Nakajima Ki-84 Hayate Frank Pt. 3 SPEED!

[@Madkite]

A Christmas present to watch.

[@ironteacup2569]

My exact thoughts

[@darrenmoore7779]

The gift that keeps on giving, thanks Greg 🏴󠁧󠁢󠁥󠁮󠁧󠁿🇺🇸

[@kracerx]

In regard to the Spitfire vs Ki-84, there do appear to have been a few encounters with the Spitfire VIII in Burma, based on Chris Shores research. As far as the P-51D, the 7th AF units on Iwo Jima used 115/145 grade fuel per Jim Tapp, a pilot with the 15th FG. There is also some mention of them using 81” of manifold pressure (similar to the RAF +25lbs setting) to get their overloaded Mustangs off the short island runway. So most of the Mustang escorts over Japan were probably running the higher boost settings. There are also some records of encounters with P-38Ls in the Philippines and over Formosa and Indochina, so that’s another potential comparison. Great stuff - love to see these new details about the Japanese planes that most of us know so little about.

[@demetridar506]

McGuire and another super ace were bagged by a single Ki-84 over the Philippines, flying P-38L's. The third and fourth P-38's were saved by cloud cover.

[@givenfirstnamefamilyfirstn3935]

Was 150 octane fuel available in Australia or Burma?

[@rokuth]

Not to mention RAAF fighter squadrons flying MkVIII Spitfires in and around New Guinea.

[@Splattle101]

@@rokuth Unfortunately, the RAAF squadrons got very little air to air combat after early 1944, not long after they got their MkVIIIs. They were relegated to mopping-up ops, and it was one of the reasons for the so-called mutiny.

[@Splattle101]

There were a few RAF squadrons of Spitfire VIIIs in Burma. At a glance I can see photographic evidence for squadron Nos. 155, 136 & 607 operating MkVIIIs in Burma and I presume there were more. I don't know anything about encounters with Ki-84s, but if they were present in the theatre a clash would seem likely enough.

[@commandplay]

This series was well researched and I applaud you for this analysis of the Ki-84. Besides the A6M zero, Japanese WW2 planes are not looked into that much.

[@TP-ie3hj]

Takes 19 min, but he gets around to it, The Thunderbolt , best fighter of WW2 hands down.

[@SkinkUA]

Babe, wake up, new Greg video just dropped

[@icewaterslim7260]

@@SkinkUA Lol

[@cannonfodder4376]

Never knew that the IJN fuel was of higher octane rating than the IJAAF fuels. Learn lots new with every video. Most informative as always Greg.

[@marckyle5895]

Can't have that Sakae radial hiccuping as your A6m3 put-putts at 150 knots for four hours from Rabaul to Guadacanal, can we? Then 15 minutes of combat at WEP and then returning while sweating out the fuel remaining... You want the best gas you can get!

[@fazole]

@@marckyle5895 Good point and accurate! The A6m3 was the "Hamp" version and it had shorter wings for more speed and faster roll but less fuel! Right when the IJN air arm decided to require shorter range interceptors is exactly when they required long range fighters.

[@fazole]

I think I read an article in Air Force Magazine which was written by a radar operator who was on Okinawa in 1945. He stated the Frank was so fast, they wouldn't even bother to scramble P-51s as they couldn't catch them. His quote was "forget it, it's a Frank", as I recall. Great analysis!

[@wrathofatlantis2316]

All Ki-84 units had their own special octane fuel, I think 92, so there was no "Army" fuel octane... I don't know if this applied to all Army fighters, but it might have, as the Japanese pilots preferred the Ki-43 all the way to the end, not because of its reliability but because of its turn performance (14-15 seconds), despite this being already good (17 seconds to the left, 20 seconds to the right) in the Ki-84.

[@justcarcrazy]

I thought it was my crappy internet that put the charts out of sync with the sound. Thanks for the quick fix, and thanks as always for quality research and presentation.

[@bryangrote8781]

Thanks for bringing us the best video anywhere of what is probably one of the most anticipated and desired fighter match ups on the net. And Merry Christmas!

