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#46
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One thing for sure, the FAA will blame the pilot.
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#48
03-01-10, 10:25 AM
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It seems that he may have had the plane up for sale. There is a web site that has all of the specifics .... http://www.jackairllc.com .. and though the full content has been removed, the "cached" information in the form of the text is still fully stored.
It lists things like spoilers, max speed of 300 mph, TSIO-520-NB (300hp ??), Flint tip tanks and a fuel capacity of 163 gallons. How would the combination of horsepower (he lists the top speed as 300), and things like the spoilers affect the aircraft. Here, I get fully lost; wouldn't it be SOP to have the spoilers out for a descent? The interplay between the engine mods and the tip tank/STOL mods? You folks will understand what he had and it sounds like there was little held back in building this ship with the electronics like a stormscope etc. The posted link did not work ... but ... just Google in .... riley super skyrocket .... and it will be a few from the top and you can see the jackairllc tag .. hitting the cached feature will bring up the text. Last edited by oldyuki : 03-01-10 at 10:29 AM.
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#49
03-01-10, 11:19 AM
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You wouldn't use spoilers or speed brakes from a starting altitude of 1400' in a "watch this" dive. You would use them in a controlled descent from altitude to avoid overspeed. I am not familiar with the Rocket, but isn't the 300+/-mph an issue of 2% speed gain per 1000' and it flys at 30,000 feet, thereby increasing the groundspeed but not the IAS? I can't imagine that the Rocket has significantly different operating parameters than a regular of pressurized 337.
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#50
03-01-10, 04:40 PM
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The advertising of the Super SkyRocket said max speed 300 MPH, cruise speed 250 MPH, that was all at 20,000 feet. On an ISA day, flat out, you could achieve a true air speed of 300, they said. No one would fly flat out, for more than 5 minutes, at any altitude. The cruise, again, was at 75% power, and again at 20,000, oh and at medium weight.
That all translates to advertising stuff, and the theory that as altitude is gained, resistance is lessened.
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#53
03-03-10, 08:58 PM
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PS The P337 is limited to 20,000 ft. Out of safety I presume since it should be capable of 30,000 as is the T337. My guess is that they didn't want 337 pilots of pressurized aircraft to have to have the skills of a jet jocky in case of depressurization.
Dave Dillehay N84E
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#54
03-04-10, 12:03 AM
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You're on the right track. My understanding is the 20K limit was based on "newer" certification requirements back in the early 70's. But you're right, the airplane could fly higher, but not maintain cabin pressure, so in the eyes of the FAA its service ceiling is 20K.
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#55
03-04-10, 07:23 AM
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My airplane, N374DN, best altitude after operation at several altitudes from 14 to 22,000 without a doubt is 16,000 nominal ... I'm sure the wing extensions from Owen Bell would greatly improve performance above FL 18,000 ...
Jack
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#56
03-04-10, 11:06 AM
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Regrettably, I've flown FL180, FL190, FL200 only a couple of times.
I have the various wing mods from Owen Bell and I loved the performance. I was putting along at about 175KIA , 22GPH (combined). roughly 70% power on 1500hr engines. I've since hung zero-hour rebuilds on front and rear and 3-blade composits and cant wait to get past my break-in so I can go up and check my numbers. I have no other skymaster experience, so I cannot say if this is an improvement or not. But I like it....a LOT. Cole
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#57
03-04-10, 12:50 PM
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I am really interested in the MT props ... Their performance comparison ...
From your picture, it appears you have the wing tip extensions ? Bet that is quite an improvement at altitude ... One of the drawbacks to the Riley is weight .. Thus, the normal 337 wing gets pretty tired at altitudes above 16,000 ... My airplane ... If I had a lot of years remaining to fly, and as much as I enjoy my 337, I would install the mod ... Probably going to sell 74DN this year .. Jack
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#58
03-05-10, 11:31 AM
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Ground Effect and the Crash?
A discussion with another old Skymaster pilot raised an interesting discussion point on the impact of ground effect.
An aircraft flying at or very nearly at Vne, descending into ground effect, would see the airspeed increase as the wing became more efficient, with the concurrent reduction in induced drag, assuming the power setting remained constant. A second point is whether there is any impact on the loads and stresses if an aircraft enters into ground effect in a bank -- i.e., one wing is in ground effect, while the other is not. I don't know if the load changes related to ground effect have ever been studied AT HIGH SPEEDS. Does anyone have knowledge of that? To my knowledge, ground effect research is typically focused on low speed impacts, improvements in the efficiency of the wing while in ground effect at the extremes of the envelope (meaning that the aircraft is able to fly in ground effect at an extreme weight or temperature, but is beyond the envelope and unable to climb out of ground effect until sufficient weight of fuel is burned off, etc.).
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#60
03-06-10, 03:54 PM
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I did my first aerobatic - upset training today and the instructor was explaining to me how in a banked dive when attempting to pull up, the "up wing" is loaded with about 50% more G's than the lower wing. He went on to explain how in most accidents where a plane breaks up in the clouds, they usually find the outboard last 3 feet of one wing, about two miles back in the flight path. This because when the pilot tries to pull up and out of his dive/spin, the up wing usually break away at the end due to the over-G.
The insturctor knows his stuff, and trains upset for both the Army and Navy. I asked him then if he had read the Skymaster crash in NJ, which he said he did. His opinion was that it was a banked turn / pull up that over stress the higher wing. Meanwhile upset training was the most fun I've had in years 
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