S97 Raider
High speed SAR has been discussed before... at one point it was hoped that a 609 tiltrotor variant with a wider door and retractable hoist would be a good fit for the US Coast Guard. So he range and speed of a twin Raider style aircraft isn't a bad fit for the mission, though making an aircraft that can handle landing on ships in severe sea states isn't something Sikorsky has tackled yet. If that's not part of the mission requirements, then sure, it's worth consideration as an idea.
Performance at the cost of low availability and high maintenance is not always a good trade.
Moving forward to the S-97 thread, I believe there is a lesson to be relearned. Is the added performance provided by the highly complex composite structure, three rotor, fly by wire S-97 worth the lower availablity and higher maintenance when compared to a modern equivalent to a Kiowa?
Is the added performance provided by the highly complex composite structure, three rotor, fly by wire S-97 worth the lower availablity and higher maintenance when compared to a modern equivalent to a Kiowa?
Or a ...... Commanche?
So - it would seem that the proven tiltrotor format of the Valor (notwithstanding a static rather than rotating nacelle) appears to be a lot lower risk than the S-97?
With admittedly no expertise whatsoever in this area - the Valor intuitively `looks right'
And as (ironically) Kelly said - "If it looks right..."
Fascinating project - hadn't realised the split into FVL light, medium, heavy and ultra.
Now I see what you mean by the Commanche comment SAS.
With admittedly no expertise whatsoever in this area - the Valor intuitively `looks right'
And as (ironically) Kelly said - "If it looks right..."
Fascinating project - hadn't realised the split into FVL light, medium, heavy and ultra.
Now I see what you mean by the Commanche comment SAS.
Join Date: May 2010
Location: PNW
Posts: 76
Likes: 0
Received 0 Likes
on
0 Posts
If I can throw a question out here, as a non-expert in this area:
To what extent is the competition between ABC and tilt-rotor designs determined by radar profile? Tilt-rotors obviously presenting a larger target in cruise mode. Or does that not matter anymore, with current AA radar tech being able to pick up anything of that size inbound and flying low?
To what extent is the competition between ABC and tilt-rotor designs determined by radar profile? Tilt-rotors obviously presenting a larger target in cruise mode. Or does that not matter anymore, with current AA radar tech being able to pick up anything of that size inbound and flying low?
If I can throw a question out here, as a non-expert in this area:
To what extent is the competition between ABC and tilt-rotor designs determined by radar profile? Tilt-rotors obviously presenting a larger target in cruise mode. Or does that not matter anymore, with current AA radar tech being able to pick up anything of that size inbound and flying low?
To what extent is the competition between ABC and tilt-rotor designs determined by radar profile? Tilt-rotors obviously presenting a larger target in cruise mode. Or does that not matter anymore, with current AA radar tech being able to pick up anything of that size inbound and flying low?
Join Date: May 2010
Location: PNW
Posts: 76
Likes: 0
Received 0 Likes
on
0 Posts
Join Date: May 2010
Location: PNW
Posts: 76
Likes: 0
Received 0 Likes
on
0 Posts
"The V-22 is equipped with two counterrotating three-bladed proprotors. The blades are constructed primarily of composite material with a metallic leading edge abrasion strip and integral de-ice blanket. "
V-22 Osprey
Each blade is also wired for green LED lights at the blade tips, for ground crew safety (you may have seen photos of the "green ring" on these things at night). So they're not 100% composite, and whatever metal is in there is spinning to form a disk in cruise mode. A metal leading edge strip would probably light up pretty good.V-22 Osprey
This was the only info I could find about the radar cross section, from "V-22 crew chief Staff Sgt. Brian Freeman’s letter to Gannett’s Marine Corps Times," quoted in defenseindustrydaily.com:
"Nevertheless, the countermeasures dispensing system was found to have insufficient capacity for longer missions, and radar reflection from the V-22’s total propeller disc area of more than 2,267 square feet rivals that of two Boeing 707s in formation.146 (Given that situation, one can only wonder at the logic behind the development of top-secret "stealth paint" for the fuselage at a cost of $7,500 per gallon; the one aircraft they painted required 10 gallons for a paint job costing $75,000 -- but those huge, whirling discs were still there, bouncing back radar signals with gusto.)"
