![b-2-spirit](http://defense-update.com/wp-content/uploads/2010/11/b-2-spirit1.jpg)
The U.S. Air Forces’ Research Laboratory (AFRL) has implemented Hot Trailing Edge (HTE) skin composed of AFR-PE-4 composite material on the B-2 stealth bomber. Through the implementation of the new composite AFRL expects to virtually eliminate field repairs, reduce downtime, and achieve higher mission capability rates for the bomber.
![b-2-spirit](http://defenseindex.com/wp-content/uploads/2010/11/b-2-spirit1.jpg)
Located behind the exhaust nozzles on the aircraft’s upper surface, the B-2 HTE experiences repeated thermal and vibro-acoustic stress. The polyimide material presently used for HTEs degrades quickly in this operational environment; as the incessant exposure to heat and engine exhaust exceeds its capabilities, the material cracks and the resin disintegrates. Recognizing the need for a more resilient material in late 1990s, AFRL commenced its design of a new application based on AFR PE 4. Through the recent demonstration the new skin was confirmed to be more durable, higher-performing material, compared to the HTE material currently used on B-2s. Following the recent tests, future AFRL activities will include preparation of the demonstrated materials for flight evaluation on the B-2.