The Airplane Thread

[Llarry]

Here's another photo I appreciate -- the deck of the USS Enterprise (CV 6) in World War II with Grumman F6F Hellcats recovering onboard. The forwardmost F6F has already folding the wings in preparation for joining the pack of parked aircraft forward. The next F6F back is taxiing forward and will fold its wings momentarily. And a third Hellcat is approaching the landing area at an indicated airspeed of about 80 knots (90+ miles per hour) to land. The carrier is moving through the water at 30 knots; on a calm day with no wind, the F6F will land with a speed of 60 knots relative to the deck. If there's a wind -- and carriers always head into the wind to launch or recover planes -- the relative speed will be hopefully somewhat less.

The F6F Hellcat was a real sweetheart at low speeds -- the saying went that all these fighter pilots were "shoe salesmen" just a year or two earlier, and the F6F was easy to fly -- but stuff happens in the unforgiving environment of an aircraft carrier's deck. What if the arresting hook skips over all the wires? What happens if the F6F catches a wire but then the wire breaks? All sort of death and destruction might ensue. The oncoming fighter probably weighs 11,000+ pounds with minimal residual highly-flammable gasoline.

The deck handling crew mostly has their backs to the oncoming fighter. If the worst happens, they're going to have to move very fast indeed to avoid death or injury.

An excellent illustration of why the angled deck landing area was such an important innovation in carrier aviation, but it would be another ten years before a clever Royal Navy aviator had the idea. And by then the jets had arrived and the landing speeds had increased considerably, adding to the danger.

[Llarry]

I don't have a good handle on the Airbus line, though Airbus and Boeing seem to be neck and neck in the competition for airliner sales. But there's one Airbus that intrigues me: The giant Airbus A380 -- the largest passenger airliner in the world.

The A380 is now out of production after a mere 251 were delivered to airlines from 2003 to 2021. Some are already stored, having been withdrawn from service due to economic factors.

Nevertheless, the A380 is an awfully impressive aircraft. Perhaps in the modern widebody twin market a has-been, but a technically brilliant achievement by Airbus nonetheless. The A380 has a full two-deck arrangement -- which we have discussed makes it much less usable for conversion to a freighter. The airframe is 20% composites.

https://en.wikipedia.org/wiki/Airbus_A380

I have not much discussed interior features on the Boeing aircraft, but the A380 has some incredibly luxurious suites in first class. Singapore Airlines has private suites -- some with a double bed -- as well as a long list of other amenities. I'm sure the price of admission is eye-watering, but if you've got it, might as well flaunt it.

On the other hand, @Lady Jane wants both a Bombardier AND a Gulfstream. Those might not have all the amenities of an A380 first-class suite on an Emirates or Singapore A380, but you get to leave when YOU want to, etc. I'm sure a first-class A380 suite ticket is less than buying your own bizjet.

[Llarry]

Attempts to prolong the service of the last U.S. Navy patrol flying boat...

The P-5 (formerly P5M) Marlin was the last USN patrol flying boat. Unlike its much earlier PBY predecessor, it was judged impractical to make it an amphibian with the capability to operate from runways. The reason for this was probably the poor performance of the P-5 when one of its two Wright R-3350 radial engines failed. In the event of an engine failure, the aircraft would typically start to lose altitude and the crew would frantically jettison anything on board possible to forestall a landing in the open ocean. Open ocean landings in any but the calmest seas would typically be disastrous. Fitting the airplane with landing gear would've added more than a ton of weight.

The P-5 was originally fitted with a classic tail gun turret with tail gunner and twin 20mm cannon. Durning its service life, the guns were removed -- weight savings for a weapon judged to have minimal effectiveness in the primary antisubmarine warfare mission.

In the 1960s, an inexpensive project was undertaken by the Naval Air Test Center to solve the P-5's power/performance problem: the installation of a small jet engine in the now-vacant tail of the flying boat. The air intake for the jet was the backward-facing former tail gunner's window location and the jet protruded from the former gun position. The project was accomplished on the cheap with a spare J85 jet engine. Limited trials demonstrated that the jet solved the P-5's problem and that an engine failure of one of the radials would no longer be the catastrophe as previously seen. (I'm afraid I can't find a decent photo of the jet installation in the P-5.) But the death knell was already sounding for the flying boat in the U.S. Navy; the rationale for the flying boat was access to maritime regions of the world where land-based patrol planes could not access -- and the then-new Lockheed P-3 Orion had shown excellent long-range performance with the potential to close those previous gaps. So in 1967, the last P-5 squadron relinquished their flying boats and transitioned to the P-3. The last-ditch effort to save the flying boat failed.

