Cessna tests new “Skycourier” and it’s actually not too terrible

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Sockmonkey

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Also the Lockheed "Flatbed" concept of the 1980's: Lockheed Flatbed - Wikipedia

But no, rather than a detachable pod (although that might work very well with intermodal containers!), I was thinking of something much more like the C-119 or any of the 1950's cargo airplanes with noses that swung completely aside. The airplane's gear would be height-adjustable to match the bed-height of the truck delivering or picking up the standard cargo containers, and you just roll-on/roll-off directly between truck and aircraft. Put a couple of cargo-bay buffers on the lower lip of the airplane cargo bay and, with the nose or the rear full-width doors wide open, just back the truck right up to the airplane.

Something like you describe could be an airplane that would roll right over an intermodal container on a truck, winch it up against the bottom of the aircraft between the booms, clip on a nose cone and tail cone, and head for the runway. You'd have a drag penalty from the ribbing on the side of the container, but the convenience and quick-turn might be worth the extra fuel.
Maybe put a raised platform at the edge of the tarmac the same height as the floor of the cargo bay. Back up to the thing and roll the cargo off so you don't have to worry about aligning two different vehicles. One side of the platform could slope to match the height of the truck too. Very easy to implement.
 

Vigilant1

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The fleet safety folks will go to great lengths to avoid having crews back planes up as a routine practice, if it can be avoided.

The green eyeshade folks know that running turbine engines on the ground wastes fuel and expensive engine time.

In the grand scheme of things, loaders and trucks are cheap and provide a lot of flexibilty. Just be careful with them around the crunchable, pricey airplanes.
 

Doggzilla

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There are a few reasons why they don’t push cargo designs further.

First, unloading single large pieces of cargo is dangerous because once the container passes the halfway point it can tip itself or the aircraft over.

Secondly, loose cargo in the box shifting can cause crashes from CG shifting. There is a famous military crash caught on video caused by shifting cargo on takeoff.

Thirdly, open containers slung underneath are not FAA approved. They would need special FAA containers with their own certification process.
 

Hephaestus

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Too bad they didn't talk to Boeing. I hear they wanted to restart ov10 production.

A few extra feet of fuselage, dump everything military. You'd have a ton of operators who just need refreshers.
 

Mad MAC

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Having ground vehilces driven by the lowest trained and labour on airfeild drive upto an aircraft and little appreciation how delicate aircraft, may look cheap till one crunches an airframe. One of the pioints of containers is they are relatively idot proof. Just look at the 747 that crashed because the tie diwns weren't derated sufficently for the geometry they were used and the armoured vehicles all piled in the back.
 

BJC

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The cargo ships load the containers from the top with a crane. And I think they unload directly to the truck trailer.
The primary objective is to have the ship idle for the least amount of time. Most ports unload to shuttle trucks and load from shuttle trucks, not to the truck that will transport the container to the next destination. Designing the optimum load sequence is a highly complex mathematical challenge.


BJC
 

Doggzilla

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Yes, the shuttles (often called “yard dogs”) bring in empty trailer chassis that the cranes lower the box onto. The shuttles then drop the loaded trailer in a parking lot and the assigned truck then picks it up from that spot.
 

Victor Bravo

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Fedex might prefer a swing tail, but Cessna will sell a lot more of these to other operators even if Fedex is the launch customer. I suspect Cessna will want a design that is going to be popular with other operators as well.
A swing tail would also be beneficial to other operators besides FedEx. There are 75 year old C-46 Commandos and C-47 Dakotas that are making a daily living up in Alaska and Canada because they can move large fuel and oil drums and water tanks. This Cessna with a swng tail could move lumber and construction materials, sections of pipe, stuff that's palletized, maybe even smaller vehicles, boats, etc. And a swing tail can be disabled when it is not being used, or simply not ordered as an option when you buy the airplane for passenger use. It's not really that complicated to achieve on a manual (pushrod and cable) control system, and there are even hydraulic swivel connector units.
 

Riggerrob

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Side doors are still lighter, simpler and cheaper than tail ramps or swinging aft fuselages.
Side doors are most efficient when sized for specific cargo containers.
 

Riggerrob

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Dear Topaz,
A few years back I sketched a pseudo- XC-120 with inflateable nose and tail cones for the cargo container.
We wonder how much drag would be created by container side corrugations, especially on the short legs typically flown by parcel courier airplanes.
I suspect that icing would a greater hazard.

OTOH FedEx would probably develop a specialized, smooth-sided, light-weight ISO 20 shipping container for this mission.
 

Mad MAC

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Side doors are still lighter, simpler and cheaper than tail ramps or swinging aft fuselages.
Side doors are most efficient when sized for specific cargo containers.
I have no problem with that regarding the tail ramps (plus the drag rise is terrible), but do you have a reference for the cargo doors verse swing tail weight gain?

