolk Island laugh.gif

Cheers
Gary

PostPosted: Fri Nov 14, 2008 10:27 am
by Adamski
Ian Warren wrote:
QUOTE (Ian Warren @ Nov 14 2008, 11:21 AM) <{POST_SNAPBACK}>
I bumped into a session in flight planning years ago , transit the Pionair DC-3 to Australia , I recall Norfolk Island as a stop of / divert , .. I do believe they had ferry tanks and the flight was to be 8.5 hours , this is due to the Tasman slipstream and winds of the season coming to NZ's winter , a strong headwind .


Well ... I lobbed all the passengers out on to the tarmac ... yet still ended up ditching around 100 miles short of Brisbane, after carefully throttling back and leaning back as much as I could. Looking at the winds though, it seems I had a 21k headwind. When you're only doing about 120k anyway, that's a HUGE effect, isn't it?

I'll have to try the return to AKL to see if I make it!

PostPosted: Fri Nov 14, 2008 10:35 am
by Ian Warren
Adamski wrote:
QUOTE (Adamski @ Nov 14 2008, 11:27 AM) <{POST_SNAPBACK}>
the winds though, it seems I had a 21k headwind. When you're only doing about 120k anyway

It would be nice to get my hands on that flightplan , ill make a couple calls and see who may be off help .

PostPosted: Fri Nov 14, 2008 11:27 am
by Adamski
Chairman wrote:
QUOTE (Chairman @ Nov 14 2008, 11:22 AM) <{POST_SNAPBACK}>
The documentation for the MAAM dc-3 says at 100% payload you'll max out with 50% fuel. However there's max and there's Max ...

What are you using for a MTOW ? The MAAM DC-3's use 26,900 while the default fs9 dc-3 uses 26,200. RNZAF wartime MTOW was 29,000, and after the war the UK government set a civil MTOW of 28,000.

Based on the MAAM bird - Fuel weighs 6 lbs / gallon, and the main tanks between them hold 404 gallons, so that's 404 * 6 = 2424 lbs. 29,000 - 2424 = 26,576, so based on the civil MTOW you're probably using you could carry enough extra fuel to fill both main tanks again just by loading to a military MTOW.

So how do you carry it ? Well there's an old trick called DIY ferry tanks ... Squeeze as much fuel in as you can, then as much payload as you can up to your high MTOW. When fuel starts to get low just "transfer some fuel from the ferry tanks into the main tanks" by reducing the payload by 1200 lbs and increasing the fuel by 200 gallons.

Another thing that may be handy, although it's definitely cheating - I edited my aircraft.cfg so that all the fuel is carried in the main tanks. I didn't increase the capacity, just changed where it was carried. The result is that I don't have to get up in the middle of the night to change from aux tanks to main tanks halfway through a long flight, and as an added bonus I don't get any of those nasty moments caused by the main tanks running dry while the fuel gauge selectors are still set to look at the aux tanks.

Code: Select all
[fuel]
LeftMain=   0.0, -9.7,  0.0,  402.0,  0.0
Center1=    0.0,  0.0,  0.0,  001.0,  0.0
RightMain=  0.0,  9.7,  0.0,  402.0,  0.0
Center2=    0.0,  0.0,  0.0,  001.0 , 0.0
//LeftMain=   0.0, -9.7,  0.0,  202.0,  0.0
//Center1=    0.0,  0.0,  0.0,  200.0,  0.0
//RightMain=  0.0,  9.7,  0.0,  202.0,  0.0
//Center2=    0.0,  0.0,  0.0,  200.0 , 0.0
fuel_type=1.0
number_of_tank_selectors=2
electric_pump=1


Or you could just go via Norfolk Island laugh.gif

Cheers
Gary


Thanks Gary ... I'll check my MTOW next flight. I'm using the default FSX DC-3 with the RNZAF repaint.

Just checked ... it was 20,109lbs.

I did the return flight back to AKL - with a tailwind ... and just made it in with 2.35 gal/14 lbs of fuel left after I switched off at the gate. I wouldn't have made a "go-around" laugh.gif

So ... still something wrong somewhere ...