Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!usc!zaphod.mps.ohio-state.edu!pacific.mps.ohio-state.edu!linac!att!cbnews!cbnews!military From: Steve.Bridges@Dayton.NCR.COM (Steve Bridges) Newsgroups: sci.military Subject: Re: Autorotation of AV-8B Harrier Message-ID: <1990Dec11.015631.26706@cbnews.att.com> Date: 11 Dec 90 01:56:31 GMT References: <1990Dec4.002219.9452@cbnews.att.com> Sender: military@cbnews.att.com (William B. Thacker) Organization: AT&T Bell Laboratories Lines: 53 Approved: military@att.att.com From: Steve.Bridges@Dayton.NCR.COM (Steve Bridges) In <1990Dec4.002219.9452@cbnews.att.com> sasbrb@unx.sas.com (Brendan Bailey) writes: >From: Brendan Bailey > What is auto-rotate for the av-8b? Someone I know said that the av-8b >doesn't have it. Do some have it and some don't or do none of them have >this feature? What capability does this give a plane(harrier?) that has it? Auto-rotation does not exist for any fixed wing aircraft, only for helicopters. An auto-rotation (or auto as it is sometimes referred to), is done when the motive power to the rotor systems ceases to function (e.g. the engine quits). Since the helicopters derives it's lift from the spinning of the rotor system, when the rotor stops spinning, the helo will drop like a rock (probably with the rotor blades broken off, since they are held rigid only by centripital force when in flight). An auto consists of lowering the collective pitch control (this controls the pitch of the main rotor blades), neutralizing (or feathering) the main rotor blades. In addition, a target airspeed is set by using the cyclic to provide some forward velocity. In the configuration, the rotor system will continue to spin, "storing" energy for hopefully a soft landing. When you are close to the ground, the collective is pulled up, increasing the AOA of the main rotor blades, slowing the descent. In addition, rear cyclic is used to slow the foward velocity. Then a "normal" landing is made, reducing the collective until contact with the ground is made. Note: when I started by helicopter training, we did autos in the first lesson starting from 1000' agl in a Robinson R-22. With it's light rotor system, autos were fast (1500 fpm down, 50-55 KIAS foward velocity). That works out to about 45 seconds to lower the collective, set the airspeed, and look for a place to land. Since the Harrier is an airplane, not a helicopter, it will glide just like any other airplane. -- Steve Bridges | NCR - USG Product Marketing and Support OLS Steve.Bridges@Dayton.NCR.COM | Phone:(513)-445-4182 622-4182 (Voice Plus) ..!ncrlnk!usglnk!uspm650!steve | AOPA #916233 ..!uunet!ncrlnk!usglnk!uspm650!steve| PP-ASEL, AMEL (I want a P-38 type rating)