Friday, September 22, 2017

MV-22 and Landing Zones

Hopefully, you’ve all seen videos of Vietnam era UH-1 Huey aviation assault landings.  The helos come in fast in a turning, gut-wrenching drop, tightly packed, land hard, disgorge their troops in seconds, and haul out.  The entire assault landing is over and done in seconds.  The landing zones (LZ) were generally fairly small – just a clearing wide enough for several helos to land at the same time.

Now, let’s consider the MV-22 and LZ’s.  I’m led to understand that the MV-22 requires 250 ft separation when it lands – so much for a tightly packed group of assault craft!  Assuming several MV-22s (or more!) make up the assault package, where are we going to find an LZ that’s big enough to support several MV-22s all spaced 250 ft apart?  That’s going to require an LZ covering several city blocks!  That immediately rules out the type of small clearings that constituted LZs in Vietnam.

On a related note, a USMC Basic Officer Course assault document specifies the LZ diameter for a single MV-22 to be 175 ft if bordering obstacles (trees, buildings, etc.) are 5-40 ft tall and an LZ diameter of 250 ft for a single MV-22 if bordering obstacles are 40-80 ft tall.  In comparison, the LZ diameter for a UH-1 helo is 100 ft for an LZ with bordering obstacles 5-40 ft tall (1).

The implications of the preceding are:

  • LZ choices will be limited and much more predictable by the enemy

  • Large, wide open LZs will place the troops in open fields without any cover and require them to move across large spaces, potentially under fire the entire time, in order to reach cover around the periphery of the LZ

The alternative to large, wide open LZs is to land aircraft sequentially, one at a time.  Given the very slow landing performance of the MV-22, that will result in an assault landing going on and on, one aircraft at a time with each aircraft, in turn, becoming the focus of enemy fire.  Survival rate ought to be around zero in a contested landing.

These considerations may force the MV-22 to land only in uncontested, unopposed areas.  If so, this further degrades the assault effectiveness of the MV-22 by ruling out most useful LZs and pushing the landings so far away from the ultimate target as to eliminate the element of surprise and speed.  In short, I don’t see the MV-22 as being a viable option for contested assaults.

I am also unaware that the Marines have ever conducted a full scale MV-22 combat assault exercise.  They may have done so but I doubt it or we would have heard about it in glowing terms, no matter how badly it went, and we’ve heard nothing.  Shouldn’t we conduct such an exercise and find out now what the MV-22 can do rather than find out the bloody way, in actual combat?

Let’s take that America class amphibious ship that has no well deck and conduct a full scale aviation assault and see what happens. 

Before we conclude, let me be clear – there is very little public domain information on MV-22 combat landing performance so much of what I’ve discussed is speculative.  However, it is all reasonable speculation backed by data.  For example, I have seen no public information on MV-22 LZ landing speed (the time from entering the LZ’s small arms fire range until the aircraft has landed and troops can begin debarking) but there are plenty of videos of MV-22 landings and they are painfully slow.  I’m sure they would be faster in combat but the point remains that they won’t be anywhere near as fast as the helos they’re replacing.



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(1)“Assault Support Capabilities / Operations”, USMC The Basic School, Marine Corps Training Command, Camp Barrett, VA, Basic Officer Course, B2C0355XQ

35 comments:

  1. Pic of the new V-280 Valor for Army, same problem as MV-22, 100+ feet in width ?

    http://www.bellhelicopter.com/~/media/bell/news/press%20releases/2017/280-226a/280-216a.ashx?w=1900&la=en

    Pic of V-280 on test stand, using a specially built hump to enable rotors to tranition to vertical while on ground, otherwise it smash its rotors and dig chunks of concrete from runway if it landed conventionally:)

    http://www.bellhelicopter.com/~/media/bell/news/press%20releases/2017/280-233a.ashx?w=1900&la=en

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  2. The flight restrictions below are from the current V-22 NATOPS (pilot's manual):

    VTOL/CONV: Minimum separation is 250 ft cockpit-to-cockpit and 25 ft of step up. During approach and landing phase, maintain step up until lead lands or maintain 250 ft separation. While maintaining 250 ft separation, avoid 5 to 7 o'clock position downwind of the upwind aircraft.
    a. Crossovers in descending, turning flight prohibited.
    b. Crossovers in descending, wings level flight prohibited with ROD in excess of 500 fpm.
    c. Crossovers shall maintain at least 50 ft of step-up.

    ___________________

    These V-22 limits were imposed because the wake or downwash from another aircraft can affect one tiltrotor before the other, causing an instant snap roll and crash. As a result, V-22s must remain a football field apart and fly at different altitudes. A "wave" of V-22s is never more than three aircraft, and only one can take-off or land at a time. Such restrictions do not apply to helicopters.

    And V-22s must land straight, slow, and steady to keep balanced between wingtip engines. Otherwise, they risk VRS and a rollover. USMC official videos always edit out part of this very slow landing process. Helicopters can swoop in near top speed, flare to brake, and plop down. You don't see this in peacetime as it is not allowed since it stress the rotors, but this was common in Vietnam.

    Since the V-22 are as big as the CH-53E in empty weight, they are big targets, and the last batch cost $91 million each per the DOD budget office, up from $72 million during the first year of this multi-year buy. And a recent USNI article says they will be rebuilt every 5-6 years since they wear out quickly, so the production line will never close.

