Can Cessna trap the Otter?

[Sparweb]

In my news feed this week:

http://txtav.com/en/newsroom/2017/1...aspx?sc_camp=8AC52FFA3FD24CA486A1C461A445F2A7

This doesn't sound like good news for Viking Air, which is struggling to keep the Twin Otter line alive.

The key seems to be the endorsement of FedEx, but it seems to me several things had to be done to get FedEx on board:
[ul]
[li]Fit a 64" LD3 container in the cabin (and through the loading door)[/li]
[li]Fuel in the wing, not in the belly[/li]
[li]No short-field take-off/landing capability[/li]
[/ul]
Does this kill the Twin Otter?

STF

 

[verymadmac]

I can't understand why they didn't just go with a 12,499 lb airframe that looks like a bigger version of the Caravan, you can get 3 LD3 cans in an airframe that big & the single engine cost verse twin engine would more than cover any payload loss.

I can't see this directly killing the Otter, but they are pretty vague on detail.
Where does the passenger bags go & are they loaded through the same door as the passengers (big pain in the ass).
What keeps the cans out of the cockpit, nets need a lot of space.
Is it pressurized don't think its likely is but it would really open up the market if it is. As then it would be a replacement for J31/32 series, Sa227 & 1900 series plus numerous cessna & piper twins otherwise it is a somewhat crowded market (Technam, Beechcraft, Dornier, Otter). FedEx apparently really don't like buying airframes with passenger windows or even seeing presentations with airframe models with windows.

 

[berkshire]

The other thing Textron will be fighting , is that the development costs on the twin otter are already paid for.
B.E.

You are judged not by what you know, but by what you can do.

 

[verymadmac]

And throw in the lost design skills for small aircraft as demonstrated by two spinning events they had with the skycatcher (which were simply lack of tail).

 

[Sparweb]

Who knows what introductory price FedEx paid, but the Cessna press release quotes an initial 5.5 million USD price, while Viking's Twin Otter now starts at 6.5M USD.
Cessna has some room to stretch. I can't see an instrument panel or avionic spec's in the brief or on the website. Kitting up with weather and nav could even the odds.


STF

 

[rb1957]

btw, "Otter" is the DHC3, "Twin Otter" is the DHC6.

That pricing is stunning, maybe Viking should protest "dumping"; a la Boeing vs CSeries ??

But I guess the major difference is that the DHC6 was never designed for the LD3 ... I don't think it existed in the early 60s !?
Although it does have a big cargo door ?

another day in paradise, or is paradise one day closer ?

 

[Sparweb]

The original Otter, and the derived Twin Otter that uses the same basic fuselage, were designed to haul crates measuring roughly 4 feet wide and high. There are no standard containers that fit that space. There were no standard containers at the time of the Otter type design, as others have observed. The smallest LD that I could find was only slightly smaller than the LD3, but still far too tall to fit in the Otter cabin or through the door. A very very rough sketch of the Cessna 408 cross-section, superimposed on a fairly accurate sketch of the Otter:

STF

 

[WKTaylor]

This boxy acft appears roughly similar to the Dornier Do 228

https://en.wikipedia.org/wiki/Dornier_Do_228

... except with a T-Tail.

Cessna made an odd/complex design-choice for this new twin TPE cargo bird: a T tail is guaranteed to complicate the design... aerodynamics, structures, mechanical systems, maintenance... relative to a conventional fuselage-mounted stab. I hope Cessna didn't build-in a T-tail for reasons other than solid value-added engineering [IE: 'aesthetics']. Unfortunately another project... the Scorpion inherited twin vertical stabs... for reasons that don't necessarily add value to the design [light attack].

KC-390 [] is a new Embraer cargo and air refueling [AR] tanker with twin TFEs + a T-tail... the following incident highlights an IFE that was almost catastrophic when pitch control was compromised during a test flight... but, then similar things have happened to conventional tailed TPE transport acft [IE: 'special configuration' C-130]

Hair-raising test flight of Embraer KC-390!!

http://www.airliners.net/forum/viewtopic.php?f=10&t=1376603

Follow-on articles say that primary structure is ~undamaged; and that worst damage was limited to secondary structure... expecting this test acft was will fly again, soon, after repairs/parts-replacement.

https://www.flightglobal.com/news/a...kc-390-set-to-resume-flight-testing-a-443141/

I suspect that the quoted price of $5.5M/acft is 'optimistic'... unless there are R&D, tool-up, etc costs that will also be covered up-front... and NOT be built into the contract.

Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

 

[rb1957]

yes, deep stall is a known (and I'd've thought well understood and predictable) problem with T-tails ... KC390 would have had the benefit of complete analysis, so maybe it is not so predictable?

