questions_responses-Air_Data_Test_Set.pdf

NASA Armstrong Flight Research Center

Questions/Responses

NND16593117Q

Air Data Test Set Pressure Controller

1) Please advise if NASA is able to supply a suggested manufacturer. Will you be accepting

“equal” products?

We will accept equal products provided they meet the same specifications identified under

Modification 1 of the solicitation. Products we cannot accept are Fluke 7750i, Druck

ADTS405/Barfield DPS500. These have been tested at AFRC with unsuccessful results due to lack of volume output.

2) The NASA PR requirements prohibits others from being compliant. No company will redesign their unit to match their competition. Please have NASA re-define the ADTS test requirement or except our current ADTS or ADC as fully compliant equipment.

NASA’s specific requirements are mandatory due to our unique flight research functions and experiments. We have clarified those requirements in more general terms under Modification

1 of the solicitation.

3) Can NASA provide further clarification or more detail information regarding the requirement note: NASA requirement: Must pressurize and control with stability a 5187 cu. In./87-liter volume and provide documentation demonstrating this capability (such as testing output results)

Must pressurize and evacuate a large volume (sealed box) and do so in an efficient, predictable and controlled manner. Evidence could be an Excel graph showing recorded test results, or other documentation demonstrating unit is capable of meeting the specifications.

4) Can NASA provide the following test parameters?

Volume Size Must pressurize and control with stability a 5187 cu. In/87-liter volume and provide documentation demonstrating this capability

Unit of measurement (Aeronautical or Pressure) Engineering units = pressure units, with potential aeronautic units required in the future.

Range of Pressure or Altitude Set Point > 100,000 ft alt = less than 0.15 psia pressure

Pressure Rate or Altitude Rate of Climb/Descent Feet per minute Rate cannot be quantified, however, unit must pressurize cabin to 43 psia within 10 minutes or less

Range of Pitot (Pt) or Airspeed Set Point Not a tested parameter

Pressure Rate, Airspeed Rate or Velocity Knots per minute Not a tested parameter

Control stability tolerance (aeronautical or pressure units) +/- 0.25 psi

Type of pumps being used with the air data controller Rotary vane; bottled GN2.

5) Can NASA describe the actual test requirement?

Testing will be done in accordance with DEI-O-050 Rev A and must meet output specifications as identified in our requirements

6) Is this test associated with cabin pressurization or air data/pitot static test requirements?

Both. Cabin pressure related, with potential ADTS workload in the future. Replacing an unsupported Ruska 6610 ADTS.

7) Is NASA expecting the supplier to deliver vacuum and pressure pumps with the Air Data

Controller?

No. Vacuum and pressure pumps are not required.

8) We manufacture equipment to suit this application. However, the IEEE-488 bus which we incorporate as an option is not set up in SCPI format. Of course all the same commands are available. Can you please confirm that this is a mandatory requirement for this solicitation?

The unit must support SCPI. This a mandatory requirement.

9) Please define the operational aeronautical and pressure units required for the Air Data

Controller. Examples: Feet, Knots, Inches of Mercury, Millibar, PSIA; PSIG’ Mach, EPR, Qc

InHg, Pt InHg, Ps InHg

Engineering units = pressure units, with potential aeronautic units required in the future.

10) Will this Controller be used to calibrate NASA Pitot Static Test sets or Air Data Test sets which are RVSM on Non RVSM compliant? For example ADTS-405F, ADTS-3300JS or

ADTS-405D or TTU-205J?

Controller is end item use, and will not be used to calibrate other standards.

11) Does the Air Data controller need to be approved by the US Government?

The unit must meet all identified requirements to be deemed technically acceptable.

12) While we understand further information regarding the application may be classified it really would be most helpful to understand more about the application. Air data test sets are inherently designed to calibrate aircraft instruments either separately or together. Pressure controllers generally are designed not only to calibrate but to control into larger volumes in a laboratory environment. In this instance the requirement is stated as being an air data test set pressure controller which is fine but some of the specifications appear to be a mixture between pressure calibration and air data instrument calibration. We have been trying to envision the application so that we are sure to offer an instrument which will fulfill the requirement. The response to this question and the ones below will help us in proposing the instrument. The main areas of information are regarding the volume and pressure ranges.

This acquisition is to replace a Ruska 6610 ADTS that is no longer supported.

13) Does the volume of 5187 cubic inches/87 liter include hoses, fittings, etc. Also, are both Ps and Pt feeding into the same volume or are there two separate volumes?

Only one volume and only the Pt channel. Ps measures ambient pressure. Hose and fittings volumes are negligible in comparison. All flow is through AN-4 fittings.

14) The upper end for Ps (100,000 ft) and Pt (900 KTS) are understood. The low end for Ps of 36ʺ

Hga seems unusual for an air data calibration considering that sea level is approximately 29.9ʺ

Hga. Confirmation of the ranges would be appreciated. Please note that this is not a problem for the instrument but it does extend the range which could have an effect on the rate of change requirements referenced Below in question 15.

The requirement specifications have been clarified under Modification 1 to the solicitation.

The wording ‘minimum 36 inHga’ is in reference to the upper range limit of the channel, so that the maximum pressure that the channel can generate should be at least 36 inHga.

15) Please can you advise the rate of change requirement for both Pt and Ps. It should be noted that the large volume may limit the rate of change specification. Air data test sets are generally designed to work into a smaller volume while achieving the rate of change capabilities of military aircraft. Rate will change as valves open

Rate cannot be quantified, however, unit must pressurize cabin to 43 psia within 10 minutes or less

16) RVSM compliance is understood, but this generally only relates to the accuracy of the Ps

(>.003ʺ Hga). Is there an accuracy requirement for Pt?

NASA assumes that Pt accuracy specifications will be in line with most Pt specifications on

RVSM compliant ADTS’s.

17) Is there a control stability specification?

No. There is no specification for control stability and will not be a tested parameter.

18) There is some confusion on our side regarding the pressure range stated on the original specifications. Is it 40ʺ Hga or 100ʺ Hga?

The requirement has been clarified in Modification 1 to the solicitation. It is 40 inHga (at least 36 inHga) for Ps, and 100 inHga minimum for Pt.

19) It is presumed that NASA has a suitable vacuum/pressure source to meet the calibration requirements through the ADTS?

Yes. NASA has a suitable vacuum/pressure source to meet calibration requirements.