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    1. Thank you for that NATOPS information. That's hardly a prescription for a successful combat assault landing, is it?

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    2. What helicopter has the range of an Osprey to replace it?

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    3. Wrong question. The right question is why do we even want to attempt aviation assaults against peer defenders? Helos/V-22s are non-survivable in contested skies, as history has shown.

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    4. “These V-22 limits were imposed because the wake or downwash from another aircraft can affect one tiltrotor before the other, causing an instant snap roll and crash. As a result, V-22s must remain a football field apart and fly at different altitudes. A "wave" of V-22s is never more than three aircraft, and only one can take-off or land at a time. Such restrictions do not apply to helicopters.”

      This is a gross oversimplification. These comments also seem to conflate vortex ring state (VRS) phenomena with induced loss of lift from the wake/downwash of a preceding aircraft. While similar, they are not the same thing. In both cases the “instant snap roll” is recoverable with appropriate pilot action. The most effective way to recover in the V-22 is to decrease nacelle pitch in order to change the velocity vector and put the proprotors in clean air. Anecdotal evidence from V-22 pilots suggests that former helicopter pilots get themselves into trouble in the V-22 by attempting to correct by increasing collective (i.e., increasing prop pitch but not altering nacelle pitch), which may exacerbate A-VRS (asymmetric VRS) in the V-22. It seems that former fixed wing pilots and brand new V-22 pilots without rotary-wing experience are less susceptible to this error.

      VRS is induced by a POWERED descent that is too fast IN RELATION TO FORWARD AIRSPEED. This also has nothing to do with autorotation (i.e., every helicopter requires forward air speed to autorotate, which is why an autogyro cannot hover). As an aside, the V-22 can autorotate but the rate of descent is too fast to ensure a survivable landing; autorotation in the V-22 does not induce VRS. The V-22s higher disc loading/faster induced flow actually makes the V-22 less susceptible to VRS than “pure” helicopters with lower disc loadings. What is somewhat unique about the V-22 is A-VRS in roll due to the transverse prop rotor arrangement. There is plenty of coverage of this subject but little understanding of it by those in the media.

      Note also that wake and/or downwash turbulence is generated by EVERY aircraft. Watch landings at any major airport. After a large aircraft (e.g.,a 747, 777, or A380) lands, subsequent aircraft in the lineup, but smaller aircraft in particular (e.g., 737s, and A320s), touchdown on the runway AHEAD of where the larger aircraft touched down in order to avoid flying through the wake turbulence of the larger aircraft, which can take MINUTES to dissipate under some atmospheric conditions. Plenty of fixed wing aircraft have crashed and/or experienced hard landing because of the associated and unpredictable loss of lift. Helicopter downwash is no different. It is probably fair to say that a V-22s relatively fast induced flow increases the likelihood and magnitude of persistent turbulence, and that the V-22 has unique and potentially challenging behavior in disturbed air due to the transverse proprotors, but it is wildly inaccurate to say that “such restrictions do not apply to helicopter.”

      If you have the time and interest, read through this thread on PPRuNe.

      http://www.pprune.org/rotorheads/204936-what-s-latest-news-v22-osprey.html

      Note the testimony of McPave (a verified, high ranking V-22 driver), ospreydriver, usmc helo, Gregg, and jeffg who have been up close and personal with the V-22 and/or the people that actually fly and maintain them. Alternatively, feel free of join, in my opinion, the tinfoil hat brigade.

      Also consider:

      http://breakingdefense.com/2012/09/flying-the-osprey-is-not-dangerous-just-different-veteran-pilo/

      http://www.military.com/NewContent/0,13190,NI_Myth_0904,00.html

      https://www.globalsecurity.org/military/systems/aircraft/v-22-vrs.htm

      http://pogoblog.typepad.com/pogo/files/v22_operational_and_live_fire_test_and_eval_report.pdf

      https://www.verticalmag.com/features/20112-flying-the-v-22-html/

      Like anything, the V-22 has advantages and disadvantages and its own unique characteristics.

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  3. Ospreys are limited in descending speed to maintain lift and avoid crashes. Propellers also block door gunners from engaging targets from 10 to 2 o'clock of the aircraft. A normal helicopter door gunner can shoot to almost 12 o'clock.
    There is no helicopter with the range and speed of an Osprey. Bet Gen Mattis would have loved an Osprey squadron when he did the long assault on Kandahar from the amphib deck, but its usefulness in hot LZs is more limited

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  4. The after-action report for "Operational Rhino" noted the V-22s would be nicer for the landing (was not an assault) but would have proven a huge hindrance logistically. All fuel had to be flown in and the V-22 burns six times more fuel per mission than a CH-46E since its twice a big and far less efficient with proprotors, yet can't carry any more payload VTOL.

    The V-22 has 40% greater speed than helicopters of similar size, but no greater range. The CH-53K and MH-47G have much greater range. V-22 range stats are bogus when details are examined, like assumptions that it has extra fuel tanks in its cargo bay, or that it will fly in thin air at 25,000 feet. It can fly that high, but not with passengers or equipment as it lacks a cabin heater and everything freezes within a hour, and no oxygen for passengers either. So V-22s fly at 8000 feet just like helos.

