Industry QA 6.docx

Responses to Questions Received

1. The Government has been receiving questions regarding the performance increases the 144kW GPU outputs will be required to perform that the 72kW GPU will not be able to perform. At this time, that is to be determined by the Air Vehicle group that is currently developing its requirement. The GPU team is working closely with this group to provide as much information as possible in an unclassified manner. However, the GPU team is going to move forward with the assumption that there will be very little 270VDC information available from this particular group due to both the sensitive and aggressive timeline nature of their development effort. Both teams are moving forward with their respective efforts simultaneously; thus, the GPU team likely isn’t going to have the information to provide prior to the 144kW GPU contract award.

In order to mitigate this potential performance risk, the Government fully intends to issue a change order to incorporate the classified 270VDC performance document as a supplement to the 144kW GPU PD that is awarded with the contract. As with all change orders, the contractor will be able to submit an ECP and potential cost impact for review and negotiation prior to incorporation into the contract.

The purpose of providing this information at this time is to provide transparency to all interested vendors about a potential gap in performance requirements at this particular time. Additionally, the Government would like to solicit industry’s feedback and concerns regarding this potential approach.

2. For 3% input THD, is that referring to voltage? PAR. 3.4

Response: Yes. See paragraph 3.4.3.14

3. In lieu of separate, individual self-contained LRU’s, would one LRU (all outputs in one box) built modularly—with each output having its own design--be acceptable? This proven design still meets the intent of being easily repairable, but greatly shortens the MTBF of the LRU units. Bottom line: Both size and weight are considerably lessened if acceptable. PAR 3.4

Response: This could be acceptable. But, there are other requirements that must also be met, such as: the GPU’s MTBF shall be 500 hours (paragraph 3.10.7); and an enclosure that fully contains the engine, generator, and all other components (paragraph 3.9.2).

4. Would GPU outputs controlled by a digital display (Engine controls and gauges will be still analog) be acceptable? This allows operability when artic gear is required. PAR 3.4

Response: See note in paragraph 3.6 “Instrumentation may be any type of digital or analog…”

5. GPU output cables connections: Can these cables be permanently terminated to the output contactors inside the LRU? Typically GPU carts are assembled in this fashion. The document is not explicitly clear on the configuration required. PAR 3.4

Response: The Government may not fully understand the question. Power cables cannot be permanently terminated or installed. Power cables will fail and therefore must be replaceable. Refer to the cable specifications identified in the PD regarding cable terminations.

6. Will the winterization kits need to be operable with 380vac input shore power? PAR 3.5.2.3

Response: We have asked our customer for clarification, and the customer appears to want this capability if the impacts of requiring the winterization system of being able to work on Standard European power are not too great. Therefore, a question on the impacts has been added to Questions for Industry Feedback below.

7. Is EMI testing strictly for the unit, or is this criteria expected for the end of output cables as well? PAR 3.10.4

Response: Yes. The cables will act as antennas and therefore must be included in the testing.

8. Will color coding on wires 16awg and lower be acceptable in lieu of numerical markings? PAR 3.12.4

Response: Per paragraph 3.12.4, “…All wires must be numbered…”, and “The use of colored wire coating as a marking scheme is prohibited.”

9. What is driving the current dimension requirements? Multiple points of the published PD spec doc are pushing a Tier 4, Stage 5 engine design. Although a Tier 4, Stage 5 design would be much more eco-friendly, the trade-off in required size makes meeting the current trailer dimensions unattainable. PAR 3.9.1

Response: The dimension requirements are being driven by the air transportability requirements of 3.10.6.2. Per paragraph 3.5.1, the GPU’s diesel engine is to be able to run on kerosene based aviation fuels that contain over 15 parts per million sulfur. It is our understanding that this requirement is incompatible with the Tier 4 diesel engines.

