The purpose of this Bulletin is to acquaint prospective users with the capabilities of the NSF/NCAR C-130Q Hercules aircraft (Tail Number N130AR). Its long-range and large-payload capabilities provide an ideal platform for a variety of applications in airborne geosciences research. The aircraft can make worldwide airborne measurements not only in the atmospheric sciences but also in disciplines such as oceanography and other earth sciences. The aircraft is available for research with an extensive set of standard instruments.
The Lockheed C-130Q Hercules is a four-engine, medium-size utility aircraft which has proven to be one of the most well-known and versatile aircraft ever built. For reference purposes, the aircraft is similar to a standard model C-130H except for electrical and air-conditioning modifications. It has twice the heating/cooling capacity of a standard C-130H and ultimately more than twice the electrical power. (At present only about 90 kVA are available for research.) The aircraft is an all-metal, high-wing monoplane, powered by four Allison T-56-A-423 turbo-prop engines. It is equipped with dual-wheel, tricycle landing gear with the main gear wheels arranged in tandem and the nose gear arranged side-by-side. N130AR was placed in service (by the USN) in 1985 and is the youngest aircraft in the NSF/NCAR/RAF fleet.
The performance figures for the NSF/NCAR C-130Q Hercules aircraft are summarized in Table 1 below. Research Aviation Facility Bulletin No. 6, presents detailed information for scientists to outline realistic, research flight plans. During a research program, the NCAR pilots, who are responsible for the detailed planning of specific flight profiles, will work closely with the requestor.
The interior of the Hercules includes a flight deck and a "payload" cabin compartment. During flights, the flight deck has a crew of three and a mission-scientist station position. This area also has two crew-rest positions which can accommodate two temporary observer stations. The aft cabin area is approximately 40 feet long, 9 feet in height, and 10 feet wide. An integral loading ramp and cargo door system is located under the tail section. Figure 3 shows the cross section of the fuselage. The configuration of the cabin can be changed to accommodate individual project instrumentation needs. Sectionalized seat tracks (rails) are installed to rack up instrumentation anywhere in the cabin area.
RAF has modified the C-130Q aircraft to accommodate a wide variety of instrumentation used for geosciences research. Figure 5 shows the external configuration of the aircraft modifications, which includes:
Utilization of the instrument pods for user-supplied instrumentation could require significant lead time to complete engineering design and fabrication requirements. (These requests have to be reviewed on a case-by-case basis.)
The standard research instrumentation aboard the aircraft is quite extensive. The specific set of instruments flown on a given project is generally a subset of the complete instrumentation list given in Table 2. Refer to other RAF Bulletins for details of the various instruments and equipment. RAF assumes responsibility for installing, calibrating, and maintaining the requested RAF-supplied instrumentation.
The NSF/NCAR C-130Q Hercules aircraft has been modified to accommodate a wide variety of instrumentation used for atmospheric and oceanographic research. These modifications and sensor-mounting locations are shown on the schematic in Figure 5.
Aerosol, cloud droplet and precipitation spectra can be obtained from Particle Measuring System's (PMS) probes (either 1D or 2D). The C-130Q can carry up to 10 of these probes.
A second-generation Aircraft Data System (ADS2) has been developed using a distributed-sampling approach. Four Data System Modules (DSM) are located at strategic points around the aircraft and communicate with each other and with display computers through a distributed computer network.
Analog and digital inputs from the instrumentation are sampled, recorded, and displayed by a Linux PC computer-controlled data system. The data are recorded on 36GB disks and backed up by Exabyte (Model EXB-8505) 8mm tape cartridges (currently with 4.0 Gb capacity). Two drives are used for redundancy. Sampling rates available for all measurements are 5, 25, 250 and 1K sps (higher for special requirements). All channels are simultaneously sampled and digitized at 10K sps. Each analog channel includes a single-pole, 5 KHz, anti-alias filter. The sampled data are decimated with FIR (finite impulse response) digital filters. Each DSM can sample up to 64 analog channels plus blocks from various serial devices, such as navigation systems and PMS 1-D and 2-D probes. This new system supports user-provided workstations (generic UNIX with TCP/IP protocol) aboard the C-130Q using the in-flight network.
