Almost every aviation geek has seen the famous film Top Gun. But few of them know that if Maverick and Goose flew an F-14B they would not have had to eject during the flat spin they experienced in the movie.
Developed in the late 1960s as a multi-mission fighter, the F-14’s missions were to protect U.S. Navy Carrier Battle Groups (CBG – now CSG where “S” stands for Strike) from potential raids conducted by the Soviet bombers armed with long-range cruise missiles and to provide fighter cover for Navy attack aircraft.
The Tomcat was fitted with the potent AWG-9 radar which, supporting six AIM-54 missiles, gave the F-14 unprecedented and unparalleled mission capabilities.
Still, even though it was one of the most capable fighters in the aviation history, one problem that plagued the F-14A was the reliability of its TF30 engine. In fact, the fan blades of the Pratt & Whitney engine could break free, causing aircraft stalls and spins as a result of airflow induced engine stalls.
These problems were solved when the F-14B (former F-14A Plus), powered by a new engine, the General Electric F110-GE-400, began to enter in service in 1987.
As explained by Grumman’s Chief Test Pilot Kurt Schroeder to aviation artist and author Lou Drendel, in an interview released towards the end of the 1980s for his Squadron Signal Publications book Modern Military Aircraft: Tomcat:
“The TF30 engine’s highest stall margin, which means the difference between its operating line and where the engine will stall, occurs when it is stabilized at military power. If you would like to go to idle power when you are maneuvering, you stand a very good chance of stalling the engine. The F110 has tremendous stall margin everywhere and, at idle power, it’s higher than anywhere else. When you are maneuvering with the F110 engines, you can do whatever you want to do, whenever you want to do it.”
Moreover, with the new engine, the afterburner thrust went from 20,000 pounds per side up to 28,000 pounds per side, while dry power increased from 11,000 pounds per side to 16,000 pounds per side.
Thanks to the improved performances, Schroeder told Drendel that Maverick and Goose would not have had to bail out from their jet if they had flown a F110-powered Tomcat.
Indeed, Grumman’s Chief Test Pilot explained that the flat spin shown in the movie was “a very concern early in the F-14 program. When the aircraft is in a fully-developed flat spin, it’s going at a very high yaw rate and it is spinning down in a very small radius. In the ejection sequence, the canopy leaves first, then the back seat, then the front seat. […] The concern in a spin is that the canopy will be ejected straight up, followed shortly by the seats and the possibility exists for a collision. We have had several ejections in spins and I believe there was one case where the RIO brushed the canopy. So the scene (of the movie) was entirely possible.”
Some concern existed about the possibility of generating a stall or a spin even with the 110 engine in case its greatly increased thrust was applied asymmetrically, but Schroeder affirmed that “We deal with that easily in 110 powered aircraft. If the aircraft departs for any reason, we just pull the throttles back to idle, which just takes all the thrust effects out of the equation and you recover the aircraft. Since the 110 loves to run at idle, there is no problem. Unfortunately the TF30 does not love to run at idle and you can’t apply this solution.”
According to Schroeder the enhanced maneuverability of the 110 powered Tomcat was able to make the F-14B and F-14D superior to its adversaries in the Air Combat Maneuvering (ACM) arena.
Then, as the experienced F-14 driver said to Drendel, alongside with the new engine, the digital flight control system improved the handling qualities of the aircraft making of the Tomcat airframe the perfect platform for air to ground missions:
“The F-14 was designed to carry bombs. The Navy, however, chose not to develop that capability. There is now more and more emphasis on carrier deck loading and development of multi-mission aircraft, with the F/A-18 as the primary example of that. The F-14 is very capable of performing the air-to-ground mission, mainly because of our range and the fact that we carry the weapons conformally on the fuselage between the engine nacelles, which results in much less of a drag penalty than carrying bombs on the wings. The technology to enhance the radar for this mission has already been developed in the form of the F-15E.”
The F-14 was retired on Sep. 22, 2006, but the last years spent as U.S. Navy’s premiere fighter bomber confirmed Schroeder claims and were a proof of the reliability reached by the Tomcat thanks to the improvements it had received, the most important of which was the F110 engine.
