Jump to content

Is 59.3 the ideal CG before descent?


Ray Proudfoot

Recommended Posts

Ray Proudfoot

The ultimate test. This is the state of the fuel when parked plus one when 6/8 were empty. A couple tonnes less than CPS-X estimated but I did mess up the first part of the transonic climb leaving it on Pitch Hold instead of Max Clb. But landed with 8.2T which is okay. 60 pax too.

Where there is an imbalance in fuel in 6 and 8 I just use the 6-7 or 5-8 transfer switch to even them up. All four collector tanks had exactly the same fuel when 6/8 were empty. My most satisfying EGLL-TBPB flight yet.

Just noticed I forgot to move TRIM TRFR switch to its forward position when starting down. :(

Conc_TBPB_6&8Empty.png

TBPB_Parked.png

Link to post
  • Replies 150
  • Created
  • Last Reply

Top Posters In This Topic

  • Fraser Gale

    68

  • Ray Proudfoot

    61

  • AdrianSmith

    6

  • Andrew Marshall

    6

Top Posters In This Topic

Popular Posts

Oh, and somebody not to far away also made a Concorde profile for PFPX that was reasonably accurate.... so even if CPS does become unusable at some point, we will survive!

I would hope the virtual pilots would already be well aware of the systems that were and still are ahead of their time. Anyway, short of reopening the Airman's Training Centre at BAC Filton, I th

Just as a small addenda to this discussion, I have finally found the "old" instructions regarding fuel management dated 1988 which are basically the way that I normally use: - trim transfer in no

Posted Images

Fraser Gale
10 hours ago, AdrianSmith said:

As Ray said, it is quite difficult to see small differences in elevon positions.

If there is little or no difference in elevons, but a significant difference between 6 & 8 (frequently in the order of two tonnes) then surely when 6 empties 1 & 2 will no longer be topped up and will drop well below 3 & 4, which if you are in AFT TRIM mode means 1 will get well too low by the time you reach ToD.

Without balancing the contents laterally I would never get to the same situation as Ray's last photo where 1,2,3,4 are almost identical

To be honest, I just handle the fuel without really thinking about it but if you transfer across as I've suggested then you shouldn't have an issue. If you need to balance it then do so.  Sometimes I do, but often I don't.

Link to post
Fraser Gale
8 hours ago, Ray Proudfoot said:

Adrian,

Check the contents of 5,6,7 and 8 before your next flight. I'll do the same after using CPS-X to load the fuel. Logically 5 and 6 should match 7 and 8 otherwise there's an imbalance before we start.

Frazz doesn't use CPS-X so I wonder how he loads fuel. Manually through the FSL interface I imagine. But how does he know how much to put in each tank to ensure equal loads? His BA charts perhaps.

By switching off the feeds from 6 and 8 to 2 and 3 at the relevant time it ensures all four collector tanks have equal amounts when 6/8 are empty. Have you tried that procedure yet?

Talking about me as if I'm not here now...are you saying I don't know how to load the fuel now??

For your information I load the fuel manually through an XML file (because I don't need CPS) and I load it according to the chart from the fluid replenishment manual.  Although to be frank there is nothing wrong with the FSLabs fuel slider for doing this, as it knows where to put the fuel anyway. 

Link to post
Fraser Gale
6 hours ago, Ray Proudfoot said:

This is the fuel load for EGLL-TBPB. There is an imbalance of 1470Kg in the loads of 5/6 compared to 7/8. All other tanks are either equal or centrally located. Any suggestions why?

TBPB_Fuel.png

There is an error in the CPS loading here - the full level for both tanks 6 & 8 should be 11690kgs at 0.80kgs/ltr.  The difference between 5 and 7 is correct because they are slightly different sizes. 

I also notice that the takeoff CG is set to 53% here?

Link to post
Ray Proudfoot
6 minutes ago, Fraser Gale said:

There is an error in the CPS loading here - the full level for both tanks 6 & 8 should be 11690kgs at 0.80kgs/ltr.  The difference between 5 and 7 is correct because they are slightly different sizes. 

I also notice that the takeoff CG is set to 53% here?