Real-time data display is through the WINDS (WINdow Display System) software system. The system displays aircraft data in either real-time or post-processing mode. This interactive display system includes a variety of x-y plots, (e.g., time series, skew-t log-p, sounding, and track), fixed and scrolling alphanumeric lists, 1D-probe histograms and 2D probe images. Displays can be printed in color with on-board PostScript color printers. (See details of the WINDS system by Horton, 1994, Ref. 2.)
Data system display stations are located on the flight deck for the mission scientist position and in the "quiet room" area. One or two additional interactive display stations can be made available in the payload area depending on the project's requirements. Video cameras mounted in the cockpit and on the side of the aircraft can be viewed in real time on any of the display stations.
Extensive documentation is provided to the users following each project.
Data files (and tapes) generated during flights are processed and quality controlled by the RAF Project and Data Support Group to produce output files containing data (in engineering units) from measured and derived variables. The standard RAF data set consists of 1 sample-per-second (sps), averaged data from all measured variables. (See Research Aviation Facility Bulletin No. 9.) After the standard data processing is completed, high rate (25 sps) data may be provided by special request for certain flight segments.
Please note that flux calculations derived from high-rate scalar measurements can be affected by measurement uncertainties associated with flow distortion around the aircraft. Investigators are encouraged to contact RAF to discuss any planned application of this technology. (See Ref. 3.)
Usually accompanying C-130Q field projects is a quick-look, post-flight, data-processing system. This computer system is used primarily for quality assurance but is also available for limited data processing.
Several special instrument packages can be made available to C-130Q users on an "as needed" basis. These must be specifically requested. The deployment of the Dropwindsonde depends upon resources provided by the EOL In-Situ Sensing Facility (ISF) at NCAR. The special air chemistry equipment and the passive remote sensing tools (AIMR and MCR) are held in the RAF but may incur substantial additional deployment costs.
Dropwindsonde--A light-weight dropwindsonde can be launched from the C-130Q. This dropwindsonde system consists of an aircraft data system and a light-weight, digital sonde (300 g) developed and supported by RTF. The sondes can provide temperature, humidity, and wind data profiles while descending to the surface.
Inquiries concerning dropwindsonde requests should be directed to Steve Cohn, ISF, Earth Observing Laboratory voice: (303) 497-8826, FAX: (303) 497-8770 or via email.
Special Air Chemistry Measurements--Measurements of CO2, fast-response O3 and other chemical species require special arrangements with RAF before they can be made available for a given project.
Inquiries concerning chemistry instruments should be directed to Teresa Campos, Research Aviation Facility, Atmospheric Technology Division, voice: (303) 497-1879, FAX: (303) 497-1092 or via email.
Airborne Imaging Microwave Radiometer (AIMR)--This instrument is a passive remote sensing system that produces images of the terrain below the aircraft, sensing the thermal radiation emitted from the surface. Four channels at two frequencies (37 and 90 GHz) and two polarizations provide the brightness temperature maps. Applications can be for soil moisture, ice reconnaissance and snow depth mapping, measurements of ocean temperature and salinity, and others.
The AIMR is a special instrument and may be available from RAF through special arrangements. Inquiries should be directed to Amanda Cox, RTF, Atmospheric Technology Division, voice: (303) 497-2032, FAX: (303) 497-8770 or via email.
NASA/NCAR Multichannel Cloud Radiometer (MCR)--This instrument is a scanning radiometer with six channels in the near infrared and one channel in the thermal infrared. The MCR is ideally suited for remote observation of cloud physical properties, such as optical thickness, cloud top temperature, optical mean radius, thermodynamics phase, and others.
The MCR is a special instrument and may be available from RAF through special arrangements. Inquiries should be directed to Julie Haggerty, RAF, Earth Observing Laboratory, voice: (303) 497-1090, FAX: (303) 497-1092 or via email.
Considerable freedom is permitted in mounting user-supplied instrumentation on the aircraft. Procedures and limitations are described in detail in Research Aviation Facility Bulletin No. 11. RAF will supervise the installation of all user-supplied instrumentation to ensure compatibility with existing RAF instrumentation and the data system, and to satisfy aircraft safety requirements. The user-supplied equipment must be designed to satisfy the requirements of Research Aviation Facility Bulletin No. 13.
