Business jet and TP modifications
OEM and third-party adaptations improve aircraft performance and keep them compliant with current regulations.
By Shannon Forrest
ATP/CFII. Challenger 604, G-IV
Contributing Writer
Product modification induces an interesting psychological phenomenon. Some people are satisfied with a basic stock model fresh off the production line, while others are never satisfied with the run-of-the-mill product and are always looking for ways to improve or customize a base model.
The most lucrative aftermarket modifications outside of aviation are directed at cars, boats, guitars, guns, golf clubs, and electronics. Nearly all of these are driven by performance, with the goal being to gain some sort of measurable improvement. The post-production modification process generates billions in revenue and represents an industry in and of itself.
In aviation, there are 3 main reasons to modify aircraft – regulatory requirements, efficiency/functionality gains, and/or cosmetic/personal preferences.
The International Civil Aviation Organization (ICAO) standard that prescribes maximum noise levels for aircraft is an example of a purely regulatory requirement that forced modification of an existing airframe.
The United States began codifying and applying these noise standards back in the 1980s, and the current iteration outlines an increasing scale from 1 to 5. Each escalation establishes a subsequent maximum decibel noise level for aircraft in phases of flight. In January 1988, aircraft had to comply with the Stage 2 maximum.
Mandated mods
The real effect began when the Airport Noise and Capacity Act (ANCA) was enacted by the US Congress in 1990. The first mandate was a phase-out of aircraft over 75,000 lb that were not operating within Stage 2 noise limitations. The deadline was December 1999.
This directive primarily affected transport category aircraft in airline service, but for the most part left corporate and private aircraft unscathed.
The first blow to corporate flight departments came in 2012, with FAA’s Modernization and Reform Act. This piece of legislation required that all civilian jets be Stage 3 compliant by January 1, 2016. At the time of the rulemaking, FAA noted that 599 business jets would be affected.
And yet there was no existing modification for 382 of them. Owners of the IAI Westwind, Lockheed JetStar, Rockwell Jet Commander, and North American Sabreliner had a problem without a solution. A few companies manufactured hush kits – a modification to the existing engine – at a top-end price of around $1.5 million for Gulfstream II and III twin jets.
Hush kits were also available for Learjets and Falcon 20s that didn’t meet the Stage 3 metrics. In lieu of a hush kit, Falcon 20 operators could retrofit the aircraft with Honeywell TFE731 engines, which were already Stage 3 compliant.
Although FAA has no plans in place to phase out Stage 3 aircraft, air carrier aircraft manufactured after 2017 must be Stage 5 compliant.
Hybrid mods
Stage 3 modification served a strictly regulatory function without any regard to aircraft performance. However, sometimes a mandated modification can be a hybrid in that it can achieve compliance while improving the aircraft or the system in which it operates.
The big scare for corporate flight departments in Q1 2020 was the FAA mandate for all business aircraft to have ADS-B installed. Despite admonitions from avionics manufacturers to schedule installation sooner rather than later, just 4 years before the mandate deadline, more than 10,000 US-based aircraft had failed to comply. As the deadline loomed closer, it seemed that the popular opinion was that the sky was falling, and installers would be overwhelmed with last-minute requests.
Somehow, those who needed it were able to get it done before time ran out. The rule also served as the impetus for innovation as avionics manufacturers fought to get a share of a market that ranged from large business jets to smaller recreational piston aircraft.
Although the ADS-B requirement was a forced modification, it did garner some advantages for operators in terms of safety and efficiency.
Some modifications are only necessary to operate in certain airspace. Therefore, choosing to perform such modification enacts a benefit in terms of preferential routing, separation, or altitude. The Future Air Navigation System (FANS) 1/A required to fly in the North Atlantic illustrates the model. As of 2020, FANS-1/A was required to operate in the North Atlantic Minimum Navigational Performance Specifications Airspace (MNPSA) from FL290 and above. FANS-1/A began to evolve in February 2013, with aircraft that were equipped having access to the most desirable tracks. Now it’s either all or nothing.
Renowned providers
Clay Lacy Aviation developed an FAA-approved STC for FANS-1/A at the onset of the paradigm. It was available for the Gulfstream IV, IV-SP, and V, and Bombardier Challenger 601 lines. The leading avionics manufacturers offer a variety of FANS compliant equipment, with a lot of options that can be tailored to specific operations.
Satcom Direct’s FANS-1/A Data Link Unit is a standalone box that separates cabin and cockpit communications. It uses a standard ARINC data interface over Aircraft Communications Addressing and Reporting System (ACARS) or Automatic Flight Information Service (AFIS) networks, and is an approved system for FANS over the Iridium satellite network.