[@keithplymale2374]

In the F4U the tail planes are behind the rudder, In the P-47 the tail planes are even with the rudder, in the Ki-84 the tail planes are in front of the rudder. Greg I think you mentioned the why of this before. Can you cover that a bit more at some point? Not a car person sorry but the aircraft deep dives are always illuminating. Thanks for what you do.

[@icewaterslim7260]

Started with the A6M I believe. The rudder is clear to maneuver that way. It's probably what makes the Zeke's Hineri Komi reportedly the best of them. (The maneuver was practiced before the A5M was operational I believe.) Saburu Sakai mentions the tail arrangement and manuever in one of his interviews on KZbin.

[@gordonwallin2368]

I like Japanese motorcycles and cars, so as a pilot-a Spitfire worshiper-( when I see pictures of the English coutryside, I'm always imagine to be in a Spitfire) This was a great treat Greg. Thanks, Merry Christmas, and Cheers from the Pacific West Coast of Canada.

[@paulstoddart7412]

This is an excellent analysis of a subject complicated by the fact that several of the performance figures available are not fully specified. It is entirely on line with Greg's other presentations: very well researched, very clearly explained, very well illustrated, very interesting, and very usefully filling serious gaps in our knowledge.

[@stevemadak6255]

@7:20 I've heard(have you?) that in the Pacific as well as Europe after the war ended it took quite some time to get everyone back home. This led to pilots and mechanics and all the staffs there with them to have time to do stuff they might not do during wartime. I think this led to a lot of tests like this taking place. " Hey we aint got much else to do, lets rebuild this Hayate and see what she can do"

[@icewaterslim7260]

The TAIU tests of the Ki84 took place in the states. But I'll bet that was a fun duty to be working with them no matter what your specific job was. I'm thinking they'd take advantage of any opportunity to take their time until the powers that be said: "Y'all gonna make a career out of this or what?"

[@Jagdtyger2A]

I really liked the math you presented in this video. It allowed me to estimate the perfosmance of a P-39 modified to use a 3000 hp Napier Saber or Rolls Royce Griffon power plant

[@GregsAirplanesandAutomobiles]

Thanks Steven, you don't know how rarely I get a comment like this. Usually, it's "I hate the math". In fact a lot of people skip that entire part or exit the video at that point which creates a real quandary for me. Do I back up what I'm saying with the actual math? Or should I just put up the answers and expect people to take my word for it? I'm going to lean towards showing the math.

[@StabyMcStabsFace]

@@GregsAirplanesandAutomobiles It's super appreciated. I'm rewatching the video, a 2nd time today, just to make sure I'm understanding the math.

[@prycenewberg3976]

​@@GregsAirplanesandAutomobiles (Old comment, I know) Please don't ever withhold the math. It is greatly appreciated.

[@r.u.s.e3586]

@@GregsAirplanesandAutomobiles I know this video is very old, but personally I love this stuff!

[@BoomVang]

The ungainly looking p-47 keeps shining more and more in this channel.

[@billballbuster7186]

Great presentation as usual. I don't know if the Ki-84 got to South East Asia, but it would have been interesting to see a comparison with RAF Spitfire MkVIII and Griffon Spitfire MkXIVe used 1944-45.

[@demetridar506]

The Ki-84 did go to south east Asia. Apparently, it never got into a direct scramble with Spitfire VIIIs. They were used in hit and run fighter bomber, and Spitfire VIII's tried to catch them, but at low altitude the Ki-84's would out run them without a fight. The orders to the Ki-84 pilots were to avoid engagements. Funny, the Ki-43III's that accompanied the Ki-84's had to deal with the angry Spitfire VIII's, because unlike their big brother, they could not outrun the VIII's. On an interesting side note, the experienced Ki-43 pilots considered the Spitfire VIII as their only worthy opponent, since this was the only allied fighter plane that could really "mix it in" with them. Obviously, the VIII's could not really out turn the Ki-43 in an extended turning fight, but unlike other allied fighters, they could "walk away" upwards at the low speed dogfight and escape when in trouble. However, many Spitfire pilots (especially of the V mark) got carried away and paid the price. On another side note, there is a very famous engagement in Burma where Ki-43's made a surprise attack on a forward base of Spitfire VIII's. Two of them managed to take off, and one shot down. It was a miracle that the other survived. No allied fighter could have fought the Ki-43's at low altitude with no altitude advantage other than the VIII, and even that was barely. My guess is that there were several inexperienced pilots on the Japanese side. As for the Spitfire XIV's, they did not make it on time for the fight. They were held for the European front (only 950 were built) and when that conflict ended, it took time for them to find their way to Burma.

