Learjet Acoustic Test Requirements and SOW.pdf

SPECIFICATION / STATEMENT OF WORK

1.0 Scope and Background

The NASA Glenn Research Center is planning a flight test to be conducted in 2020 using a Learjet 25 aircraft with CJ610 engines to assess flyover noise levels. Previous tests were conducted in 2001 using a NASA Learjet 251. The purpose of the new test is to repeat a portion of the measurements with improved data acquisition for aircraft position during 500’ flyovers and documenting engine operating conditions. Since NASA no longer has a Learjet 25 aircraft, an external source is being sought to provide the aircraft and test support.

2.0 Task Description

It is anticipated that five total mission flights will be required at 2 hours per sortie. The flights will need to be conducted on favorable weather days in VMC conditions. The minimum current and or forecast weather between 0 and 500’ shall be wind speeds as follows; maximum wind speed < 13 knots, average wind speed < 10 knots, maximum crosswind < 9 knots, and average crosswind < 6 knots. The relative humidity (RH) and temperatures shall be inside the box shown in Figure 1.

Figure 1 – Target relative humidity and air temperature at measurement location.

1 Brown, C. and Bridges, J., “An Analysis of Model Scale Data Transformation to Full Scale Flight Using Chevron Nozzles,” NASA TM-2003-212732, December 2003.

In the event that the weather requirements are not met, contingency tests will need to be planned until all 5 sorties are completed. The weather go/no-go decision will be made by a NASA representative.

The objective of the test is to measure the noise for constant altitude (500’) flyovers for various engine pressure ratio (EPR) values, flight speeds and aircraft configurations (flap settings). It is anticipated that all flyovers will be done with landing gear up. During each test, the one engine shall be idle while the other engine is set to satisfy the flight condition. A notional test matrix for one sortie is shown in Figure 2. It is expected that two sorties will be flown in one day during morning hours when the wind speeds are lower. A pre-test flight will be required to determine the actual set points for EPR, flaps and aircraft speed. Figure 3 shows a representative flyover test setup with ground microphones.

Run Time Description Flaps Speed

1 ~6 AM 1.6 EPR TBD TBD

2 6:04 1.6 EPR TBD TBD

3 6:08 1.6 EPR TBD TBD

4 6:12 1.6 EPR TBD TBD

5 6:16 1.6 EPR TBD TBD

6 6:20 1.6 EPR TBD TBD

7 6:24 1.7 EPR TBD TBD

8 6:30 1.7 EPR TBD TBD

9 6:34 1.7 EPR TBD TBD

10 6:38 1.7 EPR TBD TBD

11 6:42 1.7 EPR TBD TBD

12 6:46 1.7 EPR TBD TBD

13 6:50 1.8 EPR TBD TBD

14 6:54 1.8 EPR TBD TBD

15 6:58 1.8 EPR TBD TBD

16 7:02 1.8 EPR TBD TBD

17 7:06 1.8 EPR TBD TBD

18 7:10 1.8 EPR TBD TBD

19 7:14 1.9 EPR TBD TBD

20 7:18 1.9 EPR TBD TBD

21 7:22 1.9 EPR TBD TBD

22 7:26 1.9 EPR TBD TBD

23 7:30 1.9 EPR TBD TBD

24 7:34 1.9 EPR TBD TBD

25 7:38 2.0 EPR TBD TBD

26 7:42 2.0 EPR TBD TBD

27 7:46 2.0 EPR TBD TBD

28 7:50 2.0 EPR TBD TBD

29 7:54 2.0 EPR TBD TBD

30 7:58 2.0 EPR TBD TBD

Figure 2 – Notional test matrix for one sortie.

Figure 3 – Ground microphone arrays.

Engine operating conditions (EPR, EGT, and RPM) and aircraft flyover position as a function of time shall be recorded and time stamped for correlations with the acoustic measurements. The engine instrumentation shall be calibrated prior to the tests to determine uncertainties. A digital recording of the data shall be provided. NASA is also interested in obtaining recorded engine pressures and temperatures from the existing transducers in the engine at the inlet and exit.

The test location will be selected by NASA based on availability, weather conditions and background noise levels. The Contractor shall provide cost estimates for the following test scenarios:

1) A flight test facility provided by the Contractor.

2) A flight test facility specified by NASA. The location will be within the continental U.S. and will have support infrastructure for servicing the aircraft.

The Contractor shall:

• Provide a Learjet 25 test aircraft equipped with CJ610 turbojet engines with no thrust reverser.

• Provide support for installation and ground checkout of test equipment not associated with acoustic or weather data.

• Provide range coordination and secure airspace to fly mission sorties.

