banner
banner

06 Dec 2019, 04:34 [ UTC - 5; DST ]


Greenwich AeroGroup



Reply to topic  [ 54 posts ]  Go to page Previous  1, 2, 3, 4  Next
Username Protected Message
 Post subject: Re: Otto Aviation Celera 500L Flew This Week
PostPosted: 13 Nov 2019, 20:49 
Offline



User avatar
 Profile

Joined: 11/08/12
Posts: 11230
Post Likes: +3998
Location: Jackson, MS (KHKS)
Aircraft: 1959 Travel Air
Is there any reason to think a liquid cooled diesel won’t work up high?

Is there any reason to think a propeller will work at mach whatever?

Would jato help? (Seriously). Like for climbing 5000>25000


Top

 Post subject: Re: Otto Aviation Celera 500L Flew This Week
PostPosted: 13 Nov 2019, 21:09 
Offline


User avatar
 Profile

Joined: 11/08/13
Posts: 1232
Post Likes: +559
Location: KCRQ
Aircraft: Breeezy, 182,601P
>Is there any reason to think a liquid cooled diesel won’t work up high?
The red Ao3 says good to 50 K ft, so close maybe yes.
The real question is cooling drag, and that is/should be tied to heating/ the cabin.
Is 65K ft thin enough that radiative effects matter here?


>Is there any reason to think a propeller will work at mach whatever?
TU-114. (mach 0.71)

>Would jato help? (Seriously). Like for climbing 5000>25000
No, I've built a lot of rockets....
A Jet engine that is only used for climb... maybe, Jato... no
carrying your own oxidizer is really heavy.


Top

 Post subject: Re: Otto Aviation Celera 500L Flew This Week
PostPosted: 13 Nov 2019, 22:03 
Offline



User avatar
 Profile

Joined: 11/08/12
Posts: 11230
Post Likes: +3998
Location: Jackson, MS (KHKS)
Aircraft: 1959 Travel Air
If they can heat the interior of that unpressurized beluga to 150 degrees it will shed quite a bit of heat


Top

 Post subject: Re: Otto Aviation Celera 500L Flew This Week
PostPosted: 13 Nov 2019, 22:52 
Offline


User avatar
 Profile

Joined: 03/03/11
Posts: 934
Post Likes: +719
Aircraft: Solitaire
Looks like a piaggio in that the fuselage is a lifting body. On p180 it accounts for about 20%


Top

 Post subject: Re: Otto Aviation Celera 500L Flew This Week
PostPosted: 13 Nov 2019, 23:38 
Offline


 Profile

Joined: 06/24/18
Posts: 10
Post Likes: +1
Aircraft: bonanza
Username Protected wrote:
I just noticed how little rotation angle it can achieve before striking the ventral tail. Yikes. If it does get produced I can't imagine how many tails strikes they're going to have...


According to the patent (figure 1C) there will be a tail wheel:

A tail wheel gusset 30 may be connected to the bottom surfaces of the rear bulkhead 25 and elevator bulkhead 34 to provide ventral fin and propeller protection from a tail strike due to over rotation during takeoff or landing. A wheel extension arm 31 and wheel 32 are rotatively affixed to one end of the gusset 30. An actuator unit 33 is affixed to the bottom surface of the nose cone 24 between the gusset 30 and the end of the cone 24 such that the wheel extension arm 31 and wheel 32 can be extended during and retracted during flight.


Top

 Post subject: Re: Otto Aviation Celera 500L Flew This Week
PostPosted: 14 Nov 2019, 00:59 
Offline


 Profile

Joined: 07/02/13
Posts: 2721
Post Likes: +2473
Location: Stamping Ground, Ky
Aircraft: twin bonanza
Username Protected wrote:
I wonder how they will solve the descend to breathable altitude issue? On the piaggio, the original design spec was to go to fl450 but they couldn’t meet the descend to breathable altitude test (I don’t recall what the time was, 6 min maybe). Even with two big turbines at flight idle, you pick up a head of steam going downhill.

There is no question in my mind planes can be radically more efficient than present. Just hard to make economics work to get it there.