RAF can advise and, in some instances, assist users in the aeronautical, chemical, and electrical engineering design and fabrication of special equipment. Guidance in sampling and measurements can also be provided. RAF can help project scientists with experimental design and planning, including flight planning.
1. Brown, E.N., C.A. Friehe, and D.H. Lenschow (1983): The use of pressure fluctuations on the nose of aircraft for measuring air motion. J. Climate and Appl. Met., 22, 171-180.
2. Horton, G. (1994): A graphical user interface system for real-time and post-processing display and analysis of aircraft measurements. Preprint volume of the Tenth International Conference on Interactive Information and Processing Systems for Meteorology, Oceanography, and Hydrology, January 23-38, 1994, Nashville, TN. Published by the American Meteorological Society, Boston, MA.
3. Wyngaard, J.C. (1988): The effects of probe-induced flow distortion on atmospheric turbulence measurements: Extension to scalars. J. Atmos. Sci., 45, 3400-3412.
Investigators interested in discussing any use of the NSF/NCAR aircraft or its instrumentation, including questions on scheduling, may contact the Facility Liaison for Field Projects, voice: (303) 497-1058, FAX: (303) 497-1092, or via email.
| Table 1 NSF/NCAR C-130Q HERCULES (N130AR) Basic Performance Figures | |||
|---|---|---|---|
| Dimensions | |||
| Length | 102 ft | ||
| Wingspan | 136 ft | ||
| Height | 39 ft | ||
| Cabin Floor Area | 414 sq ft | ||
| Weights | |||
| Gross Weight | 155,000 lb max | ||
| Payload | |||
| 23,000 lb max | |||
| 13,000 lb with full fuel | |||
| Performance | |||
| Altitude | 26,000 ft (max operating) | ||
| Range | |||
| 1,800 nmi (at 1,000 ft cruise altitude) | |||
| 2,500 nmi (at 10,000 ft cruise altitude) | |||
| 3,100 nmi (at 20,000 ft cruise altitude) | |||
| Endurance | 10.0 hours max with IFR reserve (single crew) | ||
| Speed | 290 kt TAS (typical at cruise altitude) (Airspeed limited to 250 kt IAS with instrument pods installed.) | ||
| Acceleration Limit | +2.5 to 0 G (flight load) | ||
| Flight Crew | Two pilots + flight engineer (Up to 16 seats available for project participants, depending on equipment payload) | ||
| Engines | Four Allison T-56-A-423, 4,300 SHP each | ||
| Electrical Power | |||
| 90 kVA, 115 Vac @ 400 Hz | |||
| 21 kVA 115 Vac @ 60 Hz | |||
| 400 A 28 Vdc | |||
| Base | Jefferson County Airport, Broomfield, CO, USA (BJC) | ||
Please Note: The figures quoted for payload, range, altitude, and endurance are maxima that may be reduced due to high temperatures, extensive IFR weather conditions or other factors too numerous to list here. In some circumstances, these values may be increased based on experience, base-instrumented weights, inclusion of extra flight crew, etc. Each project is planned and executed according to the circumstances prevailing at the time. See Research Aviation Facility Bulletin No. 6 for more details on C-130Q flight planning.
Due to insurance liability considerations, the crew must be limited to the necessary project participants. The maximum number of people on a given mission is 19.
