[jhb_airlines] Re: B747-400

  • From: "bones" <bones@xxxxxxx>
  • To: <jhb_airlines@xxxxxxxxxxxxx>
  • Date: Sun, 9 Dec 2007 19:36:12 -0000

Lift is generated by several factors but the only two directly in control of
the pilot are speed and Angle of Attack. Both are complimentary in that for
level flight you either have slow speed and a high AoA or high speed and low
AoA. It really does sound like you are flying too slowly.

In normal cruising flight an aircraft is designed to have about 4 degrees
AoA. This matches the wing's Angle of Incidence so that the fuselage is
level in the cruise.

bones

-----Original Message-----
From: jhb_airlines-bounce@xxxxxxxxxxxxx
[mailto:jhb_airlines-bounce@xxxxxxxxxxxxx] On Behalf Of Franklyn Fisher
Sent: 09 December 2007 10:30
To: jhb_airlines@xxxxxxxxxxxxx
Subject: [jhb_airlines] Re: B747-400


Thanks Gerry

Will have another go, have been progressingly reducing the figures to find
the right combination.

As far as fuel calcs go, it is a black art to me.

I just fly a route, note how much is used, then apply that the next time, or

just wing it.

But it is that 10% nose up that worries me, or is it normal?? What flights I

have done, had no problems walking up and down the aisle.

Frank F

----- Original Message -----
From: "Gerry Winskill" <gwinsk@xxxxxxx>
To: <jhb_airlines@xxxxxxxxxxxxx>
Sent: Saturday, December 08, 2007 11:37 PM
Subject: [jhb_airlines] Re: B747-400


> If it's the Default B747-400, then I've used that for several
> TransAtlantic flight without any problems. I climbed with selected speeds
> and kept rate of climb to no more than 1500 fpm, initially. Nearing the
> end of the first step I had to reduce to 1000 fpm.
> The other thing that helps is not to carry significantly more fuel than
> you should. I do the fuel calcs, having calibrated fuel consumption in
> various flight phases. Don't use the FSC fuel calc, it's absolute rubbish
> and leaves you seriously short of sustenance.
>
> Gerry Winskill
>
>
> Franklyn Fisher wrote:
>
>> Bones
>>
>> Rated cruise FL340 at 400kts
>>
>> TO speed 160. vsi1800
>> Climbspeed 250 to10000 VSI 1800
>> FL100-FL200 VSI 1500 speed 280
>> FL200-FL300 VSI 1200 reducing to 1000.
>>
>> The 10% noseup is at all flightlevels and speeds.
>>
>> Have tried altering the C of G and passenger load, with no success.
>>
>> TO has to be manual to hold max 10% climb rate with 20 flaps.
>>
>> Auto pilot heading and climb hold is engaged above 1000 and gear
>> retracted, flaps retracted above 5000, this to hold a stable climb.
>>
>> After turn to WP, FSC engaged. (with all other AC, I can engage full
>> auto, from liftoff, with no problems)
>>
>> As I approach FL300 and and before starting to increase speed to
>> cruise,
>> it then starts to go into a noseup stall very rapidly. And it is then
>> uncontrolable. Time to cruise level, approx 30 minutes.
>>
>> Will have a go with the other Boeing to see if it is the same, no
>> problem
>> witht the other default aircraft .
>>
>> I only have default AC, so cannot use another long range craft.
>>
>> I suppose I should purchase a PMDG craft for the job.
>>
>> Frank F
>>
>>
>> ----- Original Message ----- From: "bones" <bones@xxxxxxx>
>> To: <jhb_airlines@xxxxxxxxxxxxx>
>> Sent: Saturday, December 08, 2007 9:14 PM
>> Subject: [jhb_airlines] Re: B747-400
>>
>>
>>> It sounds like you are flying too slowly and getting on the back of
>>> the
>>> drag
>>> curve. What sort of speed are you using for the climb?
>>>
>>> Also make sure you don't set a specific rate of climb for any jet.
>>> It's
>>> fine
>>> setting 1800fpm at sea level but if the autopilot is trying to maintain
>>> that
>>> rate of climb at higher levels it can only do so by losing airspeed. The
>>> autopilot should be set to maintain a speed value instead - which it
>>> will
>>> maintain as you get higher by automatically reducing the rate of climb.
>>>
>>> This is the trouble with autopilots - you can direct them to do the
>>> wrong
>>> thing very easily. In FS4 we had no option with the climb - if you
>>> dialled
>>> in a height and speed it would always give priority to rate of climb.
>>> The
>>> result was that the higher you got the more the aircraft lost speed
>>> until it
>>> eventually stalled. Later sim versions were more intelligent and rate of
>>> climb is no longer the default value driving the aircraft - but you can
>>> still set the aircraft to do this.
>>>
>>> The 747 should be able to climb up to FL310 without any problem but
>>> if
>>> heavy
>>> with fuel it may need to fly for an hour or so before stepping up the
>>> FL350
>>> and (eventually) FL390.
>>>
>>> bones
>>>
>>> -----Original Message-----
>>> From: jhb_airlines-bounce@xxxxxxxxxxxxx
>>> [mailto:jhb_airlines-bounce@xxxxxxxxxxxxx] On Behalf Of franklyn
>>> fisher
>>> Sent: 08 December 2007 15:23
>>> To: jhb_airlines@xxxxxxxxxxxxx
>>> Subject: [jhb_airlines] B747-400
>>>
>>>
>>> Help please
>>>
>>> I am trying to set up a trans-atlantic flight using the default
>>> B747-400 FSX.
>>>
>>> After numerous takeoffs, I have found the way to do a smooth takeoff
>>> and climb, before engaging FSC.
>>>
>>> However, dispite modding the config file, am unable the get the AC
>>> to
>>> cruise
>>>
>>> at less than 10% nose up.
>>>
>>> Have found that stepping up to cruise (with a step down in the VSI)
>>> is required. But once at FL300, any futher increase to the stated
>>> cruise, results in the nose going up, speed rapidly dropping to
>>> zero, and am on the deck in seconds.
>>>
>>> Very frustating.
>>>
>>> The CRJ700 wont make the trip in one, without midair refuel..
>>>
>>> Either I am not doing something right, or M$ has not done their
>>> homework.
>>> this is supposed to be their own tried and tested.
>>>
>>> Frank F
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> --
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>>> Version: 7.5.503 / Virus Database: 269.16.17/1178 - Release Date:
>>> 08/12/2007 11:59
>>>
>>>
>>
>>
>>
>>
>
>
>
>
>
> --
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> Checked by AVG Free Edition. Version: 7.5.503 / Virus Database:
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>
>





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