Relay-Version: B 2.11 6/12/87; site scolex Path: uunet!uunet!fernwood!cronos!reed From: reed@airrick.Metaphor.COM (Rick Reed) Newsgroups: rec.aviation Subject: Re: Box canyons? Message-ID: Date: Wed, 07 Aug 91 12:27:39 PDT References: <3410210@aspen.IAG.HP.COM> <1991Aug6.224834.3757@casbah.acns.nwu.edu> <19148@darkstar.ucsc.edu> Sender: news@cronos.metaphor.com Organization: Metaphor Computer Systems, Mountain View, CA Lines: 41 In-reply-to: bobg+@andrew.cmu.edu's message of 7 Aug 91 17:24:30 GMT In article bobg+@andrew.cmu.edu (Robert Steven Glickstein) writes: [stuff deleted] do a steep turn, but ran out of room," and then went on to opine, "He would have had no problem if he'd had a little bit of aerobatic training; a hammerhead would've gotten him out of that in a jiffy." Would it have? Is this a good last-ditch emergency procedure? It's quite unlikely that the airplane would have enough performance to complete a hammerhead, and if it did, it could probably climb out of the canyon either straight ahead or in a chandelle. Any vertical maneuver (loop, hammerhead, etc.) must be started with a lot of excess airspeed (usually obtained by diving), and hence they're not very energy-efficient. In attempting a retreat, the goals are maximum rate-of-turn, minimum radius-of-turn, and minimum loss-of-energy, all of which are, for the most part, obtained at the lowest feasible airspeed. The last parameter really determines the optimal airspeed. If the canyon sides are steep, you're probably better to give up some climb angle (or even altitude) to make the turn as quick and small as possible. Trade your excess airspeed for altitude, drop the flaps, and slow towards MCA. If you don't make it, you're in the best configuration for meeting the terrain. If you're in more of a shallow bowl, probably better to keep Vx to get the best climb angle. The key is low airspeed since that makes a BIG difference in turn-rate, turn-radius and survivability if you hit the rocks. A steep turn just wastes energy and raises the likelihood of an accelerated stall/spin. An aerobatic maneuver at high altitude in a non-aerobatic airplane (meaning weak control effectiveness, not the 6G load-limit) will probably just result in loss of control with no altitude to recover. Now, I'm not a mountain flying expert. The above is just my own common sense and normal/acro flying experience, so I'm very open to criticism. Rr