Disclaimer: This material is being kept online for historical purposes. Though accurate at the time of publication, it is no longer being updated. The page may contain broken links or outdated information, and parts may not function in current web browsers. Visit https://espo.nasa.gov for information about our current projects.


SIERRA 07/26/13 - 07/27/13

Download PDF
Flight Number: 
Payload Configuration: 
Nav Data Collected: 
Total Flight Time: 
4.5 hours
Flight Segments: 
Start:07/26/13 21:48 Z Finish:07/27/13 02:15 Z
Flight Time:4.5 hours
Log Number:13R301 - Completed as of this flight.PI:James Maslanik
Funding Source:Randy Albertson - NASA - SMD - ESD Deputy Airborne Science Program
Purpose of Flight:Science
Comments:The aircraft was fueled to a capacity of 10 gal for this flight which would be its first science flight of the mission. Takeoff was normal with slightly lower climb performance since this was the first time the aircraft had been flown at 400 lbs TOGW. The transit to international airspace was followed by a north/south transect and an east/west mapping pattern over the sea ice edge. The aircraft appeared to be operating normally and was approximately 2/3 complete with the 6 hour flight and halfway thru the mapping pattern when at approximately 1813 local, there was a momentary loss of the Iridium C&C link. The GCS operator was recording this event when the Iridium system reacquired the signal after approximately one minute (note that loss of Iridium is expected and had been occurring occasionally during the flight with reconnect times ranging from 1-4 minutes). Upon reacquisition of the Iridium C&C link, the RPM and Alternator warning lights were illuminated on the GCS display. The RPM display was at zero RPM and the bus voltage was 24V, indicating the aircraft was operating solely from batteries and that the engine-driven alternator was not charging them. The aircraft was already descending lower than its commanded altitude of 1000’ MSL in a controlled glide at the commanded 56 kts. The aircraft continued this glide until impact with the surface at which time the Iridium link went down at 1815 local. Post-mishap actions were executed and an Accident Investigation Board will be convened to determine the cause of the accident.
Flight Hour Summary: 
Flight Hours Approved in SOFRS80
Total Used5.8
Total Remaining74.2
13R301 Flight Reports
Date Flt # Purpose of Flight Duration Running Total Hours Remaining Miles Flown
07/26/13 - 07/27/1380Science4.55.874.2

Flight Reports began being entered into this system as of 2012 flights. If there were flights flown under an earlier log number the flight reports are not available online.