[@TempusFugit1159]

@@demetridar506 The Ki-43 was not to be taken lightly, it had extremely fast acceleration. Wing Leader Clive "Killer" Caldwell did much better against Me-109s in his P-40 in North Africa than he did fighting Hayabusas with Spitfires in the defense of Darwin, Australia.

[@demetridar506]

@@TempusFugit1159 Agreed, please look at my other comment that I started. I think that this is a message I am trying to get through to Greg. In his Ki-61 video (which of course in general I liked) Greg said that the Ki-61 pilot was in much better position than in the Ki-43. I did not agree with that statement. The Ki-43 could not protect the Japanese bombers very well, nor attack allied bombers very well, but in close combat, it was unbeatable. The Ki-84 had many of the trades of the Ki-43, but could also defend Japanese bombers, and attack US bombers effectively.

[@countzero7]

Was just about to type that it could face Mk.VIIIs in Burma. Also could they be in Manchuria when Soviets stormed in late in war, facing P-63s, Yak-9s and LA-7s... did quick check and 104th Sentai had Ki-84s in Manchuria when soviets atacked and used them for GA on soviet units.

[@demetridar506]

@@countzero7 I have read nothing about Ki-84s vs. the red airforce. The La-7 could perhaps keep up with acceleration and climb rate with the Ki-84, but there would be no contest in a turning fight. However, that front was not a high priority for Japan, so I doubt there would have been too many experienced pilots stationed there.

[@paulgregg722]

Brilliant as always Greg. I like your pacing and mix of context that helps understanding of what could otherwise be dry technical detail. Instead your videos are the best , most effective, narration on these fascinating aircraft types I’ve ever experienced. If you plan a visit to the UK- be sure to talk to The RAES in advance, with a view to appear as an honoured guest lecturer. You’re up there with the best.

[@kevindolin4315]

Greetings from an expat in Japan with a long-time interest in Japanese aircraft. I hope someday you get around to doing one on the Kawanishi N1K1-J & N1K2-J Shiden (紫電, "Violet Lightning"), code name George. It was originally a floatplane that was turned into a land-based fighter (hence the '-J'). It was to the IJN what the Ki-84 was to the IJA. It was a superb fighter that could more than hold its own with any Allied fighter. However, like the Ki-84, it was too little, too late.

[@andrewjensen7413]

The other differents is the higher RPM limit between the engine type's witch is why the USA test speed of 427 mph over the lower 381 mhp in the Japanese flight settings. Fantastic videos I've watched all parts back to back and it's Great seeing your coverage of the War in the Pacific.👍

[@paladin56]

A fascinating film, Greg. I really appreciate the effort you put in to it. It is really refershing to come across a channel in which the author extensively researches their facts rather than using sensationalism and regurgitation of already well known statistics (many of which turn out to be incorrect but have been cited so often that they have become 'facts'). Keep up your excellent work.

[@heydonray]

Greg, great detail as always. GET WELL SOON sir.

[@elgato9445]

What can I say..the best and most informative aviation content out here. I guess I did say something. Thanks Greg. The thoroughness and time you put into these episodes is greatly appreciated. Happy New Year to you and yours!

[@k9killer221]

One of the strange but very accurate metrics in WWII aircraft is the close correlation between the number of rivets in the plane and the eventual cost. This was told to me by an old aviator and employee of Lockheed.

[@TheHarryMann]

Doesn’t apply to the Mosquito though, does it, a quite expensive aircraft to make, certainly nowadays

[@markfryer9880]

@@TheHarryMann Well when you consider that the Mosquito was literally moulded in two halves and then joined together, in a similar way that plastic model aircraft are put together today, what was once a production advantage becomes a repair and refurbishment nightmare.