[Llarry]

Let me add a postscript to the U.S. Navy flying boat story. In the mid-1950s, the Navy held a competition to replace the P5M (later P-5) with a new flying boat. This one was bigger and much more powerful (heard that one before?) There were competitors from both Martin and Convair, both suppliers of flying boats to the Navy of long standing.

Convair won the competition and the new airplane was designated the P6Y. In place of the two R-3350s of the P5M, the P6Y proposed to have three R-3350s. But that was not all: to facilitate landings and takeoffs in rougher water, there was also a J85 jet engine that was used to blow air over the wing (boundary layer control) to reduce the stall speed. This is much like the current Japanese Shin Meiwa US-2 four-engine amphibian works and why the US-2 has unparalleled capability in rough water.

In the end, though, a new flying boat did not survive the budgetary process and although two serial numbers were allocated to prototypes, no actual metal was cut for the XP6Ys. The P5M was left to carry the load.

Here's a photo of a "what if" model of the P6Y. Note the parasol wing above the fuselage -- a bit like the layout of its remote ancestor the PBY Catalina. Some sources state that a former engineer from German company Dornier was a key contributor; this design shows a bit of Dornier DNA in its layout.

[Llarry]

A U.S. Navy carrier task group raided Truk (now known as Chuuk) atoll in late April 1944. There was a lot of apprehension among the aircrews as Truk was known as Japan's "Gibraltar of the Pacific" and intelligence on the bases there was sparse.

Predictably, Japanese antiaircraft fire took its toll of the raiding airplanes and some aircrews ended up parachuting or ditching in the huge lagoon -- a perilous position to be in with Japanese naval installations on all sides. The brave aircrew of a Vought OS2U floatplane from a USN battleship or cruiser landed in the middle of the lagoon and taxied back and forth picking up downed aircrew. They ended up with nine survivors (see photo) in addition to the two crewmen of the floatplane, but were unable to take off again with that many.

During WWII, American aircrew captives were often summarily executed when recovered by Japanese forces.

I do not know how the story ends, but I believed they all made it out. Perhaps several other floatplanes landed and each took on one or two.
It's even possible that a U.S. submarine entered the lagoon through one of the poorly-charted channels between islands and brought the survivors aboard. (EDIT: See #1660 below for more of the story)

(On a personal note, my Dad participated in these raids in his F6F Hellcat from the carrier Yorktown; fortunately, he was never shot down or had his fighter damaged during the war.)

[JJ 911SC]

Originally Posted by Llarry

... It's even possible that a U.S. submarine entered the lagoon through one of the poorly-charted channels between islands and brought the survivors aboard...)

That kind of rescue happened more than once.

[3798j]

68 years ago...

[Llarry]

Originally Posted by JJ 911SC

That kind of rescue happened more than once.

The Truk raids were probably some of the earliest uses of the lifeguard submarines but they became standard operating procedure in the WWII. A great idea.

[M-technik-3]

Originally Posted by 3798j

68 years ago...

Well that must have been an embarassing moment.

[Llarry]

The photo of the OS2U rescuing down aircrewmen reminds me that I haven't featured the main two U.S. Navy battleship and cruiser floatplanes of World War II. These were the Curtiss SOC Seagull and the Vought OS2U Kingfisher, both also used by the Coast Guard.

The biplane SOC was an earlier airplane, first flying in 1935 and scheduled to be phased out mid-war. But its replacement, the SO3C Seamew, was a failure -- largely due to an unsatisfactory engine -- and was withdrawn from service early, as posted earlier. The SOC was on the way out in 1943 when this happened and gave it a new lease on life which kept it in service until the end of the war in 1945.

https://en.wikipedia.org/wiki/Curtiss_SOC_Seagull

The Vought OS2U Kingfisher first flew in 1938 and entered service in 1940 for use, like the SOC and later SO3C, on battleships in the gunfire spotting role and on cruisers in the scouting role. Plenty of OS2Us were also used at Pensacola, Florida, as trainers.