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    1. FFS

      1) How hard is it to comment with an alias?

      2)

      "The V-22 has 40% greater speed than helicopters of similar size, but no greater range. The CH-53K and MH-47G have much greater range."

      http://pogoblog.typepad.com/pogo/files/v22_operational_and_live_fire_test_and_eval_report.pdf

      The V-22 has unequivocally demonstrated a 200nm radius at 3,000 ft and cruise speed of 255 kts with 24 combat troops. Yeah, that's not quite what some of the marketing brochures want you to believe, but the V-22 exceeds the threshold requirements (however much they've been reduced) and has at least the same range, albeit less payload, as the 53s and 47s when similarly configured. It's unclear what the true maximum figures are.

      Note also the findings that the extra speed significantly increases survivability versus surface-to-air threats, including, MANPADs, by an estimated 40% (pages 39-41) during transit to the LZ. It seems like that might be worth a few extra seconds/minutes in a LZ under fixed-wing cover. Note also that neither CNO's source nor the '05 OPEVAL contemplate insertion into what the OPEVAL classifies as a "known high-threat environment" (i.e., a LZ within direct fire range of the enemy; OPEVAL, page 16). The OPEVAL further notes that the preferred tactic of V-22 pilots is to utilize the V-22's greater speed to minimize exposure time instead of evasive, "helicopter-like" maneuvering. The OPEVAL recommends studying expansion of the flight envelope into more helicopter-like evasive maneuvering in high-threat environments but does not indicate that such maneuvers are necessarily impossible or better than the current V-22 approach.

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    2. "extra speed ... during transit"

      This is, of course, true and may increase transit survivability due to speed (dubious, as the speed relative to surface to air missiles is ineffective) and decreased exposure time to enemy air defenses of whatever type (logically true). However, the situation changes at the LZ where the V-22's slower landing performance and larger size greatly decreases survivability.

      No one plans to intentionally land in a heavily defended LZ but, as Vietnam proved repeatedly, it's almost impossible to assure an undefended LZ unless the landing is moved so far away from any possible enemy presence as to render the mission unachievable. It is this situation, an unexpected hot LZ that will highlight the V-22's landing performance deficiencies relative to smaller, more nimble helos.

      I've already noted the required landing area size and how that potentially exposes the landed infantry to enemy fire without cover. Thus, it is possible that even if the V-22 were exactly equal to the legacy helos in landing performance, the overall landing would be negatively impacted by the greater exposure of the disembarked troops.

      All of this speculation and theorizing on our parts simply reinforces the need to conduct realistic, full scale, opposed landing exercises and find out what the V-22 performance is in an all out assault landing and to find out what tactics can improve the chances of success (or conclude that assaults are not feasible).

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  5. Your source seems to exclude UH-1Ys from the transports. I've also never seen the USMC use UH-1Ys in combination with either the V-22 or CH-53 to insert combat troops or equipment in photos on DVIDS or on youtube. I'm interested to know if any service members can confirm whether or not it's done.

    I have seen V-22s and CH-53s operating together a lot. The operational range of the V-22 and CH-53E are comparable and appear to far exceed that of the CH-46E, UH-1Y, and AH-1Z, so it makes sense that the V-22s and CH-53s would train together.

    Does anyone know if the CH-53s take off first and the V-22s catch up before insertion into the LZ?

    A similar document to your source also includes comparable LZ parameters for the CH-46E in addition to the UH-1, V-22, and CH-53. Also note the “Helicopter Capabilities” listed on pages 27-31.

    http://www.trngcmd.marines.mil/Portals/207/Docs/TBS/B2C3197%20Helicopter%20Capabilities%20and%20Operations.pdf?ver=2015-07-09-093903-257

    "Helicopter Capabilities/Operations," USMC The Basic School, Marine Corps Training Command, Camp Barrett, VA, B2C3197.

    The recommended LZ diameter for the CH-46E is the same as the V-22 and CH-53. The carrying capacity of the CH-46E is listed as 12 combat troops.

    Your source also lists aircraft capacities as 8 for the UH-1Y, 24 for the V-22, and 30 for the CH-53E (up to 37/55 with a waiver). The CH-53's LZ size requirements are the same as the V-22 per your source.

    So in terms of LZ size, you're actually gaining a lot with the V-22 versus the UH-1Y and CH-46E in terms of number of troops per LZ spot. And the speed of the V-22 in combination with the CH-53 might enable two launch and two recovery cycles per V-22/CH-53 insertion while maximizing the range of both if my thinking is correct (i.e., the CH-53s launch first and recover second; V-22s launch second but recover first; the V-22 catch up near the LZ (and possibly overtake the CH-53s) on the way in and overtake the CH-53s on the way out).

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    1. Troop capacity is an interesting subject. On the one hand, the greater the troop capacity, the fewer aircraft are needed and the quicker the landing can be completed (neglecting LZ size constraints and that impact on the number of aircraft that can land simultaneously). On the other hand, the larger the troop carrying capacity, the greater the impact of an aircraft loss. Losing 8 troops, for example, would be significantly less critical than losing 24. Dispersal of risk is a long recognized military goal.

