급유기 KC-135보다 시동이 오래 걸리는 KC-46A

[위종민]

KC-46A의 APU가 KC-135의 APU보다 시작/초기화 시간이 오래 걸려서 4발인 KC-135보다 (정확히 공개되진 않았지만) 시동 시간이 오래 걸린다고 합니다. 

그래서 22 공중급유비행단의 부사관들이 비행승무원들이 KC-46에 탑승하기 전 APU 시동버튼을 원격으로 누를 수 있는 장비를 개발했다고 하네요. 

보잉 767의 APU가 가동된 후 몇 분이나 작동해야 엔진 시동이 가능하길래 이런 대책까지 마련하는지 모르겠네요. 한 뉴스그룹에서 검색해보니 "10분은 너무 길고 1분이면 충분하지 않을까? 명확한 지침은 없다. 727에서는 전자장비 가동에 1분, 유압 안정화에 3분 걸렸다."는 답글은 있네요. 

https://www.airandspaceforces.com/kc-46-apu-remote-start

Staff Sgt. Hunter Diedrich, 22nd Air Refueling Wing Innovation Lab noncommissioned officer in charge, and Senior Airman Douglas Vargas, 22nd ARW Innovation Lab intern, work on the KC-46A Pegasus Auxiliary Power Unit Start System (APURSS) at McConnell Air Force Base, Kansas, Nov. 14, 2024. (U.S. Air Force photo by Airman 1st Class Paula Arce)

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KC-46s Take a While to Start. These Airmen Want to Fix It

Nov. 22, 2024 | By David Roza

Airmen at McConnell Air Force Base, Kan., are working on a device that will start up the KC-46 refueling tanker faster and cut down the time it takes for crews to take off and gas up aircraft in need.

First delivered in 2019, the KC-46 is the Air Force’s newest tanker. But despite its youth, the two-engine aircraft takes much longer to start up than its four-engine cousin, the KC-135, which is about 61 years old on average.

The difference is the auxiliary power unit (APU), a smaller engine that helps start up the main engines. APUs also get the aircraft’s climate control and other systems running, and they can be used as an emergency power source to restart the engines in flight. The APU on the KC-46 has “a substantially slower start/initialization time” than the one on the KC-135, John Van Winkle, chief of public affairs at McConnell’s 22nd Air Refueling Wing, told Air & Space Forces Magazine.

“This means that the crews have to start the APU when arriving at the aircraft and wait for it to run its initialization and diagnostics prior to applying battery power or attempting to start the aircraft engines,” he said.

U.S. Air Force Staff Sgts. Tamlin Soucy and Alexander Desmarais, both engine mechanics with the 157th Air Refueling Wing, use fish pole lifting equipment to lower an auxiliary power unit from a KC-46A Pegasus at Pease Air National Guard Base, New Hampshire, Sept. 27, 2022. (U.S. Air National Guard photo by Staff Sgt. Victoria Nelson)

Winkle could not share exact times due to security concerns, but the wait was long enough that two Airmen at McConnell wanted to do something about it. Staff Sgt. Hunter Diedrich and Senior Airman Douglas Vargas are part of the 22nd Air Refueling Wing’s Innovation Lab, a space for Airmen to whip up fixes and inventions.

Diedrich and Vargas invented the APU Remote Start System (APURSS), a device that physically presses the APU start button remotely before the crews get aboard the KC-46. Vargas worked out the device’s software while Diedrich handled its physical design.

“We were relieved when the APURSS worked the first time because we had a few unknowns if the actuator would be strong enough to press the button and if the unit was going to be able to stay on the aircraft,” Diedrich said in a Nov. 19 press release.

The prototype is already making an impact, Capt. Timothy Schwanke, chief of the Innovation Lab, said in the release.

“This has already proven to significantly reduce the alert time for the KC-46 crews as they are conducting routine training,” he said. “Prior to this, the KC-46 had a severe disadvantage to alert timing in comparison to its KC-135 Stratotanker counterpart, and the APURSS device has effectively reversed those statistics.”

Senior Airman Douglas Vargas, 22nd Air Refueling Wing Innovation Lab intern, works on the KC-46A Pegasus Auxiliary Power Unit Start System (APURSS) at McConnell Air Force Base, Kansas, Nov. 14, 2024. (U.S. Air Force photo by Airman 1st Class Paula Arce)

The signal is so strong that crews can trigger the APURSS from several states away, Diedrich said, though Van Winkle clarified that the intent is for the control module to stay at the same base as the APURSS. McConnell continues to use APURSS in operational exercises, “but it is anticipated that all KC-46 units will want this device once it is developed at a larger scale,” Schwanke said.

For now, the device is still the early stages of prototyping and creating proof of concept for the Air Force, but the Innovation Lab has already partnered with a few organizations to develop the idea.

Those partners include FirePoint Innovations Center, a defense technology hub at nearby Wichita State University, and the Defense Innovation Unit, which secured $250,000 to research and develop APURSS. FirePoint and Innovation Lab are also working with a Wichita company called PWI, which will take the lead on research and development, prototyping and commercialization of APURSS for the entire KC-46 fleet. How long that will take is not yet clear.

“It really will depend on when the funding officially comes in from DIU and how fast PWI can design and build a product for us to use on a larger, more robust scale,” Van Winkle explained. “Higher headquarters will be the ultimate authority on if and when the APURSS will actually be utilized real world.”

In the meantime, the partnerships are a promising start.

“We hope that with this funding from DIU, and business partnership with PWI, we can build a suitable product that the Air Force will want to purchase for fleet-wide implementation,” Van Winkle said.

A ​​McConnell Airman marshals a KC-46A Pegasus at McConnell Air Force Base, Kansas, July 1, 2024 after the KC-46 circumnavigated the globe. (U.S. Air Force photo by Airman Paula Arce)

apu on a 767 - PPRuNe Forums

apu on a 767 - PPRuNe Forums