I don’t think emergency descent times will matter. When I was in the Air Force, a pressure suit was required above FL500. Lose the cabin at 65k, even with O2 on, you are pretty much dead iirc. Something about partial pressure of O2 even at 100% being too low to remain conscious. 65,000 feet isn't just a higher version of 41000 feet.


Top

 Post subject: Re: Otto Aviation Celera 500L Flew This Week
PostPosted: 14 Nov 2019, 01:04 
Offline


 Profile

Joined: 12/07/17
Posts: 2606
Post Likes: +1885
Company: Malco Power Design
Aircraft: Baron 58 N2110L
Username Protected wrote:
I wonder how they will solve the descend to breathable altitude issue? On the piaggio, the original design spec was to go to fl450 but they couldn’t meet the descend to breathable altitude test (I don’t recall what the time was, 6 min maybe). Even with two big turbines at flight idle, you pick up a head of steam going downhill.

There is no question in my mind planes can be radically more efficient than present. Just hard to make economics work to get it there.

I don’t think emergency descent times will matter. When I was in the Air Force, a pressure suit was required above FL500. Lose the cabin at 65k, even with O2 on, you are pretty much dead iirc. Something about partial pressure of O2 even at 100% being too low to remain conscious. 65,000 feet isn't just a higher version of 41000 feet.


Gonna need at least a pressure demand mask to stay conscious much above 450.
_________________
Last 12
11/8/19 IPC


Top

 Post subject: Re: Otto Aviation Celera 500L Flew This Week
PostPosted: 14 Nov 2019, 01:13 
Offline


 Profile

Joined: 07/02/13
Posts: 2721
Post Likes: +2473
Location: Stamping Ground, Ky
Aircraft: twin bonanza
I dont think pressure demand will be enough. You need a pressure suit much above 50. Not sure the pax will like that.


Top

 Post subject: Re: Otto Aviation Celera 500L Flew This Week
PostPosted: 14 Nov 2019, 02:59 
Offline


 Profile

Joined: 11/03/08
Posts: 9537
Post Likes: +12316
Location: Stoke-on-Trent, UK
Aircraft: in storage
Username Protected wrote:
Is there any reason to think a liquid cooled diesel won’t work up high?

Is there any reason to think a propeller will work at mach whatever?

Would jato help? (Seriously). Like for climbing 5000>25000

Diesels struggle mightily at altitude. Efficiency goes in the crapper and a restart will be impossible. We make major modifications to diesel powered equipment to make them function and start at the highest terrestrial altitudes - mid teens.


Top

 Post subject: Re: Otto Aviation Celera 500L Flew This Week
PostPosted: 14 Nov 2019, 10:04 
Offline


 Profile

Joined: 06/24/18
Posts: 10
Post Likes: +1
Aircraft: bonanza
First official pic

https://twitter.com/otto_aviation/statu ... 21632?s=21


Top

 Post subject: Re: Otto Aviation Celera 500L Flew This Week
PostPosted: 14 Nov 2019, 11:09 
Offline


User avatar
 Profile

Joined: 02/26/11
Posts: 435
Post Likes: +265
Company: 135/Contract Pilot
Location: Dallas, TX
Aircraft: Legacy 600
I'd be willing to guess that they are building this for autonomous operation. Probably to be on the leading edge of computer flown passenger legs. Will start out as cargo and move to pax.


Top

 Post subject: Re: Otto Aviation Celera 500L Flew This Week
PostPosted: 14 Nov 2019, 12:47 
Offline


User avatar
 WWW  Profile

Joined: 02/20/18
Posts: 65
Post Likes: +13
Company: Paramus Flying Club
Location: KCDW
Aircraft: C182 PA18 B75N Z242
Username Protected wrote:
Is there any reason to think a liquid cooled diesel won’t work up high?

Is there any reason to think a propeller will work at mach whatever?

Would jato help? (Seriously). Like for climbing 5000>25000

Diesels struggle mightily at altitude. Efficiency goes in the crapper and a restart will be impossible. We make major modifications to diesel powered equipment to make them function and start at the highest terrestrial altitudes - mid teens.


