DA20 GOV FLC ON DATA GATHERING FLT TURNS INTO CLOUDS AND ACCUMULATES ICE. INTAKE HEAT AND ENG IGNITING ACTIVATED AND A LOUD NOISE WAS HEARD INDICATING ICE INGESTION. MISSION CANCELED.

Narrative

XX00 AM WE WERE CONDUCTING A DATA FLT AT HOLLOMAN AFB WHITE SAND MISSILE RANGE IN NM. THE WX BRIEF WAS RPTED TO BE CLR SKIES UNLIMITED VISIBILITY. ON DEPARTING HMN WE COULD MAKE OUT THE LIGHTS OF ABQ; NM; SOME 90+ MI TO THE NW. DURING OUR CLB TO THE N PART OF THE RANGE WHERE WE WERE CONDUCTING OUR TEST; WE FOUND A VERY SCATTERED LAYER OF CLOUDS AT 12000 FT MSL. ONCE ON STATION AT 14000 FT MSL WE CONDUCTED OUR SCHEDULED RUNS WHICH WERE N AND S IN NATURE. DURING THIS TIME THE PNF OCCASIONALLY CHKED TO MAKE SURE WE WERE NOT IN ANY CLOUDS BY TURNING ON THE LNDG LIGHTS. WE COULD SEE SOME SCATTERED CLOUDS BELOW US AT APPROX 12000 FT MSL. ON THE EXECUTION OF THE THIRD RUN; THE ACFT WAS SBOUND WHEN I INITIATED A PROC TURN (90-270 DEGS) TO REVERSE COURSE. THE ACFT ENTERED A CLOUD FORMATION FOR THE DURATION OF THE TURN WHICH LASTED APPROX 2 MINS. (MOONLESS NIGHT) AFTER THE ACFT EXITED THE CLOUDS; VISUAL INSPECTION WITH A FLASHLIGHT ON THE WINDSHIELD REVEALED ICE ACCUMULATION. I INSTRUCTED THE PNF TO SELECT #2 ENG INTAKE HEAT AND ENG IGNITORS ENGAGED TO ELIMINATE THE POSSIBILITY OF INTAKE ICE. SHORTLY THEREAFTER A LOUD NOISE WAS HEARD AND ENG INSTS INDICATED THAT THE #2 ENG HAD INGESTED ICE. I BEGAN A CLB TO 20000 FT MSL TO OBTAIN A SAFE ALT SHOULD A FLAMEOUT OCCUR AND TO AVOID ANY FURTHER ICING CONDITIONS. THE #2 ENG WAS NORMAL INDICATING AT THIS TIME AND I INSTRUCTED THE #1 ENG INTAKE HEAT AND AIRFRAME ANTI-ICE ON WITH THE INSTRUCTION THAT WE WERE RETURNING TO HMN (HOLLOMAN ATC). A VISUAL DSCNT WAS MADE TO HOLLOMAN WITHOUT FURTHER INCIDENT. UPON VISUAL INSPECTION AFTER SHUTTING DOWN; BOTH ENGS HAD SUFFERED ICE INGESTION CAUSING DAMAGE TO THE COMPRESSOR BLADES AND AFT FAN BLADES OF THE FALCON 20 JET (GE ENGS). THERE WAS 1 INCH OF CLR ICE ON OUR ANTENNA AND NOSE CONE OF THE ACFT. WHAT HAD BEEN A CLR NIGHT HAD BROUGHT A CLOUD THAT CONTAINED CLR ICING TO THE ACFT IN THE MATTER OF MINS. WE MADE A 90-270 DEG TURN TO GET OUT OF THE CLOUD AND BACK ON COURSE WHICH HAD BEEN CLR OF CLOUDS ON TOP OF A SCATTERED AREA. CONTRIBUTING FACTORS WAS THAT THE FAA MANDATED THAT WE CONDUCT THESE TESTS AT NIGHT. A CLOUD FORMATION FORMED THAT NOBODY HAD PREDICTED AND WE FLEW INTO IT. SEE AND AVOID PRACTICE WAS VERY DIFFICULT AT BEST.