The Wikipedia article on the OS2U provides some additional detail on the Truk rescues of April 1944 posted earlier. The pilot of the OS2U, Lt Burns, made two trips from the Truk lagoon out to the lifeguard submarine USS Tang and saved a total of 10 aviators. Burns was awarded the Navy Cross -- and no doubt the undying gratitude of ten men -- for his heroic efforts that day.

Both the SOC and OS2U were also built by the Naval Aircraft Factory in Philadelphia as the SON and OS2N respectively. Vought OS2Us were flown not only by the USN, but also by the U.S. Coast Guard, the UK Royal Navy and Royal Australian Air Force. OS2Us were also provided to a number of Latin American Navy/Air Force users.

https://en.wikipedia.org/wiki/Vought_OS2U_Kingfisher

Both planes could be flown without floats in wheel form, and both were replaced late in WWII by the single-seat Curtiss SC floatplane discussed earlier in the airplane thread, which was in turn replaced by the helicopter a few years later, thus ending the era of U.S. Navy floatplanes. There was an exception, though: a few ancient N3N floatplanes were retained at the U.S. Naval Academy at Annapolis for use in indoctrinating midshipmen in aviation until the late 1950s.

[vreihen16]

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[Llarry]

Originally Posted by vreihen16

F130 engine

Very cool -- I had no idea that the F130 was related to the RR-BMW turbofans.

[Llarry]

Vought Aircraft used the name Corsair for a number of their aircraft over decades.

The first Vought Corsair was the O2U (O = Observation, 2nd model, U = Vought) of the 1920s. Vought used the newly available Pratt & Whitney radial engine, the R-1340 Wasp, to power their new aircraft. The new Corsair was a versatile aircraft which could be used from the new aircraft carriers with wheels, or on battleships or cruisers with floats. The stated mission was observation, which meant observing the fall of shot from the big guns of the fleet and helping adjust the fire as needed, but the boundary between observation and scouting, which was the search for the enemy fleet, was a fuzzy one and O2Us were used for both purposes. Neither mission included bombing and the armament of the O2U consisted of a fixed .30 machine gun operated by the pilot and a flexible .30 operated by the crewman in the rear seat.

https://en.wikipedia.org/wiki/Vought_O2U_Corsair

The O2U was followed in 1930 by the O3U, which differed only slightly from its predecessor. Some models were powered by a more powerful P&W R-1690 Hornet radial. The mission was unchanged and O3Us were also found both on carriers and on battleships and cruisers. For the first time, Marine Corps squadrons flying Corsairs were assigned to carriers. Many O3Us were redesignated SU (S = Scout, 1 (omitted) = 1st model, U = Vought.) The mission did not include bombing, but some late model SUs got a pair of machine guns in the rear cockpit for self-defense. A number of O2U/O3U/SU Corsairs were exported.

The next Vought Corsair was in a fairly new category: SB for scout bomber, which effectively meant a dive bomber. Dive bombing put a great deal of stress on the airplane -- after dropping the bomb, the bomber had to pull out of the dive without coming apart. The earliest Navy dive bombers were built by Curtiss but the early experiences with the Curtiss were not entirely satisfactory. Vought was now a trusted supplier of Navy aircraft and got a contract in the 1930s for the SBU. The SBU could carry a 500-pound bomb on the centerline. Apart from the bomb, the SBU was armed with the usual two machine guns: One firing forward and one for the rear seat gunner/radioman.

While the SBU was still an old-fashioned biplane with struts and bracing wires and still had fixed landing gear, it did have a partially enclosed canopy for the crew. The SBU flew in 1934 and was delivered to the Navy from 1935 to 1937. It served with reserve units until 1941.

https://en.wikipedia.org/wiki/Vought_SBU_Corsair

The next Corsair hardly needs introduction; the famous Vought F4U Corsair was a mainstay in the Navy and Marines in both World War II and Korea. It was designed around the superb P&W R-2800 18-cylinder Double Wasp radial engine and in 1940 was flying faster than 400 mph; the fastest fighter extant. But the F4U had a somewhat troubled and protracted development history. It was destined to replace the Grumman F4F Wildcat in Navy and Marine Corps fighter squadrons, but its delayed introduction provided an opportunity for rival Grumman to develop the F6F Hellcat, which quickly dominated the Navy carrier fighter squadrons in 1943-45. The F4U was kept off the Navy's carriers for much of the war due to a desire to avoid spare parts issues for two, rather than one, fighter and a perceived lack of carrier suitability. The Marines, on the other hand, loved the Corsair and used it very effectively in the Pacific from land bases.