Too late to do anything about it now but I'll bear the difference in mind and balance them during flight. Yes, I did wonder about 53%. It should be 54% shouldn't it. It was further back than that during taxi and I managed to get it to 54, just.

Link to post
Ray Proudfoot
14 minutes ago, Fraser Gale said:

Talking about me as if I'm not here now...are you saying I don't know how to load the fuel now??

For your information I load the fuel manually through an XML file (because I don't need CPS) and I load it according to the chart from the fluid replenishment manual.  Although to be frank there is nothing wrong with the FSLabs fuel slider for doing this, as it knows where to put the fuel anyway. 

I'm guessing that's a tongue-in-cheek remark. ;) Of course I'm not suggesting you don't know how to load fuel. Thanks for clarifying your procedure.

Link to post
Fraser Gale
37 minutes ago, Ray Proudfoot said:

Too late to do anything about it now but I'll bear the difference in mind and balance them during flight. Yes, I did wonder about 53%. It should be 54% shouldn't it. It was further back than that during taxi and I managed to get it to 54, just.

For a Barbados load you definitely need 54% yes. How did you transfer the burn off fuel just out of interest?

Link to post
Ray Proudfoot
6 minutes ago, Fraser Gale said:

For a Barbados load you definitely need 54% yes. How did you transfer the burn off fuel just out of interest?

I moved as much as I could to 9 and when that became full the rest went into 5 and 7 but those were close to full too. That got me to 54 but the red warning light was still on. 5 and 7 pumps were on to feed 1-4.

Link to post
Fraser Gale
1 hour ago, Ray Proudfoot said:

I moved as much as I could to 9 and when that became full the rest went into 5 and 7 but those were close to full too. That got me to 54 but the red warning light was still on. 5 and 7 pumps were on to feed 1-4.

To be picky now that you are trying out the fuel system fully, you ar not permitted to transfer fuel forward for a 54% takeoff!  It must be burnt prior to the takeoff run so the correct procedure is:

- after engine start do not select the pumps on in 5/7 leave them off

- set the final tank 11 fuel figure in the tank 11 load limit controller (current contents minus burn off amount)

- select the inlet valves in tanks 9/5/7 to shut

- once around half the required burn off figure has been burnt across the four collector tanks has been used, open the standby inlet valves to 1/2/3/4 to open and set the trim transfer auto master switch to FORWARD

- confirm tank 11 pump switches are at auto, low pressure lights off and contents reducing

This will move the fuel into the collector tanks to be burnt off but still with automatic shut off when the correct contents are in tank 11.

If you have a quick taxi and find yourself at the holding point with the fuel still aft of 54% then the only official option was to ask ATC to wait until you burnt the fuel, but a quick thinking engineer would use the tank 5/7 inlet override switches to shift some fuel into 5/7 above the normal full level.  This was ok because you will have to switch on the pumps in 5/7 for takeoff anyway and when the throttles are opened they will soon be back to normal level! 

- when T11 contents are at the required level and CG at 54%, select transfer auto master to off and guard 

- set panel up for takeoff as normal

  • Like 1
Link to post
AdrianSmith

You're 24 kilos below max fuel, the simple reason is that 8 is bigger than 6!

(You DEFINITELY want 54% for take off with that weight!)

12 hours ago, Ray Proudfoot said:

Frazz doesn't use CPS-X so I wonder how he loads fuel. Manually through the FSL interface I imagine. But how does he know how much to put in each tank to ensure equal loads? His BA charts perhaps.

If you use the slider in the FSL interface to specify total fuel it will load it correctly. The FS9 version had charts for where to put the fuel, but the FSL interface will now do it correctly for you.

  • Like 1
Link to post
Fraser Gale
26 minutes ago, AdrianSmith said:

You're 24 kilos below max fuel, the simple reason is that 8 is bigger than 6!

(You DEFINITELY want 54% for take off with that weight!)

If you use the slider in the FSL interface to specify total fuel it will load it correctly. The FS9 version had charts for where to put the fuel, but the FSL interface will now do it correctly for you.

Adrian - if you read the posts above you will see that in fact the full level cutoff occurs at the same value for 6/8 according to BA loading procedures. 

