Jump to content

Shannon (EINN) to JFK (KJFK) A318 issue


Andy320

Recommended Posts

HI,

 

I believe the fuel planner data is incorrect for the A318 or the fuel flow in flight is incorrect, I just finished a test flight using FSX clear weather (no winds) and ended up landing with 540kg of fuel from 15,823kg. I thought the low fuel issue may be to do with ASN on previous pond flights, but this has proven to be wrong today.

I will now show you why I believe something is incorrect with the fuel data and please correct me if iv done something wrong.

Hopefully the pictures will send in the order I uploaded them.

So as you can see in the first picture the A318 according to aerosoft requires 10,280kg of trip fuel to make this 2721.9mile trip with nil wind, online fuel planner requires 15,516kg trip fuel. So far I'm trusting aerosoft fuel planner.

Please login to display this image.

My actual take off fuel is 15,700kg on runway 24 Shannon EINN after a shortish taxi from gate A25.

Please login to display this image.

Now in the next picture you can see that my fuel prediction at destination is 3500kg for my optimum FL390 and cost index 0 although I fuel planned for FL380. You can already see that my trip fuel is more than planned

Please login to display this image.

This is a picture from TOC, already you can see a decrease in fuel remaining from 3500kg to 3300kg now I have had small variations with the other busses so I didn't worry to much here.

Please login to display this image.

Now just before waypoint EBONY approx 240nm before descent, you can see that my predicted fuel remaining at destination is 900kg from 3500kg predicted at take off, the only thing I change not to long ago was a descent to FL380 which was already planned for. 

Please login to display this image.

Predicted fuel now 400kg at TOD, as the test was to land at KJFK I continued. 

Please login to display this image.

Fuel on final approach is 620kg and I end up with 540kg vacating the runway (AP off at around 3.5nm) 

Please login to display this image.

Here you can see my FSX flight information including my descent down to FL380.

Please login to display this image.

 

So as you can see the predicted trip fuel from Online Fuel Planner was by far most correct for this flight, if this is an issue with aerosoft fuel planner are there any plans to correct this issue?

kind regards

Link to comment
Share on other sites

I used CI 0 for this flight as iv read that BA use CI 0 for this flight, the issue is, is that the A318 predicted fuel at destination is decreasing throughout the flight, I haven't had a noticeable fuel issue from EGLC to EINN on the A318 using CI 20. My only other long or should I say mid-haul flight which I plan to fly very soon again was EGLL to UBBB with the A321.

Please login to display this image.

Here I remember I landed with roughly 7,000kg (TOF 22,xxxkg) using cost index 20 with a modified MDCU2c file on v1.3F to increase the fuel load for that flight with 155 pax (British Airways A321 G-MED_ config). I never had a fuel issue on this flight, the predicted fuel increased as I climbed in due time to an optimal FL350 by roughly 200kg. So my point is, is that I believe this is an A318 and fuel planner issue for the A318 only. I don't think you guys will have the time to perform such a flight, but if you do plan to please let me know how it goes.

Kind regards

Link to comment
Share on other sites

My guess is the fuel prediction is in error going westbound due to the headwind and the aerosoft airbus not able to use wind data in the flightplan. You can get away with it going eastbound due to the winds being predominantly from the west giving tailwinds.

Link to comment
Share on other sites

I've flown these legs with Active sky next and have to increase fuel by about 4,000kg West and East bound. The above shows my zero wind test westbound with FSX clear weather and the A318 still runs out of fuel by roughly the same figures (varies with flight time). My east bound trip back was with active sky and the fuel loss was similar.

I'm waiting to see if someone else can prove me wrong or has also experienced this issue, it seems not many people fly the BA A318 KJFK route. 

Link to comment
Share on other sites

Just to add my longest recorded A320 flight to Sharm El Sheik hasn't had a fuel issue, I've flown the A320 to Lagos Nigeria from Heathrow just for fun and once again never had a problem.

Please login to display this image.

Link to comment
Share on other sites

  • 3 weeks later...

I was hoping to embark on the A318 BA4 flight from KJFK tyo EGLC but am having problems with the flight plan (from cte but originating from PFPX) causing FSX to crash straight to desktop!

This is just another problem with another Aerosoft product :-(

I also note that this is another call for support that has gone unanswered after nearly a month of being posted. Aerosoft say that the quickest way to get support is by using the forum!?