The first Navy F4U squadron, the VF-17 'Jolly Rogers' were very much looking forward to their first carrier deployment in combat when the brass decided to pull them off their ship, replace them with a Hellcat squadron, and send them to the Southwest Pacific as a land-based unit alongside their Marine Corsair comrades. They were very disappointed, but amassed a very distinguished combat record in five months of combat in the Solomons.

To be continued...

[Llarry]

As World War II continued, Vought continued to improve the Corsair. Early Corsairs with the so-called "birdcage" canopy were replaced on the line with versions with bubble canopies for better pilot vision.

In 1944, Pratt & Whitney came up with a C series R-2800 engine offering more power and Vought fitted a four-blade propeller to the Corsair to better utilize that power. The resulting F4U-4 quickly found favor with the services. The competitor F6F Hellcat was fitted with the same engine/prop combination, but the Navy decided that the future lay with the Corsair and that they did not want to interrupt the incredible production rates that Grumman was attaining; the XF6F-6 was not ordered into production.

The event that finally brought the F4U to carrier decks was the advent of kamikaze attacks in late 1944. Suddenly the Navy needed a lot more fighters on carrier decks and needed them ASAP! Each carrier went from 50-odd fighters to 73 in early 1945. As an interim measure, many ships got Marine fighters -- after all, Marine pilots were Naval Aviators and went through the same flight training as their Navy counterparts.

To digress a bit, the UK's Royal Navy Fleet Air Arm was also an enthusiastic user of the Corsair. RN carriers had hangar decks with limited overhead height, so FAA Corsairs had clipped wingtips to facilitate storage belowdecks. Over 2,000 Corsairs went to the RN, and another 370 were supplied to the Royal New Zealand Air Force.

The F4U-4 became the standard Navy and Marine Corps fighter of the postwar period; it was armed with six .50 machine guns as most earlier Corsairs had been. Pratt & Whitney and Vought also developed a new F4U-5 version with even more power and four 20mm cannon, which was becoming the standard fighter armament of Navy/Marine aircraft. The F4U-5 had particularly good high-altitude performance but was an all-around excellent fighter.

A small number of early F4U-1s had been modified for night fighter duties as the F4U-2 back in 1944. The F4U-5 took that role much further and the F4U-5N was a major production variant in the late 1940s. During the Korean war, some F4U-5N night fighters were modified with de-icing equipment as F4U-5NLs (L = cold weather). The F4U-5N and -5NL served into the 1950s, as did the F4U-4. The usefulness of the F4U in the ground attack role led to the final version of the Corsair for the Marines, the AU-1 (A = Attack) with an engine optimized for low altitude work.

The last F4Us off the line were built for the French Navy as the F4U-7 and the last of those was produced in 1952. Altogether a good run for an airplane design dating from the late 1930s.

F4Us and AUs served in Navy and Marine fighter and attack squadrons until the mid-1950s before being retired. A few even managed to make it past the switch from overall sea blue paint to the gray & white scheme adopted in the mid-1950s.

To be continued with the last of the Corsairs: The A-7 Corsair II

[Llarry]

By 1963, the U.S. Navy had realized the limitations of the Douglas A-4 Skyhawk -- an attack plane designed for the delivery of a single nuclear weapon -- and started a competition to replace the A-4 with a more sophisticated attack aircraft. Several companies submitted designs -- all based more or less on then-current aircraft. Ling-Temco-Vought (the former Vought) based their design on the F-8 Crusader fighter, but shortened considerably so more could fit on crowded carrier decks, given much more load-carrying ability and a more fuel-efficient turbofan engine. The result was the A-7 Corsair II. (Given all those Corsairs that had come before, a more accurate name would have been the Corsair IV or so.) The official name of an aircraft is rarely used by the crews; the metamorphosis from the long, sleek F-8 to the stubby A-7 resulted in the irreverent common nickname of SLUF (Short little ugly f###er).

