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Re: Insanely long range flights

Posted: 30 Sep 2007, 00:15
by DaveB
I think we could, between us, muster up such charts if so moved Steve :) Worth noting though that, as with all things.. there are exceptions to the rule but never forget the rule ;-) Much of the gumph (or is that gumf?) kicked out by manufacturers in those days.. probably the same now but I have little (no) interest in modern real-world aviation.. quoted 'miles' and not nautical miles and the whole plethora of numbers.. though not false, were for 'ideal' situations, at ISA and in still air. ALL manufacturers did/do this so Vickers would have been unique not to follow the trend.

Thing is though that real world does throw up anomilies under the 'right' circumstances ;-)

ATB

DaveB :tab:

Re: Insanely long range flights

Posted: 30 Sep 2007, 02:50
by skeating
The thing is Dave, I like to fly as real as possible and without the Alt. capability charts I'm just making educated guesses.
A lot of people who use MSFS don't seem to realise that the altitude capability of the aeroplane isn't when it won't climb at more than so may feet per minute with such and such a power setting.
The chart should give the amount of "G" to buffet onset and the optimum alts (for buffet protection) at the current weight.
Another number thats nice to know is the "Turbulent Air Penetration" speeds, again to give you the widest possible gap between high speed and low speed buffet.

I think the flight I mentioned above was close to 5000 miles.
OFFTOPIC The longest (real world flight) I ever did was Stansted to Luanda, 14:30, but that was in a CL-44. |-)

Steve

Re: Insanely long range flights

Posted: 30 Sep 2007, 10:58
by skeating
Thanks for that Tonks.
Max alt for the VC10 was/is 43000 Steve
Thanks again, that was fairly well known (publicity blurb) but at what weight would you have to be to enable you to reach 43000 and still maintain, say 1.35 G to buffet?
The max alt charts we use these days are very much changed from those in the airline days as we have changed the way we look after fatigue
But I presume the shape of the wing hasn't changed so the altitude V buffet boundry would be the same.

Steve

Re: Insanely long range flights

Posted: 30 Sep 2007, 21:04
by forthbridge
9.2 hours so far today, with a 50kt wind off the two-o-clock.

Re: Insanely long range flights

Posted: 01 Oct 2007, 00:25
by Tom Clayton
MALTBY D wrote:...To get longer range, don't mess about creeping the altitude up, get up to cruise height quickly.
Initial crusie may only be around 31000 ft, don't worry about it. Burn some fuel & then go higher.
And I'd guess Mach 0.82 cruise would get you further. :think:

DM
If David hadn't gotten this I would have. As it is, the only thing I can add is a reason. The fuel controlers have to maintain a specific fuel to air ratio based only on weight. With gasoline, that ratio is appx 14.7:1 - I'm not certain what that number is for jets. But whatever that number, the higher you go, the thinner the air is, therefore you use less fuel to maintain that ratio. That reduced fuel use results in reduced thrust, but there's also reduced drag as well, so it all works out - only with less fuel used.

Re: Insanely long range flights

Posted: 01 Oct 2007, 07:47
by forthbridge
Cheers Tom.

My only difficulty is that I need to 'guess' what the best time to increase height is for total weight. Cheating earlier, I gave myself a nice 20kt headwind for takeoff, to get high quickly, and settled at 30ks after reversing course onto route, but I ended up getting less range from my last two attempts than from my first for some reason!

Re: Insanely long range flights

Posted: 01 Oct 2007, 16:22
by Tom Clayton
Do your testing with the "Clear Weather" (no weather) theme. This will ensure consistent results. And take notes - if you're anything like me, you'll forget what happend on the last flight before your next flight is over! :doho:

Re: Insanely long range flights

Posted: 01 Oct 2007, 18:08
by forthbridge
tooodle-idoo-dadoooo! [FANFARE]

15.8 hours, Super 10 non stop EGQL to Mount Pleasant. At engine switch off, I had 3170kg total reserves.

At around half distance, I got the best range and fuel flow - with 3440 miles remaining, I had 32000 kg on board. Projected range at my altitude and speed was 3880 miles - I did not acheive better than 500 miles 'over' distance estimate. best Fuel flow was 922 kg/h on each engine in the level cruise.

Yes, I had a ludicrously low level roof scraper off R22 at EQGL, and no wind whatsoever, but that's a perfectly flyable 7000 miles. I am sure I can squeeze a little more range out of it - the question is I can't think of an airport that has that kind of range to/from EGQL!

A new challenge perhaps? A range cup for the maltby fleet....? :lol:

Re: Insanely long range flights

Posted: 01 Oct 2007, 18:23
by Techy111
Blimey well done....I have flown to MPA twice in the RW and i thought the distance was 8300 miles.....Did you adjust the payload to empty and take out all the seats :roll:

Techy

Re: Insanely long range flights

Posted: 01 Oct 2007, 18:34
by DaveB
Techy you old boot.. did you not stop off at ASI and perhaps Brazil too before you got to MPA?? :think:

ATB

DaveB :tab: