Commercial longevity: Cargo vs Passenger. Which is longer?

[Amrick615 6]

Hello! 
 

I was looking to discuss this topic to gain an understanding about the longevity of cargo planes compared to passenger jets. 
 

Why exactly do cargo-lines (Fedex, UPS, etc) still fly older models such as the MD-11, DC-10, and A300, whereas the major passenger airlines have deemed them as outdated and inefficient for passenger travel? Are the payloads of cargo flights more lucrative since you can fit more boxes than people into a plane?

Also, where does the 767 stand on this? I feel like airlines are phasing this plane out, however cargo-lines like Prime Air are still investing in it. What’s the incentive to do this?

 

thank you! 
 

Amrick Dhillon

[qqwertz 781]

Hi Amrick,

interesting question, I am curious about the answers of more knowledgeable people as well. I always assumed that there are two reasons: (i) Safety and comfort. You probably wouldn't be allowed to fly passenger in a 1970s jet anymore without upgrading it, and people trust a newer airplane much more than an old one. (ii) Operating costs. Competition in passenger transport is fierce, but cargo transport seems to be in the hands of just a few large companies.If I look at the price for shipping cargo, it appears that they can charge more per kg payload than passenger carriers.

I am pretty sure that the airplanes do not age differently (except that passenger jets may be flown more often and accumulate miles more quickly). Smaller airplanes are used for passenger services even after 70 years or so.

Peter 

[stans 703]

I expect the overwhelming factor is procurement cost.  Cargo aircraft are often former passenger aircraft, which can be bought at a fraction of their original price.  In cargo service, the aircraft does not have to be the latest and greatest, feature amenities that appeal to passengers, so the procurement cost is spread out over an even longer period of time than most passenger aircraft. 

[G-RFRY 1,711]

One of the biggest factors is maintenance cost the older the airframe cost tend to increases, this is why you are likely to see some disappear from the sky`s due to covid 19.   

[Chock 17,769]

The short answer is, it's the cost of buying them and the cost of running them which is the main factor in the longevity of airliners in passenger and cargo roles. Skip down to the paragraph marked 'here's why it is cheaper', if you don't want to read all the other stuff, but if you do, here goes...

Two great examples of why cargo flying is cheaper than passenger flying would be the MD-11 and the Airbus A340 and their short lived airline careers owing to changes in the market and changes in technology.

The MD-11 is a development of the DC-10, which was itself developed as a successor to the DC-8 as well as a rival to the 747. The 747 had been developed with four engines in large part because of the need to have some redundancy in the amount of engines on something which might have one or possibly two engines malfunction when it was in the middle of the Pacific, which back in 1969, with jet engines not as reliable as they are today, was a possibility; the engines on the original 747 (P&W JT9D) were a brand-new model too, as well as being P&W's first high bypass turbofan, so they were at the time something of an unknown quantity.

As a result of all that new development of a big high-bypass turbofan, only using two such engines on such a craft would have been a risky proposition before the things were proven to be really reliable, but using three of these engines was feasible, since if a tri-jet lost an engine, it would still be able to maintain height on two engines and could also do so on one, albeit with a bit of effort such as dumping fuel and diverting etc. In only using three engines, tri-jets are cheaper to buy, cheaper to run and cheaper to maintain, but can still be a wide-body design capable of carrying lots of passengers, which is why in that era, there were lots of them - 727, Trident, Tristar, DC-10 being the main ones.

But they were not so vastly economically more efficient that they ousted quad-engined airliners from the skies, which is why you still saw 707s and DC-8s about. Nevertheless, Boeing did actually propose making a tri-jet version of the 747 too (it looks weird if you see the prototype drawings) but decided against it because by the time they would have completed it, there were going to be twin-jets in service which would rival it, negating the point of making such an aeroplane, so they instead began working on what would eventually be the Triple Seven.

What changed all that tri-jet monopoly more than anything was the A300. The A300 was the first ETOPS-compliant airliner, and it only managed to gain that certification by shooting for massively higher standards of reliability than most other airliners, not least in its engines. The moment the big reliable twin with long range and ETOPS certification turned up, the writing was on the wall for tri-jets, since the new twins were significantly better in almost every respect, not least of which was economy, which by that time, with increasing fuel prices, was starting to become a big factor in airliner passenger operations.