Mike

Link to comment
Share on other sites

  • 1 month later...

This is the wrong topic for your issue, this topic is regarding a very hungry A318 that is burning more fuel than the fuel planner predicts using Active sky next weather information for flights over the Atlantic. 

Link to comment
Share on other sites

On 16 January 2016 at 9:15 AM, Airbus339 said:

BA uses 15 as a cost index for this flight, not 0

Thank you, and iv done more test flights and it's a fact there is an issue regarding fuel burn with the aerosoft a318, it's burning way to much fuel than what's predicted regardless of weather. The longer the flight the greater the loss of fuel, it's like flying with a fuel leak. 

Link to comment
Share on other sites

On 1/16/2016 at 11:14 AM, acra24 said:

I think, correct me if I'm wrong, that BA use  CI = 0 for climb and then change the CI at cruise according to requirements. 

 

Yes, climb is at cost index 0, but AFAIK CI is pretty much fixed at 20 for the A320 Family and 15 for the A318

Link to comment
Share on other sites

  • 1 month later...

I found a temporary fix for this issue, I was playing around with the cruise fuel factors in the A318/319 fuel planner file and found that 1.08 gives me a more accurate trip fuel for a flight from EINN-KJFK FL390 with zero wind based on the fuel I expect to land with from the fuel planner (3.5T not eating into contingency fuel). I am also going to do some shorter flights to make sure the fuel predictions in zero wind are within +/- 500kg. I also found out that the best way to calculate trip fuel for long flights with the aerosoft buses is by using the formula NAM= NGMxTAS/TAS-GS and inserting the answer in distance directly into the trip distance on the aerosoft fuel planner and making sure you don't include trip winds (001/00kts). There are many apps to find out what your TAS will be for your planned flight to use that formula. I still haven't found out why the MCDU indicates such a high predicted landing fuel (6.9T) and then indicating roughly the correct predicted landing fuel (3.5T) by the time I reach mid decent to final approach. I haven't seen such a large variation in predicted landing fuel in any of the other buses apart from the A318. Anyway I have found a more reliable way of calculating trip fuel for long flights, I think the fuel planner is more suitable for short flights as I don't seem to have fuel issues flying from EGLC to EINN with the previous fuel factors.

Link to comment
Share on other sites

Hi Andy,

 

Excuse my ignorance, if applicable, but what is NAM and NGM?

Also in zero wind your GS is going to equal your TAS which would mean your formula returning a divide-by-zero error.

 

Mike

Link to comment
Share on other sites

Hi Mike,

 

NAM = Nautical Air Miles (vs NGM = Nautical Ground Miles).

 

Ground distance is the distance measured from point to point on the ground: air distance is ground distance corrected for the effect of wind (strictly speaking, the distance travelled through the airmass, which is obviously what the aeroplane "sees" in terms of flight time, fuel burn etc). So for example, if you between two points that are 100NM apart on the Earth's surface at 100kt TAS but with a 20kt headwind, the air distance (i.e. the distance you travel through the airmass) is 125NM (ground distance/ground speed x TAS). Essentially, however, this is the calculation that the fuel planner (or any flight planning software) should be doing automatically when you enter the wind component, so there's no reason doing it manually should produce better results unless there's a bug in the fuel planner calculation (which is possible).

Link to comment
Share on other sites

Well explained, and the reason why I use that formula is because the aerosoft fuel planner for a long-haul flight with the aerosoft A318 is useless sorry to speak. 

 

If you look at my above picture which I will zoon in and copy below

Please login to display this image.

 

You can see on my initial climb the MCDU indicates a flight time of 17:47-1208= "5:39hrs" to fly from EINN to KJFK 2727nm, that would be a TAS/GS of roughly 463kts "taking into account climb and descent" in zero wind cost index zero FL380 and FL390. Now if you look at the bottom of the next picture showing my flight data for that flight in zero wind this is not true

Please login to display this image.

It took over 6:41hrs which is over an hour difference to fly 2727nm which explains why I basically ran out of fuel, and if you look at my above pictures before this post my TAS/GS was roughly 421kts on the ND display flying a cost index 0. So already I have discovered that the MCDU and Fuel planner are predicting fuel for an incorrect cruise speed or flight time regardless of wind (from experience of flying with ASN weather).

