adam1115
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Why No Single Engine Jets?

Mon Jul 31, 2006 5:36 am

With all the press about inexpensive jets (VLJ's, eclipse 500) why aren't their single engine jet aircraft??
 
DesertAir
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 5:38 am

I would not want to fly on one for safety reasons. At least with two, one will do the job.
 
dw747400
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 5:41 am

There are several VLJs with only one jet. The Diamond D-Jet is the most notable. A single turbine is still more reliable than a single piston in most cases, and very few people familiar with the aircraft have an issue with flying on one engine. Of course, FARs limit the size/uses of single jet aircraft, but a D-jet like aircraft offers improved safety and speed over a comparably priced piston.

[Edited 2006-07-30 22:45:00]
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bond007
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 5:55 am

Quoting Dw747400 (Reply 2):
A single turbine is still more reliable than a single piston in most cases

..and 'safer' than a twin turbine.


Jimbo
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L-188
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 5:57 am

There was an attempt to produce a single engine Biz-jet called the Perigirne back in the 1980's.

One of the big issues with doing a single engine aircraft is protection for the control surface cables in the event that the engine bursts-which has happened in the past-remember that DL MD-80 that killed two people a couple of years back.

Those issues killed that product.
OBAMA-WORST PRESIDENT EVER....Even SKOORB would be better.
 
darrenthe747
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 5:58 am

and you would never get an ETOPS cert.
All animals are created equal, but some are more equal than others.
 
PPVRA
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 6:05 am

Quoting Darrenthe747 (Reply 5):
and you would never get an ETOPS cert.

By definition. But they could come up with an ESOPS cert. hehe

Extended-range Single-engine Operational Performance Standards



[Edited 2006-07-30 23:05:35]
"If goods do not cross borders, soldiers will" - Frederic Bastiat
 
IceTitan447
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 6:40 am

Quoting Adam1115 (Thread starter):
With all the press about inexpensive jets (VLJ's, eclipse 500) why aren't their single engine jet aircraft??

You really have to ask?
 
EI787
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 6:42 am

Here's the Diamond D-Jet:


View Large View Medium
Click here for bigger photo!

Photo © Mark Kryst

 
DLKAPA
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 6:46 am

There's a VLJ being produced in COS that has a single engine. If you go to Oshkosh this year you will see it...or what's left of it after the crash...on display.
And all at once the crowd begins to sing: Sometimes the hardest thing and the right thing are the same
 
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JBo
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 6:48 am

There was the Visionaire Vantage, too, but if I recall, that never went anywhere for whatever reason. I think Visionaire went under or something.
I'd take the awe of understanding over the awe of ignorance any day.
 
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jfklganyc
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 6:51 am

To be certified under Part 121 ops in the US, all aircraft must comply with Part 25 and Part 36. I believe Part 25 is redundancy and Part 36 is Noise Compliance. It may be vice versa.

Either way, every single aircraft must comply with redundancy in systems. You can not have the travelling public fly on an aircraft that does not have a back up system in place for each and every aircraft system.

Hydraulics, Landing Gear, Flight Controls, etc

That being said, Engines are the most obvious. You need to have at least two in case one goes out . . . which occasionally happens  Sad


PJ
 
777fan
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 7:10 am

Probably for the same reason there aren't any commercial gliders!  laughing 


777fan
DC-8 61/63/71 DC-9-30/50 MD-80/82/83 DC-10-10/30 MD-11 717 721/2 732/3/4/5/G/8/9 741/2/4 752 762/3 777 A306/319/20/33 AT
 
dw747400
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 7:13 am

Quoting DLKAPA (Reply 9):
There's a VLJ being produced in COS that has a single engine. If you go to Oshkosh this year you will see it...or what's left of it after the crash...on display.

You are thinking of the Spectrum 33, which is a twin, and which was also never at OSH. The company repeatedly stated it would not bring the prototype to OSH, though there is some speculation its ill-fated flight may have been a surprise visit.

Quoting JBo (Reply 10):
There was the Visionaire Vantage

The cost of certifying a jet is enormous, and I believe that is what did it in. Eviation is currently trying to build a modified Vantage (a twin), but they look like they are in bad shape in terms of securing investment.

Quoting Darrenthe747 (Reply 5):
and you would never get an ETOPS cert.

