Bizjet - straight wing?
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Bizjet - straight wing?
I have just been on the apron at a GA facility and was surprised to see straight (non-swept) wings on a couple of "little" bizjets. I was surprised to not see swept wings. Assumed they flew sufficiently fast for supersonic airflow. Am I mistaken?
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Citations: Near Jets
Great little starter jets........ lovely to fly, and own...
Early C1 was a joy to fly ...replaced by CJ series.
Straightg wing was very nice to fly, speeds not fantastic, but passengers and crew liked the early biz jets.
glf
Early C1 was a joy to fly ...replaced by CJ series.
Straightg wing was very nice to fly, speeds not fantastic, but passengers and crew liked the early biz jets.
glf
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Straight wings are easier to fly, more forgiving and I believe less development cost, but I think that ties in with my second point. #2: If the plane isn't going to be flown in or near the transonic range then there isn't really a requirement for sweepback. This PDF helps to illustrate why.
https://www.box.com/s/c95b3abe7eaade9e445d
https://www.box.com/s/c95b3abe7eaade9e445d
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A bigger question is why these little bizjets are actually jets. I would have thought that turboprop aircraft, like a C441 would have delivered everything an owner of a CJ+ could desire, except for vanity.
PM
PM
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The straight wing C jets are not business jets. They are ego massage for dentists etc, as they can be owned and flown by a single inexperienced pilot (or at least that is the perception).
Try that in an early Lear (swept wing, tip tanks), you will end up with a smoking hole.
There were a lot of smoking holes!
Try that in an early Lear (swept wing, tip tanks), you will end up with a smoking hole.
There were a lot of smoking holes!
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PM...
Speed. And vanity. A smart business man would buy a PC-12 or a King Air if he really needed... IMO.
Cessna Mustang vs King Air C90GTx
1,150nm vs 1,236nm - Range (Full fuel, max takeoff weight)
41,000' vs 30,000' - Max altitude
340KTAS vs 272KTAS - Max cruise
1,165lb vs 2,143lb - Max payload
2,580lb vs 2,573lb - Usable fuel
5 vs 8 - Pilot and pax
Both around $3.5 million. The C90GTx looks like it's a bit more expensive, depending on configuration, but you get way more bang for your buck with the King Air.
Speed. And vanity. A smart business man would buy a PC-12 or a King Air if he really needed... IMO.
Cessna Mustang vs King Air C90GTx
1,150nm vs 1,236nm - Range (Full fuel, max takeoff weight)
41,000' vs 30,000' - Max altitude
340KTAS vs 272KTAS - Max cruise
1,165lb vs 2,143lb - Max payload
2,580lb vs 2,573lb - Usable fuel
5 vs 8 - Pilot and pax
Both around $3.5 million. The C90GTx looks like it's a bit more expensive, depending on configuration, but you get way more bang for your buck with the King Air.
Last edited by italia458; 26th Jul 2012 at 10:33.
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in days of old
The Citation 1 was the only poor mans business jet, the Lear was the speed freaks killing machine. The Citation 1 was designed as the natural progression in the upgrade for owner pilots, and those who employed a pilots friend.
I spent many happy hours in the RHS of C1 and eventually became LHS on C2.
The straight wing, and the Cessna panel, made transition for prop owners to transition to jets very easy.
Yes some owners have died, in Citations, but as many professionals as well as private pilots.
The accident at Biggin Hill is a classic example of a "professional" pilot accident.
The arguments these days of props v jets is totally in a different generation.
glf
I spent many happy hours in the RHS of C1 and eventually became LHS on C2.
The straight wing, and the Cessna panel, made transition for prop owners to transition to jets very easy.
Yes some owners have died, in Citations, but as many professionals as well as private pilots.
The accident at Biggin Hill is a classic example of a "professional" pilot accident.
The arguments these days of props v jets is totally in a different generation.
glf
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A bigger question is why these little bizjets are actually jets. I would have thought that turboprop aircraft, like a C441 would have delivered everything an owner of a CJ+ could desire, except for vanity.
That is a real benefit.
I operated a B200 and a CJ2, they were on most routes similar in cost, with the speed benefit to the CJ2, flying up to FL410-430 regurlarly. With the KingAir after RVSM you`d be limited to 280 and anything higher than 310 doesnt make sense anyhow.