 

So now you can see why I have to calculate my TAS prior to my long-haul flight and then use the NAM= NGMx TAS/GS to then enable me to use the fuel planner to calculate my fuel with NAM rather than NGM and calculating fuel with zero winds to get a more accurate result baring in mind the MCDU will predict a high landing fuel until near the approach. 

 

By the way I'm still waiting for aerosoft or anyone to reproduce this but I haven't heard anything yet, hopefully this won't be an issue with the new A330 flying near max range.

Link to comment
Share on other sites

On 4 March 2016 at 11:50 AM, Andy320 said:

I found a temporary fix for this issue, I was playing around with the cruise fuel factors in the A318/319 fuel planner file and found that 1.08 gives me a more accurate trip fuel for a flight from EINN-KJFK FL390 with zero wind based on the fuel I expect to land with from the fuel planner (3.5T not eating into contingency fuel). I am also going to do some shorter flights to make sure the fuel predictions in zero wind are within +/- 500kg. I also found out that the best way to calculate trip fuel for long flights with the aerosoft buses is by using the formula NAM= NGMxTAS/TAS-GS and inserting the answer in distance directly into the trip distance on the aerosoft fuel planner and making sure you don't include trip winds (001/00kts). There are many apps to find out what your TAS will be for your planned flight to use that formula. I still haven't found out why the MCDU indicates such a high predicted landing fuel (6.9T) and then indicating roughly the correct predicted landing fuel (3.5T) by the time I reach mid decent to final approach. I haven't seen such a large variation in predicted landing fuel in any of the other buses apart from the A318. Anyway I have found a more reliable way of calculating trip fuel for long flights, I think the fuel planner is more suitable for short flights as I don't seem to have fuel issues flying from EGLC to EINN with the previous fuel factors.

Correction NAM= NGMxTAS/GS

Link to comment
Share on other sites

5 hours ago, Andy320 said:

I have discovered that the MCDU and Fuel planner are predicting fuel for an incorrect cruise speed or flight time regardless of wind (from experience of flying with ASN weather).


The MCDU at present doesn't have any facility to enter enroute winds, though I believe this is scheduled in a later update (and for the A330). I think it does takes the ambient conditions in to account for predictions to some extent but I'm not certain, and obviously on longer sectors like this one, this will lead to some very inaccurate predictions as you have discovered!

 

However, whilst I use external flight/fuel planning tools rather than the Aerosoft fuel planner, I seem to recall that the Fuel Planner has the facility to input a trip wind value, which should (if all is coded correctly) make the appropriate duration/air distance calculations for the purposes of calculating the required fuel. It would appear from your investigations, however, that something is not quite right in this respect.

Link to comment
Share on other sites

With the A319/20/21 IAE on my normal European flights as long as 2000nm I don't see a huge variation in predicted landing fuel, usually within plus or minus 500kg obviously in aviation nothing is 100% accurate when planning. The trip fuel planned for the a319/20 tends to be almost bang on for most of my flights using ASN. When I fly the A318 CFM from EGLC to EINN I tend to land with enough reserve fuel, the "unbounded fuel error" is marginal. But when I fly from EINN to KJFK the unbounded fuel error is much more noticeable. 

 

Anyway iv come up with several ways to avoide having to divert everytime. You will notice that on my screenshot of FSX tracker I burnt 33,395lb approx 15,180kg trip fuel. You will also see on the fuel planner screenshot the predicted trip fuel was 10,828kg (both in zero wind conditions). so I have come up with some concussions:

 

1. Times trip fuel by 1.4 for each flight

2. Use a cruise altitude of "approx" FL220 on the fuel planner when flying at FL380

3. Change the cruise fuel factor in the fuel planner file from 0.8 to 1.08 and use the NAM=NGMxTAS/GS and don't use the wind section in the fuel planner. (note that I haven't tested this fuel factor from KJFK to EGLC yet)

 

Note that I've flown from EINN to KJFK and back to EGLC more than the amount of fingers on my hands and if I do not apply any of the above methods I will run out of fuel every flight, this is a fact.

Link to comment
Share on other sites

Hi Andy320,

 

unfortunately, I cannot contribute anything to solve the issue, but I would like to add that I've been experiencing similar/same issues when flying the A319 CFM in longer flights of about 2000nm. I've also loaded more than the predicted fuel according to the Aerosoft fuel planner and still found myself short of fuel at the destination, with the initial fuel prediction in the MCDU varying quite significantly from what is predicted when more than half-way into the flight.