Agree that diesel performance drops off rapidly at altitude.

In the case of the SMA the turbo is turning in the ballpark of 16,000 RPM and it does not turbo-normalize in this application. Performance dropped off at the same rate as the O-470 engine it replaced.

I read this somewhere, and I can't find the source now, but SMA tested relight at 14,000 feet after 2 or maybe even 5 minutes after shutdown without issues as part of the flight testing for the STC.

We only once had our SMA shutdown after a prolonged descent at idle power. The engine cooled down too much briefly ran rough and flamed out. Relight was attempted immediately and was instantaneous. This is one drawback of an air-cooled diesel engine. The operating procedures call for not descending at idle power for that reason.

Someone mentioned heat as a big issue earlier. Spot on as cooling the oil during climbs was critical with the SMA. At altitude it became more difficult to keep the oil cool in climbs and you could push up to oil temp redline very quickly. This was something they were working on addressing in the second generation design.

These were some quirks that I believe were unique to the SMA design, and I've never flown behind the water cooled alternatives or read up on their procedures or limitations.

Now cold weather SMA starts? Ugh! It would start fine, but the battery was hard pressed with the high compression given the cold. It was critical that the battery was kept well charged.

I have seen a DA-62 fire up immediately in cold weather. I take it that the water cooling helps a lot.

Top

 Post subject: Re: Otto Aviation Celera 500L Flew This Week
PostPosted: 14 Nov 2019, 13:00 
Offline


User avatar
 Profile

Joined: 08/26/15
Posts: 5762
Post Likes: +3642
Location: Florida panhandle
Aircraft: Travel Air,T-6B,CRJ
Username Protected wrote:
Someone mentioned heat as a big issue earlier. Spot on as cooling the oil during climbs was critical with the SMA. At altitude it became more difficult to keep the oil cool in climbs and you could push up to oil temp redline very quickly. This was something they were working on addressing in the second generation design.

Did that engine have a fuel-oil heat exchanger as an oil cooler? It seems like an obvious solution, but I realize it's not quite as simple as a magic wave of my hand and asking why they didn't use one.


Top

 Post subject: Re: Otto Aviation Celera 500L Flew This Week
PostPosted: 14 Nov 2019, 14:47 
Online


User avatar
 Profile

Joined: 01/30/09
Posts: 2123
Post Likes: +1119
Location: $ilicon Vall€y
Aircraft: Columbia 400
Username Protected wrote:
Is there any reason to think a liquid cooled diesel won’t work up high?

Diesels struggle mightily at altitude. Efficiency goes in the crapper and a restart will be impossible. We make major modifications to diesel powered equipment to make them function and start at the highest terrestrial altitudes - mid teens.


I think you could probably keep it running, with enough supercharging. But a restart is gonna be really hard at altitude. (and Jeff would know a lot better than me).

Curiously - the Germans flew diesel bomber/recon aircraft, the Ju86P and R, in WWII as high as 47,000 feet. The JU86 was deployed operationally in several war fronts.

https://www.historynet.com/luftwaffes-h ... diesel.htm

Jumo 207 diesel engine:

https://airandspace.si.edu/collection-o ... sel-engine

Last edited on 14 Nov 2019, 16:46, edited 1 time in total.

Top

 Post subject: Re: Otto Aviation Celera 500L Flew This Week
PostPosted: 14 Nov 2019, 15:03 
Offline


User avatar
 WWW  Profile

Joined: 02/20/18
Posts: 65
Post Likes: +13
Company: Paramus Flying Club
Location: KCDW
Aircraft: C182 PA18 B75N Z242
Username Protected wrote:
Someone mentioned heat as a big issue earlier. Spot on as cooling the oil during climbs was critical with the SMA. At altitude it became more difficult to keep the oil cool in climbs and you could push up to oil temp redline very quickly. This was something they were working on addressing in the second generation design.

Did that engine have a fuel-oil heat exchanger as an oil cooler? It seems like an obvious solution, but I realize it's not quite as simple as a magic wave of my hand and asking why they didn't use one.