Link to post
Ray Proudfoot

Frazz,

Crikey, that’s a lot more complicated than when airborne. More printing and digesting is required. Seems odd they had to burn off valuable fuel for its longest flight. The only flaw in an otherwise excellent fuel system. Thanks for the detailed instruction.

Adrian, yes I think it’s because I didn’t select the landing radio button. When you do it correctly calculates TO CG which would. E 54 of course.

I never use the FSL fuel interface other than to select the CPS-X option which places the correct fuel in each tank.

Link to post
Seth Goodwin
5 hours ago, Fraser Gale said:

There is an error in the CPS loading here - the full level for both tanks 6 & 8 should be 11690kgs at 0.80kgs/ltr.  The difference between 5 and 7 is correct because they are slightly different sizes.

Frazz was equal fuel in 6 and 8 some sort of BA policy? Absent that, Tank 8 is larger than tank 6. The 95% volumetric capacity for 6 was 14,630 litres and 16,210 for tank 8. At .80 kg/l that is 11,704 and 12,968. The  FSL Concorde X loader would load fuel in a similar manner to CPS here

12 hours ago, Ray Proudfoot said:

This is the fuel load for EGLL-TBPB. There is an imbalance of 1470Kg in the loads of 5/6 compared to 7/8. All other tanks are either equal or centrally located. Any suggestions why?

I don't know the technical reason why, but tanks 7 and 8 are both larger than 5 and 6. 7 is 260 litres larger than 5 and 8 is 1580 litres larger than 6. But this imbalance should be present on pretty much every Concorde flight of some distance should it not? All 4 of those tanks are usually fully loaded for say JFK-LHR.

Link to post
Fraser Gale
8 hours ago, Ray Proudfoot said:

Frazz,

Crikey, that’s a lot more complicated than when airborne. More printing and digesting is required. Seems odd they had to burn off valuable fuel for its longest flight. The only flaw in an otherwise excellent fuel system. Thanks for the detailed instruction.

Adrian, yes I think it’s because I didn’t select the landing radio button. When you do it correctly calculates TO CG which would. E 54 of course.

I never use the FSL fuel interface other than to select the CPS-X option which places the correct fuel in each tank.

That's why you need a forward ZFCG because the CG is further forward, less needs to be burnt to get to 54%

Link to post
Fraser Gale
7 hours ago, Seth Goodwin said:

Frazz was equal fuel in 6 and 8 some sort of BA policy? Absent that, Tank 8 is larger than tank 6. The 95% volumetric capacity for 6 was 14,630 litres and 16,210 for tank 8. At .80 kg/l that is 11,704 and 12,968. The  FSL Concorde X loader would load fuel in a similar manner to CPS here

I don't know the technical reason why, but tanks 7 and 8 are both larger than 5 and 6. 7 is 260 litres larger than 5 and 8 is 1580 litres larger than 6. But this imbalance should be present on pretty much every Concorde flight of some distance should it not? All 4 of those tanks are usually fully loaded for say JFK-LHR.

Yes the volumetric capacity for the two tanks is different but remember that the volumetric capacity was never fully used anyway because of the air space requirements.  

For a density of 0.80 the full capacity of T6 is 11690kgs and for T8 is 12960kgs BUT according to the BA refuelling schedule for this density both tanks were filled to 11690kgs when they were both considered full. This occurred at a total fuel of 65060kgs after which fuel was placed into 5/7 and continued to be added to 10/11 with 5a/7a/9 already being full.

If it was a BA policy then good because it sounds like common sense to have a balanced fuel load regardless of the space in the tanks. Bearing in mind that HLI fuel could be added under strict conditions to top up the nominal full levels of the tanks although this did not change the CG position as the amounts added to the tanks kept the balance the same.  I guess that the fuel loading of BA was done to stop the imbalance presenting on long flights.

Link to post
Ray Proudfoot
11 hours ago, Seth Goodwin said:

I don't know the technical reason why, but tanks 7 and 8 are both larger than 5 and 6. 7 is 260 litres larger than 5 and 8 is 1580 litres larger than 6. But this imbalance should be present on pretty much every Concorde flight of some distance should it not? All 4 of those tanks are usually fully loaded for say JFK-LHR.