This was the worst thing possible for McDonnell Douglas. Struggling in a tricky market, they gambled on souping up the DC-10 with a glass cockpit and a redesign to make it much more efficient, and this they did manage, albeit at some risk. Part of the reason the MD-11 is economical (for a tri-jet at least), is that MD made the tailplane a lot smaller and redesigned the main wing, reducing the tail-down force required from the tail and using electronics to compensate for this with FBW systems. It works, but it means that on landing, the tailplane authority on the MD-11 is not what it was on the DC-10, making it tricky to land and having been the cause of some accidents and the necessity for careful training on crews. In any case, the MD-11's improved efficiency over the DC-10 was too little and too late in the face of several alternative twin-jet choices for the airlines, and so it only had a brief airliner career.

There was still a need for the odd quad-jet however, since there are some places on Earth where you just don't want to risk only having two engines, mostly this is places such as over the Antarctic or down over the very long stretches of water in the south Pacific. This is why you see Qantas flying quite a lot of quads and it is why, for a while, it was worth Airbus developing the A340 and the A380, however, the way things have gone in airliner demand, means that even these aeroplanes are falling out of favour as passenger jets, because what airlines really want, is range, rather than capacity.

Here's why it is cheaper

So as all this development has gone on, the less popular jets become available for very little money; you can buy an Airbus A340 for less than 10 million quid these days, and those things cost over 250 million quid each less than ten years ago! They are cheap because you can't compete with other types economically in the passenger market, but in the freight market you can. And here's how...

If you are in Europe or the US and you've ever ordered anything from China in the post, you will know that it can invariably take ages for it to arrive, but sometimes it can surprise you and come quite quickly. This is a function of how cargo airliners can operate as opposed to passenger airliners. A passenger airliner can carry a bit of cargo to offset operating costs a bit, but they mainly exist to carry passengers, and passengers do not want to wait around, they want scheduled flights. This means as a passenger airline you have to say your airliner will be flying from A to B, at this time on this day. and if you don't stick to that promise and someone buys a ticket for that flight and is delayed more than 3 hours in the EU, they qualify for 400 Euros in compensation, and if the delay is even longer, you have to find those passengers an hotel, feed them, and you still have to get them where they are going. This means if your Airbus A330 flying from Manchester to Orlando gets delayed by a significant amount, you are going to lose approximately £280,000, just for that one single delay.

Conversely, you have an old MD-11 or DC-10 and you are flying cargo, you can simply have a contract to fly cargo from one hub to another. So your aeroplane can sit on the ramp for several days, waiting for all that cargo to arrive at the hub and be palleted up, and then you just load that thing up when there is enough to fill it, file an IFR plan for your route to another hub and off you go. And your cargo plane might use a bit more fuel, but there are many systems on board which it does not have to have and therefore does not have the expense of maintaining - no oxygen masks for the cabin, no emergency slides on numerous doors, no seats to keep clean, no life vests and safety briefing cards to replace all the time (yes, people nick them as souvenirs - don't do this, it's hugely irresponsible!).

No tight schedule to adhere to, no cabin crew to pay, no departure lounge niceties to pay for, no check in desk staff, no TCOs running around looking for a late passenger, no luggage to check in, scan, or load, no lost bags to deal with, no luggage to unload on arrival, no catering to organise or pay for, less frequent toilet servicing, no need for cleaner in the cabin and no risk of paying 400 Euros per passenger for a three-hour delay. Cargo doesn't care how long it sits on the ramp.

Edited July 29, 2020 by Chock

[bic 44]

United used to have daily flight KEWR-EGLL using 767 workhouse.  I always saw it while out walking during lunch.  I don't go to work anymore, so don't know, but in March I was still seeing them.  I don't think the 787 are being made fast enough.

Edited July 29, 2020 by bic

[Patco Lch 1,465]

If I were a commercial pilot I would prefer cargo. No wonkie public to put up with. Of course there's some shoe string cargo outfits that don't have the best safety record not to mention employee relations and compensation may not be as good.

[HighBypass 2,339]

1 hour ago, Chock said:

Cargo doesn't care how long it sits on the ramp.

I've got an MD-11 t-shirt I made myself and the tagline I put on there is "Boxes never complain" 

I think some cargo flights do have to leave on a specific day within a time window, but that would be for livestock shipping - horse transport for example. Horses DO complain, but unlike human freight, we are allowed to sedate horses.... (sorry Spirit Airlines, I know you'd like to..) 

[SAS443 1,723]

Compared to passenger airlines, Cargo operators are not as concerned at fuel costs as they are with dispatch reliability and acquisition costs. This is due to the significantly reduced annual flight hours/year compared to a passenger airliner. A passenger jet is is the air roughly 3 times to that of a cargo jet annually. 

