Hey Muddy,
Enjoyed your post about RGS, I don’t fly anything with INS so I have never used the technique as you described. I think Flying Tiger used IRGS, maybe it crept into Fed Up. Both the FAA and Boeing advise against using this technique for microbursts. (I am not saying that they know best – because I don’t think they do.) But if it is contrary to their recommendations, few if any airline will adopt the policy of IRGS.
Quote from AC 00-54
Use of inertial reference ground speed emphasizes control of speed which is contrary to the recommended recovery technique. In addition, this technique is oriented toward compensating for the windshear and continuing the approach rather than immediately initiating the recovery maneuver. While this technique is not appropriate for microburst encounters, it may be suitable for use in other types of windshears.
Slasher,
Don’t know that the TAT would have told you anything. I read your post about CAT and that you get a temp drop several seconds prior to encounter. I don’t know (and I don’t think anybody does) if you get a similar phenomenon with microbursts. I am looking at data from 186 microbursts documented in the JAWS (Joint Airport Weather Studies) project. The core temps in this data run the range of positive and negative delta Ts. Fujita, the expert, found no correlations in the data. There is a researcher (Wakimoto) that suggests that wet microbursts are warmer then the ambient atmosphere. Don’t know how he reaches that conclusion. (Still trying to access his work.)
The accounts of your experiences both point toward microbursts. Have to say you win the rather you than me award. Any cumulus cloud can spawn a microburst. Innocuous clouds can produce them when one isn’t expecting it, and they need not be turbulent. The pilots of USAir 1016 were not aware they were in a microburst because it wasn’t turbulent like all the microbursts they experienced in the sim. And the flight attendant that survived the Eastern 66 crash commented that the approach was not bumpy.
As for how to escape microbursts, that’s up to you guys. The escape maneuver in use today, pitch for 15 degrees or stick shaker... you know the one, was developed in a Boeing 727 simulator for 727s. In their research Boeing states that ‘we are aware other procedures may provide greater performance, yadda yadda...’ That’s a paraphrase, cause I can’t find the quote right now. They do say the procedure was chosen because it’s easy to remember and do. Several researchers are doing variable pitch guidance strategies which give better escape potentials. Journal of Aircraft had one such article titled “Escaping Microburst with Turbulence: Altitude, Dive, and Pitch Guidance Strategies” (May-June 2000).
Happy Flying