Hook-On Aircraft

The long story of how our civilization never quite made it to a purpose-built hook-on airplane goes back at least to 1905, when J.J. Montgomery first sacrificed his pilot Dan Maloney – and then himself, in 1911 – to prove HTA craft could be deadly even when lifted by a balloon. In addition to the aforementioned German Zeppelin-based original parasite fighter and glider bomb (photo) experiments, they also tried deploying from semi-rigid Parseval PL 16, the Army’s P IV (here drawn by Herman Van Dyk).

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These explosive-laden efforts were unique, though there have been some manned glider launches from airships – including twice from the ZR-3 (photo). The British had several spurts of mating airship and airplane, even performing a hook-on it’s said, seeming only to lack political will to make something of their investment. Had they completed the “Empire of the Air,” some sort of provision for airplane interaction would likely have evolved, possibly beginning with R-102.

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The US Navy more successfully re-created the fatally flawed British experimental drop of an airplane from a non-rigid, with an Army JN4 and the C-1 airship. The C-1 was piloted by Lt. George Crompton and the JN4 was released over Fort Tilden, NJ in December, 1918.  Apparently neither service went any further with simple “drop” experiments, with Army airships testing the “spy basket” or “cloud car” winched down through an airship-obscuring cloud layer. It was up to the US Army to actually be the first to hook on a lightly modified airplane to a non-rigid. On December 15th, 1924, 1st LT Frank McKee held the airship TC-3 steady forward while 1st LT Clyde Finter nursed the tiny Messenger up into the slipstream. On the third attempt Finter managed to “land” on the trapeze using the corresponding hook at the end of his prop guard, both contracted and built by Lawrence Sperry, son ofimg029 - Copy Elmer Sperry, inventor of the gyro-compass. (When the producer visited the Air Force Museum years ago, he found this Sperry Messenger hanging by its hook – with no sign or graphic to note this record achievement, not even mentioned in their LTA display!) The Army lost the Roma, which they’d hoped to make the mothership, and never perfected the flying carrier concept with their semi-rigid, RS-1. (This information comes from US ARMY AIRSHIPS 1908-1942 by James Shock.)

With seaplanes at first catapult-launched to scout for fleet capital ships, BuAer Design #60’s airship had been enhanced to include seaplane-carrying capability. This was logical, since contemporary capital ships’ and submarine-based scouts were floatplanes. Yet initial hook-on testing and development started with a land plane, a single UO-1 (left), the Navy re-proving DSC02318 - Copythe Army’s demonstration of years earlier. Skilled enlisted pilot J.J. O’Brien made many evolutions launching and recovering from a more complex trapeze alongside USS Los Angeles’ keel at frame 100. Some of these flights launching from and recovering to the Lakehurst-built trapeze even made it into Hollywood movies and went public at the 1929 Air Races in Cleveland. However, UO-1 sized landplanes were too large for flight decks. As the fleet experimented with the first crusier hulls converted to flat-top ships capable of operating landplanes, the Navy hosted a competition to see which manufacturer could build a small but powerful fighter plane.

Meanwhile, the Consolidated N2Y-1 (right), military version of the Fleet Model 2, was a bright yellow basic trainer without a radio or serious instrumentation. Many were in the Navy’s inventory, and the records indicate a total of six were transferred over to Lakehurst. (No photo we’ve found shows more than three. Motion pictures of Akron’s first hook-ons with three could have been taken from a regular plane. These movies are included in our DVD “The Flying Carriers.”) Various designs of prop guards and hooks, as well as trapeze refinements, have been photographed as techniques were worked out.  Fox-Movietone recorded a synchronized sound interview with the pilots flying these experiments.

waco1The capabilities called for in an airship’s utility airplane outgrew the simple N2Y-1s.  One model of the popular Waco UBF series airplane also fit through the Macon’s hangar bay door opening (following minor wingtip clipping), and offered increased range and payload, seven-cylinder performance. As Macon arrived in California. two were acquired, skyhook-equipped and designated XJW-1 (photo). Like the later N2Y-1 configuration, the top fuselage sheet metal covering could be removed to accommodate a litter patient’s evacuation from the airship. All known motion or still photos of the Wacos, including hooking on to Macon, are included in our DVD “The Flying Carriers.  A large Martin torpedo-bomber joined the Macon complement in California, but suggestions to use it for servicing an airship aloft were not perfected. (A T3M’s tail can be seen in the distance aft of Macon in the large “full crew” photo.” No utility airplanes were aboard Macon when she sank.

