Why Supersonic Flight is Negative Training for Business Jet Pilots

By Paul BJ Ransbury, CEO at APS

If you’re looking to wisely invest in training that makes a tangible difference in your day-to-day safety margins to include on-call resilience to overcome an unexpected time-critical upset event, then robust, optimized UPRT will accomplish your objectives. In this paper, as military fighter pilots, airline pilots, and business jet pilots, we discuss the value of supersonic flight for subsonic jet pilots.

Video Below on the Value of Transonic and Supersonic Training: Before leaving this page today, please take a few minutes to join APS and Capt. Steve Stowe, former Chief US Air Force Test Pilot for the F-15, as we discuss the value of transonic and supersonic training in a recent live stream session.

The Growth of UPRT Providers: Upset Prevention and Recovery Training (UPRT) has become more widely appreciated in recent years with the industry’s increased awareness of the number one causal factor of fatalities, Loss of Control-Inflight (LOC-I). This is evidenced by major air carriers such Delta Air Lines and United Airlines, as just two examples, licensing APS UPRT methods and training solutions. In response to increased industry awareness and regulatory initiatives, the number of UPRT providers has grown. As expected, the quantity of marketing twists new entrants employ to rationalize a diversity of training platforms to gain a market advantage of some kind has similarly grown.

Grandiose Claims: Unfortunately, attempts to rationalize the use of airplanes companies happen to have on-hand has led to some grandiose claims such as their being significant training value in supersonic flight for subsonic jet pilots, the subject of this discussion.

Boondoggle: work or activity that is wasteful or pointless but gives the appearance of having value. (Oxford Languages Dictionary)

Welcome to the free market; buyer beware. As addressed below, the use of supersonic aircraft to train high altitude and high speed handling characteristics of subsonic aircraft is both inaccurate and misleading. It is little more than an expensive, short-lived experience of going supersonic flight with no tangibly-useful training value. Read on to learn more.

Critical Qualifiers for Training Platforms: For every flight training platform, two primary qualifiers must be satisfied:

1. Positive Transfer of Skill Dominates the Training
2. The Experience Provides Meaningful Training Value

Supersonic flight for non-supersonic jet pilots fails on both counts.

Why?

Supersonic Jet - Performance Characteristics

The following three items frame the main areas of concern from several perspectives. Training managers must exercise caution before thinning the value of a safety training budget on supersonic Mach runs for their pilots:

1. Supersonic fighters are designed to exceed Mach 1. Those supersonic designs eliminate the aerodynamic characteristics and small operating margins of transonic flight up to the sub-Mach Mmo of non-supersonic jets. 
   • Result: The experience of achieving a Mach higher than your airplane’s Mmo in a supersonic jet has no tangible training value as the characteristics are completely different. 
2. Further, experiencing high transonic and supersonic speeds with characteristics that are markedly different than the pilot’s own aircraft is arguably negative training. This experience introduces an attitude of complacency concerning high Mach operations and creates a false expectation of docile aerodynamic cues and handling characteristics at Mach numbers beyond the trainee’s own aircraft’s Mmo. Neither are desired training outcomes. 
   • Result: Supersonic flight demonstrations have no relevant application to the flight envelope of today’s jet transport category aircraft operation. 
3. Supersonic jets are expensive to operate even if they aren’t being used for a supersonic ‘Mach Run’ to get the t-shirt. Their wing designs typically require higher thrust to overcome their generally higher drag characteristics due their shape and thickness in the speed regimes compared to subsonic training jets. Moreover, subsonic jets used in upset training, such as the Marchetti S211 used by APS, have wing designs directly relevant to the typical business jet wing design with optimal transferable training value when combined with their all-attitude capability.
   • Result: Today’s business jets don’t use supersonic wing designs and typically demonstrate significantly different handling and performance characteristics at or about Mmo than are demonstrated by supersonic jets at the same Mach. Arguably, this is negative training. 