With a range in the 1,000nm bracket, there are very few people who would want to take a D-Jet far out over the water.

Quoting Bond007 (Reply 3):
..and 'safer' than a twin turbine.

I'd agree safer than a twin piston, but not a twin turbine. Most twin turbines do not suffer the kind of performance degradation twin pistons do with a failed engine, thanks to the power of the turbine. Ultimately, it all comes down to how well the pilot can handle the situation--you are only safe if the pilot can fly the aircraft well in an emergency configuration.


Cirrus has said they intend to offer a single-engine jet as their next aircraft.
CFI--Certfied Freakin Idiot
 
2H4
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 7:26 am



Remember, the D-Jet and upcoming single-engine Cirrus jet are targeted at owner/pilots who are currently flying multi-engine piston aircraft. These modern, single-engine jets will almost certainly have lower accident and fatality rates than those of multi-engine piston aircraft they are intended to replace.




2H4


Intentionally Left Blank
 
lincoln
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 8:13 am

Quoting Darrenthe747 (Reply 5):
and you would never get an ETOPS cert

I thought ETOPS was only applicable to commercial operations?

Lincoln
CO Is My Airline of Choice || Baggage Claim is an airline's last chance to disappoint a customer || Next flts in profile
 
adam1115
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 9:28 am

Quoting IceTitan447 (Reply 7):
You really have to ask?

I don't follow what's wrong with my question. There are tons of single engine prop planes, what's wrong with a single engine jet??
 
2H4
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 9:33 am




Quoting Adam1115 (Reply 16):
I don't follow what's wrong with my question. There are tons of single engine prop planes, what's wrong with a single engine jet??

For what it's worth, I think it's a perfectly acceptable question. Much research has gone into comparing single-engine turboprops with multi-engine turboprops....your question should produce some interesting perspective on the issue. That said, I think the whole discussion might go over better in Tech/Ops...




2H4


Intentionally Left Blank
 
captaingomes
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 10:07 am

Let's not forget the successful PC-12 single-engine turbine, which is I believe one of only two single-engine aircraft certified to fly over water. This new generation of single-engine jet aircraft will definitely spawn a growth in the air-taxi world.
"it's kind of like an Airbus, it's an engineering marvel, but there's no sense of passion" -- J. Clarkson re: Coxster
 
IceTitan447
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 10:12 am

Quoting Adam1115 (Reply 16):
I don't follow what's wrong with my question. There are tons of single engine prop planes, what's wrong with a single engine jet??

I didn't in any way mean to be rude, I re-read my post and apologize for that. I wouldn't and would NEVER fly a 1 engine jet to Europe or even ORD for that matter. 1 engine means 1 chance, not good odds.

Sorry again. Smile
 
adam1115
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 10:40 am

Quoting JFKLGANYC (Reply 11):
That being said, Engines are the most obvious. You need to have at least two in case one goes out . . . which occasionally happens Sad

But there are plenty of single engine planes out there. What's the difference between a single engine prop and single engine jet as far as certification goes??
 
dw747400
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 10:55 am

Quoting Adam1115 (Reply 20):
But there are plenty of single engine planes out there. What's the difference between a single engine prop and single engine jet as far as certification goes??

When talking about a private aircraft, not much. It becomes more complicated for aircraft certified under Part 25 for Part 121 operations. Part 91 and 135 operations (private and charter) can use a light jet with one engine.

Part of the reason these jets have been slow to emerge is the lack of a suitable powerplant. Now that efficient 1000 to 2000 pound thrust engines are on the market, these aircraft can get reasonably good economics when compared to single turbines (and even some piston twins).
CFI--Certfied Freakin Idiot
 
bond007
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 12:24 pm

Quoting Dw747400 (Reply 13):
I'd agree safer than a twin piston, but not a twin turbine. Most twin turbines do not suffer the kind of performance degradation twin pistons do with a failed engine, thanks to the power of the turbine. Ultimately, it all comes down to how well the pilot can handle the situation--you are only safe if the pilot can fly the aircraft well in an emergency configuration.

Right, and the pilot training issue is valid on a twin piston and a twin turbine. I think you'll find statistics show that there are more fatalities from an engine failure on a twin turbine, than their are on a single turbine. The handling characteristics of most of the single turbines are quite benign in the event of an engine failure, with slow (hence safer), stall speeds. The same cannot be said for many twin single or turbine aircraft, where many fatalities are due to the problems handling and landing the aircraft.