I don't know the reason for the imbalance but 5-8 probably wouldn't be at 100% for all as that route was well within Concorde's max range. Definitely full for the Heathrow-Barbados run though.

Link to post
Ray Proudfoot
4 hours ago, Fraser Gale said:

That's why you need a forward ZFCG because the CG is further forward, less needs to be burnt to get to 54%

Does that equate to having as many pax as possible in the forward section of the aircraft? Maybe move some cargo forward too.

Link to post
Fraser Gale
4 hours ago, Ray Proudfoot said:

Does that equate to having as many pax as possible in the forward section of the aircraft? Maybe move some cargo forward too.

Load as much as possible in the forward hold and take as little cargo as possible in the rear, staying within volume and floor loading limitations of course. 

  • Like 1
Link to post
Fraser Gale
4 hours ago, Ray Proudfoot said:

I don't know the reason for the imbalance but 5-8 probably wouldn't be at 100% for all as that route was well within Concorde's max range. Definitely full for the Heathrow-Barbados run though.

Sorry Ray but as I've stated above, in BA's case 8 was never completely full, as it was loaded to the full level of tank 6 to remain in balance.  They might have both gained a few hundred kilos (same amount) if high level incremental fuel was added above the normal maximum but that was all. 

  • Like 1
Link to post
Seth Goodwin
19 hours ago, Fraser Gale said:

BUT according to the BA refuelling schedule for this density both tanks were filled to 11690kgs when they were both considered full. This occurred at a total fuel of 65060kgs after which fuel was placed into 5/7 and continued to be added to 10/11 with 5a/7a/9 already being full.

Thanks. That helps. I'll have to consider how I want to "simulate" HLI loading on pushing the limit destinations going forward.

Link to post
Fraser Gale
10 hours ago, Seth Goodwin said:

Thanks. That helps. I'll have to consider how I want to "simulate" HLI loading on pushing the limit destinations going forward.

The best thing to do as I've advised Ray, is to load with a forward ZFCG (forward of 52.3 or so) which allows you to load more fuel into tank 11.

Link to post
Fraser Gale

Just as a small addenda to this discussion, I have finally found the "old" instructions regarding fuel management dated 1988 which are basically the way that I normally use:

- trim transfer in normal way from Mach 0.7

- when complete transfer from the "A" tanks as soon as possible and select AFT TRIM switch to AFT

- when 5/7 empty select pumps off and pumps on in 6/8

- when 6/8 reach 4000kgs  select AFT TRIM switch to NORM

- when 6/8 empty select pumps off, all collector tanks should be at normal full level at this point

- when any one of the collector tanks reach 2500kgs transfer fuel forward into 5/7 from 11 and when 5/7 have a minimum of 100kgs in them select pumps on to transfer to collector tanks

- when CG reaches 58.7% switch off pumps in 11 and close inlets to 5/7

- providing that tank pressure remains between 1.2 and 1.5 psi the minimum fuel in the collector tanks is 1000kgs at which point deceleration must take place

After that as normal. 

Now, we could debate which procedure of the two was used but I suspect the more complex one was designed to eek out the last bit of range from the fuel in the cruise and was probably to help with the BGI run.  In the ITVV program which was filmed in August 1996, the SEO uses this more simple (older) procedure despite the manual I have from round the same time quoting the more complex one as standard ops, which could have been for many reasons including even the fact that as he was one of the earliest flight engineers to be trained with the older procedure, he maybe just stuck with it because it was clearly used without major incident for over 10 years anyway. So for us sim pilots, I think we can use whichever we want as long as you reach firm ground at the end of the flight!

 

  • Like 2
Link to post
Ray Proudfoot

Thanks for that Frazz. Regarding "when 6/8 reach 4000Kg select AFT TRIM to NORM" I think I'll stick with your procedure which works well for me.

One extra question. On some flights CPS-X (and maybe the FSL Fuel dialogue) fills 6/8 before 5/7. I don't know the reason for that but how does it affect 5a and 7a? Would you still only start those pumps when 9 and 10 were empty? Because it takes so long for 5a and 7a to empty I cannot use any fuel in 5/7 until they are as it's burnt quicker than it can be fed.