V-22 Osprey: A Flying Shame?
Maybe there have been upgrades since then, and I remember seeing something recently about Bell developing new prop/rotor blades. But I think that was mainly for cost-savings? Anyway, it's just something I find interesting when comparing tiltrotor, tiltwing, and more conventional designs for military use.
V-22 Osprey: A Flying Shame?
After all these years it is suprizing to me how many people still don't understand "stealth".
Stealth technology is not limited to detection by radar. Stealth technology includes acoustic detection, thermal signature, and visual detection.
Designing an aircraft to incorporate stealthy radar characteristics is highly dependent on its intended mission. No aircraft is completely invisible to radar. Comprises are made to provide stealth where it makes the greatest mission benefit.
For a B-2 bomber it is penetration at high altitude that is of greatest importance. While on the dogfighting F-22 needs to be concerned all directional aspects need to be considered.
So before dismissing the benefits of Low Observable paint on a V-22, think about the V-22 mission.
Stealth technology is not limited to detection by radar. Stealth technology includes acoustic detection, thermal signature, and visual detection.
Designing an aircraft to incorporate stealthy radar characteristics is highly dependent on its intended mission. No aircraft is completely invisible to radar. Comprises are made to provide stealth where it makes the greatest mission benefit.
For a B-2 bomber it is penetration at high altitude that is of greatest importance. While on the dogfighting F-22 needs to be concerned all directional aspects need to be considered.
So before dismissing the benefits of Low Observable paint on a V-22, think about the V-22 mission.
Join Date: Sep 2007
Location: USA
Posts: 601
Likes: 0
Received 0 Likes
on
0 Posts
I believe one advantage of tilt rotors versus helos is their ability to quickly climb and cruise at altitudes beyond MANPADS. There are many things Bell can do to reduce detection of this tilt rotor. They are using composite materials for most of the airframe structures and rotor. The straight single-piece wing makes it easier to manufacture and repair, and also simplifies the interconnect rotor drive system. One major reason for using the non-tilting engine was due to the fact that there were no suitable tilting turboshaft engines available.
one piece of anything is harder to repair compared to segmented design.
Modern chopper can easily beat manpads in service today in terms of practical ceiling and climb no slower than TRs. The only benefit for current gen of TRs are the range and speed. Anything else is just sell pitch.
Modern chopper can easily beat manpads in service today in terms of practical ceiling and climb no slower than TRs. The only benefit for current gen of TRs are the range and speed. Anything else is just sell pitch.
As to a tilt rotors rotor radar cross section. The rotor blades in airplane mode operate at high angles which provides the same faceting effect as on a F117 to deflect radar from returning to its source. NAVAIR tried a Lawerence Livermore airframe mounted radar blade tracker which worked ok when the target section of the blade was perpendicular to the tracker, but useless with even a few degrees of pitch as the return was deflected. The proposed solution was to add a 360 degree radar reflector to the blade to ensure a return. Obviously this was rejected as stupid. V-22's still use optical trackers for a rare maintenance action.
Note: Radar cross section is closely guarded, has little to do with presented disk area (disk presented solidity somewhat), and something a Staff Sargent would never have a clue of.
Note: Radar cross section is closely guarded, has little to do with presented disk area (disk presented solidity somewhat), and something a Staff Sargent would never have a clue of.
Last edited by The Sultan; 6th May 2017 at 18:48.
Originally Posted by Vertical Mag - Flying the V-22
Climb capability is where the Osprey excels, with rates approaching 4,000 feet a minute depending on environmental conditions.
At AHS today, Mark Miller from SAC mentioned the S-97 has 18 total flight hours to date in 13 flights, which is over the course of 2 years.
Also disclosed they have attained 150kt in level flight and 130kt in a 45 degree bank, which aligns with the footage released recently.
Also disclosed they have attained 150kt in level flight and 130kt in a 45 degree bank, which aligns with the footage released recently.
Climb no slower? The climb rate in airplane mode is not matched by conventional helicopters, and that's precisely what riff was referring to.
A 75-100% increase would indeed be in another class.