The elusive Cessna Model 330

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walter

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Anyone ever seen a photo of a Model 330? ???
This twin is described as derived from the Model 340 (Model 411?), but smaller/lighter and intended to fit between the Models 310/320 and 340.
First flight given as 30 November 1966 and engines as two Continental TSIO-520.
Registration N3764C
 
walter said:
Anyone ever seen a photo of a Model 330? ???
This twin is described as derived from the Model 340 (Model 411?), but smaller/lighter and intended to fit between the Models 310/320 and 340.
First flight given as 30 November 1966 and engines as two Continental TSIO-520.
Registration N3764C
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Hi Walter,


here is a small info if you want to search about it,serial number; N3764C (c/n 659).
 
N3764C is a Thorp T-18. I read elsewhere on SPF that the 330 was supposedly based on the 411. If the 330 was supposed to be between the 310 and 340, that's interesting because the 411 is even larger than the 340 so I think it'd be difficult for it to fit between those two.
 
famvburg said:
N3764C is a Thorp T-18.
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Surely you are aware that civil registrations are not once-and-for-all allocated to one single aircraft.

When an aircraft has crashed, was exported or no longer flies, its registration becomes available again and is often reallocated to another, completely different type.

N3764C may be a T-18 at present time, but various sources clearly indicate that selfsame registration as applying to the sole Model 330 prototype of 1966.
 
Yes, I'm aware. But the current registered aircraft doesn't do much to locate the 330. Neither do the conflicting descriptions. Also, just because an aircraft has crashed doesn't mean it is stricken, only if it is totaled out and no longer will fly.
 
I just noticed that hesham lists Cessna 340 with "Model 411?" in parentheses, possibly confusing 'the' 340 and 411, which they are very different designs, so which 340 is he referring to in 'between the 310/320 and 340? When I said the 411 is bigger than the 340 so if the 330 was to be between the other two it's conflicting. I've noted that the 401 and 402 designs both flew in 1966, the same year as the elusive 330. Is hesham inferring that the in-house or original designation for the 411 was 340? If so, since the 401 is a 411 subtract 10, and is powered by TCM TSIO-520s, a 401 would certainly be between a 310 and 411. Therefore, the Cessna 330, again assuming hesham is saying the original 411 was designated 340, then a Cessna 330 is simply a 401, i.e., a 340 (411) subtract 10. OTOH if the 340 is the commonly known 340, there's not a lot of room for something to be between it and a 310/320.
 
hi famvburg/stargazer2006 ;D
Seems lots of uncertainties on the planned role for the 330. If it was intended to fit between the 310/320 and 340 I guess we should not think of dimensions, but probably weight/engines etc. In my old notes I found that the 330 reportedly had 41.167ft wingspan and 33.33ft length, making it roughtly 411 size.
However, the first 340 (285hp TSIO-520) was only flown in 1970, while the 330 (285-300hp TSIO-520) flew 20 November 1966. The first 401 (300hp TSIO-520) flew in 1965 and the first 411 (340hp GTSIO) in 1968.
The 340/411 were possibly already on the drawing board in 1966 (when the 330 was flown).
Stargazer2006 advised c/n 659 for the 330. Does anyone have knowledge of the Cesssna c/n system with experimental/prototype aircraft. I saw c/n 687 (303), c/n 635 (first 320), c/n 672-673 (2 prototypes 340), so maybe Cessna used a separate series?
 
@walter @famvburg @hesham :
Still no photo, but finally a proper writeup on the Cessna 330, a lot more different from the other models than we assumed.

Sometime before the development of the Cessna 340 was started, there was a project that did not go into production.
The Cessna Model 330 was developed and flown, but not brought to market. This airplane is considered the most direct predecessor of the Cessna 340.
The Model 330 shared the cabin of the 340, except the cabin windows were shaped similarly to the cabin windows in the 441 Conquest. With the new 330, Cessna tried a laminar flow airfoil that they had not flown before, and the vertical tail shape was very elliptical, with a cruciform horizontal stabilizer.
New manufacturing concepts were tested as well. This wing would be a wet wing, replacing the tip tanks and bladders used up to this point; although the prototypes were tested with and without tip tanks.
It also differed from previous Cessna twins by having a greater aspect ratio.
The wingspan would be 40 feet, 6 inches, more than 3.5 feet longer than the Model 310 wing. The flaps were a Fowler type.
Due to poor handling characteristics (primarily stall issues) and economic timing, the project was stopped in the late 1960s.
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Source: "Cessna 340: Development and Design", in Cessna Flyer, July 2022

