PPRuNe Forums

PPRuNe Forums (https://www.pprune.org/)
-   Tech Log (https://www.pprune.org/tech-log-15/)
-   -   787 Performance (https://www.pprune.org/tech-log/500312-787-performance.html)

Airspeedintervention 13th Nov 2012 01:00

787 Performance
 
Took my first IOE flight in the 787 last night. We had a full load of Pax -219 but were light on fuel as it was a domestic flight. We went right to level 400 @ speed mach .86 and a fuel flow of 4500lbs per hour per side. Aircraft weight at the time of observation was 367,000 lbs.

Check Airman 13th Nov 2012 03:29

Seems pretty impressive. How does that compare to the 777 and 767?

nitpicker330 13th Nov 2012 04:34

Our A330 with 250 pax at about 400,000 Lbs AUW will show a FF of around 5,000 lb/hr each Engine at around FL 400 Mach .81

A330 equates to 21.7 lb/anm
B787 18.5 lb/anm

So the 787 is impressive.

G&T ice n slice 13th Nov 2012 07:49

787 = 41.1 lb/hr/pax
330 = 40.0 lb/hr/pax

fullforward 13th Nov 2012 07:57

Hey G&T
 
Bad math: the 787 will cover 50 nm more on the same amount of time.
So 787 is much more fuel efficient thant the Scarebus, hands down.

Durban 13th Nov 2012 11:36

G&T ice n slice
 
Were there any cruise speed figure associated with those figures?

G&T ice n slice 13th Nov 2012 11:49

No..... mathematically my calculations are correct.

I made no further comment than that.

Now, if you had chosen to maybe make a calculated example....

let's say Haneda-Itami?

Spooky 2 13th Nov 2012 11:59

Give a city pair and I'll give you a number for the 787. Don't have any AB data or pax capacity

DaveReidUK 13th Nov 2012 12:54

This isn't rocket science.

The B788 and A332 carry more or less the same number of passengers.

The 787 burns less fuel per hour while flying faster.

Which is more fuel-efficient ? (Hint: the only metric the airlines give a toss about is fuel burn per seat-km).

G&T ice n slice 13th Nov 2012 16:18

OK here goes, ignoring a whole bunch of variables, just looking at the "steady state" and using some slightly suspect numbers...

distance = 913Kms = 1 hour 787 = 1.06 hours AB

fuelburn/hour 787 = 9000, AB = 10000
so for 913kms burn 787 = 9000, AB =10,617

seat 787 = 219, AB = 250

assume fuelcost 2.05/us gallon = $0.308/lb (approx)

Delta fuelcost 787-AB = 1,617lbs = $498 (AB more)

Assume average saleable $250/pax then revenue 787 = $54750 AB = $62500 and Delta earnings = $7750 (AB more)

"incremental" is added $498 cost but $7252 (nett) revenue

ratio incremental revenue/fuelcost (hours basis 787 distance)
1 hour = 14.5
2 hours = 6.8
3 hours = 4.2
4 hours = 2.9
5 housr = 2.1

In other words on basis up to 3 hours (787 distnce) there is some advantage in terms of revenue potential to operating the AB. with average revenue $250/pax.

(scuse spelling etc, it's this dratted keyboard)

p.s. I'm an accountant

Lyman 13th Nov 2012 16:24

The Dream holds 219? That's all?

Put a plug in the 737-8 and pack the pineapples, Kona here we come....

B-HKD 13th Nov 2012 19:11


The Dream holds 219? That's all?
Depends on the airline :ugh:

United (219): Configured with 36 Business (lie flat), 70 Economy+ and 113 Economy.

Ethiopian (270): 24 Business (lie flat), 246 Economy

ANA Domestic (222): 42 Business, 180 Economy.

ANA International (158): 46 Business (lie flat), 112 Economy.

Qatar Airways (254): 22 Business (lie flat), 232 Economy.


Amazing aircraft which is enabling many new routes to be launched, such as:

NRT-BOS-NRT (JAL, Already operating)
NRT-SAN-NRT (JAL)
NRT-SJC-NRT (ANA) ---- (AA operated the route until 2005 on the B772)

Qatar will eventually launch:

DOH-DTW-DOH
DOH-BOS-DOH
DOH-ATL-DOH

Phil Squares 13th Nov 2012 19:16

p.s. I'm an accountant

That's the problem!!

Looking at the burn/hr/pax is really meaningless. You need to look at the burn/ANM. You will see the 787 is more efficient and cheaper to operate when looking at operating costs.

