No, usmc helo, I did not know either Major Brow or Major Gruber, the two pilots who died (along with the other Marines) at Marana that night. But I feel that I've come to know them. And I am not ready to write them off, nor write the Marana accident off as "...pilot error, pure and simple." I am sympathetic to them, and defend them because they did not know that they were de facto test pilots for Bell-Boeing. They did not realize that they'd been given an aircraft that had defective, unexplored flying qualities.
I do not believe that the V-22 is any more or less susceptible to VRS than any helicopter; I just believe that the consequences of Asymmetrical-VRS are much more deadly.
People keep equating VRS in the V-22 to VRS in a helicopter, and this is a mistake. It is definitely *not* the case. When *one* proprotor goes into VRS, the tilt-rotor aircraft will roll over and dive to earth. If this happens up high, say around 2,000 or 3,000 feet, no problem! The pilot need only recognize what's happening, then beep the nacelles forward and voila!, instant escape. But VRS, or A-VRS does not happen up high.
Asymmetical-VRS will happen down low, at the bottom of an f'ed up approach, as happened to Majors Brow and Gruber. The start of the accident sequence will be subtle, just as it was in Marana. The crew will be in one of those "high gain" task situations, concentrating on getting into an LZ and dodging enemy fire. The ship will bank in one direction or other, and the pilot will "correct" by adding anti-roll control input. But he'll be doing exactly the wrong thing, making things worse, by increasing the pitch of the affected proprotor. Before he knows what's happening, the ship will be rolling uncontrollably.
This *will* happen.
Most people assume that the Marana V-22 crashed because the pilots initiated and held a rate of descent of 4,000 fpm, until the ship got into "VRS." This is not true. In point of fact, yes, the initial RoD had been very high as they maneuvered to stay in position on Lead, but the V-22 had actually decreased its rate of descent to 150 fpm where it stabilized for at least 6 seconds or longer (count it out if you must). The high rate of descent had been arrested. Or at least they were in a transition mode as they leveled off at 566 feet. They then increased their rate of descent again to 800 fpm at 500 feet, which is when the A-VRS got them.
There are now strict limitations on V-22's with regard to multiple-axis control inputs *and* yaw inputs when operating in helicopter mode. Why? Because the handling of the V-22 is still deficient in these areas. And the Navy knows it.
Pro-tiltrotor advocates gloss over A-VRS as inconsequential or insignificant. "Easily detectable! Easily escapable!" they claim. "Why, all the V-22 pilot has to do is keep his rate of descent below 800 feet per minute! ...And make no multiple-axis control inputs...and make no yaw inputs either. That's all! Easy as pie."
Uh-huh. In combat. Yeah.
I know I harp on this like a broken record. But the aerodynamic deficiencies that resulted in the Marana crash have not been corrected...can never be corrected. And thus, an accident of that same type will be repeated. If anyone can live with that, well, you are more callous and heartless than I am. I think our military pilots, crewmembers and servicemen who fly in these aircraft deserve better than that.
If that makes me an emotional dribbler, well, so be it.