The unit can tie into Honeywell’s AFIS data management unit (DMU), and its PlaneView, EASy, and Pro Line 4/21 flight decks; Collins Aerospace’s communication management unit (CMU); and Universal’s UniLink. The investment offers preferential routing, which can be quantified in lower fixed and variable operating costs.
West Star Aviation is a maintenance, repair, and overhaul (MRO) provider with multiple locations in the US. It has partnered with Honeywell to provide a FANS-1/A and Controller Pilot Data Link Communications (CPDLC) combination upgrade for the Citation X. This all-in package comes complete with a Honeywell Mark II+ CMU, dual Honeywell CD-830 Control Display Units (CDUs), Honeywell TR-866B Comm and mini cabinet, and the necessary hardware for an Iridium connection. Added to the package is a Universal cockpit voice recorder.
Enhanced and precise communication through the CPDLC eliminates transcription errors reminiscent of weak or heavily accented voice communications. The increased speed of a digital text-based communication link pairs nicely with an aircraft as fast as the Citation X.
Performance mods
Raisbeck Engineering’s performance modifications improve the handling characteristics of the standard production Beechcraft King Air.
In the world of strictly performance-enhancing modifications, no one compares to Raisbeck Engineering and the impact it has had on the Beechcraft King Air platform. Raisbeck touts that it’s dedicated to improving performance and efficiency for aircraft owners by providing aerodynamically designed enhancements that deliver better performance results, improved passenger comfort, and aesthetic ramp appeal.
Raisbeck sells modification à la carte or as a complete package through a network of authorized dealers. The company’s top-of-the-line out-the-door complete modification for the King Air 200 (just as an example) is the Raisbeck EPIC Platinum Package.
Modifications include proprietary Swept Blade Propellers, Ram Air Recovery System (RARS), Enhanced Performance Leading Edges, Dual Aft Body Strakes (DABS), and High Flotation Gear Doors. The advantages are increased climb rates, better speed and range, a quieter cabin, and the flexibility to operate into airports with shorter runways. More importantly, the sales pitch is backed up by performance calculations readily available from Raisbeck.
Blackhawk Aerospace. Engine overhaul time provides the impetus to decide whether to maintain the status quo or upgrade to a higher-performing option. Price is a major factor in the decision-making process, and a disparity between a stock overhaul and an upgraded aftermarket version can deter buyers – unless there’s a significant demonstrable advantage for the modification.
A modification that’s been proven time and again is the Blackhawk XP series engine. The XP52 is designed to replace the King Air 200 series stock engine. In terms of performance, Blackhawk advertises that the XP52 will give a 31% increase in available horsepower (1800 rpm at FL280), which translates to an additional 27 kts of cruise speed on a standard day. An operator who flies 100,000 nm per year is expected to see a cost saving of around $45,000 using the metric of saving 45¢ per mile over a stock engine.
The XP52 engine overhaul cost is $190 per hour, versus the $230 per hour expected with the OEM powerplants. If resale value is a consideration, Blackhawk engines – regardless of airframe – fetch a higher price compared to similar aircraft equipped with traditional PT6s.
Aesthetic solutions
Duncan Aviation. Operators who have completed regulatory mandated modifications and are satisfied with aircraft performance have a final option when it comes to refitting, and that’s a remodeled interior or an exterior paint job.
Duncan remains one of the busiest paint facilities in the country, with 3 locations that paint more than 200 aircraft per year. Owners can work with a professional designer to develop a custom paint scheme that’s applied in an EPA compliant process.
Elliott Aviation has 5 locations in the US. It is another high-demand refurbishment organization with the capability to complete interior and exterior upgrades.
Professional designers have a knack for laying out which veneers, fabrics, carpets, and headliners work well together. Another consideration is functionality. Stock aircraft interiors are designed for mass appeal and may not work well for every individual. Changing the footprint or layout of the interior can improve the flow drastically.
Conclusion
In today’s market, the cost of new aircraft continues to increase. There’s also an issue with lag time between ordering a new aircraft and receiving it. The decision to modify an existing airframe is an opportunity to improve performance, increase marketability (should a future sale become necessary), and get an aesthetically pleasing aircraft while at the same time minimizing the wait time associated with a new aircraft purchase.
Shannon Forrest is a current line pilot, CRM facilitator, and aviation safety consultant. He has more than 15,000 hrs TT and holds a degree in behavioral psychology.