While that may make sense for pressurized fuses (they have to be round with a flat floor, and are overbuilt to account for pressurization), so there is a reasonible amount of volume above & below the door cut (& the cutout forward of the wing), but unpressurized fuses tend to be flat roofed and with a shallow floor depth so the door cutouts are much bigger as a percentage of the fuse depth and the base line structure much flimsier.
 

Riggerrob

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A nasty taste in your mouth can linger for a long time.
We suspect that Ayres Loadmaster was stiffled by the same FAA official who stiffled the Soloy Dual Pack engine retrofit for the Cessna 208 Caravan. Engiens were a pair of Pratt and Whitney of Canada PT6D-114 turbo-shaft engines similar to those installed in Bell Twin Huey helicopters. The Caravan conversion included a 79 inch stretch to the aft fuselage for balance.
Soloy obtained an FAA Supplementary Type Certificate (#SE00482SE) in 1997, but decided not to manufacture it because the FAA required much tighter certification standards for airplanes carrying more than 9 passengers.

Odd! Caravan jump-planes routinely carry 15 or 19 skydivers. Albeit, many Caravan jump-planes have been up-engined via STC.
 

Tiger Tim

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Are you making fun of my beloved California
Wouldn’t dream of it. If the couple layovers I’ve done in Long Beach and San Francisco are indicative of the rest of the state, I think I’d like to wander around there a bunch with an old car or old airplane some day.
 

Riggerrob

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Dear Mad Mac,
No I do not have specific weight numbers for swing-tail freighter airplanes. Consider that you need to build a pair of stiff bulkheads, plus hinges, plus latches, plus hydraulic actuators. That weighs three or four times as much as a simple bulkhead.

Canadair only built a few swing-tail versions of the Yukon/Bristol Britannia freighter for Flying Tigers cargo line. A few were converted in Mini-Guppies for odd-sized cargo. Even with carefully engineering, mechanics still struggled to maintain correct tension on control cables (all routed via the right-fuselage hinge-line).

For a more modern look at swing-tails. see the www.youtube.com video on how Boeing converted a handful of 747s to carry odd-sized airliner components. These modified Boeing 747s replace Super Guppies and compete directly with Airbus Belugas. To keep weight low, Boeing only pressurized cockpits. These specialized freighters were built quite delicate and require specialized ground handling equipment to prevent damage while hinging open. A courier service would never waste that much time swinging the tail open.

As for fuselage cross-section ... an unpressurized airframe can mimic the rectangular shape of shipping containers. If you don't need to open a tail ramp in flight, it can be any streamlined shape you want. Hint: look at the CASA 212s that only fly Coast Guard missions. They have an extra conical aerodynamic fairing under the ramp.

Many freighters) install pogo-sticks under the aft fuselage while loading. Twin Otter pogo-sticks swing backwards and are supposed to automatically drop off if you taxi away with them still installed. I have seen it happen!
 

Turd Ferguson

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We suspect that Ayres Loadmaster was stiffled by the same FAA official who stiffled the Soloy Dual Pack engine retrofit for the Cessna 208 Caravan.
The FAA had little to do with demise of the Loadbast....oops Loadmaster. They did it to themselves.

Soloy Pathfinder 21. DOA for a package hauler because the operating numbers were awful.





Re: all the cargo load/unload suggestions - You guys are way overthinking this. A small package hauler did a cost analysis and the biggest efficiency gain was have the freight containerized vs. bulk loaded. The reason was labor.
 

Angusnofangus

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Why do airlines still hand load baggage?
I'll posit numerous reasons: Baggage come in all shapes and sizes, automatic loaders would be constantly trying to put square pegs in round holes. Belly baggage compartments in airliners are flat on the bottom and have curved sides and just not conducive to automatic loading. An apparatus for automatic loading would be heavy and complicated mechanically, not to mention it would take up room that could be used for baggage. That said, there is something to be said for containerized baggage, easier to load and off load from the aircraft, but still needing bodies to pack and unpack.
 

cluttonfred

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Be careful what you wish for! I can definitely imagine the day when there will be a mandatory hard luggage standard, one for carry on, one for checked, and everything must fit inside, period. Overhead bins will be sized for exactly that standard, just a series of slots for one piece per seat, and checked luggage will be small (half size) or large (full size) and would also fit in racks, all automated loading and unloading.
 

Riggerrob

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Dear Angusnofangus,
LD3 baggage containers are designed specifically to fit in odd-shaped, under-floor baggage compartments. That is why one corner is missing. The missing corner can be turned down to fit a pair of LD3s in a semi-circular belly baggage compartment, or turned upwards to match the circular curvature of main cabins in cargo planes.
 
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