Link to post
Fraser Gale
12 hours ago, Ray Proudfoot said:

Thanks for that Frazz. Regarding "when 6/8 reach 4000Kg select AFT TRIM to NORM" I think I'll stick with your procedure which works well for me.

One extra question. On some flights CPS-X (and maybe the FSL Fuel dialogue) fills 6/8 before 5/7. I don't know the reason for that but how does it affect 5a and 7a? Would you still only start those pumps when 9 and 10 were empty? Because it takes so long for 5a and 7a to empty I cannot use any fuel in 5/7 until they are as it's burnt quicker than it can be fed.

Whatever works for you, I must confess I often just do it the easier (older) way as it has no adverse affect on anything on a normal New York run. 

Assuming that you are doing a relatively short sector because you aren't carrying fuel in 5/7 the drill (from memory) would be to burn the fuel from 6/8 as though they were 5/7 and transfer aft as normal because during the aft transfer you should be pumping into 5/7 after 11 is full.  Once 5/7 have at least 100kgs in, turn off the 6/8 pumps and turn on the 5/7 pumps making them feed the collector tanks.  When trim transfer complete open the transfer valves from the "a" tanks as usual.  If it is a very short sector then you should start the transfer from the "a" tanks early as you are not permitted to land with fuel in them!  If I remember correctly the rule on very short flights was start transfer at least 20 mins before commencing an approach.

Link to post
Ray Proudfoot

Thanks Frazz. On some flights like EGCC-LPPT the balance in 9/10 once 11 has reached its limit is less than 2000Kg. As long as there's no rule about how early 5a and 7a can be fed into 5 and 7 I might start doing that whilst 11 is still being filled from 9/10.

Link to post
Fraser Gale
12 hours ago, Ray Proudfoot said:

Thanks Frazz. On some flights like EGCC-LPPT the balance in 9/10 once 11 has reached its limit is less than 2000Kg. As long as there's no rule about how early 5a and 7a can be fed into 5 and 7 I might start doing that whilst 11 is still being filled from 9/10.

Let me double check the manuals because the "a" tanks were left full during the climb to minimise wing bending moments which would imply leaving fuel in there till the acceleration is complete, however it was even more important not to land with fuel in them because the weight would bring the wing closer to the ground during approach and having fuel may not allow you to get the CG to 53.5 or less for landing. 

Link to post
Ray Proudfoot

Okay, thanks. Total flight time for that route is 1h 25m with the decel starting around the hour mark.

Link to post
Fraser Gale
11 hours ago, Ray Proudfoot said:

Okay, thanks. Total flight time for that route is 1h 25m with the decel starting around the hour mark.

Flight time not much help as there isn't instructions for specific flight lengths.  For short supersonic flights additional guidelines are:

- when 55% CG obtained on the climb check transfer from 9, 10 & 11 into 5 & 7, while maintaining 55% and lateral trim

- stop transfer when the addition of contents of trim tanks 9, 10 & 11 equal the extracted tank 11 contents for supersonic cruise from the cruise control manual

- During the acceleration transfer 9 and 10 into 11 giving 59% CG and transfer from 5a & 7a as usual

- when collector tanks contents reduce to 2500kgs transfer from 11 bringing CG forward to 57.7% as per normal procedures

NOTE: if "A" tanks are still transferring during deceleration the pump low pressure lights will come on before the tanks are empty due to aircraft attitude

For subsonic sectors with weight less than 140T:

- when 55% CG obtained in climb check transfer from 5a/7a and maintain CG by adjusting trim tank contents

NOTE: the "A" tanks can take as long as 25 minutes to empty and must be empty on landing.  Very short flights will require transfer to be commenced at least 25 minutes before landing irrespective of above guidelines.

For subsonic sectors with weight greater than 140T:

- transfer from 9/10/11 into 5/7 when space available while maintaining 55% CG

- when aircraft weight has reduced to 140T transfer from 5a & 7a into 5 & 7

NOTE: delaying "A" tank transfer until 140T relieves wing bending loads in subsonic flight

Having re-read this part of the manual I notice that it quotes 57.5% as a forward CG position near the end of cruise more than once, which makes me think our forward bug is too far aft.  I will see if I can investigate this further. 

