[jhb_airlines] Re: F100 performance

  • From: gwinsk@xxxxxxx
  • To: jhb_airlines@xxxxxxxxxxxxx
  • Date: Fri, 24 Dec 2004 17:11:34 -0000

I've flown both the F70 and F100-620, today, to record fuel useage in climb, 
cruise and 
descent, for entry to FSNav. FSNav then gives me the fuel required for the 
flight. Last 
week, using the deafault FSNav figures for the F100, I finished a flight into 
Manchester 
and, whilst waiting for FS9 ATC clearance to cross 24R, all went quiet; I'd run 
out of 
fuel.
 Assuming the figures I've put into FSNav are realistic, I know I should allow 
extra for 
possible diversion to a named alternate but what other reserves should I carry?

Gerry Winskill
gwinsk@xxxxxxx



On 24 Dec 2004 at 16:58, Bones wrote:

> Thanks for that - I was so busy recording values that I forgot to
> adjust = the rpm value up from 98. That extra 10 will make a lot of
> difference.
> 
> Just a quick recap on weights.
> 
> Empty Weight - (EW or AEW) self explanatory but this is a measured
> value = for each aircraft. It includes everything bar the loadable
> weights. On some aircraft it even includes unusable fuel weight and
> oil.
> 
> Maximum All Up Weight (MAUW) is the certified maximum weight for
> flight. = You cannot exceed this without implications on structural
> integrity. Often called MTOW (Maximum Take Off Weight).
> 
> Maximum Ramp Weight (MRW) is the same as above but will include the =
> extra fuel for taxy. MRW - taxy fuel =3D MAUW.
> 
> Maximum Zero Fuel Weight (MZFW) is the maximum weight an aircraft can
> = carry before any fuel is loaded. Effectively it is Empty Weight plus
> Payload. = So, the max payload that can ever be carried is MZFW - EW.
> 
> Maximum Landing Weight (MLW) is the weight at which the aircraft has
> got = to be down to before a landing can be made. Exceeding MLW means
> greater = stress on the landing gear. This is one reason why you hear
> of aircraft having = to circle around for a long time to dump fuel
> before making a landing. It = is quite a low figure.
> 
> The usual calculation method is the start off with Empty weight and
> add = your payload. If this is above MZFW you have to shed load. Next
> you add your fuel weight to get your Gross Weight. This must be =
> below MRW. Take away your taxi fuel and the resultant figure has to be
> below = MAUW.
> 
> If things are OK to this point you then work out your sector fuel burn
> = and subtract this weight from the Gross Weight to get actual landing
> weight. Obviously this has to be below the MLW figure and if it isn't
> you have = to shed either fuel or payload..
> 
> bones
> 
> -----Original Message-----
> From: jhb_airlines-bounce@xxxxxxxxxxxxx
> [mailto:jhb_airlines-bounce@xxxxxxxxxxxxx] On Behalf Of gwinsk@xxxxxxx
> Sent: 24 December 2004 15:56 To: jhb_airlines@xxxxxxxxxxxxx Subject:
> [jhb_airlines] Re: F100 performance
> 
> 
> Without increasing the thrust scalar, my climb, at max allowable AUW,
> = didn't run out of=20 puff as badly as yours. I altered the Autopilot
> Autothrottle_Max_rpm = from 98 to 108. That=20 was advised for most
> jets, I think in the Flightsimvets Forum.
> 
> Gerry Winskill
> gwinsk@xxxxxxx
> 
> 
> 
> On 24 Dec 2004 at 15:34, Bones wrote:
> 
> > Just a quickie before I have to nip out.
> >=20
> > The F100 has an empty weight of 60631lb. In the notes it says the
> > MZFW =
> 
> > =3D is 79000lb so this means your maximum payload (pax and cargo)
> > is=20 limited to 18369lb. It's dead easy to exceed this as it is in
> > real=20 life but that's =3D your base figure for passenger loading.
> >=20
> > Assuming you hit this figure you are only going to have another=20
> > 165000lb =3D for fuel. In other words never expect to fill the
> > tanks=20 full unless you have =3D got a really low pax load. About
> > 80% is the=20 maximum you will achieve. Again =3D this is like real
> > life - aircraft=20 hardly ever fly with full fuel load now.
> > Obviously it's better to fly=20 with minimum fuel load to increase
> > =3D performance and decrease costs=20 (what is the point of lugging
> > a huge weight of fuel uphill only to=20 bring it down again).
> >=20
> > With the F100 loaded up to max I took off and set her in a climb at
> > =
> =3D=20
> > 1800fpm. At FL100 I increased speed from 250kts to 280kts as per
> > the=20 handbook but =3D she was running out of puff at FL150. At
> > FL150 I=20 dropped ROC to 1500fpm. At FL200 I dropped it again to
> > 1000fpm and at=20 FL250 down further to 800fpm. =3D At FL270 I
> > reduced it to 500fpm and=20 the aircraft held 280kts and 500fpm up
> > =3D to FL310. I didn't try for=20 the operational ceiling of FL350
> > but I'd guess =3D you would have to=20 reduced climb rate even
> > further.
> >=20
> > During all this time N2 stayed at 97.9.
> >=20
> > HC@xxxxxxxxxx
> > http://fsaviation.net
> >=20
> >=20
> 
> 
> 
> 



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