Learjet 35A: An Appealing Choice for the Right Buyer

My first introduction to the Learjet 35 came in the form of an engineering drawing while I was employed with an aircraft seating company. The drawing was of a single, side-facing seat opposite the airplane’s entry door. Lifting its cushion revealed a commode seat atop a too-small stainless-steel bowl that could be filled with blue-water disinfectant.

This, I was told, was the toilet. 

Thus, there is no lav, per se—just a small commode with a little “privacy” curtain. And sometimes, there is no lav at all, according to John Yegerlehner, president of Spectra Jet in Springfield, Ohio, a company with expertise in maintaining the make and model. “Ninety percent of our customers for the 35 disable the toilet,” says Yegerlehner, who has worked on 35s since 1988, beginning with the U.S. Air Force’s fleet, which once numbered into the 80s. “They keep it dry, so they don’t have to worry about corrosion or servicing it [after use]. The longest trips in the airplane are three to four hours and most people can hold it that long, or, if it’s a charter they will do shorter legs, land, and let people get out. It is such a pain to keep those toilets in working order.” 

Learjet produced 738 copies of the aircraft between 1973 and 1994. The 35 and the more ubiquitous 35A were basically model 25s with a slightly longer fuselage, bigger wings, and more powerful, fuel-efficient, and quieter Honeywell TFE731-2-2B engines (3,500 pounds of thrust each). More than 400 Learjet 35 and 35As remain in service. In the U.S., Michigan-based Royal Air Freight/Royal Air Charter operates one of the largest civil fleets while the U.S. Air Force still flies 18 for officer/executive transport with the designation C-21A. You can obtain a used copy for as little as $400,000, though updated aircraft in prime condition can fetch nearly $1 million. 

The airplane requires two pilots and can seat eight passengers—although any more than six is decidedly uncomfortable. This is an airplane built for speed. The cabin measures a tight 12.9 feet long by 4.9 feet wide by 4.3 feet tall and volume is just 268 cubic feet. The baggage “compartment” is something of an afterthought: a mere 40 cubic feet of space that you access by folding down the cabin’s rear bench seat. The good news is that you can do this in flight. The bad news is that, if that seat is occupied, someone must move for you to do it. The aircraft’s available three-foot-wide cabin door and 9.4-psi cabin pressure differential, which allows the aircraft to maintain sea-level cabin altitude up to 25,700 feet, have made it a favorite with air ambulance providers. 

Speedy but a Gas Guzzler

The 35A can fly at speeds up to 464 knots and has a brisk climb rate of 3,500 feet per minute, a maximum altitude of 45,000 feet, and a range of 2,400 nautical miles. Under standard temperature and altitude conditions, it can easily use runways shorter than 5,000 feet. But bring your gas card. The aircraft burns up to 200 gallons per hour at cruise power and has a fuel capacity of 931 U.S. gallons. By way of comparison, a similar aircraft of the era, the Cessna Citation V, burns 182 gallons an hour at cruise but is more than 30 knots slower. 

Numerous modification kits were fitted to the Learjet 35 series from both the factory and third-party providers that can increase gross weight; improve engine performance, range, and handling; reduce approach speeds and runway requirements; and add baggage capacity via wing lockers. Two key providers of these mods are Raisbeck and Avcon. About 30 percent of the in-service fleet has been modified with kits from one or both of these providers. Similarly, a variety of instrument panel modernizations are available. However, the aircraft’s low hull value makes it difficult to justify investing in upgrades beyond those that are mandated by regulation, such as ADS-B Out. You would be hard-pressed to find a Learjet 35 retrofitted for Wi-Fi. 

Despite its lack of a restroom, the model is an appealing choice for the right buyer, typically a Part 91 operator who flies 200 hours or less per year. Honeywell continues to support the engines, many of which are enrolled in its MSP Gold hourly service program. Yegerlehner says, moreover, that despite the model’s age and cabin limitations, the values of some aircraft are increasing. “I had a customer who bought one five years ago for $450,000,” he comments. “He sold it last year for $750,000. Getting one in any condition is pretty much worth it.” 

Some Maintenance Issues

However, like any other legacy aircraft, the 35/35A has some rather specific maintenance issues related to scarcity and the idiosyncrasies of its original manufacture. Yegerlehner notes that the model was in a state of almost constant evolution during its production run and few aircraft are exactly alike. And big-ticket maintenance items—including the thrust reversers, tip-tank boots, and landing gear—can present sourcing challenges as Bombardier no longer supports the aircraft save for engineering. 

The Aeronca engine thrust reversers must be inspected every 1,400 hours and reassembled with new bushings and bearings. Any other defective components on the reversers discovered during the inspection need to be replaced and sometimes those can be hard to come by. The tip tank boots have to come off at the 12-year inspection and the rubber boots that are part of the connection from those tanks to the main wet wings must be replaced as part of that process. 

Finding landing gear and replacement parts for it can be a bit of an adventure, with major inspections on these components beginning at 6,000 landings. Yegerlehner’s firm has also discovered delaminated honeycomb floorboards during 12,000-hour inspections when the wings and horizontal stabilizer must come off and be X-rayed. The floorboards needed replacement, an event he characterizes as “a pretty big deal.” Some 35As currently on the market are coming up on the 12,000-hour mark and the cost of those inspections, along with the required replacement parts, can easily top $100,000. 

Global Parts in Augusta, Kansas, provides parts support for classic Learjets, series 20–50. “They still have quite a bit of stock on a lot of things,” Yegerlehner says, adding that other parts can be obtained from various salvage yards in Kansas and Oklahoma. Despite its age, Yegerlehner thinks the Learjet 35A is a good, reliable airplane. Royal Air still runs some of its 1970s vintage 35As up to six hours a day. “They have their normal failures like any other airplane, but on the whole, they are quite mission capable,” says Yegerlehner. 

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1985 Learjet 35A at a Glance

Price: $2.85 million (new), $770,000 (typical used)

Engines (2): Honeywell TFE731-2-2B turbofans, 3,500 pounds of thrust, each

Crew: 2 

Passengers: 6–8 

Cabin: 4.3 ft (H), 4.9 ft (W), 12.9 ft (L)

Baggage: 40 cu ft (internal) 

Range: 1,930 nm*

Maximum cruise speed: 470 ktas

Maximum takeoff weight: 18,300 lb

Payload with maximum fuel: 1,992 lb

Maximum altitude: 45,000 ft

Balanced field length: 4,224 ft

*Maximum NBAA IFR range at long-range cruise speed with all passenger seats occupied.