  • Like 1
Link to post
Fraser Gale

I have just check two graphs for the CG corridor and at weights above 165T the forward CG limit at Mach 2 is 58% but this moves forward linearly below 165T until at an aircraft weight of 105T the forward limit is about 57.1%.  This might be something for @Andrew Wilson to look at as I'm not convinced this forward movement is working correctly in the current incarnation of Concorde-X...?  

This also affects how long you can stay in supersonic cruise because at the moment we can't take as much fuel as we should be able to out of T11 to burn from the collector tanks. 

Not sure why I haven't noticed this before...

Link to post
Ray Proudfoot

Thanks Frazz. More to digest and note. I think an extended fuel handling document is required given how varied the requirements are for given flights. Maybe something for @Andrew Wilson to consider along with the point you raised.

Was it always a requirement for the “a” tanks to be filled even on shorter trips? Seems odd when there’s plenty of space in the rest.

Link to post
Fraser Gale
17 minutes ago, Ray Proudfoot said:

Thanks Frazz. More to digest and note. I think an extended fuel handling document is required given how varied the requirements are for given flights. Maybe something for @Andrew Wilson to consider along with the point you raised.

Was it always a requirement for the “a” tanks to be filled even on shorter trips? Seems odd when there’s plenty of space in the rest.

I think that a lot of the people who fly in the sim would never need such a detailed document and the time it would take to compile wouldn't be offset by the requirement.  Even I don't use all the above on a daily basis, besides it is now all in this forum!

To answer your question on the filling of the "a" tanks, logic would dictate that the requirement to restrict wing bending loads exists on every flight regardless of length, especially as the greatest loading is experienced in the initial climb. 

Looking at the refuel schedule again for 0.800kgs/ltr the "a" tanks have 270kgs each for a total fuel of 25000kgs, and are full by a fuel load of 31220kgs.

As the minimum permitted fuel for a subsonic sector is 25000kgs and for a supersonic sector is 35000kgs then yes, there is always fuel in the "a" tanks. 

  • Like 1
Link to post
Ray Proudfoot

Frazz, thanks for that. With nearly 1300 reads this topic is being followed by more than you might imagine. It’s certainly been educational for me and many others I would think. So fuel always in the a tanks.

Link to post
Ray Proudfoot
7 hours ago, Fraser Gale said:

It would be nice to cover something other than the fuel system for a change. As important as it was it wasn't the most clever part of Concorde...

There is an option at the top of the forum to create a new topic. :D

Link to post
Fraser Gale
3 hours ago, Ray Proudfoot said:

There is an option at the top of the forum to create a new topic. :D

It is much better to discuss things from a question rather than boring people with random information...

Link to post
Ray Proudfoot
5 hours ago, Fraser Gale said:

It is much better to discuss things from a question rather than boring people with random information...

But unless someone asks about Concorde's "clever" things how are we to know what they are? Make the subject title interesting and it won't be boring.

Link to post
Fraser Gale
1 hour ago, Ray Proudfoot said:

But unless someone asks about Concorde's "clever" things how are we to know what they are? Make the subject title interesting and it won't be boring.

I would hope the virtual pilots would already be well aware of the systems that were and still are ahead of their time.

Anyway, short of reopening the Airman's Training Centre at BAC Filton, I think we've covered everything possible on the fuel system!

  • Like 1
  • Haha 1
Link to post
Ray Proudfoot

Thanks Frazz. It’s been a very informative thread and I hope I’m not alone in having learned a lot from it.

Link to post
Seth Goodwin

I still wonder how sensitive Concorde was to lateral fuel imbalances particularly at subsonic speeds. The only technical reason I can think of for having tank 8 being larger than 6 is it allows you more fuel forward for c/g purposes (assuming you fill it). I have to think that was an intentional design decision on the part Aérospatiale/BAC, meaning it likely was fine on especially in early stages of flight. Obviously it appears BA made an operational decision not to use it for some likely very valid reasons.