      Personally, I come down on the side of dispersal of risk especially given the V-22's significantly poorer landing performance at the LZ which is where the bulk of aircraft losses will occur, as shown in Vietnam. I expect to see a 2x-3x greater loss rate for the V-22 at the LZ than for legacy (Vietnam era) helos and those Vietnam loss rates were staggering, themselves. I just don't see aviation assault as a viable concept no matter what aircraft is used!

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    2. "I just don't see aviation assault as a viable concept no matter what aircraft is used!"

      I concur. I think that our military more or less acknowledges this against a peer or even near-peer adversary, but they have to come up with some line other than we're basically effed versus China or Russia and may have serious problems putting boots on the ground versus an Iran-class adversary.

      As I've said before, if we had to do it, the V-22 would not be my choice. I think a SB-1/S-97 type aircraft has the speed, low-speed maneuverability, and defensive armament to have the best shot at pulling it off. The V-280 is interesting, and seems to address a lot of the V-22 deficiencies, but I think physics is still against it for this scenario. They're also sized to carry, at most, one squad. Everything I've read suggests the you'd get essentially all the benefits of a UH-60 and V-22 (at moderate ranges) with the only significant downsides being increased cost and complexity versus a UH-60.

      Since I think we've basically conceded that an opposed aviation assault isn't viable against a competent adversary, I think we actually went too small with the V-22. In reality, the V-22 is a fairly dedicated troop-carrier that is also good for dense, time critical internal cargo in relatively benign environments. In the troop-carrying role, the V-22 is volume, not mass limited.

      While at the risk of creating another F-35 sized program, my thinking is that we should have designed a fuselage of about the size of that of the C-27J and used it as a basis for a heavy-lift helicopter (preferably a slightly larger CH-47), tilt-rotor (preferably a larger V-280, not a larger V-22), and turboprop (larger C-2). Wings/control surfaces and/or engines would unique or a suitable variant with respect to each type of aircraft. I think that such a family of aircraft would have met a lot of our pressing needs and the SB-1 would be great to adequate for anything not requiring such a large aircraft (e.g.,medium and high threat assaults, CSAR, Medivac, and ASW). Just my $0.02.

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    3. "I think that our military more or less acknowledges this against a peer or even near-peer adversary"

      Then why are we procuring America class LHA's without well decks and why are we emphasizing aviation assaults? If the only assaults we can actually execute are against undefended, low threat, non-peer enemies then we don't need the amphibious fleet (hey, I should do a post about that! - oh wait, I did).

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    4. “Then why are we procuring America class LHA's without well decks and why are we emphasizing aviation assaults? If the only assaults we can actually execute are against undefended, low threat, non-peer enemies then we don't need the amphibious fleet (hey, I should do a post about that! - oh wait, I did).”

      Because distributed lethality contemplates separating the LHAs from LHDs and/or LPDs? If the LHAs are going to be carrying F-35Bs, V-22s, and CH-53Ks, they can stand off further than the LHDs and LPDs that need to get close enough to the beach for the LCACs, LCUs, and AAVs (and UH-1s and AH-1s to a lesser degrees) to be effective. This gives the LHA a bit more protection and could potentially give its aviation asserts more operational flexibility and tactical surprise depending on the local geography.

      I might post my thoughts as to the size of the amphibious fleet in that post, but I will suggest here that we'll still want to force a non-peer to giver consideration to the beaches, ports, and the likely LZs.

      My questions is: why didn’t we build the “light” carriers we seemingly want instead of the LHAs, angled flight decks and all? The damn LHAs are about the size of post-refit Essex-class carriers and about the size of the pre-refit Midway-class carriers. Members of both classes finished their careers with angled flight decks. I always kinda figured a secondary reason for pursuing AAG and EMALS was that they can potentially be more easily incorporated into smaller, non-nuclear vessels than the previous systems. I think the idea of building light carriers for the USMC has merit within the “distributed lethality” doctrine, the LHAs are just half-assed versions of ones. Then again the state of procurement doesn’t exactly inspire a lot of optimism that we could quickly and cheaply build such a carrier, even if it’s no bigger than the LHA/LHDs.

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    5. "My questions is: why didn’t we build the “light” carriers we seemingly want instead of the LHAs, angled flight decks and all? The damn LHAs are about the size of post-refit Essex-class carriers and about the size of the pre-refit Midway-class carriers."

      I don't understand that either. And with a top speed of 22kts they are big and expensive, but limited in their role. I'd take a 28-30 kts speed to aid in getting wind over the deck, and at least a ski jump to aid in increased payload.

      If we could build something like that at cheap cost, then we have a real flexibility. Of course, then we might want to look into some AWACS aircraft for the type....

      But once we start talking like this we start getting into CNO's idea of midway sized carriers.

      I'm confused by the whole gator fleet anymore. It costs a ton, but seems overbuilt for non-peer adversaries.

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    6. "seems overbuilt for non-peer adversaries."

      It IS overbuilt for the kind of low end, third world use that we encounter in "peacetime". It's just like using Super Hornets to plink pickup trucks - huge overkill.

      On the other hand, it's poorly designed for high end, peer war.

      So - bad either way!

      Regarding light carriers, what you never hear from proponents is how such a ship fits into actual combat operations.

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    7. To me a 'light carrier' is one of two things, fulfilling two different roles. One is a midway class designed to distribute some risk and lower acquisition cost (Your idea, I believe, that I'm aping). The second is something like a 'phib but more like a modern day Essex. Something that should be cheaper to build and that could launch something like a Super Tucano (if we could navalize it).