 

I haven't had these issues with the A320 and A321 CFM models on longer routes. Sure, the fuel predicition in the MCDU will always vary a little, also due to winds, but I found the A320/321 predictions (both fuel planner and MCDU) to be a lot more reliable than the A319 ones.

 

I do love the Aerosoft Airbus, but sometimes there are just a little too many things that give you a harder than necessary time if you're more into realism than the average customer base that Aerosoft might have designed this product for.

Link to comment
Share on other sites

47 minutes ago, bpcw001 said:

Hi Andy320,

 

unfortunately, I cannot contribute anything to solve the issue, but I would like to add that I've been experiencing similar/same issues when flying the A319 CFM in longer flights of about 2000nm. I've also loaded more than the predicted fuel according to the Aerosoft fuel planner and still found myself short of fuel at the destination, with the initial fuel prediction in the MCDU varying quite significantly from what is predicted when more than half-way into the flight.

 

I haven't had these issues with the A320 and A321 CFM models on longer routes. Sure, the fuel predicition in the MCDU will always vary a little, also due to winds, but I found the A320/321 predictions (both fuel planner and MCDU) to be a lot more reliable than the A319 ones.

 

I do love the Aerosoft Airbus, but sometimes there are just a little too many things that give you a harder than necessary time if you're more into realism than the average customer base that Aerosoft might have designed this product for.

 

Thanks for the feedback bpcw001, this looks like an issue with the smaller CFM buses. The A319 IAE doesn't have a fuel burn issue, I only fly the a318 CFM and all the IAEs but never the A319 CFM before. It's now been confirmed that this is an issue with the smaller CFM buses. When I have time I'm going to find what files deals with fuel burn and see if I can figure something out.

 

I'm not trying to be funny but I didn't plan to buy an aircraft with a fuel planner that isn't compatible up to the aircrafts max range and then be ignore in the forums by the developers. I absolutely love this product, I believe if someone is going to do or implement something at least do it properly or don't do it at all regardless of how much you are selling it.

Link to comment
Share on other sites

After flying to and from the United Kingdom and New York with the A318 I found that a fuel factor of 1.08 in the flight planner file works well with the current fuel burn of the A318. Note that if you are flying from EGLC to EINN (short flights) you will land with roughly an extra 300-500kg more than the previous fuel factor of 0.8.

Link to comment
Share on other sites

  • 4 weeks later...

I have almost come up with a temporary solution to end this topic, I just need to perform one more flight in the A318 to confirm.

Link to comment
Share on other sites

Ok guys iv found a temporary solution for the A318 high fuel burn. Iv recently joined Simbrief to test how well it's trip fuel predictions match the aerosoft airbuses trip fuel using equal Zero Fuel Masses and I'm happy to say it's pretty much bang on within 500kg of all the IAE buses fuel burns (I haven't tested nor do I fly CFM engines apart from the A318 hence the topic). Unfortunately it is very evident that the A318 CFM (the only aerosoft A318 :banghead1_s:) is in fact burning more fuel then it should regardless of the duration of flight. Now what is my solution? My solution is to except the A318 CFM as it is, iv noticed Simbrief allows you to edit the fuel factor of it's aircrafts 

Please login to display this image.

You will notice iv chosen a fuel factor of P12 or 12%, from the many test flights iv done iv found out that the A318 CFM is burning roughly 12% more fuel for each flight. I will now show you my latest flight from EINN to KJFK and you will see how the predicted trip fuel is almost identical to the actual trip fuel using P12.

Please login to display this image.

 

You will see here that my trip fuel predicted with the current ZFM and weather is

Trip fuel= 17,211kg flight time 7:10hrs

Planned fuel remaining= 3,500kg.

 

Now here is the data from the actual flight

Please login to display this image.

 

Fuel used (actual trip fuel)= 37,718 lb= 17,109 flight time 7:21hrs

Landed fuel (fuel remaining)= 8,086 lb= 3,668kg

(Cost index 15)

 

So to rap this up you can either use Simbrief or PFPX and increase the fuel factor to P12 or 12% and/or change the Aerosoft fuel planner fuel factor for the A318 to 1.12 (1.13 recommended) within the fuel planner folder found in documents. I hope this helps.

 

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. Privacy Policy & Terms of Use