Frazz have you purchased the Barbados operational notes? I've been tempted, but the shipping to me in the States is nearly the cost of the item itself. And i just realized we lost Pete Finlay too this year... :(

Link to post
Fraser Gale
4 hours ago, Seth Goodwin said:

I still wonder how sensitive Concorde was to lateral fuel imbalances particularly at subsonic speeds. The only technical reason I can think of for having tank 8 being larger than 6 is it allows you more fuel forward for c/g purposes (assuming you fill it). I have to think that was an intentional design decision on the part Aérospatiale/BAC, meaning it likely was fine on especially in early stages of flight. Obviously it appears BA made an operational decision not to use it for some likely very valid reasons.

Frazz have you purchased the Barbados operational notes? I've been tempted, but the shipping to me in the States is nearly the cost of the item itself. And i just realized we lost Pete Finlay too this year... :(

She was more sensitive to lateral imbalance at supersonic speeds.  Imagine you are a passenger in a car driving at 30 miles per hour and you stick your hand out the window, with your hand flat there is minimal drag. Now move your hand so that the palm is facing the front of the car and you can feel the resistance of the air, which is drag.  If the car then speeds up to 60mph and you do the same thing, you would feel a heck of a lot more resistance!  Now supersonic laws are reversed so the rate of drag increase with speed reduces as you accelerate - in the case of Concorde anyway, which is why she is more economic at Mach 2 than at Mach 1, because although the drag is increasing, it is doing so at a slower rate than the efficiency of the intakes is increasing. Never the less, even a 1/2 degree difference in elevon angle across the wing will have an effect on fuel consumption due to drag increase. 

I actually am reasonably sure that the only reason for differences in tank sizes was because of the wing space available - every inch that could take fuel was used.  In fact it is a well known fact that each aircraft in the fleet had slightly different sizes of tank! This made fitting the Kevlar liners even more of a headache as each one had to be made unique. As I stated before, BA treated tank 6 and 8 as if they were the same size. 

I have had the Barbados notes for several years, although I would say that unless you do absolutely everything "by the book" and treat the sim like a real aircraft, I don't think it will be of much assistance in the sim.  Indeed, Pete passed away sadly, he lived not too far from me but his main service etc was planned to be in his native Yorkshire.  He had been quite ill for some time and in and out of hospital.  He loved talking about Concorde over the many emails we sent back and forwards and enjoyed the fact that being from a younger generation, I loved her as much as he did.  

Link to post
James Burke

This thread reminds me of the old days on pprune with the Concorde captains chipping in once in a while with neat bits of information. Great thread here, sticky worthy really.

When I have time maybe I'll pitch some of the Concorde FBW and other electrical systems questions out there for people to take a swing at.

  • Like 1
Link to post
Fraser Gale
5 hours ago, James Burke said:

This thread reminds me of the old days on pprune with the Concorde captains chipping in once in a while with neat bits of information. Great thread here, sticky worthy really.

When I have time maybe I'll pitch some of the Concorde FBW and other electrical systems questions out there for people to take a swing at.

And the flight engineers more importantly - most of them knew the aircraft better than the pilots, and the best captains admitted it!  One poster on that thread in particular was a very experienced, highly knowledgeable retired flight engineer who occasionally still flew as FE on vintage aircraft for flight displays.

It would be nice to discuss something different....

Link to post
  • 2 years later...
Andrew Marshall
On 9/23/2018 at 1:25 PM, Fraser Gale said:

I advised you to get the deals manuals on CD a while ago, then you would have all the charts and procedures.

Hi Fraser,

Curious what you mean by the "Deals Manuals". Is this the name of the CD? Is is someone's name who put this information together?

Link to post
Fraser Gale
On 1/21/2021 at 5:34 PM, Andrew Marshall said:

Hi Fraser,

Curious what you mean by the "Deals Manuals". Is this the name of the CD? Is is someone's name who put this information together?

Nope, it looks like an auto correct gone wrong.... it should say the real manuals!!

  • Haha 1
Link to post
Andrew Marshall

Ah ok! Do you have any recommendations for sourcing the CD/real manuals? I’ve looked at why is on offer at eBay but what I’ve seen is incomplete at best. I’ve also come across the Air France version which seems more complete, but my French is not up to the task!

Link to post
  • Ray Proudfoot changed the title to Is 59.3 the ideal CG before descent?

×
×
  • Create New...