      The main role of this would be to fight all the Hi-Lux plinking roles we have. In a peer war it stays home or operates as a sea control ship like the tiny Brit carriers.

      I realize not everyone shares my ideas with that.

      I just can't stand the fact that we spend so much money on flight time and burning the wings off of 4th generation jets to bomb AK infantry and Toyota Tanks.

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  6. Another thing they always forget to mention is the frontal RCS of the V-22 i mean c'mon that thing will light like a Christmas tree on radar scopes thanks to those huge fans.
    The next thing - how noisy is a V-22 compared to a Chinook for example?

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    1. By all accounts much quieter in fixed-wing flight and noisier in the hover. The transmission automatically switches to a higher proprotor rpm, and thus noisier, mode in rotary-wing flight. The tactics seems to be to transition to rotary-wing flight as late and as low as possible on insertion and as quickly and as low as possible on LZ departure in order to minimize exposure time. The '05 OPEVAL states that V-22 pilots prefer to delay transition to rotary-wing flight until about 1 mile from the LZ.

      Helicopter and turboprops aren't exactly known for small RCS signatures either. Unless we have some sort of twin engined, troop carrying F-35B, everyone is going to know we’re coming if we go in at altitude.

      V-22 tactics are consistent with all documented evidence that I've been able to find online with respect to Vietnam-era helicopter tactics; initial approach at 1,500 ft AGL and a terminal approach (i.e.,the final 5-10 km) into the LZ at tree-top height as fast as possible in order to conceal the location of the LZ as much as possible and reduce exposure to ground fire. Granted, most of the detailed information that I’ve found is with respect to the insertion of small reconnaissance teams, but I can’t think of any reason why large-formation tactics would be any different. Does anyone have any concrete sources that describe different tactics?

      Propeller-driven aircraft and helicopters are sitting ducks for MANPADs and medium-caliber AAA at 1,500 ft. The 1,500 ft mark is just to get out of range of small-arms fire, but in doing so, puts you within essentially the ideal envelope of heavier, more advanced threats. Unless you really, really trust your route reconnaissance, my hunch is that any air assaults in the future are going to be conducted at very, very low altitudes and with as much speed as possible against adversaries with more advanced weaponry. The higher speed and lower acoustic signature of the V-22 in fixed wing flight or a compound helicopter are probably very advantageous in such scenarios.

      Most of the detailed information that I’ve found is with respect to the insertion of small reconnaissance teams, but I can’t think of any reason why large-formation tactics would be any different unless relying on the firepower of escorting aircraft to suppress the enemy while making a terminal approach to the LZ at higher altitudes.

      https://murdercube.com/files/Combined%20Arms/heliguide_tactics_vietnam.pdf (sees pages 17-24)

      https://www.youtube.com/watch?v=krfCNmxiOSY

      https://www.youtube.com/watch?v=xyH952sWHdo

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    2. As you note, the documentation applies to single helo insertions into "known" safe areas where stealth is the objective. How that would change for a mass helo assault landing, I have no idea.

      The videos I've seen from Vietnam helo assault landings are phenomenal in their speed. From visible on the horizon, the helo touches down in about 15 sec, disgorges its troops in about 8 sec, and is gone on the horizon in another 15 sec. From what I've seen of MV-22 landings/takeoffs, I simply can't imagine anything remotely approaching that kind of speed from the MV-22. Simply disembarking the troops will require much more time on the ground due to the greater number of troops carried (a drawback to greater troop capacities). Time spent motionless on the ground is vulnerable time!

      Watch some of the MV-22 landing/takeoff videos and then the Vietnam assault videos and see if you can imagine the MV-22 being remotely able to perform that way. Admittedly, the MV-22 videos are peacetime training where speed is not required. Of course, one can ask why we aren't practicing max effort combat/assault landings and takeoffs since that's what we'll be doing - train like your fight, fight like you train.

      I'll say it one more time, we need to practice full scale assaults against opposition and see if it's even viable. To the best of my knowledge, such an exercise has never been attempted.

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    3. I'm not going to argue that the V-22 performs like a UH-1 or UH-60 when it comes to "dynamic" insertions. The thing basically weights as much as a CH-53E and those lang pretty gingerly too. The momentum alone probably precludes such maneuvers, not to mention that offload is done via the relatively narrow rear ramp and not dual side doors.

      I've spent more time than I care to admit watching UH-1, UH-60, CH-47, CH-53, and V-22 landings since this post went live. My reasonably informed(?) eye says that the V-22 is roughly comparable with the CH-47 and CH-53 in landing on an individual basis. Which makes sense given the relative weights. Landings between aircraft of the same type also seem to vary significantly it terms of terminal rate of descent over the final landing spot. V-22s, for example, seem to have much higher terminal rates of descent when landing on LHDs versus in brown-out conditions. Kinda makes sense. I also remember reading in one of the sources that I've posted, I think, that pilots "fly the V-22 onto the deck of the ship" more so than in other types of landings due to turbulence caused by the superstructure and sometimes having one prop rotor over the deck and one over the water (i.e. they land more quickly/aggressively to minimize the destabilizing effects of these conditions).