It must have been seen as an acceptable if begrudging budget-driven compromise to accept landplanes for extended overwater operations with the airship. So it came to pass the airship’s fighter criteria was a short list – with item number one that it would fit through the ZRS-4’s hangar bay door.  Of three airplanes built for the small fighter competition, the Curtiss XF9C-1 seemed the least of the evils. Curtiss got wind of the narrowed choice and, sans contract -with its own money – engineered fixes for the prototype’s ills,  producing the XF9C-2 (photo).

Ironically the ZRS program was itself juxtapositioned at a piviotal point in airplane development, as reflected in its adapted airplanes. The utility craft were old-school; structures largely of wood that required the skills of the aviation carpenter’s mates, covered with doped fabric stitched on with seamstress’ and riggers’ skills.  The Sparrowhawk was Curtiss’s first all-aluminum monocoupe-fuselage aircraft img031for the Navy. Like their famous endurance flyer of the same year, the Robin, the Curtiss XF9C-1 featured stamped aluminum wing ribs.  Quite a handful to keep on course while looking for the enemy fleet and tapping out Morse code, at 2770 lbs. the F9C-2 was strong enough to withstand brutal carrier landings. The photo here shows one liaison for which the tail hooks were re-attached for a trip down to USS Lexington, as mentioned by RADM Miller.

After the prototypes XF9C-1 had its “skyhook” added and XF9C-2 proved itself,  six production F9C-2 airplanes were ordered with a standardized “skyhook” and prop guard (left). Deliveries began in the summer of 1932 with the planes rolling off the line and reporting to Lakehurst, seen in the next photo resting comfortably on Hangar #1’s brickyard-like  floor. Though the Akron had scant time with a full complement of airplanes, home movies included in our DVD “The Flying Carriers” show F9C-2s decorated with her USS Akron belly band, “man on the flying trapeze“ art, and tri-color tails. Similar full color paintjobs on Macon’s planes are the most commonly published.  It is important to remember, however, the F9C-2 was not designed as a hook-on airplane from the ground up. Adding the sky hook caused the gunsight to warp out of alignment after a number of “belly bumps,” as landings were called. The gull wing hardly made for good observation. Good forward vision was needed, but F9C-2’s oil cooler sat right in the way. The tiny cockpit had no good place to put the radio key, and where it wound up made its use quite awkward. There was absolutely no room for the navigation/scouting board, so it was mounted on the control stick. Wing hand-holds allowed crewmen to steady the airplane as it transited the img041hangar bay door line using boat hooks, However, noted was the lack of any kind of tie-down rings that might have been used to secure the planes as the airship rolled and pitched.  The heavy landing gear could withstand bashing flattop arrested landings, but such permanence worked against the airshipmen who found took forty-five minutes to remove the gear in preparation for swapping its weight for the belly tank. And that tank could not be used right away, since the airplane’s fuel system returned unused fuel to the main tank – which would have no room if full.


This is the original artwork created for the meticulously accurate Williams Brothers model kit. (An equally striking painting was created for the kit’s more recent re-issue.) The “Royal Red” cowl and wheel pants just happened to be the color on NASM’s own Sparrowhawk, assembled from two but assigned BuNo 9056. The production airplanes’ cowls and pants used other colors:

9057   White     9058  True Blue    9059  Black    9060  Willow Green    9061  Lemon Yellow

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These non-regulation paint jobs hearkened back the the “Flying Circus” recognition excuse,  esprit the underlying reason. The pilots were known to fly in a red,white and blue formation order. F9C-blued - Copy Word came down from Washington to knock it off, and several photos verify there was a operating period when the tails were darkened.  Soon the plane’s tails were blackened to align with ComAirBatFour standards, and the trapeze symbols were removed. In RADM “Min” Miller’s presentation, he mentions “the white” airplane, and other photos indicate the cowling colors remained. However, early in 1934 operations, the long-suggested removal of the landing gear (making the exterior fuel tank more practical) was finally accomplished. Probably because this evolution was only necessary or even practical once aboard the airship, no still photographs of this configuration are known to exist.