Specific Example: Transport category aircraft at high Mach numbers and at high altitudes have a number of characteristics that supersonic aircraft do not exhibit. Two examples:

• • Thrust-limited Operations: The drag rise at altitude when approaching Mmo in non-supersonic jets is substantial. Very high thrust levels are typical with the sense of hitting a ‘brick wall’ in performance (ie. being at full thrust and not being able to go any faster in level flight). 
  • High Speed Buffet: Transonic jets have significant performance concerns operating above Mmo. As one type-specific example, the 777-300ER is limited to FL410 as when operating near Mmo at higher altitudes, high speed buffet is presented that feels much like initial low speed buffet and can be very confusing. 777-300ER pilots would not benefit from flight demonstrations at or above its Mmo above FL410 in a supersonic fighter as no noteworthy performance issues are encountered. 

Enough said on supersonic training for business jet and commercial airline pilots.

Subsonic Jet - Transferrable Performance Characteristics

So, where is the value in on-aircraft jet training concerning compressibility effects? Correct; maximum training value for civilian jet pilots is extracted from subsonic jet trainers and appropriately-capable advanced simulators. There are three main reasons subsonic jet training is superior to supersonic training for today’s civilian jet pilots:

1. Optimum Transferability: Significant, positively transferable training value is maximally extracted from transonic training in swept-wing, glass-cockpit, all-attitude capable, subsonic complex jets and representative advanced simulators within their Validated Training Envelope. Value is gained at both low and high altitude when delivered under the guidance of an expert UPRT instructor. 
2. High Altitude Transonic Handling: The industry is currently weak in high altitude manual handling in the transonic regime in transport category, non-supersonic jet aircraft. This is a necessary training focus area.
3. Misrepresentation of Supersonic Training Value: There is a risk of negative training for a transport category pilot if the supersonic flight and unique supersonic jet designs are not highlighted appropriately as non-transferable by the training provider compared to transport category aircraft. Providers promoting supersonic jets and supersonic flight as having significant transferable value to today’s subsonic jet operators makes the informed sharing of this reality a significant area of concern.

Subsonic Training Conclusion: Clearly, there is a business case for high altitude UPRT in the transonic regions of flight.  However, today’s subsonic jet pilots have no need for supersonic skill sets at this time since we have no current supersonic transports. Comprehensive UPRT (academic, on-aircraft, and simulator) is an industry standard that requires appropriate tools and platforms to develop knowledge and skill sets applicable to the pilot’s main aircraft and parameters. 

Other than bragging rights, supersonic training is difficult to justify for business jet pilots. 

APS Training Platform Selections: At Aviation Performance Solutions (APS), we only provide UPRT. It’s all we do; it is our sole focus. We only select training platforms based on their ability to impart substantial transferrable training value, both alone and in combinations with other effective training platforms, to thoroughly prepare pilots to overcome the risk of LOC-I. When supersonic civil jet operations substantially enter the market, APS will be a leading training provider for supersonic commercial jet pilots. That is not the world today.

Contributing Experts to this Article

• Capt. Clarke McNeace, APS VP Standards, former airline captain and USN fighter pilot
• Randall Brooks, APS VP Training, former business jet captain and Eclipse jet UPRT program manger
• Capt. Steve Stowe, USAF test pilot school graduate, former F-15 chief test pilot, former airline captain, and test pilot for Boeing, Bombardier, and Mitsubishi
• Capt. David Carbaugh, USAF T-38/F-5/F-15 instructor pilot, retired Boeing Chief Pilot Technical and Safety for Test and Evaluation, and co-author of the Airplane Upset Recovery Training Aid

About the Author. Paul ‘BJ’ Ransbury is the CEO of Aviation Performance Solutions (APS). Paul is a former military F-18 fighter pilot, Fighter Weapons Instructor Course (FWIC) graduate, former airline pilot, 7-time Master CFI, and senior UPRT check airman at APS. 

[VIDEO]: The Value of Supersonic and Transonic Training

Join APS and Capt. Steve Stowe as we discuss the value of transonic and supersonic training in the video at the end of this article. Steve is a graduate of the USAF Test Pilot School, where he also served as an instructor. As a military test pilot he was the Chief US Air Force Test Pilot for the F-15, and flew an exchange tour with the Royal Air Force Fighter Test Squadron in England. Following military service, Steve joined Delta Air Lines flying the B727, 737, 757, 767, and MD-11. As a civilian test pilot, Steve has held senior flight test positions with Boeing Defense Systems, Bombardier, and Mitsubishi Aircraft Company. In these positions, Steve has flown envelope expansion flight tests in multiple new fighter aircraft, commercial airliners, and business jets.