| C-130Q HERCULES CABIN PRESSURIZATION | |
|---|---|
| Aircraft Altitude | Cabin Pressure Differential (cabin pressure - outside pressure) |
| 5,000 ft | 0 to 5.0 inches Hg |
| 10,000 ft | 0 to 9.2 inches Hg |
| 15,000 ft | 3.8 to 12.8 inches Hg |
| 20,000 ft | 6.7 to 15.1 inches Hg |
| 25,000 ft | 9.4 to 15.1 inches Hg |
| Table 2 NSF/NCAR C-130Q HERCULES (N130AR) AIRCRAFT INSTRUMENTATION SPECIFICATIONS Page 1 of 6 | |||||
|---|---|---|---|---|---|
| Variable Measured | Instrument Type | Manufacturer & Model No. | Combined Performance of Transducer, Signal Conditioning, and Recorder | ||
| Range | accuracy | Resolution | |||
| Aircraft Latitude (LAT) | Inertial Navigation System | Honeywell Laseref SM IRS | ± 90° | ± 0.164° (6 hr) |
0.00017° |
| Aircraft Longitude (LON) | Inertial Navigation System | Honeywell Laseref SM IRS | ± 180° | ± 0.164° (6 hr) |
0.00017° |
| Aircraft Position & Ground Speed (GLAT, GLON, GALT & GVEW, GVNS) | GPS Navigation Sensor | Trimble Navigation Model TANS III | 4-Satellite, 3-D pos. 3-Satellite, 2-D pos. |
± 100 M (horiz) ± 156 M (Vertical) ± 0.1 M/s (Velocity) |
<= 0.5 M <= 0.5 M <= 0.05 M/s |
| Aircraft Ground Speed (VNS, VEW) | Inertial Navigation System | Honeywell Laseref SM IRS | 0 to 400 M/s | ± 4.115 M/s (6 hr) |
0.0020 M/s |
| Aircraft Vertical Velocity (IVSPD) | Inertial Navigation System | Honeywell Laseref SM IRS | ± 200 M/s | ± 0.1524 M/s (6 hr) |
0.0095 M/s |
| Aircraft True Heading (THDG) | Inertial Navigation System | Honeywell Laseref SM IRS | 0 to 360° | ± 0.2 deg (6 hr) |
0.00017° |
| Aircraft Pitch Angle (PITCH) | Inertial Navigation System | Honeywell Laseref SM IRS | ± 90° | ± 0.05° (6 hr) |
0.00017° |
| Aircraft Roll Angle (ROLL) | Inertial Navigation System | Honeywell Laseref SM IRS | ± 180° | ± 0.05° (6 hr) |
0.00017° |
| Table 2 NSF/NCAR C-130Q HERCULES (N130AR) AIRCRAFT INSTRUMENTATION SPECIFICATIONS Page 2 of 6 | |||||
|---|---|---|---|---|---|
| Variable Measured | Instrument Type | Manufacturer & Model No. | Combined Performance of Transducer, Signal Conditioning, and Recorder | ||
| Range | Accuracy | Resolution | |||
| Fuselage Static Pressure (PSFD) | Oscillation Frequency (digital output) | Rosemount, Inc. 1501 | 250 to 1035 mbar | ± 1 mbar | 0.034 mbar |
| Fuselage Static Pressure (PSF) | Variable Capacitance | Rosemount, Inc. 1201F | 250 to 1035 mbar | ± 1 mbar* | 0.07 mbar |
| # Cabin Static Pressure (PCAB) | Variable Capacitance | Rosemount, Inc. 1201F | 600 to 1035 mbar | ± 1 mbar* | 0.07 mbar |
| Indicated Airspeed Pressure (QCF, QCR) | Variable Capacitance | Rosemount, Inc. 1221 | 0 to 125 mbar | ± 0.7 mbar | 0.006 mbar |
| Total Air Temperature (TTR, TTL) | Platinum Resistance | Rosemount, Inc. 102E2AL | -60 to +40 C | ± 0.5°C | 0.006°C |
| Total Air Temperature (TTWH) | Deiced Platinum Resistance | Rosemount, Inc. 102E | -60 to +40 C | ± 1.0°C | 0.006°C |
| # Ambient Air Temperature (OAT) | Infrared Thermometer @ 4.25 µM | Ophir Corporation III | -40 to +40 C | ---- | 0.05°C |
| Dew-Point Temperature (DPT, DPB) | Thermoelectric Hygrometer | General Eastern Instruments 1011B | -65 to +50°C | ± 0.5°C (> 0 C) ± 1.0°C (< 0 C) |
0.006°C |
| ## Dew-Point Temperature (DPCRC) | Cryogenic Hygrometer | NCAR-developed | -85 to -15 C | ± 0.5°C | 0.01°C |
|
* Assuming transducer is exposed to <
