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Aircraft Operations Division 

Johnson Space Center 

N992NA Payload Interface 

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Aircraft Operations Division 

Johnson Space Center 

5/3/2017, Revision A 

N992NA Payload Interface 

 Aircraft Summary 

• General 

 Gulfstream III, N992NA 

 Operated out of Ellington Field by NASA/JSC Aircraft Operations Division 

(AOD) 

 Modifications were completed in 2012 to integrate an external radar payload 

and the supporting instrumentation 

 Modifications were completed in 2016 to add sonobuoy launch tube in aft end 

of aircraft 

 Cabin is configurable between science missions 

 This document contains the approved payload operating envelope and the 

available aircraft systems for payload interface 

– Expansion of operating envelope and systems possible through 

coordination with AOD engineering 

Derek Rutovic, mihailo.rutovic-1@nasa.gov, 281-244-9871 2 
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Aircraft Operations Division 

Johnson Space Center 

5/3/2017, Revision A 

N992NA Payload Interface 

 Aircraft Summary (cont.) 

• Payload capabilities 

 External pod via belly mounted MAU-12C/A interface 

 Cabin equipment racks mounted to seat track for payload interface and 

operation 

 Dry-air supply to the external pod from pressurized cylinders in the cabin 

 Pressure bulkhead feed through from the cabin to payload for power, data, 

and signals 

 Aircraft systems 

– AC/DC power 

» Both to the pod and inside the cabin 

– Flight Management System (FMS) / GPS, IRS, air data 

– Platform precision autopilot 

– Wireless intercom system between cabin experimenters and flight deck 

– Satellite phone 

– Spare GPS antennas 

– Iridium antennas 

Derek Rutovic, mihailo.rutovic-1@nasa.gov, 281-244-9871 3 
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Aircraft Operations Division 

Johnson Space Center N992NA Payload Interface 

 External Pod 

• MAU-12C/A interface, manually operated locks, 30” hook spacing, figure 1 

• Weight and center of gravity 

 1200 lb maximum 

 Center of gravity limits, figure 2 

Figure 1 

Figure 2 

Derek Rutovic, mihailo.rutovic-1@nasa.gov, 281-244-9871 4 5/3/2017, Revision A 
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Aircraft Operations Division 

Johnson Space Center N992NA Payload Interface 

 External Pod (cont.) 

• Shape 

 Aerodynamically shaped cylinder up to 30” 

in diameter and 130” long 

• Structural Integrity 

 Must be compliant with requirements given 

in FAR part 25 and AOD document 

#8594002 

– If requirements conflict between 

documents, the more conservative 

requirement shall be applied 

 Compliance with “crash loads” given in part 

25.561 is not required 

• Maximum airspeed and altitude 

 337 KCAS, M0.82, 45,000 ft MSL 

• Disconnect panel installed in forward portion of 

pylon to provide electrical connection between 

pod and payload, figure 3 

Figure 3 

Derek Rutovic, mihailo.rutovic-1@nasa.gov, 281-244-9871 5 5/3/2017, Revision A 
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Aircraft Operations Division 

Johnson Space Center N992NA Payload Interface 

 Cabin and Cockpit Equipment 

• Available cabin area, figure 4 

 Installation of instrumentation must allow path for emergency egress 

Figure 4 

Derek Rutovic, mihailo.rutovic-1@nasa.gov, 281-244-9871 6 5/3/2017, Revision A 
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Aircraft Operations Division 

Johnson Space Center N992NA Payload Interface 

 Cabin and Cockpit Equipment (cont.) 

• Existing equipment racks 

 Accommodates standard 19” rack 

equipment, figures 5 to 6 

 22” x 25” x 50” 

 Maximum 3450 lb or 6225 in-lb 

overturning moment 

Figure 5 Figure 6 

Derek Rutovic, mihailo.rutovic-1@nasa.gov, 281-244-9871 7 5/3/2017, Revision A 
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Aircraft Operations Division 

Johnson Space Center N992NA Payload Interface 

 Cabin and Cockpit Equipment (cont.) 