10. What is driving the current weight requirement? The published PD doc states total weight must include a full fuel tank (extra 900+ lbs.). Meeting the increased size and required fuel weight on the current PD specs is extremely challenging—if not impossible. PAR 3.9.1

Response: The weight requirement in 3.9.1 is driven by the need to be able to manually push the GPU around the flightline. The lower the weight, the fewer airmen required to move the GPU.

11. When we can expect answers to all vendor submitted questions?

Response: The Government strives to have responses to industry questions posted within a week of response.

12. As part of the answers provided by the government, can you provide an update on the timeline and strategy on which way the procurement intends to proceed (72kW only or 72kW and 144kW)?

Response: At the time of this document posting, the strategy previously provided to industry in previous Q&A documents posted has not changed. The Government is still considering a consolidated contract effort for the 72kW GPU, 144kW GPU and universal load bank, along with a second contract for 72kW GPU only.

The Government is anticipating a formal solicitation being issued in the May 2021 timeframe; however, this anticipated time of release is subject to the acquisition process the Government must follow and all regulatory requirements.

The Government intends to continue these Q&A postings up through the formal solicitation release to ensure all interested parties are kept abreast of the Government’s intentions and any potential strategy/requirements changes that may arise.

Questions for Industry Feedback

1. Is it possible to meet the requirements of the 72kW GPU PD (to include the physical packaging), if the maximum height requirement was lowered from 83 inches to 72 inches? (See PD 3.9.1) Note: reducing the overall height of the GPU allows for additional air transportability options such as KC-10, KC-35, and KC-46.

2. PD paragraph 3.5.7.3 currently requires commercial aviation fuel (Jet A and Jet A1) to be “emergency use only” due to the inherent lack of lubricity that can be damaging to certain styles of high pressure diesel engine fuel pumps. Given that any engine selected for the GPU will have a common rail fuel system, is it possible to utilize Jet A and Jet A1 as secondary fuels rather than limited “emergency” use? And if so, what changes, such as an additional lubricity filter(s), might be needed for the GPU engine to operate with Jet A and Jet A1 during its 500 hour servicing window?

3. What is the impact to size, weight, and cost of adding the requirement for the winterization system heaters to operate from standard European power of 220VAC at 50Hz? (See PD 3.5.2.3) Are the same heating devices able to be operated from both single phase 120 VAC, 60Hz AND single phase 220 VAC, 50 Hz?

4. Support Equipment and Vehicles desires to incorporate applicable tenants of Model Based Systems Engineering (MBSE) into this acquisition to support the greater Department of Defense vision of a digital enterprise. The ultimate goal is to create an integrated "digital ecosystem" that provides enterprise access to the data individuals need to develop, test, field and maintain complex systems. The United States Air Force has three defined three main categories of model based acquisition:

Model-Supported Acquisition, wherein specific analytical models are used to address specific engineering concerns.

Model-Collaborative Acquisition, wherein specific analytical models and system descriptive models are used in parallel with architecting and engineering activities. In this approach, modeling "documents" the architecture and engineering activities.

Model-Centric Acquisition, wherein models are primary artifacts with the capability to generate required documentation or model views. In this approach, modeling is the basis of the architecture and engineering activities.

a. Please share the names and uses of any modeling tools and processes your company utilizes, not just by engineering, but also by program management, configuration and logistics managers, finance managers, and contracting across the product life cycle (idea conception through termination of product).

b. Do the modeling tools currently in use by your company utilize Unified Modeling Language (UML), Systems Modeling Language (SysML), or Lifecycle Modeling Language (LML) standards?

c. What is the data file format for models used within your tool(s)? Is it compatible with XML Metadata Interchange (XMI)?

d. As this acquisition may utilize a high percentage of commercial components, commercial sub-systems, and contractor owned, “pre-developed” sub-systems (i.e. control system, associated logic, firmware, etc.; converters/inverters; etc.), what portions of digital engineering, and in particular, what portions or tenants of MBSE, does your company feel are most applicable?