1°C/min rate of temperature change # Available from RAF upon request ## Available from RAF via special arrangement |
|||||
| Table 2 NSF/NCAR C-130Q HERCULES (N130AR) AIRCRAFT INSTRUMENTATION SPECIFICATIONS Page 3 of 6 | |||||
|---|---|---|---|---|---|
| Variable Measured | Instrument Type | Manufacturer & Model No. | Combined Performance of Transducer, Signal Conditioning, and Recorder | ||
| Range | Accuracy | Resolution | |||
| # Absolute Humidity (RHOLA) * | Lyman-alpha Hygrometer | NCAR Developed LA-3 | 0.1 to 25 g/m3 | ± 5 % ** | 0.2 % |
| Angle of Attack (ADIFR) | Flow Angle Sensor, Radome | Rosemount, Inc. 1221F | ± 10° | ± 0.134° | 0.002° |
| Angle of Sideslip (BDIFR) | Flow Angle Sensor, Radome | Rosemount, Inc. 1221F | ± 5° | ± 0.096° | 0.002° |
| Radiometric Surface Temperature (RSTB, RSTB1) | Bolometric Radiometer (spectral range 9.5 to 11.5 µM) | Heimann Infrared Model KT19.85 | -50 to +60 C | ± 0.5°C (plus 0.7 % of difference between housing and object temperature) | 0.005°C |
| # Radiometric Sky Temperature (RSTT) | Bolometric Radiometer (spectral range 9.5 to 11.5 µM) | Heimann Infrared Model KT19.85 | -50 to +50 C | ± 0.5°C (plus 0.7 % of difference between housing and object temperature) | 0.1°C |
| Infrared Radiation (IRT, IRB) | Pyrgeometer 3.5 to 50 µM (Silicon Dome) | Eppley PIR (NCAR modified) | 0 to 600 W/M2 | ---- | 0.40 W/M2 |
| Visible Radiation (SWT, SWB) | Pyranometer .285 to 2.8 µM (Clear Dome WG7) | Eppley PSP (NCAR modified) | 0 to 1500 W/M2 | ---- | 0.12 W/M2 |
| Ultraviolet Radiation (UVT, UVB) | Photometer .295 to .385 µM | Eppley TUVR (NCAR modified) | 0 to 200 W/M2 | ---- | 0.12 W/M2 |
| ## Spectral Vegetation Radiometer (WV650, WV862) | Two-wavelength device (650 & 862 nm) | NCAR Developed 1992 | Suitable for characterizing Normalized Difference Vegetation Index (See NCAR Technical Note NCAR/TN-370+STR.) | ||
|
* Stub or crossflow type (Available only for high-rate projects) ** Long-term accuracy is slaved to measurement from a thermoelectric hygrometer. # Available from RAF upon request ## Available from RAF via special arrangement |
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| Table 2 NSF/NCAR C-130Q HERCULES (N130AR) AIRCRAFT INSTRUMENTATION SPECIFICATIONS Page 4 of 6 | |||||
|---|---|---|---|---|---|
| Variable Measured | Instrument Type | Manufacturer & Model No. | Combined Performance of Transducer, Signal Conditioning, and Recorder | ||
| Range | Accuracy | Resolution | |||
| Geometric Altitude (HGM232) | Radar Altimeter | APN-232 | 0 to 8,000 M | ---- | 0.1 M |
| Cloud Liquid Water Content (PLWC) | Heated-wire | PMS Model KLWC-5 | 0 to 5 g/M3 | 0.02 g/M3 | 0.001 g/M3 |
| Icing Rate Detector (RICE) | Accretion of Cloud Droplets | Rosemount, Inc. 871FA | 0 to 0.5 mM increments | ---- | 0.0005 mM |
| # Photography | S-VHS Video Cameras:
|
Up to 6 hours of recording per cassette (w/wo voice) | |||
| # Available from RAF upon request--must choose location(s) and direction(s) | |||||
| Table 2 NSF/NCAR C-130Q HERCULES (N130AR) AIRCRAFT INSTRUMENTATION SPECIFICATIONS Page 5 of 6 | |||||
|---|---|---|---|---|---|
| Variable Measured | Instrument Type | Manufacturer & Model No. | Combined Performance of Transducer, Signal Conditioning, and Recorder | ||
| Range | Accuracy | Resolution | |||
