Number 36 of 100 in 100, the Lockheed Martin F-117 Nighthawk 🛦

Conceptualization:

The Lockheed F-117 Nighthawk was conceived during the Cold War, a time when advancements in radar technology and radar-guided surface-to-air missiles (SAMs) exposed the vulnerabilities of traditional aircraft. The Vietnam War and other conflicts underscored the need for an aircraft that could evade detection and strike high-value targets within enemy territory. The U.S. military responded by developing an aircraft with unprecedented stealth capabilities. During this period, the aviation market focused on increasing aircraft survivability in heavily defended airspaces. There was a growing demand for a platform that could penetrate enemy defenses undetected, enabling precision strikes without interception. 

Original Design:

The F-117 Nighthawk's design prioritized stealth, breaking from traditional aircraft norms. Its faceted, angular surfaces minimized radar cross-section by deflecting radar waves, rendering the aircraft nearly invisible to radar. The use of radar-absorbent materials (RAM) further reduced detectability, and the aircraft’s weapons were housed internally to maintain its stealth profile.

The Nighthawk’s engines were designed to minimize radar and infrared signatures, with exhaust nozzles dispersing hot gases to reduce heat detection. A sophisticated fly-by-wire control system managed the aircraft’s inherently unstable design. The cockpit was optimized for single-pilot, night operations, further emphasizing its specialized role in precision strikes.

Photo Credit: Lockheed Martin Official Website

Principal Designer:

Ben Rich, the head of Lockheed’s Skunk Works during the F-117's development, played a pivotal role in advancing stealth technology. Succeeding aerospace legend Kelly Johnson in 1975, Rich led a team that included key figures like Alan Brown and Denys Overholser. This team overcame significant challenges to deliver the world’s first operational stealth aircraft, setting the stage for future designs like the B-2 Spirit and the F-22 Raptor. Rich’s leadership and the team's efforts cemented the F-117’s place in aviation history.

Production Run:

The production of the Lockheed F-117 followed the successful testing of the "Have Blue" prototypes. The first operational F-117A aircraft rolled out in the early 1980s, with full-scale production continuing until 1990. Over this decade, a total of 59 operational F-117A aircraft were produced, along with 5 YF-117A prototypes, bringing the total number of Nighthawks to 64.

The production of the F-117 was relatively limited, reflecting the aircraft’s specialized role as a stealth attack platform. Unlike more versatile aircraft, which saw larger production runs, the F-117 was designed for a specific purpose—penetrating heavily defended airspace to deliver precision strikes. This focus on quality over quantity meant that production volumes remained consistent throughout the aircraft’s manufacturing period, with no significant changes in volume.

The last F-117 was delivered in 1990, and the aircraft remained in service until its retirement in 2008, having participated in several major conflicts including the Gulf War and the Kosovo War. The aircraft’s limited production run and specialized use highlight its role as a precision tool in the U.S. military’s arsenal.

Photo Credit: airliners.net - Ken Hajic

Evolution:

Throughout its service, the F-117 underwent upgrades to maintain effectiveness against evolving threats. Avionics enhancements improved navigation and targeting systems, while RAM coatings were periodically updated to ensure the aircraft’s low radar cross-section. The F-117’s weapon systems were also upgraded to accommodate newer munitions like the JDAM. Although the F-117 did not see significant variants, experimental modifications post-retirement contributed to the development of future stealth technologies.

Specifications:

General characteristics

• Crew: 1
• Length: 65 ft 11 in (20.09 m)
• Wingspan: 43 ft 4 in (13.21 m)
• Height: 12 ft 5 in (3.78 m)
• Wing area: 780 sq ft (72 m²) 
• Airfoil: Lozenge section, three flats Upper, two flats Lower
• Empty weight: 29,500 lb (13,381 kg) 
• Max takeoff weight: 52,500 lb (23,814 kg)
• Powerplant: 2 × General Electric F404-F1D2 turbofan engines, 9,040 lbf (40.2 kN) thrust each

Performance

• Maximum speed: 594 kn (684 mph, 1,100 km/h)
• Maximum speed: Mach 0.92
• Range: 930 nmi (1,070 mi, 1,720 km) 
• Service ceiling: 45,000 ft (14,000 m)
• Wing loading: 67.3 lb/sq ft (329 kg/m²) calculated from
• Thrust/Weight: 0.40

Armament

• 2 × internal weapons bays with one hardpoint each (total of two weapons) equipped to carry:
  • Bombs:
    • GBU-10 Paveway II laser-guided bomb with 2,000 lb (910 kg) Mk84 blast/fragmentation or BLU-109 or BLU-116 Penetrator warhead
    • GBU-12 Paveway II laser-guided bomb with 500 lb (230 kg) Mk82 blast/fragmentation warhead
    • GBU-27 Paveway III laser-guided bomb with 2,000 lb (910 kg) Mk84 blast-fragmentation or BLU-109 or BLU-116 Penetrator warhead
    • GBU-31 JDAM INS/GPS guided munition with 2,000 lb (910 kg) Mk84 blast-frag or BLU-109 Penetrator warhead
    • B61 nuclear bomb

Comparison to Other Aircraft in Its Class:

1. Northrop Grumman B-2 Spirit (Stealth Bomber):

• Role: Strategic Bomber with Stealth Capabilities
• Speed: Mach 0.95 (about 630 mph)
• Range: 6,000 nautical miles (without refueling)
• Payload: Up to 40,000 pounds of ordnance
• Stealth: Extremely low radar cross-section, similar stealth technology but larger and more advanced than the F-117.
• Comparison: The B-2 is a larger, longer-range platform capable of carrying a much heavier payload, but it was developed later and for different strategic purposes. It shares stealth design principles with the F-117 but operates at a different scale.

