FH, do you consider Mast Bumping to be a fatal flaw of the Huey? Just curious. It is a feature that comes with the rotor system and head, as designed. It can kill you, if you don't account for it in your handling of the aircraft.
For some reason, I get the idea that this has been discussed before, possibly even in this very thread.
Some people seem to make the mistake of thinking that the Chinook rotors act independantly of each other all the time.
No, I don't think so.
This is not...I think...the case. They overlap by, what, 30%? Not only that, the masts are at different angles with respect to each other. Even in a hover the Chinook rotors are interacting with each other.
That is irrelevant to the point that you
can end up with thrust asymmetry if the forward rotor and the aft rotor are rotating in different quality air. Thats aero 101, but depending upon the magnitude of the difference, may not create a substantial handling problem.
A scenario: landing on the back of a ship, like a destroyer, that has a tall hangar. The mini-version of the Chinook, CH-46, has to account for this during approach to land. If you are making an "up the rear" approach, you may find, as you move forward over the deck, that the front rotor disk will begin to hit the turbulent air that swirls off of the superstructure before the rear rotor does. Typically, it isn't of sufficient magnitude to make controllability a problem, but you will find in the NATOPS wind limits for such approaches. As with most transitional maneuvers, there is an adjustment to be made, depending upon the wind and aspect.
Your point is well made, however, that the distance between the centers of thrust are proportionally greater when comparing the V-22 to the Chinook or its baby brother. That is what has the gears churning in my brain.
The proprotors on a V-22 do act individually...and need to act individually because it has been discovered that when they interact with each other (as in the shipboard testing) the results can be nearly disastrous.
Indeed, they are not the same as the tandem rotors in the Phrog or Chinook.
But whether the Eglin crash was the result of "A-VRS roll off" or "wingtip vortice roll off" makes no difference.
It might to whomever is writing the NATOPS manual, or the Dash 1, as there may need to be a change in guidance for handling.
The aircraft rolled over and crashed (we know at least that much) which strongly hints at unequal lift on one side.
You are being redundant there. Unequal lift in a system that produces lift from two sources requires, by definition, that one side's lift production isn't equal to the other.
It still strengthens my point that the tiltrotor concept is DEFECTIVE.
I don't think your point is supported by the evidence of the thousands of hours of successful operation.
When one proprotor loses lift that piece of crap flips over on its back and crashes.
I am not so sure that's right, in terms of design. As I understand the design, if one of the engines fails, or some of the subsystems fail, you will have torque asymmery and thus transient uncommanded rolling moments. (Best translation from the NATOPS (old) that I have access to).
In other words, not every asymmetry in thrust / torque causes a roll to inverted state, but the risk is there. The handling issues are both addressed and as I understand it, part of the training program: just as you or I would be aware of how to deal with stuck pedals in a Jet Ranger or a Huey. The handling is a bit more difficult, and if not done quite right can result in a wreck, but if done right can result in a safe landing.
Critical engine and rudder in twins, fixed wing, anyone?
It is only a miracle that anyone on the Eglin aircraft survived. (And don't give me that BS about "See how survivable a tiltrotor crash is!")
Not buying your argument here. Are you aware of the significant efforts the Army went to in order to upgrade crashworthiness and crash survivability for the Blackhawk versus the Huey? That isn't the only aircrft to have benefited from the work they did.
Asymmetric loss of lift is asymmetric loss of lift.
No kidding. I hear an Israeli F-15 flew home missing a good portion of a wing. I've flown fixed wing in split flap condition (annoying as hell) due to a system failure. I didn't roll inverted.
Let's just keep whittling down what the V-22 *cannot* do until we find what's left that it *can* do safely. Which in my book is nothing. "Fatal Flaw." I'm telling you. Watch for it soon.
Methinks you overstate the case.