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Piasecki - Vectored Thrust Ducted Propeller (VTDP)
- Thread starter Birdog8585
- Start date
Austin, Great post....NOT. Thanks for sharing your opinions and thoughts about the article. Next time put a bit more into your next NEW thread or I WILL DELETE IT.
As for the Helo, the VTDP would increase the weight, combat radius, & speed of the craft but at what cost? Fuel, payload, time airborne? This seems to be an "ADD-ON" to the current H-60 line. Will this end up like the HWMVV; overweight and underpowered?
-ea6bflyr
As for the Helo, the VTDP would increase the weight, combat radius, & speed of the craft but at what cost? Fuel, payload, time airborne? This seems to be an "ADD-ON" to the current H-60 line. Will this end up like the HWMVV; overweight and underpowered?
-ea6bflyr
Appologize, however, I am merely a butter-bar in Primary and therefore cant really speak intelligently about the aerodynamic characteristics, payload capacity comparison, range comparison, or what it could mean for the helo community other than the obvious - speed. That's is why I chose to not say anything and leave it to the aviators to voice their experience based opinions.
This is a new concept like the Osprey was and I figured I would foster a discussion to see what the fan base (no pun) thinks.
I will put my thoughts in the post next time.
This is a new concept like the Osprey was and I figured I would foster a discussion to see what the fan base (no pun) thinks.
I will put my thoughts in the post next time.
MasterBates
Well-Known Member
I think it's a viable option. Replacing the tail with the ducted fan does not increase weight that much.
The wings unload the head, reducing the onset of retreating blade stall and reducing drag. I read something more in depth on this a couple years ago, and basically when it gets to wingborne flight, the rotor goes to a much lower pitch setting, mainly using the disc as a attitude control.
It weighs about a ton more than the pre-modification helo, but increases useful load. I'd say eliminating two gear boxes probably helps with the weight, and efficiency. (the fan is direct drive off the tail drive IIRC)
They claim a 500# increase in useful load, which is not much, but the 3x combat radius due to increased speed and reduced fuel burn at that speed is the main benefit. 70 more knots may not sound like a big increase for the FW side of the house, but when your cruising speed is 120-140, it is quite substansial.
I can see use for this in the Navy for CSAR and some HSL missions would make use of the much higher cruise and dash speed. What would be my concern for USN/USMC uses is how well does this work at the boat. I've seen the video and it seems to hover fine, but if it makes yaw contol "mushy" it may be sporty on a small boy.
The wings unload the head, reducing the onset of retreating blade stall and reducing drag. I read something more in depth on this a couple years ago, and basically when it gets to wingborne flight, the rotor goes to a much lower pitch setting, mainly using the disc as a attitude control.
It weighs about a ton more than the pre-modification helo, but increases useful load. I'd say eliminating two gear boxes probably helps with the weight, and efficiency. (the fan is direct drive off the tail drive IIRC)
They claim a 500# increase in useful load, which is not much, but the 3x combat radius due to increased speed and reduced fuel burn at that speed is the main benefit. 70 more knots may not sound like a big increase for the FW side of the house, but when your cruising speed is 120-140, it is quite substansial.
I can see use for this in the Navy for CSAR and some HSL missions would make use of the much higher cruise and dash speed. What would be my concern for USN/USMC uses is how well does this work at the boat. I've seen the video and it seems to hover fine, but if it makes yaw contol "mushy" it may be sporty on a small boy.
Just when you thought a helo couldn't be any less pleasing to look at, they go and do this.
phrogpilot73
Well-Known Member
It also says that it would increase base weight by ~1700 pounds. But again, if it increases the payload by 500 pounds, increases speed and combat radius, then I'm not really seeing the negative.
Not knowing that much about aerodynamics, other than what I taught in flight school, it seems that it may also reduce any problems with tail rotor effectiveness. Anyone else know if that is the case?
Not knowing that much about aerodynamics, other than what I taught in flight school, it seems that it may also reduce any problems with tail rotor effectiveness. Anyone else know if that is the case?
MasterBates
Well-Known Member
I can see it eliminating some of the 60's LTE problems, but I'm not sure if it has ones of its own that are worse.
Austin,
No problem....Even Butter Bars have an opinion. Like you said highlighted above would have been better than the original post. Carry on, young 'un!
-ea6bflyr
From a structural standpoint I can't see a Romeo being able to absorb the extra weight. From an aerodynamic standpoint it would reduce t/r problems at high speeds but low speeds/hovers might be problematic. Regardless, I don't know what kind of time frame "near term" is but 7.8 million doesn't show any commitment to anything other than not letting it die.
Interesting (probably more so to the army), but pointless at the moment.
EDIT: There would be a heck of a contest between CAG, Boss, and the handler over who wanted that pig on his deck the least. Not to mention getting it into the hangar on a small boy.
Interesting (probably more so to the army), but pointless at the moment.
EDIT: There would be a heck of a contest between CAG, Boss, and the handler over who wanted that pig on his deck the least. Not to mention getting it into the hangar on a small boy.
I could see it as a poor man's V-22, marketable to other operators who want some of the capability of a V-22 without the cost and the 'risk'. And they are probably looking at foreign operators just as much as domestic ones, it would be a great C/SAR platorm for many countries.
Austin, sounds like another one of your crazy concepts (like the osprey whose rotors fold back and turn into turbofans). But seriously, if the main rotor does little more than attitude control at high speeds it seems like a very inefficient design. Obviously the numbers show that it improves the performance of the H-60 platform, but I'd imagine the concept will soon reach it maximum potential. I think the tiltrotor/Osprey which makes full use of the rotors in vertical and horizontal flight has much more potential.
skidz
adrenaline junky
Speaking of concepts, I would like to see if a slimmed down attack version of the V-22 would be plausible. Jet engines instead of props, tandem pilot arrangement. I know that the -22s already scorch the grass when in idle, so jet engines could cause some serious problems everywhere, if left in the vertical position. Just wondering though.
Slimmed-down, yes. Jet instead of of prop, no. At least not easily. Remember that the proprotors also serve as control surfaces at high nacelle settings, with the rotordiscs tilting just like a helicopter's to manuever. To move about the same way with jet engines would require some monstrous thrust vectoring, and would probably be very inefficient.
skidz
adrenaline junky
How would you free up the wing space for armament? That's a lot of area to leave out.
What about a combination of the Harrier's thrust nozzle system? Each engine then has a main rear nozzle and a pair of the Harrier's type on them as well, leaving three ways to adjust. It would be too much for one to do without a computer, but I guess everything is that way now.
Hell, I don't know. I'm not the one building the damn thing.
If you want a jet-powered CAS platform that can land vertically, there already is one. It's called the Harrier. Making a jet into a V/STOL platform is difficult and involves a lot of compromises, as the Harrier and the STOVL version of the F-35 show.