I love the B200, probably the best airplane I ever flew, but its heydays are over.
Going back to swept wings, the C680 and CJ 4 wing are swept back by only 16 degrees, Yet the speed range of the C680 is from Vrefs around 95 when light to VMO/MMO to 305/.8. That is remarkable IMO.
The straight wing C jets are not business jets.
Last edited by His dudeness; 28th Jul 2012 at 11:26.
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Hey dude, read that in the context of the rest of the sentence!
Must admit, if i won the lottery, top of the list for self gratification would be a Hunter or an L39. Family runabout would be a king air or a single pilot cjet!
Must admit, if i won the lottery, top of the list for self gratification would be a Hunter or an L39. Family runabout would be a king air or a single pilot cjet!
Last edited by PURPLE PITOT; 28th Jul 2012 at 20:12.
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Thanks for (most of) the comments.
Follow on question:
I keep reading "The air flow over the swept wing is at 90 degrees / perpendicular to the leading edge, so the air is actually veering towards the fuselage, and is tricked into thinking the aircraft is flying slower, and therefore the airflow over the wing is not reaching supersonic range, and having associated shockwaves / drag."
OK, but what "law of physics" stops the air from just flowing STRAIGHT from front to back over the SWEPT wing??? Why does the sweep reroute it at 90 degrees? At what sweep angle does effect collapse??????? Surely a (rediculous angle for argument's sake) 80 degree swept wing wont divert air at 90 degrees to leading edge? Airflow would nearly be sideways???
I hope somebody can see my confusion and give me a "eureka" moment.
Thanks in advance.
Follow on question:
I keep reading "The air flow over the swept wing is at 90 degrees / perpendicular to the leading edge, so the air is actually veering towards the fuselage, and is tricked into thinking the aircraft is flying slower, and therefore the airflow over the wing is not reaching supersonic range, and having associated shockwaves / drag."
OK, but what "law of physics" stops the air from just flowing STRAIGHT from front to back over the SWEPT wing??? Why does the sweep reroute it at 90 degrees? At what sweep angle does effect collapse??????? Surely a (rediculous angle for argument's sake) 80 degree swept wing wont divert air at 90 degrees to leading edge? Airflow would nearly be sideways???
I hope somebody can see my confusion and give me a "eureka" moment.
Thanks in advance.
Wangus,
John Farley gave, what was to me, the most succinct description of wing sweep that I have ever read, in this thread: http://www.pprune.org/tech-log/46399...ng-theory.html
John Farley gave, what was to me, the most succinct description of wing sweep that I have ever read, in this thread: http://www.pprune.org/tech-log/46399...ng-theory.html
Take a straight non tapered wing and saw through it at 90 deg to the leading edge.
Now cut through at the sweep angle of your choice.
The two cross sections will have the same thickness but the one with sweep has a longer chord
Hence the thickness chord ratio is less on the swept wing.
Thickness chord ratio determines the speed at which shockwaves form.
Now cut through at the sweep angle of your choice.
The two cross sections will have the same thickness but the one with sweep has a longer chord
Hence the thickness chord ratio is less on the swept wing.
Thickness chord ratio determines the speed at which shockwaves form.
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Follow on question:
I keep reading "The air flow over the swept wing is at 90 degrees / perpendicular to the leading edge, so the air is actually veering towards the fuselage, and is tricked into thinking the aircraft is flying slower, and therefore the airflow over the wing is not reaching supersonic range, and having associated shockwaves / drag."
I keep reading "The air flow over the swept wing is at 90 degrees / perpendicular to the leading edge, so the air is actually veering towards the fuselage, and is tricked into thinking the aircraft is flying slower, and therefore the airflow over the wing is not reaching supersonic range, and having associated shockwaves / drag."
The air actually veers away from the fuselage. The top of the wing is a low-pressure region which, on a straight-winged airplane, would mean a streamline at every station (from root to tip) experiences it's lowest pressure at the same time (ie. same longitudinal position), more or less. When the wing is swept a particle of air first "experiences" the low pressure which is inboard the particles "usual" station; this pulls the particle toward the fuselage slightly. As the particle moves further aft across the wing it is then pulled outboard by the low pressure region occurring further aft on the wing at the more-outboard station. Hence some aircraft have wing "fences" to inhibit the spanwise flow.