G&T ice n slice 13th Nov 2012 19:52

Hi Phil,

not meaning to be rude, but this is why I am an accountant and you are a pilot (I assume).

You look at the technical aspects and say "this is the best aircraft"

I look at the financials and say "I'm an accountant, what's the answer you need to swinhg this one past the shareholders and get that huge bonus?"...

err sorry umm rather "what are the financial implications of a 250 seat aircraft against a 219 seat aircraft"

The financial implications (just on the fuel burn) are that with an extra 31 fare-generating seats the fuel penalty is not signifcant (within certain parameters).

Phil Squares 13th Nov 2012 20:45

Yes a pilot but with a MBA too!!

The problem with your analysis is you are comparing apples to oranges. It is a meaningless comparison. If the extra pax generate extra revenue and at the same time increase incremental costs then it makes no sense. That is why you need to look at fuel/ANM.

The 787-8 will take 250 but then it might not be right for the route structure, while conversly the 330 might take 280 but it it can only fill 220, then it's too much.

Each airline looks at the purchase of new aircraft very differently from the next airline. That's why it's very difficult to make broad sweeping all encompassing remarks.

DozyWannabe 13th Nov 2012 21:04

Impressive stuff - Boeing should be proud.

That said, how is the B787 being more fuel-efficient than an A330 supposed to be surprising? It's like comparing a 2008 Toyota Prius with a 1992 BMW!

There'll be no meaningful like-for-like comparison in that regard until the A350 goes into service, and even then there are subtle but important differences in the specifications of both.

Fuel efficiency is but one factor in the total cost of ownership, and there things tend to get complicated. Airbus's ace in the hole has always been much more cost-effective conversion training between types, and Boeing has never tried to compete in that regard. Conversely, Boeing have tended to have the edge in terms of raw performance - but up until recently they have tended to compete directly on a common vision of how civil aviation works. This represents the first time in the last 30 years that either company has staked its reputation and future on a significantly different view of future demand.

The truth is that as end-users and customers our needs are best served in the short term by both major airframe builders being successful, because history teaches us that monopolies are usually a bad thing.

(As an aside, my experience teaches me that MBAs are like foundation IT courses in that they give people just enough information to be dangerous without the requisite background knowledge)

DaveReidUK 14th Nov 2012 06:29


The problem with your analysis is you are comparing apples to oranges. It is a meaningless comparison. If the extra pax generate extra revenue and at the same time increase incremental costs then it makes no sense. That is why you need to look at fuel/ANM.
At the risk of stating the obvious, that's just another way of saying that both seat-km and aircraft-km costs have to be factored into fleet planning decisions.

So, for example, the 747 will have a lower cost per ASK than the 737, but if you're only getting 737-sized loads ...

And since competing manufacturers don't make identical aircraft, any comparison is never going to be 100% apples-for-apples.

Phalanger 14th Nov 2012 07:07


err sorry umm rather "what are the financial implications of a 250 seat aircraft against a 219 seat aircraft"

The financial implications (just on the fuel burn) are that with an extra 31 fare-generating seats the fuel penalty is not signifcant (within certain parameters).
And this is where your comparison falls to pieces half way through.

You compared two different layouts which command different revenues in different markets which is an assumption with an error factor well beyond the difference. It also assumed all other costs are the same which is for sure wrong and every seat is sellable without having to cut sales revenue on each seat.

The comparison by anm at least allows the airlines to then work out how to divvy the costs. Doing it by seat shows nothing as the value of each seat is not similar.

G&T ice n slice 14th Nov 2012 07:41

Well... I did say:



ignoring a whole bunch of variables, just looking at the "steady state" and using some slightly suspect numbers
To be absolutely honest my very first post was a bit naughty. It was just that the seat discrepancy (219 vs 250) was so extreme. (actually I thought that the 219 for the 787 was way too low)

Obviously basing my entire argument on just 2 sets of numbers (given mach & given seats) is pretty much like constructing a skyscraper on sand and without foundations.

But it still stands that a slightly less fuel efficient aircraft can be financially the better option if that ac has a higher revenue-generating potential.

(and that the demand exists and etc etc etc)

Denti 14th Nov 2012 07:52

The 787-8 is quite a small airplane actually. Boeing says on its website that it aims for the 210 to 250 seat market, the latter one in an all economy configuration. The 787-9 will be a better comparison to the A332 in my opinion as it aims at the 250 to 290 seat configurations. Probably i'm a bit biased because we operate the A332 in a 303 seat two class configuration and the A333 (which is going to leave the fleet soon) in a 387 seat all eco configuration.


All times are GMT. The time now is 05:45.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.