| # Aerosol Spectrum (PCASP) | Laser Spectrometer | Particle Measuring Systems, Inc. | 0.12 to 3.12 µM | ---- | 0.025 to 0.375 µM (progressively weighted) |
| # Cloud Droplet Spectrum (FSSP-100) | Laser Spectrometer | Particle Measuring Systems, Inc. | 0.5 to 47 µM | ---- | Selectable 0.5, 1, 2, 3 µM |
| # Cloud Droplet Spectrum (FSSP-300) | Laser Spectrometer | Particle Measuring Systems, Inc. | 0.3 to 20 µM | ---- | 0.05 to 2.0 µM (progressively weighted) |
| # Cloud Droplet Spectrum (260X) | Laser Spectrometer | Particle Measuring Systems, Inc. | 40 to 620 µM | ---- | 10 µM |
| # Hydrometeor Spectrum (200Y) | Laser Spectrometer | Particle Measuring Systems, Inc. | 300 to 4,500 µM | ---- | 300 µM |
| # Cloud Particle Spectrum - 2D (2D-C) | Laser Spectrometer | Particle Measuring Systems, Inc. | 25 to 800 µM | ---- | 25 µM |
| # Hydrometeor Spectrum - 2D (2D-P) | Laser Spectrometer | Particle Measuring Systems, Inc. | 200 to 6,400 µM | ---- | 200 µM |
| # Available from RAF upon request | |||||
| Table 2 NSF/NCAR C-130Q HERCULES (N130AR) AIRCRAFT INSTRUMENTATION SPECIFICATIONS Page 6 of 6 | ||||||
|---|---|---|---|---|---|---|
| Variable Measured | Instrument Type | Manufacturer & Model No. | Combined Performance of Transducer, Signal Conditioning, and Recorder | |||
| Range | accuracy | Detection Limit | ||||
| ## Cloud Droplet Nuclei (CVCNO, CVLA) | Counterflow Virtual Impactor (CVI) | NCAR laboratory constructed | 0 to 1,000 per cM3 0 to 20 g/M3 |
---- | 1 per cM3 0.1 g/M3 |
|
| # Aerosol Concentrations (CONCN) | Butanol Condensation Nuclei | TSI Model 3760 | 0 to 10,000 per cM3 | ± 6% (reading) |
1 per cM3 (Selectable) |
|
| Variable Measured | Manufacturer | Principle of Operation | Combined Performance of Transducer, Signal Conditioning, and Recorder | |||
| Range | Accuracy | Precision | Time Response | |||
| # Ozone (TEO3C) | Thermo Electron, Inc. | UV Absorbance | 0 to 1 ppmv | ± 4 ppbv | 1 ppbv | 0.1 Hz |
| # Fast-Response Ozone (03FC) | NCAR laboratory constructed | NO2 Chemiluminescence | 0 to 300 ppbv | ± 5 % | 0.5 ppbv 1ppbv |
1 Hz 3Hz |
| # Carbon Monoxide (COCAL) | Aero-Laser | Vac UV Resonance Fluorescence | 0 to 200 ppm | ± 3 % | 3 ppb | 3 Hz |
| # High-Precision CO2 | NCAR-modified LI-COR 6252 | Non-dispersive IR Absorbance | 0 to 500 ppmv | < ± 0.5 ppmv | 100 ppbv (typical) | 0.05 Hz |
|
# Available from RAF upon request ## Available from RAF via special arrangement | ||||||
| Table 3 NSF/NCAR C-130Q HERCULES (N130AR) SPECIFICATIONS FOR AIR VELOCITY COMPONENTS |
||||||
|---|---|---|---|---|---|---|
| Variable Measured | Instrument Type | Range | Accuracy (M/s) | Resolution | Upper Limit Frequency Response (Hz) | |
| Relative, Short-term (< 10 min) |
Absolute, Long-term (t in hours) |
|||||
| * Wind vector horizontal component (UI, VI) | Input from radome gust probe and INS | 0 to 100 M/s | ± 0.1 | ± (1.0 + 0.5t) ** | 0.012 M/s | 10 |
| * Wind vector vertical component (WI) | Input from radome gust probe and INS | ± 15 M/s | ± 0.1 | ---- | 0.012 M/s | 10 |
| Horizontal wind direction (WD) | Input from radome gust probe and INS | 0 to 360° | ± COT-1 (UI/VI) | ---- | 0.001° | 10 |
|
* RAF-computed winds are a combination of the mean and fluctuating
components components (i.e., UI = UI + UI' ). ** With GPS corrections, long-term absolute accuracy improves to ± 1. M/s. |
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