A good defense would be a (fwd) canard wing.

As this plane is a cargo hauler it would benefit from a canard configuration and a rear loader (door or ramp) then would be an ideal para-drop too.

another day in paradise, or is paradise one day closer ?

 

[Sparweb]

Wil,
Did the KC-390 start with a conventional tail? Not all drawings of the aircraft that I can find look the same.
You might find these interesting:
Found on this website: [URL unfurl="true"]http://www.defesaaereanaval.com.br[/url]

and this:

It would make me think that Embraer had a change of heart about the tail configuration. I cannot vouch for the validity of these graphics. They just showed up when I did a Google image search for "KC-390"


STF

 

[WKTaylor]

SparWeb...

Shades of C-17Jr.

I think Boeing began informal-partnering with Embraer on this project about ~2009[?]. Unsure of the exact date the partnership was formalized.

For grins... take a look at the Kawasaki C-2 transport acft...

https://en.wikipedia.org/wiki/Kawasaki_C-2

https://en.wikipedia.org/wiki/Kawas...1202)_at_Gifu_Air_Base_October_25,_2015_b.JPG

Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

 

[verymadmac]

Something a bit closer to the original post, I suspect its currently out of funding (I did some of the performance estimation on this about 8 years ago).

https://soraaircraft.com/the-sora-utility-aircraft/features-and-benefits/

I guess there probably a great many other similar sized airframe programs that never made it.

 

[tbuelna]

I'm sure Cessna thought this project through, and felt confident they could generate a profit based on the 50+ orders from FedEx. It looks like this aircraft gets better performance from using a composite airframe rather a metal airframe.

 

[rb1957]

better performance maybe, but at what cost ? I doubt 50 airplanes make the project, but it'd give some confidence to launch it, and hope for thousands of orders from China and India. I'd guess that a clean sheet design would cost something like $1b to certify. Using existing pieces (LG, engines obviously, material layups, ...) would clearly reduce that.

another day in paradise, or is paradise one day closer ?

 

[WKTaylor]

tbuelna... Good point about composite airframe... and in line with the shadow-merger of Cessna and Beechcraft under Textron.

Beech has an impressive composites capability... so Cessna shouldn't have much all-composite airframe development 'pain'; and it makes 'sense' for both companies to cooperate.

Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

 

[rb1957]

ah yes .. the Starship ... (smile), I know Beech have done other projects with composites.

another day in paradise, or is paradise one day closer ?

 

[Sparweb]

It looks like this aircraft gets better performance from using a composite airframe rather a metal airframe.

Can you show me where you saw a reference to a composite airframe? The press release from Textron says it's all-aluminum:

https://www.ainonline.com/aviation-...ron-launches-cessna-skycourier-100-plane-deal

I wouldn't expect Cessna (or FedEx) to be keen to repeat the composite problems experienced on the Cessna 350/TTX/Corvalis/Columbia (whatever they call it) program.
Some of us will remember the 2011 in-flight wing delam during certification flight tests:

https://www.flyingmag.com/news/faa-hits-cessna-25-million-fine

I've been poking around the subject and discovered the LET 410 already has the cabin size (barely) big enough to fit one of these palletized containers. Unfortunately the door is too small (by half).

STF

 

[WKTaylor]

Beechcraft Premier series jets are all-composite airframes.

https://en.wikipedia.org/wiki/Beechcraft_Premier_I

NOTE.
As far as I can recall, Cessna has had relatively solid history for adhesive-bonded aluminum structure.

Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

 

[Sparweb]

"Solid history" yeah, I'd have to agree with that... Ever try to get the nacelle cowling off of a Cessna 425? You could call that solid, for sure. But seriously, I think Cessna is still staying away from the composite airframe world, with the sole exception of the Columbia single.

There are many important similarities in the mindsets required to build good long-term reliable adhesively bonded metallic structures and good long-term reliable all-composite structures.
But I don't think you can walk the team of people out of one building and into another, say "hey let's cure a whole new carbon wing today" and just roll up your sleeves.
I'm waiting for Tbuelna to clarify if they know something I don't about the 408 airframe (it wouldn't be the first time, or the last). Cessna is still building its bizjets from aluminum. For now I'm taking Cessna at its word: all-aluminum structure for the 408.

I'm not seeing the relationship between Beech and Cessna as clearly as others seem to. True, they both got bought by the same parent company. Does that mean there is an active cross-pollination going on? Somehow, that just sounds like business-is-business. Wouldn't it be more likely that folks at one or the other will expect their company to get sold someday, to the next musical chairs partner, so why erode the value by giving away the family secrets?


STF