The F9C-2s were equipped with GF series radios, manufactured by the Aircraft Radio Corporation. Ranging out greater distances from their dirigible, pilots complained they needed more reliable voice communication at greater distances. It was sometimes possible to see the airship as much as 50 miles away and still have to resort to the Morse code key to communicate. This was finally solved in the final months of Macon’s operations. Also in the final days came promising testing of a trailing wire antenna, which offered better radio communications without complicating hook-on ops or storage in the hangar bay.

F9C-2 - tank - textThe configuration shown here, also illustrated in the otherwise perfect 1991 National Geographic’s magazine’s fold-out graphic, did not actually exist. The “squadron” insignia had been removed and the tails blackened by the time landing gear removal ops commenced.

F9C-handleRADM “Min” Miller’s presentation page two offers a first hand account of hook-on flying with the F9C-2. This photo shows the arrangement on-wing compass mount (outboard of the hand grip) and the handle used to release the hook. (Pilots suggested the compass be mounted on the centerline on the next-generation hook-on airplane, hoping for a larger cockpit.) Note the padding designed to increase pilot survival against sudden stops. The long black centerline tube was the gunsight.  Roy Gibbens’ home movies, included in our DVD “Flying Carriers,” shows crewmen on the Opa-Lock field winding up the inertial starter, access hole for its crank seen on the port side. Aboard the airships, with no place for that hand-cranker to stand, the 110v electric starter was employed via cord handed down from the trapeze and plugged into the instrument panel’s jack.

2016-08-27-FF - CopyWhile the airship would not have seaplanes, the F9C-2 at least featured emergency flotation bags hidden in the wings. In the event of a water ditching, the pilot could fire the internal carbon-dioxide bottle to inflate the floats (left). It is possible to see the blow-out panels (arrow below) on the upper wing of BuNo 9056.

img036-copyFour F9C-2s went down with the Macon.  The remaining planes suffered various mishaps. 9056 had been banged up badly enough to have its wings swapped with another survivor before Leroy Simpler suggested it be saved for the Smithsonian.  In the photo, before its restoration, 9056 sat with hook, wheels and tank in the old Smithsonian building, pretty much as it had arrived after being donated by the Navy.

img043 In the mid-1970s the NASM undertook a full restoration of #9056. It hung proudly from its hook in the new National Air & Space Museum’s small but rich LTA exhibit when it opened in 1976, after which the producer snapped this photo. Later, the NASM exhibitors rotated LTA out of existence and loaned #9056 to the Navy Aviation Museum in Pensacola, where it was the center of the rigid airship rotunda for many years. Recently, #9056 recalled from Pensacola for what was hoped to be new emphasis on LTA or at least the ZRS program. Instead, 9056 now sits on its wheels in the Udvar-Hazy Center as if it were some ordinary airplane much like any other in the collection.

A number of Fleet model 2 airplanes are today operated by private owners. At least one has been given a skyhook and painted as a hook-on airplane. An aircraft labeled as an N2Y-1, sporting a skyhook and bearing a serial number that the record reports as having been surveyed, was hung by its hook near the LTA display at Pensacola’s Naval Aviation Museum for years. (For whatever reason, last time we checked it has been lowered to the floor and its skyhook removed.) 

Macon’s remains were located in 1990 (and revisited in 2008 and 2016). Therein are resting those four airplanes that had performed the last scouting missions, on 12 FEB 35, from their unique hangar in the sky.

Read on to “Min” Miller’s Own Words Part One


Not created for, but rather adapted to the role, the Sparrowhawk pilots longed for an airship-friendly design that would harness the system’s unique capabilities. Much-improved planes were evolving 1935 through 1939; once the reader is versed in the historical record, one is ready to understand the root philosophy we will use for the movie’s planes.

Read on to Planes for ZRCV & ZRS the movie


Read on to “P-77”, our Silence Twister


Read on to Ground Handling Evolution

Purchase DVD “The Flying Carriers”

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