As they argued with the 4 engine vs 2 engine airlines .... twice as likely an engine will fail if you have twice as many of 'em!


Jimbo
I'd rather be on the ground wishing I was in the air, than in the air wishing I was on the ground!
 
DLKAPA
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 1:04 pm

Quoting Dw747400 (Reply 13):
You are thinking of the Spectrum 33, which is a twin, and which was also never at OSH. The company repeatedly stated it would not bring the prototype to OSH, though there is some speculation its ill-fated flight may have been a surprise visit.

I'm pretty sure I'm not:

http://www.ainonline.com/issues/04_05/04_05_vlj_62.html

Quote:
Monument, Colo.-based Excel-Jet made rapid progress in constructing the single-engine Sport-Jet prototype over the past six months. However, the start-up manufacturer’s VLJ is in a holding pattern since its supplier in Poland is “severely behind schedule” in delivering a set of composite wings for the airplane.

The plane crashed due to wake turbulence taking off for a test flight from COS about a month ago. As it rotated, right wing dipped and impacted and the plane cartwheeled several times down the runway and rolled off to the side. The MFR's will display the plane's wreckage this year at OSH because both pilots walked away.
And all at once the crowd begins to sing: Sometimes the hardest thing and the right thing are the same
 
CRJonBeez
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 1:26 pm

for the record, avocet is out of the running on VLJ's...they dropped the program. the "third partner" that was rumored to help was beech, who turned the program down and instead decided to go forth with the king air C90GT.

when i spoke with the folks at diamond, they were shooting for a "simple approach" to the aircraft. instead of shooting for a higher service ceiling, they skipped that idea. they seemed to pull out the "simplicity with speed" card when i spoke with them.

my concern with the D-Jet is not so much in the single engine, as it is, where the hell will ATC put them??? a plane of that speed with a 25,000 ft. ceiling seems kind of awkward doesn't it? can anybody enlighten me?

when it comes to the VLJs, i'm putting my money on the eclipse!
 
2H4
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 1:37 pm




Quoting CRJonBeez (Reply 24):
my concern with the D-Jet is not so much in the single engine, as it is, where the hell will ATC put them??? a plane of that speed with a 25,000 ft. ceiling seems kind of awkward doesn't it?

So I'm guessing they'll fly in the high teens/low twenties at around....what....250 kts? Isn't that about the same as Saab 340 flights?




2H4


Intentionally Left Blank
 
Cadet57
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 1:47 pm

Quoting JFKLGANYC (Reply 11):
That being said, Engines are the most obvious. You need to have at least two in case one goes out . . . which occasionally happen

then how can Cessna Caravans be used for pax service?
Doors open, right hand side, next stop is Springfield.
 
GAIsweetGAI
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 6:27 pm

strange that no one mentioned the Scaled Composites/Rutan/Virgin GlobalFlyer...

It's not a commercial A/C but it's a single engine jet...
"There is an art, or rather a knack to flying. The knack lies in learning how to throw yourself at the ground and miss."
 
CargairMax50
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 9:26 pm

In an aviation magazine i read they compared the new TBM 850 specs and results they got from their tests to the specs of a good bunch of Microjets (The D-jet for example). On a 500nm route the Microjet would be 7 minutes faster than the TBM but would cost 50% more to operate.

On a longer route (1200nm) the microjet would have to run on economic cruise and would be 11 minutes late over the TBM and still cost 50% more!?

I don't think that the SE turboprops are to dissappear with those impressive performances.
 
bond007
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 9:43 pm

Quoting CargairMax50 (Reply 28):
On a 500nm route the Microjet would be 7 minutes faster than the TBM but would cost 50% more to operate.

Correct, and this is true for jet airliner flights vs small turboprops today on short routes. On a trip of a few hundred miles, most of the flying is done below 200 or 250 kts anyway, and at lower altitudes.


Jimbo
I'd rather be on the ground wishing I was in the air, than in the air wishing I was on the ground!
 
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tjwgrr
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 10:49 pm

Boeing has been secretly working on one:

Modified Airliner Photos:
Direct KNOBS, maintain 2700' until established on the localizer, cleared ILS runway 26 left approach.
 
