Viewing page 111 of 172

This transcription has been completed. Contact us with corrections.

In summary, the proper criticality rating for the brakes depends on how they are planned to be used and what assumptions are used for rollout analysis.  By carefully and realistically assessing all relevant factors and properly restricting acceptable landing conditions, the criticality of the brakes should remain 1R.  The issue is whether the current Flight Rules provide adequate braking margins for TAL aborts. These Flight Rules and criteria to be used to compute the real-time rollout margins will continue to be evaluated based on the latest available data from tests and flight experience.

XXI. TAL ISSUE OVERVIEW

The TAL issues brought out by crew concerns and systems review are summarized in table 6 below in a manner similar to the KSC landing concerns.

Table 6 TAL Issue Overview

[[3 columned table]]

| Topic | Issue | Response |
|---|---|---|

| Weather Availability | Varies per TAL site  Weather limits are wider even with more demanding landing conditions | Small likelihood of abort plus very small exposure window allow weather and energy limits to be raised to that of the basic design-limit reduction in work (proposed) |

| Forecast Ability | Poor data availability | Conservative forecast plus short time interval of forecast and on-site observer significantly minimize risk |

| Nosewheel Steering | Does not provide redundant control (only response to high speed double tire failure plus allows use of brakes for stopping vs crosswind steering for a design capability landing) | Nosewheel steering is certified system to be used in this situation |

| Brakes  Short Runways | Shorter runways and higher landing energy compromise ability to stop in runway | Ground tests have shown that brake energy will be available even after astator failure. Brake energy placards may be changed (proposed) | 

-B36-