‘We used to have a joke in flight training: “What happens to a prop aircraft when it loses its engine? It becomes a glider. What happens to a jet when it loses its engine? It becomes a rock.”’ Josh Bennet, US Navy Naval Flight Officer
The Lightweight Fighter (LWF) program of the US Air Force (USAF) aimed to create a day fighter with air superiority that was compact, lightweight, low-cost, and easy to maintain.
The Northrop YF-17 and the General Dynamics YF-16 competed one versus the other in the LWF program. Many in the fighter community felt that aircraft such as the F-15 Eagle were too large and expensive for many combat tasks, which led to the creation of the LWF.
Secretary of the Air Force John L. McLucas said at Edwards Air Force Base (AFB) on January 13, 1975, that the YF-16 had defeated the YF-17 in the competition for full-scale development as the USAF’s next Air Combat Fighter. Notably, in October 1980, the F-16 Fighting Falcon was declared combat-ready. Since then, the F-16 has been acquired by other foreign countries, including Belgium, Denmark, Turkey, Egypt, and Israel.
The YF-17, also known as “Cobra,” was the last in a long line of Northrop designs that started with the N-102 Fang in 1956 and went through the F-5 family. Despite losing the LWF competition to the F-16, it was chosen for the new Naval Fighter Attack Experimental (VFAX) program and eventually became the F/A-18. In enlarged form, the F/A-18 Hornet was adopted by the US Navy and US Marine Corps to replace the A-7 Corsair II and F-4 Phantom II, complementing the more expensive F-14 Tomcat. Originally intended to be a small, lightweight fighter, this design was scaled up to become the Boeing F/A-18E/F Super Hornet, which shares a size similarity with the original F-15.
Why did the Navy choose the YF-17 over the YF-16?
‘I won’t dwell on this question for too long, but much of the reason why the navy chose [the YF-17 over the YF-16 for the VFAX program that evolved into the F/A-18] is that the [YF-17 and the subsequent] F/A-18 have 2 engines,’ Josh Bennet, US Navy Naval Flight Officer, says on Quora.
‘We used to have a joke in flight training:
‘“What happens to a prop aircraft when it loses its engine? It becomes a glider. What happens to a jet when it loses its engine? It becomes a rock.”
‘Without getting too deep into engines and aero, the aspect ratio (wing) of a Jet is much much smaller compared to that of larger commercial aircraft. Why? Because jets need to pull more Gs and they can’t do that with a wing that has good glide performance. The shorter, stubbier wing handles the force of the G’s much better ensuring that they don’t fall off in flight.
‘Without letting myself get too far off track, because of the lack of glide capability, if a jet loses an engine, it loses power needed to sustain lift. If this were to happen on a jet approaching a carrier on final approach, the pilot could very well not have time to eject before hitting the water. The F/A-18 has two engines, so if it loses one, it still has another working engine to get it home.
‘Other factors for why the F/A-18 was chosen over the F-16 include the size of the landing gear (landing gear is designed to fit the aircraft itself and the smaller gear on the F-16 wouldn’t be able to support the weight of the jet on a carrier landing), as well as how they conduct A2A refueling (drogue v boom).’
The YF-17 relied on the boom system for aerial refueling and lacked landing gear intended for aircraft carriers; nevertheless, after the Navy chose the Cobra, its design was modified for naval use. The F/A-18 Hornet is equipped with a drogue system for aerial refueling and landing gear made to operate on service flattops.
Bennet concludes;
‘For more information, google has hundreds of articles about 18 v 16, funding, joint aircraft, etc that delve into the details about how, when and why the Navy chose the F/A-18 and the Air Force chose the F-16, but personally, the number of engines is the determining factor.’
Photo by U.S. Air Force and U.S. Navy