No it did not though that idea sounds good. There was an intercooler and oil cooler each on opposite sides of the lower cowling and fed via separate ducts.

Top

Display posts from previous:  Sort by  
Reply to topic  [ 54 posts ]  Go to page Previous  1, 2, 3, 4  Next



uAvionix (banner)

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  

Terms of Service | Forum FAQ | Contact Us

BeechTalk, LLC is the quintessential Beechcraft Owners & Pilots Group providing a forum for the discussion of technical, practical, and entertaining issues relating to all Beech aircraft. These include the Bonanza (both V-tail and straight-tail models), Baron, Debonair, Duke, Twin Bonanza, King Air, Sierra, Skipper, Sport, Sundowner, Musketeer, Travel Air, Starship, Queen Air, BeechJet, and Premier lines of airplanes, turboprops, and turbojets.

BeechTalk, LLC is not affiliated or endorsed by the Beechcraft Corporation, its subsidiaries, or affiliates. Beechcraft™, King Air™, and Travel Air™ are the registered trademarks of the Beechcraft Corporation.

Copyright© BeechTalk, LLC 2007-2019

.McPeck_85x50.jpg.
.ForeFlight.jpeg.
.methodseven-85x50.jpg.
.centex-85x50.jpg.
.saint-85x50.jpg.
.jandsaviation-85x50.jpg.
.camguard.jpg.
.CiESVer2.jpg.
.weatherspork_85x50.jpg.
.bkool-85x50-2014-08-04.jpg.
.Anrim_85x200.png.
.Outright_85_50.png.
.dshannon.jpg.
.dbm.jpg.
.Expert_Aircraft_Solution_85x50.jpg.
.AAI.jpg.
.Davis_Aviation_85x50.jpg.
.Rocky-Mountain-Turbine-85x100.jpg.
.rtc-85x200.jpg.
.Electroair.jpg.
.gallagher_85x50.jpg.
.airmart-85x150.png.
.fortner-85x50.jpg.
.sierratrax-85x50.jpg.
.tempest.jpg.
.wilco-85x100.png.
.hpair-85x50.jpg.
.ABS-85x100.jpg.
.planelogix-85x100-2015-04-15.jpg.
.truecourse.jpg.
.Latitude.jpg.
.avidyne-85x50-2017-11-22.jpg.
.cubcrafters.jpg.
.aviationdesigndouble.jpg.
.geebee-85x50.jpg.
.jetaviva-85x50.jpg.
.Marsh.jpg.
.Bendix_85x50(1).png.
.midwest2.jpg.
.heartlandsm.jpg.
.KalAir_Black.jpg.
.temple-85x100-2015-02-23.jpg.
.sureflight-85x50.jpg.
.kadex-85x50.jpg.
.tas-85x50.jpg.
.ps_engineering.gif.
.STLAir_85x50.jpg.
.Trace.jpg.
.pdi-85x50.jpg.
.bpt-85x50-2019-07-27.jpg.
.wildblue-85x50.jpg.
.uavionix-85x50.png.
.avionicssource-85x50.jpg.
.lopresti_85x50.jpg.
.westsky.jpg.
.L3_85x100.jpg.
.FreeFlight_85x50.jpg.
.airpower-85x50.jpg.
.byerlyaviation-85x50.png.
.airplanesusa-85x50.png.
.blackhawk-85x100-2019-09-25.jpg.
.headsetsetc_Small_85x50.jpg.
.Steel_85x50.jpg.
.tulsair-85x50.jpg.
.kingairacademy-85x100.png.
.Genesys_85x50.jpg.
.Wentworth_85x100.JPG.
.selectairparts-85x100.jpg.
.Showalter.jpg.
.instar.jpg.
.chairmanaviation-85x50.jpg.
.kingairdom.jpg.
.MountainAirframe.jpg.
.daytona.jpg.
.tat-85x100.png.
.avfab-85x50-2018-12-04.png.
.ei-85x150.jpg.
.cav-85x50.jpg.
.garmin-85x200-2019-11-01.jpg.
.aircraftassociates-85x50.png.
.jetacquisitions-85x50.png.
.SCA.jpg.