• Other custom equipment racks 

 Must be adapted with Gulfstream seat track and fittings 

– Seat track fitting utilizes 3/8”-24 threaded post for mounting, figure 7 

» Forward/aft spacing of fittings is 3/4” increments, figure 8 

– 2 seat tracks per side in the cabin, left and right with center aisle 

» Lateral spacing of seat tracks is 12” on center, figure 8 

Figure 7 Figure 8 

Derek Rutovic, mihailo.rutovic-1@nasa.gov, 281-244-9871 8 5/3/2017, Revision A 
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Aircraft Operations Division 

Johnson Space Center N992NA Payload Interface 

 Cabin and Cockpit Equipment (cont.) 

• Available seating 

 Aft couches, 8 people 

 Standard Gulfstream chairs, 1 person per chair 

 Two seats with locking, inertial reel harnesses to allow sensor operator to 

operate and monitor equipment racks during taxi, takeoff, and landing, figures 

9 and 10 

Figure 9 Figure 10 

Derek Rutovic, mihailo.rutovic-1@nasa.gov, 281-244-9871 9 5/3/2017, Revision A 
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Aircraft Operations Division 

Johnson Space Center N992NA Payload Interface 

 Cabin and Cockpit Equipment (cont.) 

• Dry-air supply to pod 

 Two 1300 in3, 1950 psi cylinders installed in cabin below aft couches 

 Pressure bulkhead feed through provides routing to pod 

 Pressure delivered to the pod is adjustable between +0 to +5.5 psig (relative 

to cabin) 

• Wireless intercom system to connect cabin experimenters with flight deck through 

push-to-talk button 

• Yoke mounted tablets with Ethernet/GPS/Power interface 

Figure 11 

Derek Rutovic, mihailo.rutovic-1@nasa.gov, 281-244-9871 10 5/3/2017, Revision A 
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Aircraft Operations Division 

Johnson Space Center N992NA Payload Interface 

 Electrical Power 

• AC, 115V / 60Hz 

 Power cord (figure 12) installation on both sides of cabin provides normal 

household, 15 A outlets to cabin equipment racks 

 Maximum 60 A 

• DC, 28V 

 Power cord installation (figure 12) on both sides of cabin provides 15 A 

outlets to cabin equipment racks 

 Maximum 100 A 

Figure 12 

Derek Rutovic, mihailo.rutovic-1@nasa.gov, 281-244-9871 11 5/3/2017, Revision A 
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Aircraft Operations Division 

Johnson Space Center 

5/3/2017, Revision A 

N992NA Payload Interface 

 Aircraft Systems 

• Arinc 429 

 Air Data 

– Dual, independent sources 

 IRS 

 FMS/GPS 

– Capacity to load user defined flight plans via external thumb drive 

• Discrete outputs indicating weight-on-wheels and landing gear down 

• Aircell Axxess II Iridium satellite phone 

• Platform precision autopilot for flying a given course at precise altitudes, +/- 5 m 

Derek Rutovic, mihailo.rutovic-1@nasa.gov, 281-244-9871 12 
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Aircraft Operations Division 

Johnson Space Center N992NA Payload Interface 

 Aircraft Systems (cont.) 

• Installed experimenter antennas, figure 13 

 2, GPS antennas 

– Aeroantenna Technology P/N AT2775-81W-TNCF-000-RG-39-NM 

 3, Iridium antennas 

– Antcom Corporation P/N S5GIR1616RR-PP-XTT-1 

Figure 13 

Derek Rutovic, mihailo.rutovic-1@nasa.gov, 281-244-9871 13 5/3/2017, Revision A 
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Johnson Space Center 

Aircraft Operations Division 

N992NA 

 Aircraft Systems (cont.) 

• Sonobuoy Tube 

Figure 15 

Figure 14 

Derek Rutovic, mihailo.rutovic-1@nasa.gov, 281-244-9871 14