The A-7A first flew in 1965 with the Vietnam conflict already underway. The first attack squadron got their A-7As in 1967 and went into action over Vietnam late that year.

The A-7A and the next model, the slightly improved A-7B, were powered by a Pratt & Whitney TF30 turbofan and encountered some difficulties with their first-generation military turbofan engines. But they saw intensive combat over Vietnam and proved to be attack workhorses. The Marine Corps looked at the cost per aircraft and decided to stick with the tried-and-true A-4 Skyhawk.

The U.S. Air Force, previously enamored with large Mach 2 tactical aircraft, had discovered the advantages of a lower-performance attack airplane by using ex-Navy A-1 Skyraiders in Vietnam and decided to buy a version of the Navy A-7. But they replaced the not-altogether satisfactory P&W TF30 with a Rolls-Royce Spey turbofan built by Allison as the TF41; this solved some of the problems with the earlier A-7s. The resulting USAF A-7D (and some two-seat A-7Ks) served the Air Force well for some years into the 1990s.

The Navy adopted the TF41 for the next version of the A-7; the A-7E, which was built in larger numbers and ended up serving into the 1990s as well. The Navy bought a few two-seaters as well. The A-7E had greatly improved radar and electronic systems for improved weapon accuracy and earlier twin 20mm conventional cannon were replaced by a 20mm Vulcan cannon.

By the 1980s, the fighter/attack F/A-18 Hornet was replacing the A-7s on the Navy side, while the Air Force was adopting the Fairchild A-10 Warthog for the (relatively) low-and-slow attack mission. The final A-7s were retired from service in the Navy Reserves and the Air National Guard in the late 1990s, but not before playing a minor role in the Gulf War of 1991.

https://en.wikipedia.org/LTV_A-7_Corsair_II

[Llarry]

I've mentioned the competition between Grumman's F6F Hellcat and Vought's F4U Corsair a number of times. Vought's fighter flew earlier than Grumman's but had teething issues; the two saw combat at about the same time in 1943 -- the F4U land-based mostly with the Marines and the F6F mostly carrier-based with the Navy.

So let me compare the two as of 1943-44. They were powered by essentially the same R-2800 engine with a slight difference in carburetors and had the same power output. Their weight was about the same. The differences:
-- In the F6F, the fuel tank was located directly under the cockpit, making the fuselage a bit more portly. The F4U had the fuel tank in front of the cockpit, which contributed to the "hog nose" appearance of the aircraft and didn't help the pilot's view during landing. The slimmer F4U had slightly less drag than the fatter F6F.
-- The gull wing of the F4U also slightly reduced drag at the junction of the fuselage and wing.
-- The above two factors gave the F4U a slight advantage in speed.
-- On the carrier suitability front, the F6F had the advantage of a slightly larger wing area (again, though, more drag) which, coupled with the airfoil chosen, gave the Hellcat a reputation as a sweetheart in the low speed arena, important for a carrier fighter. The F4U was a more demanding plane to fly in the landing pattern, with a wing drop at low speed (soon fixed) and worse visibility over the nose.
-- In the specialty roles of camera-equipped photo fighter and radar-equipped night fighter, the Hellcat had the advantage. It took Vought until after the war to finally engineer a photo Corsair. In 1945 some carriers had all F4U fighters but retained small numbers of F6F-5P photo aircraft and F6F-5N night fighters. Advantage Hellcat until the late 1940s.
-- Weapons: Both planes started out with six .50 machine guns, but some later Corsairs were fitted with four 20mm cannon. The only cannon-armed Hellcats were later production night fighters, which had two 20mm cannon and four .50s. The Hellcat frequently carried a 150-gallon external fuel tank on the centerline and could carry a bomb or a smaller 100-gallon fuel tank on the inner wing racks, although three external tanks was unusual. The Corsair carried external fuel or bombs on the belly: 1-3 fuel tanks or 1-2 bombs.

My conclusion is that the aircraft were close to equal with a slight advantage to the Corsair. In 1942-44, the Navy and Marine Corps were turning out fighter pilots as fast as possible and those novice pilots could master the Hellcat more easily, which was an F6F advantage.

Post-World War II, there is no argument. F6F development ceased in 1944 and production ended upon the end of the war, whereas F4U development and production continued for years after the war's end. The Corsair was the last piston engine fighter to serve the Navy and Marines into the early jet era.

