Research Aircraft

SPEC first instrumented a Model 25 Learjet in 1998, and since then the company has continued to upgrade its capabilities. In addition to serving as a test bed for SPEC instrument developments, the Learjet has participated in several field projects, including:

  • NASA FARS Cirrus Studies in Utah 1998 - 2000
  • NASA EOS Cirrus Studies in Oklahoma 2000 – 2001
  • NSF Wave Cloud Studies in Colorado 2000 - 2004
  • DOE In situ Lidar Tests in Colorado and Texas 2003 – 2004
  • DOE Sparticus Cirrus Studies 2009 – 2010
  • NSF ICE-T Cumulus Cloud Studies - 2010
  • NASA MACPex Cirrus and Anvil Cloud Studies – 2011
  • NASA Hawkeye Test Flights – 2012
  • NASA SEAC4RS Regional Studies in the Southeast U.S. – 2013

The Learjet has exceptional performance and can operate over a large range of true airspeeds, from 100 m s-1 at sea level to 200 m s-1 at 30,000 feet. Due to its high thrust-to-weight ratio, the Learjet can climb at extremely high rates, up to 6,000 feet per minute at sea level and 2,000 feet per minute at 25,000 feet. This level of performance, coupled with SPEC’s state-of-the-art cloud particle probes and a relatively low hourly cost, make the Learjet a unique platform for cloud physics research.

SPEC Learjet Performance in Research Configuration
Maximum Takeoff Weight 15,000 lbs
Maximum Certificated Ceiling 45,000 ft
Time to Climb S.L. to 0°C
(5 km 16,450 ft DA) at Maximum T.O. Weight @ ISA
 3 min
Time to Climb 0°C to -10°C (5 km 16,450 ft to 7.24 km 23,760 PA) @ ISA 2.5 min
Maximum Duration 3 hr
Maximum Airspeed 0.82 Mach (306 KIAS)
Number of Seats excluding pilots 4
Electrical Capability (2) 400 A Generators
@ 28.8 VDC = 23 KW
Research Power = 7.2 KW distributed as 5.5 KW @ 110 VAC 60 Hz, 1.7 KW @ 28 VDC

 

Equipment List Manufacturer Range Accuracy
Temperature Rosemount Model 102 & 510BH Amplifier -50 to +50 °C 0.5 °C
Altitude Royal Air FAA RVSM Certification 0 to 45,000 ft
(0 to 13.7 km)
 60 ft
(18.3 m)
Airspeed Royal Air FAA RVSM Certification 0 to 220 m s-1 1 m s-1
Cloud Liquid Water (2) Sky Tech Nevzorov LWC Probe 0 to 4 g m-3 N/A
Cloud Total Water (2) Sky Tech Nevzorov TWC Probe 0 to 4 g m-3 N/A
Aircraft Position Aventech AIMMS-20 Differential GPS N/A 10 m
Aircraft Heading Learjet Sperry Directional Gyro 0 to 360° 1°
Horizontal Wind Aventech AIMMS-20 0 to 360°
1 to 100 m s-1
 1°
1 m s-1
Vertical Wind Aventech AIMMS-20 0 to 50 m s-1 0.5 m s-1
2D-S (Stereo) Optical Array Spectrometer SPEC Model OAP 2D-S 10 µm to 3 mm 10 µm
Fast Cloud Droplet Probe (FCDP) SPEC Model FCDP-100 1.5 to 50 µm 3 µm
Fast Forward Scattering Spectrometer Probe (FFSSP) SPEC Model FFSSP-100 1.5 to 50 µm 3 µm
High Volume Precipitation Spectrometer (HVPS) SPEC Version-3 HVPS 150 µm to 2 cm 150 µm
Combination 2D-S and Version 2.5 CPI (3V-CPI) SPEC Model 3V-CPI 7 µm to 3 mm 10 µm 2D-S
2.3 µm CPI
Combination FCDP, 10 and 50 µm 2D-S, V 2.5 CPI (Hawkeye) SPEC Hawkeye 1 µm to 6.4 mm 3 µm FCDP
10-50 µm 2D-S
2.3 µm CPI
Dual-Wavelength In Situ Cloud Lidar SPEC Volumetric
(up to 1 km radius)
measurements of LWC, bext, Reff		 N/A
Tunable Diode Laser NASA GSFC Long-path measurements of water vapor N/A