The Hellcat is a Lady

by William S Friedman

"She's a lovely thing —" Seldon "Connie" Converse, Grumman Aircraft Engineering's chief test pilot used a voice men usually reserve for sweethearts and blonde vixens.

Probably the deceased sons of Nippon's air force who made up the 77 and 65 ships knocked down in recent fracases in the Pacific, could have thought up some fancier names for the Hellcat — kid sister to the already immortal Wildcat — which, as the F6F-3, is the Navy's latest bid toward Axis destruction. In a demonstration, I saw this new ship match Corsair performance, dive at the ground until it could dive no faster, then pull out within a whisper of the ground.

In the climb that followed, the ship displayed remarkable response to control. Climbing steeply for several seconds, the ship was rotated about its propeller axis. After a couple of these slow rolls at maximum climb, achieved without lowering of the nose or decrease in rate-of-climb, the pilot rolled the Hellcat over onto its back, held it there for a visible second and then rolled it back to normal position by reversing the procedure.

Such demonstrations as full-throttle attack dives, flying upside-down a few feet off the ground and other air race stunts were spectacular, but of less military value than the ship's simpler record of a rapid takeoff in escort-carrier deck distance, and landing without effort in a shorter run. Less spectacular also was the fact that the ship was capable of making a 360° turn within the diameter of the plant that built it.

The Why Of The Hellcat

The Hellcat was obviously developed to meet the known needs of the war. Current tactics demanded a fighter plane that could meet the requirements of both land and carrier-based operations, without undue sacrifice of top performance. The ship had to maintain a rate-of-climb and a tightness of turn comparable to the Japanese Zero, without giving up those things that we, as a nation, consider our pilot's battle-rights — adequate armor, heavy armament, ruggedness and self-sealing tanks.

Grumman has, in a large measure, achieved this ideal. As stated previously, the restricted top speed figure is in the same bracket as most currently-used land-based fighters. It mounts standard American naval fighter armament, carries more ammunition than the Wildcat.

It is virtually impossible to pick the single feature that W T "Bill" Schwendler, Grumman design chief, dreamed into the Hellcat to give her the spectacular performance she enjoys. Some folks in the industry declare that Grumman has been lucky again. On the contrary, the new ship is, beyond doubt, the logical descendant of the old Wildcat, with some refinements carried over from the Grumman TBF Avenger.

Starting from the front end, the Hellcat is powered by one Pratt & Whitney 2,800 cubic inch capacity 18-cylinder two-row, 2,000-hp radial air-cooled engine. The engine is fitted with a two-speed supercharger, and swings a three-bladed 13' Hamilton-Standard hydromatic propeller. The latter was preferred over the four-bladed airscrew used on the similarly powered Republic Thunderbolt because Grumman engineers deemed the additional landing-gear length required by the bigger prop a cheap price for superior efficiency at selected altitudes.

The "dropped jaw" or lip effect in the front cowl's lower segment accommodates the radiators for oil cooler and intercooler systems. Exhaust tubes are marshaled to a jet propulsion orifice or Meredith jet to produce a rocket effect which adds several miles per hour to the ship's top speed. It also pushes the air through the cowling system to add engine cooling. This allows the cowl to shroud the engine more closely than in ordinary installations, resulting in smaller frontal area and greater speed. The engine is installed, not at right angles to the line of flight, but tilted slightly forward. This cocking decreases the effect of torque on takeoff, resulting in a shorter run.

Between the reduced cowl area and the cocked engine, the Hellcat's forward visibility is greatly increased, to the extent that only fighters with rear-engine installation have better forward vision than the Hellcat. This excellent visibility is vital in combat, for a fighter plane is merely a winged gun platform. If the pilot cannot see where he is shooting, all top performance is in vain.

Larger and more comfortable, the fuselage of the F6F-3 resembles the Wildcat in general lines and construction. The same sturdy structure which distinguished the Wildcat at Wake is inherent in the new ship.

In the empennage, a laminar-flow tailplane is an important feature. It should be pointed out that, because the air that impinges on the tail is sped up by both the engine and the compressive action of the fuselage form, the need for a cross section that will minimize compressibility effect or shock waves, is felt on the tail surfaces at lower speeds than on the main planes.

The Hellcat's wing is somewhat lower down on the fuselage than the F4F's. Engineers at Grumman haven't yet decided whether it's a low mid-wing or a high low-wing installation. While the straight mid-wing installation would have been the best for high maneuverability which was one of the engineering goals, this would have meant undue lengthening of the landing gear legs, and unwarranted addition of weight.

This wing, for the most part, contains the secret of the Hellcat's maneuverability and control LeRoy Grumman follows an engineering philosophy which finds less resistance in wing area than in other parts of the plane. He believes that cutting area below a certain point to increase speed, is getting performance the hard way. The Hellcat is as big as the Corsair; weighs less than the P-47.

The thing that gives the Hellcat its excellent slow-speed characteristics is a special Grumman adaptation of the Fowler flap. The regulation Fowler flap is familiar to most aviation enthusiasts who are acquainted with the Hudson, Ventura and other Lockheed designs. It consists of a movable airfoil which slides backwards on a movable track. This movement, backward and downward, increases the wing area and proportionately decreases the wing loading, enabling the ship to take off from a smaller area.

Maneuverability at high speed, particularly making tight turns, increases the weight of the airplane in the turn, due to centrifugal force. As a result, the wing loading increases as the turn becomes increasingly tighter. The smallness of the turning radius is determined by the difference between the native wing loading of the airplane at a set speed and the maximum load the wing can sustain in the air. Some combat pilots, in order to make tighter turns, actually lower their landing gear in order to induce parasite resistance and slow down the ship.

The Hellcat has the distinction of having annoyed the Emperor of Nippon long before it was ever more than lines on a blueprint. A little before Pearl Harbor, the Navy started to worry about where Grumman was going to get the steel required for the building of their Plant No 2 at Bethpage, LI, where the Hellcats were to be manufactured. While the Navy worried, L A "Jake" Swirbul, Grumman's dynamic general manager, started to build a factory.

It seems that Jake had shown the international bad taste of bidding against His Serene Majesty, the Emperor of Japan, for the old Second Avenue elevated railroad, and the General Foods Building at New York's World's Fair. As a result of Swirbul's ingenuity, our men are now on the giving end of that metal, instead of the receiving end.

Production of the Hellcat also holds some unique records. The first experimental Hellcat flew in July, 1942. By last September, the pilot production model emerged, followed by a continuous stream of ships. In the first part of the winter's operation, assembly continued in a plant heated by floor braziers, because the heating unit was not yet in working order.

How many of the Navy's recent mass victories over Nippon's air force are creditable directly to the Hellcat is still a veiled military secret. Our engineers have exceeded the performance the Japs achieved by sacrificing armor, structural strength, fuel, safety and fire power, without making our planes unsafe or unrepairable.

The Hellcat's performance is not that of a hopped-up nag, groomed for a single burst of performance, to be cast aside, frequently along with its rider. The F6F's performance stems from sound engineering and thoroughbred combat reasoning. She's a Hellcat, as the Japs will guarantee, but this Hellcat is a beautiful lady!

This article was originally published in the November, 1943, issue of Air News magazine, vol 5, no 5, pp 16-17, 54.
The original article includes 1 uncaptioned photo.
Photo credited to Rudy Arnold.