Both these airplanes and their pilots made magnificent contributions to the war effort in World War II, as did the Vought and Grumman plants in New York that turned them out by the thousands using workers (many women) who had never touched an airplane before the war.

[Llarry]

Now we have C-130Js replacing older C-130Js.

The Royal Australian Air Force is planning to replace their existing dozen C-130J-30s with <drum roll please> twenty new C-130J-30s from 2027. Their current batch dates from 1999. Australia is really on a roll with defence expenditures lately: Eight planned nuclear attack submarines, F-35s, etc. Good on you, mate!

[Lady Jane]

Originally Posted by Llarry

Now we have C-130Js replacing older C-130Js.

You can't go wrong with a Herc. The new models might be fitted with an eight blade prop and updated avionics and flight controls.

[Llarry]

Originally Posted by Lady Jane

You can't go wrong with a Herc. The new models might be fitted with an eight blade prop and updated avionics and flight controls.

Yes, indeed. Actually the eight-blade is the retrofit for the older Hercs. The Js have a six-blade prop. Maybe they should compromise and go with seven.

One question about the extraordinary longevity of the -130 is what designation will be used for a next-generation Herc if there is one. The C-130 alphabet is just about used up; I think the only letters left are Y and Z.

[Llarry]

A quick intro to the early development of dive bombing in the U.S. Navy.

Early biplanes of wood construction were simply not strong enough to withstand the g-forces encountered when dropping a bomb and pulling out of a steep dive. As aircraft transitioned to metal construction, experiments started with steep dives (70 degrees or even more) which offered greatly improved accuracy over level bombing of a twisting and turning enemy target ship. And steep dives also complicated the enemy's efforts to shoot down the bomber. Not a few aviators lost their lives in these early bombing tests as airplane structures failed under the enormous stresses.

Not until the 1930s was dive bombing a practicality. Some of the early dive bombers were the Curtiss F11C-2 Hawks, which in slightly modified form became the BFC-2 in a new bomber-fighter class. These could drop a 500-pound bomb and successfully pull out of the dive.

It was also necessary to develop a means to prevent one's own bomb from hitting the propellor in a steep dive and a bomb displacement crutch was developed for this purpose. (The German Junkers Ju87 Stuka used a similar device.)

Other early dive bombers included the Curtiss SBC Helldiver -- the last combat biplane in U.S. service -- and the first monoplane scout bomber, the Vought SB2U Vindicator. Both these types continued in service in the early days of World War II. The SBC never saw actual combat and the SB2U proved woefully inadequate in the early battles.

Another prewar dive bomber was the Northrop BT (B = Bomber, T = Northrop) which morphed into the excellent Douglas SBD Dauntless which performed so well at the battle of Midway in June of 1942. (Northrop was bought out by Douglas.)

Another issue of the time was the size of the bomb. Early dive bombers could carry a quarter-ton bomb but that was really insufficient to deliver a mortal blow to an armored combat ship. I believe the SB2U was the first to be able to use a half-ton bomb. By war's end, the later SB2C Helldiver could deliver a 1600-pound armor-piercing bomb and post war the AD Skyraider could carry a one-ton weapon.

The SBD, SB2C and AD are beyond the scope of this post and so not pictured, except for the illustration of the SBD's bomb displacement crutch in use.

Note that virtually all of these aircraft were used as scouts as well. Photos frequently show an auxiliary fuel tank where the bomb would be carried on a dive bombing sortie.

By this time, I think those that have followed my naval aviation posts from the beginning probably qualify for at least an associate's degree in naval air history.

[Llarry]

I remember flybigjet stating that the C-17 was first in the swimsuit competition but check out this photo. Kind of a big-boned (fat?) competitor, yes?

[flybigjet]

Originally Posted by Llarry

I remember flybigjet stating that the C-17 was first in the swimsuit competition but check out this photo. Kind of a big-boned (fat?) competitor, yes?

"First in the swimsuit competition, last in the talent show" was the phrase.

But, you have to go apples to apples (i.e. airlifter to airlifter)-- I don't think anyone's ever really called a trash hauler a "sexy beast".

So, I meant comparing the C-17, C-5, C-130 and C-141 (which now is retired).

R.