2. F-22 Raptor (Stealth Fighter):

• Role: Air Superiority Fighter with Ground Attack Capabilities
• Speed: Mach 2.25 (1,500 mph)
• Range: 1,839 nautical miles (with drop tanks)
• Payload: 2 × AIM-9 Sidewinder, 6 × AIM-120 AMRAAM, 1 × 20mm cannon, and ground-attack munitions
• Stealth: Advanced stealth design with a low radar cross-section and thrust-vectoring for enhanced maneuverability.
• Comparison: The F-22 is a multirole aircraft with superior speed, maneuverability, and air combat capabilities. While it shares stealth features with the F-117, it is a much more versatile platform designed for both air-to-air and air-to-ground combat.

3. F-35 Lightning II (Stealth Multirole Fighter):

• Role: Multirole Stealth Fighter
• Speed: Mach 1.6 (1,200 mph)
• Range: 1,380 nautical miles
• Payload: Internal weapons bay + external pylons; capable of carrying a variety of air-to-air and air-to-ground munitions
• Stealth: Designed with stealth in mind, though slightly less stealthy than the F-22.
• Comparison: The F-35 is more modern and versatile, with advanced avionics and multirole capabilities, including close air support, tactical bombing, and air superiority. It is the successor to the F-117 in terms of integrating stealth into a broader range of mission profiles.

Performance:

Lockheed F-117 Nighthawk Performance Envelope

V-Speeds:

• VLO (Landing Gear Operating Speed): Approximately 170 knots (195 mph; 315 km/h).
• VLE (Landing Gear Extended Speed): Approximately 200 knots (230 mph; 370 km/h).
• VNE (Never Exceed Speed): Mach 0.92 (617 mph; 993 km/h).
• VREF (Approach Speed): Estimated around 140 knots (161 mph; 259 km/h) for landing.

G Load Limitations:

• Positive G Limit: +6.0 Gs (estimate).
• Negative G Limit: -2.0 Gs (estimate).

Maneuvers Approved:

• Stealth Operations: The F-117 was designed primarily for stealth operations and precision strikes, meaning it was optimized for flying in straight and level flight to minimize radar cross-section.
• Low-Level Penetration: Approved for low-level flight operations, where it would fly at altitudes around 500 feet AGL (Above Ground Level) to avoid radar detection during ingress and egress to target areas.
• Precision Bombing: The aircraft was highly optimized for precision bombing runs using laser-guided munitions, with specific maneuvers approved for target acquisition and weapon release.
• Night Operations: The F-117 was primarily used in night operations to leverage its stealth characteristics and reduce the likelihood of visual detection.

Overall Performance Assessment:

• The F-117 Nighthawk's performance was exceptionally well-suited for its intended role of penetrating heavily defended airspace and delivering precision strikes. Its stealth capabilities, combined with its precision weapon systems, made it highly effective in the role for which it was designed. 

Photo Credit: airliners.net - Gerhard Plomitzer

Safety Record:

The Lockheed F-117 Nighthawk, while a pioneer in stealth technology, experienced a safety record that reflected both the challenges of its innovative design, and the risks associated with operating such a specialized aircraft. Throughout its service life, the F-117 was involved in several notable incidents, some of which were related to its unique aerodynamic characteristics and the complexity of its systems.

One of the most significant incidents occurred in 1986 when an F-117A crashed in Sequoia National Forest, triggering a 150-acre brush fire. 

Another major event in the F-117’s history was the shootdown of an aircraft over Serbia in 1999. This incident marked the first time a stealth aircraft was downed by enemy action, demonstrating that even advanced stealth technology had its vulnerabilities under certain conditions.

Despite these challenges, the F-117’s safety record is comparable to other first-generation stealth aircraft, with lessons learned contributing to the safety of subsequent models like the F-22 and F-35.

Acquisition Cost:

The F-117’s acquisition cost was around $42.6 million per aircraft in the 1980s. This cost reflected the advanced stealth technology and specialized manufacturing required. While expensive, the cost was justified by the F-117’s role in pioneering stealth aircraft. Today, the remaining F-117 aircraft are used for testing.

Conclusion:

The Lockheed F-117 Nighthawk represents a significant milestone in stealth technology and military aviation. Developed during the Cold War to meet the demands of penetrating heavily defended airspace, the F-117 set the standard for stealth aircraft. Despite its limited production run, the Nighthawk proved invaluable in conflicts like the Gulf War. Although its operational career had some incidents, the F-117 maintained a strong safety record for such a complex aircraft. Its legacy continues through the technologies it helped pioneer, solidifying its place in aviation history.

Photo Credit: airliners.net - Andrew Dickie

Bibliography:

Lockheed Martin Official Website – F-117 Nighthawk

National Museum of the United States Air Force

Airliners.net – F-117

Wikipedia – Lockheed Martin F-117 Nighthawk