Flight Loads and Airframe Usage Analysis of Next-Generation Airtankers – BAe-146 and RJ-85

Details

• Creators:
  Rokhsaz, Kamran ; Kliment, Linda K. ; Rollins, Elizabeth
• Corporate Creators:
  Wichita State University
• Corporate Contributors:
  United States. Department of Transportation. Federal Aviation Administration. NextGen Human Factors Division (ANG-C1)
• Subject/TRT Terms:
  Data Flight Dynamics Flight Loads Spectrum Flight Plans Flight Profiles Statistical Analysis Statistical Loads Data Wing Loading
• Publication/ Report Number:
  DOT/FAA/TC-20/13
• DOI:
  https://doi.org/10.21949/1f49-b349
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Edition:
  Phase I Final Report
• Contracting Officer:
  Mottaghi, Sohrob
• Corporate Publisher:
  United States. Department of Transportation. Federal Aviation Administration. William J. Hughes Technical Center
• Abstract:
  This report addresses in-flight recorded data from eight BAe-146s and eight RJ-85s flown in support of the United State Forest Service aerial firefighting operations. All flight data was recorded at 32 Hz by IONode100 units supported by Latitude Technologies, Corp. All data was examined for integrity, and anomalies and inaccuracies were identified and outlined. Similarities between BAe-146 and RJ-85 were used to rationalize combining their results. Flights were divided into firefighting, ferry, and maintenance/training missions. Firefighting flights were divided into five separate phases. Statistical results of the airframe usage were presented and compared with aircraft limitations. This information includes altitude, airspeed, duration and distance, number of retardant drops per flight, maximum and minimum vertical load factors, flap cycling frequency, and takeoff and landing weights. Unreliable pitch-and-roll angle and cabin pressure recordings prevented examination of these parameters. In several cases, the vertical accelerations were shown to exceed the limit load factors with flaps extended. Detailed examination of the data revealed that these occurred mostly during the drop phase. Also, in a number of cases, the maximum indicated airspeed was shown to be slightly above the prescribed limits. The recorded normal accelerations were shown to contain frequencies due to structural vibration. Results of the effect of different filters on flight loads spectra are presented in an appendix. Based on these results, a low-pass, eighth-order Butterworth filter with an 8-Hz cutoff frequency was used to attenuate the structural frequencies. After filtering, vertical load factors were divided into gust and maneuver loads using the two-second rule. Using the method of peaks-between-means, exceedance spectra for gust and maneuver loads were developed for ground-air-ground cycles, as well as for specific flight phases. These results were compared to those of the legacy airtankers and other aircraft flown in support of firefighting missions and as civil transport. The gust load factor spectra are shown to be similar to other United States Forest Service aircraft being flown in the same environment. The maneuver load factor spectra are shown to indicate smaller loads than those of legacy airtankers, but considerably exceeding in frequency those of civil transport. Derived gust velocities were extracted for BAe-146 aircraft and their cumulative occurrences were presented. Erroneous recording of the aircraft weight prevented inclusion of data from RJ-85 airframes. The report concludes with some recommendations for improved data acquisition for future efforts.
• Format:
  PDF
• Collection(s):
  FAA William J. Hughes Technical Center for Advanced Aerospace
• Main Document Checksum:
  urn:sha-512:f87d0d8e719ca1b53d3214845efa1f1159fb2e6739010a4ae4e3adb31ee77329a3135b2fccde155e8f30ae454acfb755ca9683302b636a4d793e8bba9bd3ed37
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/89385/dot_89385_DS1.pdf
• File Type:
  [PDF - 19.47 MB ]