Aircraft climb trajectories are difficult to predict, and large errors in these predictions reduce the potential operational benefits of some advanced concepts in the Next Generation Air Transportation System. An algorithm that dynamically adjusts modeled aircraft weights based on observed track data to improve the accuracy of trajectory predictions for climbing flights has been developed. In real-time evaluation with actual Fort Worth Center traffic, the algorithm decreased the altitude root-mean-square error by about 20%. It also reduced the root-mean-square error of predicted time at top of climb by the same amount.

Separate thermostable inhibitors of cathepsins B and H (IB and 1 , ) were found in every rat and human tissue that was analyzed. The inhibitors were separated from the cathepsins by heating at 80-90 "C at pH 3. I B and I H from rat lung were purified and found to occur in multiple molecular forms. Rat lung IB and IH were very similar proteins with molecular weights of 14000. 1s and I H from hog kidney were also purified and IH was obtained free of IB. These inhibitors also displayed microheterogeneity and had molecular weights of 11000. Hog kidney IH inhibited chymopapain, but did not inhibit bromelain, chymotrypsin or cathepsin D. Rat and human serum contained thermostable inhibitors of cathepsins B and H, but these molecules had relatively high molecular weights. Therefore the low-molecular-weight 1s and IH from other tissues appear to be intracellular in origin. When extracts of kidney or liver were autolyzed at pH 3 -6, there was a large increase in cathepsin B or H activity with a concomitant decrease in I B and IH. Inhibitor destruction was apparently catalyzed by a proteinase other than cathepsin D or E. Rat kidney, liver, and spleen were rich sources of cathepsins B and H, the kidney yielding three times as much activity per gram as liver or spleen. Hog kidney was rich in cathepsin H, but yielded little or no cathepsin B. IB and 1H were also present in protozoa, tuna fish, chicken and toad. The inhibitors from Tetvahi,menapyriformis inhibited the thiol proteinase from this protozoan.

Typical aircraft trajectory predictors use wind forecasts but do not account for the forecast uncertainty. A method for generating estimates of wind prediction uncertainty is described and its effect on aircraft trajectory prediction uncertainty is investigated. The procedure for estimating the wind prediction uncertainty relies uses a time-lagged ensemble of weather model forecasts from the hourly updated Rapid Update Cycle (RUC) weather prediction system. Forecast uncertainty is estimated using measures of the spread amongst various RUC time-lagged ensemble forecasts. This proof of concept study illustrates the estimated uncertainty and the actual wind errors, and documents the validity of the assumed ensemble-forecast accuracy relationship. Aircraft trajectory predictions are made using RUC winds with provision for the estimated uncertainty. Results for a set of simulated flights indicate this simple approach effectively translates the wind uncertainty estimate into an aircraft trajectory uncertainty. A key strength of the method is the ability to relate uncertainty to specific weather phenomena (contained in the various ensemble members) allowing identification of regional variations in uncertainty.

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The Trajectory Synthesizer is a software program that generates aircraft predictions for Air Traffic Management decision support tools. The Trajectory Synthesizer being used by researchers at NASA Ames Research Center was restricted in the number of trajectory types that could be generated. This limitation restricted its ability to support the evolving NextGen research requirements. The Generalized Profile Interface was developed to address this issue. It provides a flexible approach to describe the constraints applied to trajectory generation and may provide a method for interoperability between trajectory generators. It also supports the request and generation of new types of trajectory profiles not possible with the previous interface to the Trajectory Synthesizer. Other enhancements allow the Trajectory Synthesizer to meet the current and future needs of Air Traffic Management research.