      If I had to rank these three aircraft based on quickest landings, however, I probably would put the V-22 last and the CH-47 first but the differences seem pretty marginal and the quickest V-22 landings seem quicker than the slowest CH-47 landings when it comes to terminal rate of descent. IDK, it's hard say much more than that without more concrete data. I do think that it's more complicated than X lands faster than Y based on disc loading, weight, power, etc..

      "Rolling" landings, however, do seem to be faster than "pure-vertical" landings for each type (i.e., landings with substantial forward airspeed are noticeably faster than landings with essentially zero forward airspeed). Pilots of the V-22, CH-53s, and CH-47s all seem to "hesitate" and stabilize the aircraft in the final seconds before touching down when forward airspeed is essentially zero. You do not usually see this to anywhere near the same degree when it comes to the smaller, lighter helos.

      Separation between V-22s is noticeably larger compared to that between 47s and 53s. But is that necessarily a bad thing with respect to indirect and spray-and-pray fire?

      My hunch is that vulnerability is not linear with respect to terminal rate of descent and overall insertion time (i.e., insertion of the entire force). I'm betting that below a threshold rate of descent and/or airspeed, vulnerability to ground fire is probably significant but relatively constant. For example, sometimes people mention 300 kts as a sort of threshold airspeed with respect to vulnerability to unguided AAA at medium altitude; above 300 kts manually-guided AAA cannot reliably track and lead you even if they have the time to do so, and below 300 kts, you're more less equally vulnerable regardless of airspeed, all else being equal. Similarly, I'm betting that above a threshold overall insertion time, vulnerability to indirect fire is probably significant but relatively constant, all else being equal. Finally, I'm betting that the V-22, CH-53, and CH-47 are more or less equally vulnerable in the LZ and you need a much smaller, lighter aircraft, such as UH-60 or SB-1, to see significant reductions in vulnerability.

      Regardless of aircraft, it'd be interesting to see what these trends look like in those tests of yours.

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  7. Just a couple of stories about the advantages of the CV-22/MV-22 over helicopters that are worth sharing.

    http://breakingdefense.com/2014/11/mackay-trophy-for-afsoc-osprey-crews-a-tale-of-bullet-riddled-planes/

    http://scout.com/military/warrior/Article/How-a-Titlrotor-V-22-Osprey-Helped-Take-Down-a-Taliban-Warlord-101459921

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    1. "worth sharing."

      Why are they worth sharing? There's not an aircraft in existence that can't muster up some spectacular stories. A few isolated stories prove nothing.

      Do you have a point to make that you think these stories illustrate and are relevant?

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    2. Pilots were appalled at this award, pushed by Bell-Boeing. Three V-22s get shot up by illiterate tribesmen, abort the mission and limp to another airbase. They did a good job, but this was not the greatest mission for the year.

      As for Afghanistan, the V-22 was only used for VIP visits, easy trash runs, and PR stunts. The 40-year old CH-53Ds were overdue retirement, but deployed to Afghanistan instead of more V-22s, and used seven times more often. Note how little the V-22 was flown (flight hours) since half were down for repairs at any given time, and old helos were the preference for combat missions.

      http://english.ryukyushimpo.jp/2016/01/17/24369/

      The V-22 has twice the moving parts of a helo, so costs twice as much to procure, twice as much to maintain, and is down twice more often.


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    3. There's nothing like an uncontrolled, probably, no, almost certainly, statistically irrelevant study to prove absolutely nothing.

      That study doesn't distinguish between class A, B, C, and D accidents for each type of aircraft and the differential between the V-22 and CH-53D is a whole TWO accidents. The V-22 had one class-A accident in Afghanistan during that time period on April 8, 2010 that resulted in four deaths. The CH-53D also had one class-A accident in Afghanistan during that time period on January 19, 2012 that resulted in six deaths. The article also states that four of the V-22's Class-C accidents were incurred by SERVICE personnel, having what to do with accidents per flight hour? The range of accidents is only 0-8 while the range in flight hours is 25.6 to 29,121.10. The study doesn't appear to control for number of aircraft in theater. The study only looks at FY 2010-2012...in a 2016 article. It almost looks like someone is cherry-picking data and manipulating the analysis to provide the conclusion they want.... There are bad actors on both sides of the issue.

      2 seconds of googling also reveals that your statements about the V-22 usage in Afghanistan are wildly inaccurate, even based on the unflattering sources.

      The V-22 certainly has warts, but you need to work harder to find them.

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    4. Anon has provided data and a source. The article normalizes the data to a common basis of flight hours. That's valid.

      Gripen, if you believe the V-22 usage claims are "wildly inaccurate", provide some data and cite some sources. At the moment, your claim is unsubstantiated.

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    5. “Gripen, if you believe the V-22 usage claims are "wildly inaccurate", provide some data and cite some sources. At the moment, your claim is unsubstantiated.”

      Anon’s source doesn’t substantiate his claims about V-22 usage. At least hold us to the same standard. Literally, just googling “V-22 afghanistan” turns up numerous sources that contradict anon’s unsubstantiated claims. For example, the very first search result from 2010:

      http://www.airspacemag.com/military-aviation/osprey-at-war-10288204/

      Do I need to provide a source to prove that the sky is blue as well?

      “Anon has provided data and a source. The article normalizes the data to a common basis of flight hours. That's valid.”