In effect, older generation jets in cargo ops, such as the 757F and the 737F (classics) enjoy a similar dispatch reliability compared to current generation since they are on the ground during the day which allows more time for any kind of maintenance needed.

TLDR: older generation jets are cheaper to buy and just as reliable for cargo airlines, which still makes them attractive

(I did my master thesis on aviation cargo, although this was some years ago, I Still think the reasoning above would stand today?)

Edited July 29, 2020 by SAS443

[G-RFRY 1,711]

https://www.msn.com/en-gb/money/other/boeing-unveils-sweeping-production-cuts-as-pandemic-hammers-sales/ar-BB17jW7H?ocid=msedgdhp

Goodbye to the big jets.

[Mace 1,924]

On 7/29/2020 at 2:47 AM, Amrick615 said:

Hello! 
 

I was looking to discuss this topic to gain an understanding about the longevity of cargo planes compared to passenger jets. 
 

Why exactly do cargo-lines (Fedex, UPS, etc) still fly older models such as the MD-11, DC-10, and A300, whereas the major passenger airlines have deemed them as outdated and inefficient for passenger travel?

Compared to pax aircraft, cargo aircraft don't see as many cycles.  Cargo carriers want airlift capacity available all the time, even over fuel efficiency.

The former sentence is also why some of the old jets are still around.  I can speak of Fedex, they are phasing out their MD-10 fleet but it's happening more slowly than anticipated because of the increased need for capacity.  CV19 probably has something to do with that, but demand was high and getting higher even before that. 

Last time I checked Fedex had an MD-10 that was built in 1972 as a DC-10 and it was still on the line.  Fedex currently uses DC-10's on their Memphis-to-Guadalajara route, as well as Memphis-Oakland and Memphis-Montreal and Memphis-Chicago.   That's nothing compared to what Fedex's MD-10's used to run, say, 10-15 years ago.  They were heavily used.  And today, not much by comparison.  The 767 is gradually replacing them.  Which brings me to your next question...

On 7/29/2020 at 2:47 AM, Amrick615 said:

Also, where does the 767 stand on this? I feel like airlines are phasing this plane out, however cargo-lines like Prime Air are still investing in it. What’s the incentive to do this?

The 767F (cargo variant) is still in production.  As in brand-new 767's roll off the line still.  The 767F must be the perfect size for many of the cargo carriers.  It is not a narrow-body.  Plus it is a twin-engine jet, so less fuel cost than the 3-holers typically.

A few months ago someone (maybe it was me, I can't remember) posted about the new A321 cargo aircraft.  Narrow-bodies of that size will have their market too.  It's just that the 767 (like the A300 and DC-10 before it) is right in there, more capacity than the narrow bodies, but less than the 777F.   All with twin-jet efficiency.

Anyway those are my random thoughts...

[Mace 1,924]

On 7/29/2020 at 7:12 AM, HighBypass said:

I've got an MD-11 t-shirt I made myself and the tagline I put on there is "Boxes never complain" 

Whoa.  That's way cool.  How did you make it?  One of those "make-a-T-shirt" websites?

[HighBypass 2,339]

Nope! I work for a builder's merchant who also can personalise clothing and PPE for our customers (we buy the garments in, we don't actually make them). When I'm not on furlough  my job is transferring customer logos into embroidery and print.

So, have we got any extra t-shirts not in stock? Check.

Find side silhouette of MD-11 on the interwebz and trace it in the print software. Check

Add a bit of text to the image, making sure I've got the MD-11 logo correct. Check

Use the plotter to cut the design from the "flex" Check. Flex in this case is just stretchy vinyl with heat-activated adhesive on one side of it. https://www.youtube.com/watch?v=wtyLKbGtg1E

Use heat press to apply to t-shirt. Check.

Give the boss a token amount of cash based on supplies used (all work carried out on my own time during breaks and lunch) Check.

 

[Chock 17,769]

6 minutes ago, HighBypass said:

So, have we got any extra t-shirts not in stock? Check.

Find side silhouette of MD-11 on the interwebz and trace it in the print software. Check

Add a bit of text to the image, making sure I've got the MD-11 logo correct. Check

Use the plotter to cut the design from the "flex" Check. Flex in this case is just stretchy vinyl with heat-activated adhesive on one side of it. https://www.youtube.com/watch?v=wtyLKbGtg1E

Use heat press to apply to t-shirt. Check.

Give the boss a token amount of cash based on supplies used (all work carried out on my own time during breaks and lunch) Check.

 

Cottage industry in the making - check!

[HighBypass 2,339]

I'm no cottager!