Learjet 40 vs. Learjet 45: A Deep Dive Into Two Mid-Sized Legends

When comparing aircraft in the light-to-mid-size jet class, few names stand as tall as the Learjet 40 and Learjet 45. Both aircraft are cornerstones of the Bombardier Learjet family, offering impressive performance, cabin comfort, and reliability. But which one came first, and what sets them apart?

📌 A Quick Timeline: Learjet 45 Came First

The Learjet 45 was introduced in 1998 as a clean-sheet design intended to replace the aging Learjet 35/36 series. It marked a significant leap in Learjet engineering with better aerodynamics, increased range, and a more spacious cabin.

The Learjet 40, on the other hand, entered service in 2003 — five years after the LJ45. It was derived directly from the Learjet 45 platform but modified to offer a slightly shorter, lighter, and more cost-efficient alternative.

🛫 Key Differences

1. Cabin Size & Configuration

• LJ45: Cabin length of 19.8 ft, typically seats 8 passengers.

• LJ40: Shortened fuselage (17.7 ft cabin), designed for 6-7 passengers.

While the LJ45 offers more space and seating, the LJ40’s compact size makes it a nimble option for shorter missions and smaller groups.

2. Range and Performance

• LJ45: Approx. 1,900 NM range with a full passenger load.

• LJ40: Approx. 1,700 NM range — still respectable, but about 200 NM less than the LJ45.

Both jets use the same Honeywell TFE731-20 engines, but the reduced weight of the LJ40 gives it slightly better climb performance on shorter legs.

3. Mission Profile and Market FitThe LJ45 was designed to be a serious contender in the midsize market — competing directly with jets like the Citation Excel and Hawker 800XP.

The LJ40 filled a niche for operators who wanted the reliability and performance of the LJ45 without the need for extra seating or range. It was a strategic move by Bombardier to capture customers looking for a lower operating cost and acquisition price, while still staying in the Learjet family.

🧠 Why the LJ40 Came Later

While it may seem counterintuitive for a smaller model to follow a larger one, the reasoning was strategic. Bombardier recognized the strength and popularity of the LJ45 platform and saw an opportunity to widen its market appeal by creating a derivative model — the LJ40 — that would share parts commonality but target a different customer segment.

This modular design philosophy meant:

• Easier pilot transition between models

• Streamlined maintenance and parts logistics

• Lower cost of ownership across both fleets

🛠️ In Summary: Which One Is Right for You?

Feature	Learjet 40	Learjet 45
Entry into Service	2003	1998
Cabin Length	17.7 ft	19.8 ft
Passenger Capacity	6–7	8
Max Range	~1,700 NM	~1,900 NM
Ideal Use	Shorter trips, smaller teams	Longer trips, more seating

Both aircraft offer strong value depending on your mission profile. At Elite Jet Solutions, we proudly support both models with tailored maintenance, inspections, and consulting. Whether you're managing a Learjet 40 or 45, we’re here to keep you flying reliably and safely.