      Sure, that’s “valid” but it’s nowhere near enough to reach a meaningful conclusion. The article explicitly states that the accidents considered aren’t limited to in-flight accidents. If, for example, a maintainer breaks a $100,000 fuel pump because he or she doesn’t follow the correct maintenance procedures, does that tell us anything about the V-22’s or any other aircraft's reliability or safety? No. Can we directly compare accidents per flight hour if one type of aircraft averages X flight hours per aircraft while another type averages 2 * X flight hours per aircraft? No. Do we need to consider the minimum number of flight hours and minimum number of accidents required to reach a meaningful conclusion? Yes. For example, if all aircraft types average one class-A accident per 10,000 flight hours but one type experiences one class-A accident in its first 100 flight hours, you can’t conclude that that the class-A accident rate is 100 times higher than the average for that type based on those first 100 flight hours. Do we need to factor in the operating environment of each aircraft and each type of aircraft. Yes. Do we need to factor in the missions performed by each aircraft and each type of aircraft? Yes. Do we need to factor in the level of maintenance available for each type of aircraft (e.g., depot-level vs. field-level maintenance)? Yes. That source does none of these things.

      At bare, bare minimum that study should limit the accidents counted to in-flight accidents and normalize against flight hours per aircraft (i.e., accidents per flight hour per aircraft). This is basic stuff. There’s no guarantee that doing this sort of due diligence would be favorable to one aircraft over another. Forgive me for being suspicious because such basic controls weren’t considered.

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    6. "Do I need to provide a source to prove that the sky is blue as well?"

      Oh, settle down. This is what a data based discussion is about. Data and sources are provided and the everyone can assess and analyze the data. Asking for data/sources is not a personal attack.

      "Anon’s source doesn’t substantiate his claims about V-22 usage."

      Yes, it did. It cited flight hours. If you believe there's something skewed about the data then explain it provide alternate data/sources. At a quick read, the source you cited has no actual data about flight hours, relative usage of various aircraft types, accident rates, or any other pertinent data.

      "Can we directly compare accidents per flight hour if one type of aircraft averages X flight hours per aircraft while another type averages 2 * X flight hours per aircraft?"

      Yes! That's what normalization does. Normalization, if you're not familiar with it, is a statistical analysis technique that allows comparisons by using a common basis - accidents per flight hour, for example. The normalized rate (accidents per flight hour) is independent of the number of flight hours. Now, you might be able to make an argument that more flight hours increases wear and tear and thus contributes to increased accidents but you'd have to supply some data to back that up or just call it reasoned supposition.

      If you wish to engage in these types of discussions, you need to relax, depersonalize the discussion, and simply discuss with as open a mind as you can (easier said than done for all of us!).

      Discuss rather than try to "win".

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    7. How are any of my criticisms personal? I'm merely pointing out the difference in standards that you're applying and flaws in that study. How is that personal? If I'm taking something personally, I'll let you know, as I have before.

      If anything, my attempts at humor should indicate the opposite.

      Moreover, Anon's source does not suggest in anyway that "As for Afghanistan, the V-22 was only used for VIP visits, easy trash runs, and PR stunts." My source directly contradicts this, as do sources that are too numerous to list. Do you cite sources for everything that can reasonably be taken at face value or based on cursory research? No, doing so isn't realistic on this forum.

      I'm also not making the inverse of Anon's argument (i.e., Anon's argument that the Osprey is not as reliable as legacy aircraft). I'm arguing that you can't reach Anon's conclusion based on his source. This being the case, why should my source have to prove that the Osprey is as reliable or more reliable than legacy aircraft? I'm not making that argument. I'm just using my source to show that the Osprey has been used for more than "VIP visits, trash runs, and PR stunts."

      "Now, you might be able to make an argument that more flight hours increases wear and tear and thus contributes to increased accidents but you'd have to supply some data to back that up or just call it reasoned supposition."

      That is, of course, precisely the point. Merely normalizing against flight hours isn't necessarily enough to reach Anon's conclusion if you can't discount flight hours per aircraft (i.e., that it's not necessary to normalize or control for, "wear and tear" PER AIRFRAME). In any scientific/technical review, it's not on the reviewer (i.e., me) to prove that a control is necessary (e.g., that "wear and tear" must be considered), it's on the investigator (i.e., Anon) to prove that it isn't or one that can't reasonably be quantified (e.g., that "wear and tear" is not a significant factor); if the investigator can't, the conclusion isn't necessarily valid (e.g., that the Osprey is not as reliable as legacy aircraft), but it's also not true that the conclusion is necessarily invalid or that the inverse is valid because of it (which isn't my argument to begin with). I explicitly stated, "There’s no guarantee that doing this sort of due diligence would be favorable to one aircraft over another."

      "If you wish to engage in these types of discussions, you need to relax, depersonalize the discussion, and simply discuss with as open a mind as you can (easier said than done for all of us!)."

      And I'm trying. I commented on Anon's post precisely because I believe that his source has a clear bias that he or she does not acknowledge. Pointing out that bias isn't evidence of discussing the subject with a closed mind, it's evidence of asking others to discuss the subject with an open mind. If he or she or anyone else wants to find the original study so that we can discuss it and the controls that it does or does not use more fully, I think that'd be great.