• Provide digital recording with differential GPS time-stamped data of engine operating conditions (EPR, EGT, and RPM) and aircraft position.

• Provide digital recording of engine pressures and temperatures from existing transducers.

• Provide calibration data for engine instrumentation satisfying NIST standards.

• Conduct pre-test flights to determine engine and aircraft settings that satisfy the desired flight conditions for the test matrix. These flights do not need to be done at the location of the acoustic tests.

• Provide support to satisfy NASA flight safety reviews.

NASA will:

• Conduct acoustic tests and provide all acoustic data measurement systems.

• Provide weather data and measurements of pressure, temperature, relative humidity, wind speed and wind direction.

3.0 Aircraft Operations and Airworthiness

The services defined in this statement of work are considered a Commercial Aviation Service to NASA. A Commercial Aviation Service (CAS) is defined as a full-service contract agreement through which an executive agency acquires an aircraft and related aviation services (e.g., pilot, crew, maintenance) for exclusive use.

The Contractor shall meet the following requirements in accordance with NPD 7900.4 NASA Aircraft Operations Management, and NPR 7900.3 Aircraft Operations Management Manual. Any deviations from the stated requirements require additional approval and must be coordinated in advance of the contract award.

All flights shall be conducted as public-use aircraft operations under NASA’s aviation authority. As such, NASA has a responsibility to ensure CAS aircraft are airworthy and such aircraft operations are conducted safety. All CAS operations shall be inspected by NASA Glenn Research Center Aircraft Operations Office personnel prior to contract award and be subject to on-going surveillance during the contract period. The Contractor shall provide and make available all applicable flight operations and maintenance manuals, aircraft logbooks, and personnel training records. NASA reserves the right to conduct no-notice surveillance inspections of all maintenance and flight efforts performed under the contract, regardless of Contractor/Subcontractor status. The Contractor shall support these surveillance activities and ensure Subcontractor compliance as required.

The operator of an aircraft that has performed a public aircraft operation for NASA may not return the aircraft to service in civil operations without demonstrating that the aircraft meets all the criteria as prescribed by FAA regulations to hold its airworthiness certificate. For more information, the operator should contact their local Flight Standards District Office.

3.1 Airworthiness Requirements

The aircraft configuration and airworthiness shall be reviewed and approved by NASA and a NASA Airworthiness Statement or Airworthiness Certificate must be issued prior to the first flight performed under the contract.

An Airworthiness Certificate or Statement is valid only for the specific configurations, flight envelopes, duration, locations, and operations specified in the approval. Any change to the specified configuration or flight operation requires issuance of a separate or amended Airworthiness Certificate or Statement.

All aircraft modifications and/or configuration changes performed during the contract period shall go through an appropriate level of design reviews and are subject to NASA airworthiness approval.

All aircraft modifications and/or configuration changes performed during the contract period shall be in accordance with FAA airworthiness standards such that the aircraft will maintain its current FAA airworthiness certificate after completion of the contract.

If any aircraft modifications and/or configuration changes require FAA Form 337 documentation (FAA Series 8110, 8100.9), the Contractor shall provide the Designated Engineering Representative (DER)/Designated Airworthiness Representative (DAR) evaluation and all associated documentation for review and approval.

The operator shall ensure that the aircraft and all required equipment are operated and maintained in accordance with the manufacturer’s specifications.

The operator shall comply with manufacturer Mandatory Service Bulletins and FAA Airworthiness Directives before and during contract performance.

The operator shall provide and make available a list of all Mandatory Service Bulletins and Airworthiness Directives applicable to the contract aircraft in the format shown in FAA Advisory Circular 43-9C complete with authorized signature, certificate, type, and number.

The Contractor shall support an Airworthiness Review meeting at least 8 weeks prior to the first flight under the contract.

3.2 Operations Requirements

The Contractor shall ensure that all operations are performed in accordance with 14 CFR Subchapter F – Air Traffic and General Operating Rules.

The operator shall hold and maintain a 14 CFR 121 Certificate or 14 CFR 135 Certificate and perform all operations in accordance with the requirements of their certificate. If the operator does not hold the required certificate, a waiver is required and the Contractor shall provide documentation that demonstrates an equivalent level of safety (e.g. company operations manuals, maintenance manuals, quality assurance programs, crew training records and certifications, etc.). This waiver must be coordinated in advance of the contract award. In this case, the operator shall perform all operations in accordance with the provided documentation.

The operator shall have a documented Aviation Safety Program, which shall include elements of mishap prevention and a Mishap Response Plan.

The Contractor shall support a Flight Readiness Review (FRR) meeting prior to the first flight under the contract.

4.0 Schedule and Milestones

TBD