GAIsweetGAI
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 11:24 pm

Quoting Tjwgrr (Reply 30):

LMAO!
Where do the Captain and F/O go in that one?
And how do the passengers know where to go?

great pic, but not realistic at all.
"There is an art, or rather a knack to flying. The knack lies in learning how to throw yourself at the ground and miss."
 
bongo
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RE: Why No Single Engine Jets?

Mon Jul 31, 2006 11:41 pm

Quoting Adam1115 (Thread starter):
why aren't their single engine jet aircraft??

Just imagine if the single engine fails in the middle of the Atlantic (or wherever!)
MDE: First airport in the Americas visited by the A380!
 
CRJonBeez
Posts: 310
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RE: Why No Single Engine Jets?

Tue Aug 01, 2006 12:00 am

Quoting 2H4 (Reply 25):
So I'm guessing they'll fly in the high teens/low twenties at around....what....250 kts? Isn't that about the same as Saab 340 flights?


315kas max cruise...i'm sure it's not the most efficient, but nobody else seemed to know when i asked either...a jet has to be efficient in order to succeed in a market, but at what altitude/speed does that happen for diamond?

for the record, my concern isn't with them flying among turboprops at that speed, as much it is the congestion created when those air taxi companies plan to fly the hell out of them. i know they won't all be up in the air at once, but what happens during large events when more of them are coming? sporting events always come to mind when it comes to high traffic numbers...

do the guys in flight centers figure these things out while the plane is getting certified, or do they just fly by the seat of their pants? pardon the unintentional pun
 
dw747400
Posts: 1091
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RE: Why No Single Engine Jets?

Tue Aug 01, 2006 12:19 am

Quoting DLKAPA (Reply 23):
I'm pretty sure I'm not:

I stand corrected. I thought you were reffering to the recent crash of the S33 prototype in Utah.

Quoting CRJonBeez (Reply 24):
a plane of that speed with a 25,000 ft. ceiling seems kind of awkward doesn't it? can anybody enlighten me?

315 knots isn't a heck of a lot more than the King Airs and TBMs you find at those altitudes. In fact, a TBM850 or Epic LT would outrun a D-Jet.

Quoting CargairMax50 (Reply 28):
On a 500nm route the Microjet would be 7 minutes faster than the TBM but would cost 50% more to operate.

That seems a bit excessive to me. The TBM850 burns around 57gph at high speed cruise--the D-jet's numbers are not released but based on engine capabilities I'd guess 60 to 70 gph at 315 knots. MX would be the big question, as I don't have any numbers on the D-Jet nor the TBM850. Insurance will be a higher rate on the D-Jet, but this should be cancled out by its lower hull value.

On top of this, remember the D-jet is slightly over $1 million, the TBM roughly $2.6 to $2.9 million depending on options. When financing costs are figured in, the D Jet will likely come out ahead. I think the TBMs strenght lies in useful load and cabin size, not economics.
CFI--Certfied Freakin Idiot
 
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Starlionblue
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RE: Why No Single Engine Jets?

Tue Aug 01, 2006 1:20 am

Quoting Cadet57 (Reply 26):
Quoting JFKLGANYC (Reply 11):
That being said, Engines are the most obvious. You need to have at least two in case one goes out . . . which occasionally happen

then how can Cessna Caravans be used for pax service?

All sorts of fun regs limits its use.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
CRJonBeez
Posts: 310
Joined: Mon Nov 29, 2004 8:08 am

RE: Why No Single Engine Jets?

Tue Aug 01, 2006 1:41 am

Quoting Dw747400 (Reply 34):
315 knots isn't a heck of a lot more than the King Airs and TBMs you find at those altitudes.

good point. my thought wasn't so much the max speed, as it is optimum cruise speed at altitude. my first post didn't make that clear at all. in fact, it sounds like what i wasn't trying to say at all!
 
brilondon
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RE: Why No Single Engine Jets?

Tue Aug 01, 2006 3:08 am

Quoting Darrenthe747 (Reply 5):
and you would never get an ETOPS cert.

You can not be given an ETOPS rating with one engine but you could get an EOOPS. Well maybe not a good acronym for an airplane.
Rush for ever; Yankees all the way!!

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