      Please consider my intentions with an open mind and not under the assumption that I'm trying to "win." I'm not. As you stated, we don't have much public domain information on this subject. Given that, I don't think anyone can "win." I do think that some commentators here can increase the quality of their comments.

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    8. "difference in standards"

      There is no difference. Anon made a claim and supplied data and a source to support it - exactly what I ask readers to do. I suggested that you do so but you have not yet offered any actual data/source. No difference except that he did it and you have not yet.

      "My source directly contradicts this"

      Your source, and I use the term loosely, does not offer any data. It is an anecdotal story that involves a VIP type ride on a V-22 which actually supports anon's claim!

      "it's not on the reviewer (i.e., me) to prove"

      This is not a scientific journal. It's blog comment. He made a claim and offered supporting data. If you wish to counter it, the onus is on you to provide data.

      This discussion has become semantic, pedantic, and tedious. Make a substantive point or move on.

      Delete
    9. "This is not a scientific journal. It's blog comment. He made a claim and offered supporting data. If you wish to counter it, the onus is on you to provide data."

      This discussion has become semantic, pedantic, and tedious. Make a substantive point or move on."

      In this particular case, I assert that the validity or lack of validity of my argument speaks for itself, as does yours, based on the evidence presented. It seems that we have a fundamental disagreement as to the rules of evidence here.

      Forgive me for not wanting to find the original study and spend the time and effort to do a thorough analysis of it at the risk of your oft-cited argument that "A few isolated stories [or studies in this case] prove nothing" while Anon's objectively unsubstantiated claims as to the V-22s roles in Afghanistan are allowed to stand based on an alleged, five-paragraph, foreign source....

      My points are also substantive and important. I'm stating principles upon which all professional scientific and technological discussions are based. I don't deny that they can be tedious, but that's the reality. These questions and analyses, however, are required in order to know if a conclusion can be relied on based on the inevitable assumptions made therein. I'm not willing to compromise on that. I've tried my best to abide by them and make my assumptions clear. Reasonable people can disagree on whether or not various assumptions are valid, but they need to be stated. I believe that calling out others and their sources for failing to state their assumption should be fair game here without an extensive counter-proof. That's not reasonable in a professional setting and isn't reasonable here in order to merely question the validity of a conclusion, as opposed to asserting a different conclusion. The former is all that I've done with respect to Anon's source, albeit harshly. I expect nothing less with respect to my own conclusions and sources. If you don't want to engage in these types of discussions and have these principles comprise the framework for the comment section of the blog, I believe that it's your loss, but it's also your blog.

      I expect that I will be moving on from commenting here because I no longer believe that the framework of the discussions here justify the degree of time and effort that I've previously been motivated, and felt necessary, to make. I think a serious discussion of many of the issues that you frequently bring up requires more rigorous and substantive scientific and technological discussions than most commentators here are willing to engage in. And "heated" discussions should not be mis-characterized as personal ones. These have been ongoing concerns. In short, I no longer believe that our goals are a good fit.

      Thank you for the opportunity to comment, often extensively, here and for some of the trust you've placed in me. I think that you have many good and interesting ideas, and do intend to continue following but not commenting on the blog. I mean it sincerely when I say that it has been a pleasure commenting here over the last few weeks.

      Best of luck.

      Delete
  8. "The report also found that [V-22] aircraft readiness ranged from 45 percent to 58 percent from fiscal 2009 to 2011, far short of the goal of 82 percent readiness."

    http://www.marinecorpstimes.com/news/pentagon-congress/2015/08/23/osprey-readiness-a-challenge-years-after-troubling-report/

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    1. And, then things got better. From the article, "Nearly two years since the investigation, readiness rates have improved significantly for the Osprey, said Maj. Paul Greenberg, a spokesman for Marine aviation at the Pentagon. The mission capable rate for the V-22 between July 2014 and June 2015 was 62 percent for stateside aircraft and 71 percent for deployed squadrons."

      http://www.marinecorpstimes.com/news/pentagon-congress/2015/08/23/osprey-readiness-a-challenge-years-after-troubling-report/

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    2. I can't stay away, at least when it comes to something I've started. I think (maybe you could try thinking of a screen name?).

      You're suffering from confirmation bias and not asking the right questions. Are you trying to show that the V-22 is not reliable or trying to figure out how the V-22s readiness /mission-capable rates compare to other aircraft?

      Consider TwinHueyMan:

      http://www.pprune.org/rotorheads/204936-what-s-latest-news-v22-osprey-14.html#post4301717

      usmc helo:

      http://www.pprune.org/rotorheads/204936-what-s-latest-news-v22-osprey-22.html#post5015769

      SansAnhedral:

      http://www.pprune.org/rotorheads/204936-what-s-latest-news-v22-osprey-76.html#post7069147

      And best of all, Ramen Noodle:

      http://www.pprune.org/rotorheads/204936-what-s-latest-news-v22-osprey-23.html#post5021430

      There's variability in these number and the V-22's numbers are not necessarily significantly worse than legacy aircraft, especially when you consider that, even in 2017, we still probably don't know all the ways in which the V-22 is likely to break, unlike with most legacy aircraft (e.g., some that have been in service since the early '60s). And, theoretically, what are the advantages of the V-22 worth in terms of readiness?

      "Fear is the mind-killer"

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