View Full Version : 747 information.

30th Mar 2004, 00:49
I am trying to track down some technical information on the 747 (200) preferably.
Does anyone here know of a good internet site for this .
Thank you.:ok:

30th Mar 2004, 09:15
There's a lot of very knowledgable people here, ask away.

30th Mar 2004, 18:11
Thank you.
Is the fuel system in the Classic 4 tanks and do you always run the fuel direct tank to engine.Does the fuel capacity differ between series.eg 200 to a 200 freighter.?
Is the electrical system 1 generator per engine +1 gene off the APU
Strangely enough quite hard to find a technical site with this info.
Thanks again.

30th Mar 2004, 19:26
Depending on eng type a 747-200 can have the following fuel tanks.
1 reserve
2 reserve (CF6) (dry bay on RR)
1 main
2 main
centre tank
3 main
4 main
3 reserve(CF6) (dry bay on RR)
4 reserve

Tanks between the pax and freighter on all the ones I've seen are the same.

Generators -
1 per engine
2 on APU (except BA where one was removed to save weight!)

30th Mar 2004, 21:03
Adding to spannersatcx's answer, the 747-200's run tank-to-engine when the #1 main & #1 reserve tanks equal the #2 tank capacity. Same for the right hand side with the #4 & #3 tanks.
With more fuel than that, we run on the #2 & #3 tanks as they're a lot bigger than #1 & #4 tanks.
When we have more than about 103 tonnes on board (depends on the temperature of the fuel, etc) we have fuel in the very large centre wing tank, and depending on how much is there we may or may not use it for take-off. It's used until it's down to about three tonnes (from memory - F/E's job! :) ) then the main pumps for that tank are turned off and the scavenge pump sucks the remaining fuel from it and pumps it into the #2 tank.
(The reason for the #2 tank is because the APU feeds from that tank, and so it's usually always lower than it's twin, the #3 tank)

The fuel tanks are normally the same for both freighter & passenger planes.

Each engine has a large generator, and it feeds into an electrical bus that has the same title as that engine, e.g. the #1 bus, the #3 bus, etc. The two buses on each side are tied together so that #1 & #2 are paired, and on the other side #3 & #4 are paired. Then there is a bus tie breaker that ties those two together as well. It's an extremely robust system.
The APU has two generators, each identical to the ones on the engines. Just one will easily power the entire aeroplane, though two are normally used on the ground. They can't be paralleled, and they are used for different electrical loads on the ground, e.g. one does the ground service bus for cargo doors & so on, and the other runs the ground handling bus, etc.

31st Mar 2004, 01:20
Thank you.
Do all 200s still carry flight engineers?
Do the 747-200s carry the same weights (fuel and payload) as the 200 freighter? Are freighter/Cargo aircraft one and the same aircraft or is their a difference in description.Do most freighters carry loadmasters ?
Does it stand to reason that there are four separate hydraulic systems as well ?What is max ceiling for the 747-200 ?
Great information !

Flight Detent
31st Mar 2004, 03:33
Hi TOPC (and 18-Wheeler),

In answer to your Qs,
Yes, the B747-100/200/300/SP are all crewed with Flight Engineers, it's only the B747-400 that is not!

In most cases, the B747 Classic freighters are converted pax airplanes, usually the most common way to tell is that the converted pax airplanes don't have the opening nose cone, by far the greater percentage, but not all!
The converted pax airplanes will operate at the same weights as they did as pax only airplanes, the dedicated freighter airplanes sometimes have a slightly higher capacity.

Yes, 'cargo' and 'freighter' are just different names for the same job/airplane.

In my experience, airlines don't carry loadmasters, they are based at each departure port - unless, of course, the times when the aircraft has to go to an outport with no facilities, and then they do!

The B747 does indeed have 4 seperate hydraulic systems, and further, each system is driven by BOTH an engine driven hydraulic pump AND an air driven pump(bleed air pump). That way, all hydraulic systems will still operate with an engine shut down.
Which makes system integrity pretty good.

Most companies I flew for limited the service ceiling to 39,000 feet.
Though Boeing listed it as 45,100 feet.

The B747-300 is easily the best B747 ever made, it has everything - pity there were so few of them manufactured, the -400 series arrived on the scene and promised the world, and Boeing wanted to make it the only choice available, otherwise the -400 would never have sold!

Hope this helps,


31st Mar 2004, 04:23
I have just been told that I will get to fly the 747 sim. Since I am amazed at what great memories you guys/girls have I will press my luck !!!!!!!

Hope you dont mind .

Would anyone remember the approximate Body angles/ Power / speeds ( for mid weights);- for

Straight and level (I dont know the min speeds for clean.)

Straight and level 250 kts, Approach configs(for the normal circuit)

Steep turns

3' glideslope.

Thank you 18W Flt Detent and Spanner

31st Mar 2004, 08:54
S&L roughly 2.5deg nose up, power about 1.56EPR for the Rollers or generally about 90% - 92% odd N1 rpm for any type of engine, and M 0.84 - 0.85

For 250kts I'm guessing around 5deg nose up, 80% - 85% Na (VERY big guess there). The min clean speed depends a lot on the landing weight, it'll vary from ~230kts down to ~200kts. (Vref +80)

Approach config will usually have you coming into the circuit area with about Flaps 5, ~200kts odd. As you join the ILS you normally go to Flaps 20, stabilise, then go gear down.

Steep turns, can't remember I only do them in the sim. Just push the power up about a knob's worth or so, and keep an eye on the altitude. Ignore the VSI.

3deg glideslope, about 2.5deg nose up, power to hold the speed you need. The only trick for the ILS is to wind in some nose-up trim as you go from Flaps 25 to Flaps 30, as it'll want to pitch down a bit and also drift up on the glideslope.

Gikdday FD, send me an email some time!

31st Mar 2004, 09:21
18 wheeler thank you so much.If you can think of anything that may help in the sim,I would appreciate it as I am only conversent with the 737.(A totally different beastie.)
Thanks again.

7th Apr 2004, 09:56
Are the brakes carbon fibre on the 747-200 ?

Flight Detent
7th Apr 2004, 11:37
No, the only B747 with carbon brakes is the -400 series.

Look, the -400 has most of the later refinements in wing design, engine power and economy, simply because it is the most recent model of the B747.
The basics remain that the two man cockpit doesn't work for long haul. Boeing pulled the FE out and advertised how much the airlines could save by not having to pay the extra man!

Well, not long afterwards they found that the flight restrictions with having only two were unacceptable, so they put in another, yes, another pilot, since all the cockpits were now designed for two, the third man just sat in the jump seat, and was used to 'cycle' thru the two window seats during the flight!

So, all the experience and expertise of the FE was now gone, but we still had to have three up front!

Oh, how many times have we all seen that these three are dearly and repeatedly in need of "somebody to look after the shop".

SwissAir, Qantas, Singapore and many others have all learned the very hard way that in a two place cockit, it's all fine when everything is going fine, but when something is amiss, they're repeatedly caught out.

Not to mention the number of times the FE has had to have a 'discussion' with the dispatching ground engineers, regarding the way the airplane was presented, and the consistency of the technical paperwork.

Have you ever watched a pilot do a 'walk-around' the airplane during his preflight check, I have many times, and a very high percentage may as well stayed in the cockpit for all the good it did!

It's very easy to see my view as far as this is concerned, and it's not good, and not getting any better!


7th Apr 2004, 12:14
Agreed, FD.
Not having an F/E is a backlwards step.
The incident out of LA we had (You know the one) took four of us to monitor and work out. Only having two crew up the front would have made things rather difficult indeed.