shoodawg

One of my favorite aircraft types.

Slow learner

Predominately because of range and fuel burn. Depending on weight and conditions, the A350 can cover a range of around 10,000 nautical miles, compared with a range of 8,500 nautical miles for the 777 under the same conditions. The A350 will burn about 5.8t of fuel an hour, compared to 6.8t for the 777. If you do some quick sums, using a 10 hour flight, out-and-back every 24 hours (like ATL-LHR) with a utilization outside of maintenance of 320 days in a year, the A350 will be using about 6,400 tons less fuel. Today a ton of fuel is around $800, that's an operational cost saving of around $5M per airframe/per year over the 777. It starts to add up quickly.

joeyday

Is this the case with the latest versions of the 777 or just the early versions?

unitedbusiness

thanks for the info!
you’ve made us all fast learners with your crisp and concise explanation

shoodawg

thanks a lot

DLATL777

Have to remember that Covid sped this up. I believe they still had a few years left, especially for the 200LRs, as they just spent a LOT of money retrofitting them with the new product. It was a real shame to see that go to waste.

paul21

Also they had 8-10 planes and no orders, so it was a lot of overhead for a small fleet that was tenure heavy. During the pandemic they cut MD88 and 777, and they'll cut 717 soon ish in favor of A220. Then they'll have A220, A320, 73N, A330, A350, and 7ER. Next to go is 7ER as nothing new is coming there. That's the 757 and 767 fleet.

VFR

They did have range and payload issues at first replacing the 777-200LR with the A350 on ATL-JNB, but I believe the later models got a MTOW increase that mitigated those issues.

rylan

Correct - the 777LR was able to make that route without major issues, but when they switched to the first version 350s it was a mess with the high altitude and some flights were making fuel stops and/or being cargo limited.

PupManS

Interestingly the reason the LR was able to make it out of JNB is that DL worked with the tire manufacturer (I think BFG) to do some special tire testing. The limit on getting out of JNB with that much fuel wasn't thrust or wing, it was ground speed. The LR had a massive power to weight ratio but not a lot of wing, and to use all that power to get airborne on JNB's long runways required a lot of wheel speed. More than any other route in the world on a major carrier.

The A359 had a totally different problem. It had a lot more wing and adequate thrust, but couldn't easily uplift enough fuel due to a lower MTOW (structure limits). DL got their MTOW increase and can now uplift enough fuel.

All this being a long winded way of explaining why the 777 is gone. It used a "more power" approach to the mission. More power = more fuel. That, and the fact it was a sub scale fleet that made the total cost of operation higher than it would otherwise be.

Jeff767

The A350 on that route is still a issue. They often route the bags on KLM up to AMS and then on Delta to ATL. Higher gross weight versions are only helpful if you have the performance to use that weight. Out of JNB in the summer the airframe lacks that performance. The 777LR had no real issues.
As far as removing the aircraft from the fleet the initial projection was 5 to 6 years for a return to normal international travel. That turned out to be a miscalculation but undoing it was sadly not a option. Picking up additional A350’s was more cost effective even having to live with weight issues on a limited number of flights.

Tonyh120

I am intrigued by this thread, and find the discussion about fuel efficiency and tires fascinating.

The comments are very operational in nature and maybe that's exactly the primary driver of the decision. That said, my first instinct was:

1. Do passengers prefer the A350 over the 777? If two airlines fly the same route, one with the B777 and one with the A350, is one airline generally preferred over ther other (either in share or with a pricing premium)? Since the A350 is a newer aircraft I suspect it may be more desirable (quieter, better air pressure, etc.)

2. I think (but am not sure) that Delta configured the A350 with a few more seats than the 777 - something like 306 versus 296. If that's correct, then Delta would boost its revenue per aircraft by about 3%. If I re-create the math from Slow Learner (very helpful!), then that's worth about $4MM per year. If our back-of-the-envelope guesstimates are in the ballpark, that's a $9MM delta (no pun intended between additional revenue and lower cost of the A350 over the B777.

(P.S. I'd love to get this group's views on my assumptions:
* I started with Slow Learner's (with one small tweak)
- 320 flying days per year
- Plane flies for 18hours per day (8 hours out, 10 back) - adjusted downward from 20
- Fuel cost is $800 per ton
- Fuel burn rate is 5.8 tons per hour for A350 and 6.8 tons per hour for B777
- Fuel cost is (320 x 18 x 6.8 x $800 = $31.3 MM per year) verus (320 x 18 x 5.8 x $800 = $26.7 MM per year) = cost savings of $4.6 MM per year
* I made my own assumptions for revenue
- Same parameters as above
- 306 seats (A350) versus 296 seats (B777)
- 80% of seats are revenue producing
- Average revenue per sold seat per segment = $750
- Revenue for A350 is 320 days x 306 seats x 80% yield x $800 = $117.5 MM per year (versus $113.7 for B777)

My 80% and $750 are just based on intuition (for the ATL-LHR route).

To sense check my calculation, I looked the the ratio of estimated fuel cost to estimated revenue. From the above, for the A350, we have annual fuel cost of $26.7MM and annual revenue of $117.5MM, for a ratio of 22.7%. For the B777, it's $31.3 over $113.7 = 27.6%. Looking at Delta's full-year 2022 financial results, Delta had total fuel costs of $11.45 BN and total revenue of $45.6 BN for a system-wide fuel-to-revenue ratio of 25%).

Thoughts/feedback/comments most welcome.

paul21

The MTOW increase helped more on LAX-SYD-LAX and ATL-JNB with extra cargo than JNB-ATL. Usually JNB is rated below maximum already due to the altitude.

jimrpa

why don’t they just cut the number of pax and cargo to accommodate all the baggage?

rylan

They make a lot more money on the cargo. Most if not all of the passenger bags are flying free.