WRIGHT-PATTERSON AIR FORCE BASE, Ohio – The Air Force Research Laboratory continues to provide U.S. Air Force combat aviators with specialized research and partner with the Air Force Life Cycle Management Center to provide technical support when called upon by the nation’s warfighters.
Earlier this year, the 20th Fighter Wing at Shaw Air Force Base, South Carolina, requested assistance with assessing cabin pressure, oxygen concentrations, and possible hypoxia-like symptoms reported by their F-16 pilots. The request came to AFRL through the Air Force Physiological Event Action Team and Air Combat Command officials. On Sept. 16, scientists and engineers from AFRL and the Air Force Life Cycle Management Center at WPAFB began an eight-week flight demonstration of prototype monitoring devices that meet the 20th Fighter Wing’s needs.
The request was well-timed, as AFRL and AFLCMC have been working together to develop cockpit monitoring technologies.
“We responded to the request from Shaw AFB as a team from AFRL’s 711th Human Performance Wing, the F-16 System Program Office, and AFLCMC’s Human Systems Division Aircrew Performance Branch to give them [the 20th Fighter Wing] a demonstration of all the devices that we had at the highest technology readiness levels,” said 2nd Lt. (Dr.) Dominique O’Brien, Project Lead, Airman Sensing and Assessment Product Line, with the 711HPW’s Airman Systems Directorate.
“The 20th Fighter Wing stated that several devices used for cockpit environment sensing and breathing gas monitoring met their needs, and requested that the team from AFRL and AFLCMC assist with flying these devices on their F-16s. In response, the team initiated a rigorous safety assessment. The team accomplished a battery of lab and ground integration tests that culminated in a “Safe-to-Fly” recommendation, and subsequent Airworthiness approval for two devices, all within six months of the initial meeting,” O’Brien added
One device is called the “Slam Stick,” which is available commercially, off-the-shelf (COTS). It measures tri-axial acceleration – or acceleration in all three axes, X, Y, and Z, according to O’Brien.
“It also measures temperature, humidity, and cabin pressure, has a high sampling rate and can be set to Zulu time so the actual time can be recorded,” O’Brien said. “The pilot simply inserts the device into a flight suit pocket.”
The second device is called the Insta Pilot Breath Air Monitor, or IPBAM, measures several critical parameters of the breathing gas delivered to the pilot, delivering early warnings to the pilot that help reduce the risk of physiological events.
“The IPBAM alerts the user in low oxygen or pressure conditions by haptic indication to the breathing mask, similar to a stick shaker, and by visual indicators on the IPBAM main unit,” O’Brien said. “It logs all data and alerts, and is standalone pilot gear with no aircraft integration needed. It is a small, rugged device that couples to the oxygen hose and into the oxygen regulator. It measures two main things – cabin pressure and oxygen concentration, which provides information regarding performance of the On-Board Oxygen Generation System, or OBOGS.
The flight demonstration concluded Nov. 6 following flights at both Shaw AFB and Nellis AFB, Nevada, where several aircraft from the wing’s 77th Fighter Squadron were performing temporary duty in support of an exercise, as well as participating as part of the “Red” team for the Weapons Instructor School.
At the conclusion of the demonstration, the team obtained data from 22 different pilots and 16 aircraft flying four types of missions. In total the team collected over 94 flight hours of data, which met all objectives to assess both the performance of the OBOGS in routine operations as well as the effectiveness and ease of use of the devices.
During an Oct. 2 flight, a pilot experienced physiological event (PE)-like symptoms at Shaw while flying with the devices.
“The pilot did not report it as a PE, but during debrief he stated that he felt dizzy and air-hungry at altitude, which are symptoms that could relate to a PE,” O’Brien said. “Based on a review of all available data including additional assistance from medical specialists in the Airman Systems Directorate of AFRL, the team concluded that this event wasn’t hypoxia in the traditional sense. We are also relieved that neither pilot nor aircraft safety were compromised, as the pilot was able to quickly alleviate the symptoms by going to 100 percent oxygen.”
There are many factors than can cause a PE, both physiological and cockpit environment-related, according to O’Brien.
“We concluded that the cabin pressure was sufficient and normal, and the oxygen levels provided to the pilot were likewise normal. Therefore, the event could have been caused by any of a number of additional factors, such as air quality, pilot fatigue, or low blood oxygen. We are currently developing recommendations for follow-on studies with other devices based on feedback from pilots and leadership within 20th Fighter Wing.”
O’Brien said there are two devices the AFRL/AFLCMC team are considering for a follow-on demonstration. One is a Real-Time Air Quality Sensor, or RTAQS, which measures contaminants such as carbon dioxide and volatile organic compounds. Since this device requires integration with the aircraft rather than simply mounting to the pilot’s harness, additional coordination must be accomplished for airworthiness approval.
The second device, courtesy of the Naval Air Warfare Center is called Holistic Modular Aircrew Physiologic Status, or HMAPS, which measures a pilot’s blood oxygen levels, and is simply worn by the pilot on an armband.
The team will provide an out-brief to the 20th Fighter Wing leadership in the beginning of December to conclude the first phase of the demonstration, O’Brien added “So far, our conclusion based on all data collected is that the cabin pressure and oxygen output from their OBOGS for the aircraft that we’ve seen is working well, but there are other possible contributors that require these other devices to assess, hence the need for follow-on studies.”
The process of test, evaluation, and Airworthiness approval within a relatively short amount of time required close coordination between AFRL, and the AFLCMC’s Human Systems Division and F-16 Program Offices. Taking the project from concept in March 2019, to Sept. 16, 2019, the first day of the flight demonstrations, was a huge accomplishment, O’Brien said.
“The goals and vision of the SPOs and the AFRL/711 HPW are aligned. While we were getting these monitoring devices through the process, we were also writing the new operating procedures, and developing transition plans to meet all requirements for routine use of the products” she said.
“Airworthiness approvals, especially for pilot-mounted gear, can be complicated and time-consuming,” commented 1st Lt. Lauren Kuennen, Project Lead Engineer at the AFLCMC’s Human Systems Division Aircrew Performance Branch, “but O’Brien’s team was very proactive so we were able to quickly gather the safety evidence needed to accomplish the Airworthiness Approval.”
This flight demonstration is helping the 711th Human Performance Wing create a streamlined pathway for adoption of this type of technology so future implementation can be accomplished rapidly and effectively.
“Getting flight tests done is huge for development. We cannot replicate the high-performance environment of the cockpit – Gs, acceleration, pressure, temperature, and vibration all at the same time. Flight tests and demonstrations provide critical data for both device development and eventual fielding. The opportunity was useful for the lab and addressed the immediate needs of our customers – our fighter pilots, said O’Brien.”
For all of the mainly junior military, civilians and contractors working on this flight demonstration, to see the operational side of the Air Force is energizing, O’Brien said. “Once you have the chance to work alongside and directly support the customer, you see that all this work that we’re doing in the lab is relevant, needed, and very much appreciated. It’s tremendously rewarding for myself and the team.”
“Our customers are the warfighters, and they’re really looking to us for answers. I am deeply proud of the entire AFRL/AFLCMC team for responding to their needs and helping ensure pilot safety and effectiveness,” said O’Brien.