Interestingly, the article talks about "the prototypes", implying there were more than one, although only N3746C (c/n 659) appears in the company's special experimental list. And that piece of information is confirmed by the following comment on the Airline Pilot Central Forums:
Every test airplane I've ever seen had to have an escape system for the crew. Some were very elaborate, like the Citation. It had a det cord lined area in the belly behind the co-pilot seat that would blow a hole in the skin big enough to bail out through and a bungee cord actuated spoiler that extended from the hole. Others were as simple as a knotted rope along the ceiling to get to the main door on the Cessna 330 (which became the 340) Unfortunately that didn't work too well for a test pilot that didn't make it out of the first 330.
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Makes me wonder if they might have reused the same c/n and and registration for the replacement aircraft.

Source: https://www.airlinepilotforums.com/major/46541-mr-cool-chief-787-test-pilot.html
 
Regarding the Cessna 340 program, I recall that I was told, after joining Cessna flight test in 1979, that the prototype 340 crashed on its first flight in 1976. The cause was a jammed elevator, full nose up, that resulted in an unrecoverable spin. The test pilot was unable to get back to the rear entry door in time to bail out of the airplane. This fatal accident caused a few changes to be made in the cabin class airplanes, and these changes were applied to existing and future programs.

Special inspections were performed prior to first flights of any new design, or if significant configuration changes were made, such as new wings being installed. Test pilots, design engineers and others were teamed up with mechanics and inspectors to open up panels and go over the airplane with new eyes and different points of view.

The addition of an escape rope was mandatory for initial and other hazardous flights, i.e. when parachutes were worn. The rope was about an inch in diameter and was knotted every foot or so. It was attached to a hard point just aft of the cockpit seats and ran aft past any doors, emergency exits, or any special escape provisions. To keep the rope out of the way when not in use it was tied to the ceiling with thin copper wire.

The original Citation 500 prototype was indeed equipped with a belly section that could be fractured with detonation (det) cord, to facilitate bailing out and hopefully avoid the wing or the tail section. There were a few hairy flights during the low-speed and stall tests, too. So, the story goes that after retirement of the airframe, the det cord escape hatch was tested and it failed to work. This caused some more changes to be made. The first Citation II prototype, N550CC, was equipped with a belly escape hatch with an improved design. The hatch was designed as a belly door, complete with a pressurization seal, and door pin mechanism that was pneumatically actuated from the cockpit. To help ensure that the door departed there was a "guillotine," that propelled an aluminum slab downward, that would push the leading edge of the hatch into the airstream. The slab was preloaded with bungie cords and was retained as a wind break to assist the pilots exiting the belly. Prior to the first flight with the new S/II wings, the door pin mechanism was tested by jacking the airplane and dropping the hatch onto some pads. Fortunately, it was never needed.
 
CraigD said:
Regarding the Cessna 340 program, I recall that I was told, after joining Cessna flight test in 1979, that the prototype 340 crashed on its first flight in 1976. The cause was a jammed elevator, full nose up, that resulted in an unrecoverable spin. The test pilot was unable to get back to the rear entry door in time to bail out of the airplane. This fatal accident caused a few changes to be made in the cabin class airplanes, and these changes were applied to existing and future programs.
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Thanks a lot for the input! However, the crashed 340 prototype of 1976 is different from the crashed 330, which appeared ten years earlier.
 
In case it helps and since I can't see it quoted anywhere, Cessna applied for aircraft registration N3764C/Cessna 330/s/n 659 on 22 November 1966. Possibly significant, the application was signed by VL Pyke, Divisional Controller Military Division. The registration certificate was issued on 5 January 1967.

Cessna requested cancellation of the registration on 30 January 1970 and again there was a military aspect; the request was signed by William H Prewitt, Quality Control Manager for the Military Twin Division. The registration was cancelled as "permanently retired from service at the request of registrant/owner" on 9 February 1970.
 
Sabrejet said:
In case it helps and since I can't see it quoted anywhere, Cessna applied for aircraft registration N3764C/Cessna 330/s/n 659 on 22 November 1966. Possibly significant, the application was signed by VL Pyke, Divisional Controller Military Division. The registration certificate was issued on 5 January 1967.

Cessna requested cancellation of the registration on 30 January 1970 and again there was a military aspect; the request was signed by William H Prewitt, Quality Control Manager for the Military Twin Division. The registration was cancelled as "permanently retired from service at the request of registrant/owner" on 9 February 1970.
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Thanks a lot for the info! Very interesting indeed, as it suggests that the type may have been conceived for military use (as most of the 300 series was at the time). Which may also partly explain why the project was so hush-hush and photos have never been seen.
 

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