[@ellise.2574]

Merry Christmas. Thank you for all your hard work. I always enjoy your posts. I would like to know how the P-38 would compare with the Ki-84, etc. Thanks. Ellis.

[@francisbusa1074]

It's always such a pleasure to learn from your videos, Greg. Seems you always delve into the best and most reliable information available. I've watched your other videos on the Ki-84. I'm glad our pilots didn't have to face more of these fighters, especially in '42.

[@markfryer9880]

Another great video Greg! I am no maths wiz, but I appreciated your efforts to cross check the horsepower of the engines with the stated speeds. I know that you put a hell of a lot of effort into your research of the available documents and at times it certainly feels like the errors contained within the available reports are there to trip up the researcher. So please accept my thanks for showcasing yet another aircraft that is outside the standard handful. Happy New Year to you and your family. Mark from Melbourne Australia

[@Garthbrooks4756]

Thank you for the awesome videos. If you ever have a chance, a video on "energy retention" and "vertical energy fighters" like the 109 f series would be outstanding

[@jeromestern8225]

That's what I call a real cool Christmas present. Thanks and seasons greetings, Greg!

[@rayschoch5882]

A nice Christmas present, Greg. Thanks. VF-19 started its deployment with F6F-3s with water injection, but by the time their combat tour was over, they were flying F6F-5s. I don't know that my Dad ever encountered a Frank while flying with VF-19, though others in the squadron did - and shot them down. Dad was flying an F4U-4 with VBF-150 the last 9 months of the war, in training for the invasion of Japan that never happened, but the Corsair looks a lot better on your graphs going up against the Frank than the Hellcat does. It can't / won't happen, of course, but it would have been interesting to see how Grumman's replacement for the Hellcat - the F8F Bearcat - would have done against the Frank. In any case, well done, as usual. Get well soon, and Happy New Year!

[@chrissteffen6184]

Thank you for your research on aircraft that we don't get many details on

[@charlesrichardson4032]

Merry Christmas thank you for your time and great effort to give us piston engine fix

[@Sturminfantrist]

finaly the 3rd part, thats a Chrismas gift many thx Greg.

[@googoodatte]

It was a very interesting video. I want you to compare how close the propeller tip of a high-speed airplane is to the speed of sound. High rotation and low gear ratio engine, large diameter propellers, and fast maximum speed bring the propeller tip closer to the speed of sound. In Japanese aircraft, the propeller tips of Saiun and Ki-44II exceed the speed of sound. (translated from Japanese by Google.)

[@williammorris584]

Wooo! I got a Greg’s video for Christmas!

[@jiyushugi1085]

Fantastic! Thank you. Love the 'attitude' of the mechanic standing at the wing root of 'his' P-51.

[@jonathanrobinson7573]

Wow. The one military document Greg posted in the video, points out on of the captured Franks was taken to Olmsted Field, PA- which is now the Harrisburg International Airport- not far from me. Wow, to think the rare Ki-84 was in my area at some point in history.

[@SoloRenegade]

isn't there a Ki-84 in Dayton, OH at the USAF museum? Perhaps it's the same airplane?

[@demetridar506]

There is only one Ki-84 left in one piece in the world, it is in the Kamikaze museum in southern Japan, I cannot recall the name of the town.

[@demetridar506]

No, perhaps you refer to the NiJ1. It also used the Homare, but it was not as capable an airplane.

[@jonathanrobinson7573]

The USAF Museum in Dayton, Ohio, definitely has a Japanese “George” fighter. I doubt it has a Ki-84. When I visited back in 2008, the George- which was a bit massive of the Japanese fighter- was parked next to the Enola Gay B-29.

[@icewaterslim7260]

​​@@demetridar506That is the Frank captured at Clark Field, the better example of the rebuild mentioned. I know it was from Clark Field by the "Aero" publication which I own. It was repatriated to Japan in about 1960, was demonstrated in an airshow in Japan ( there is a video on my channel) then parts were stolen from it and it remains on static display in some museum in Japan as the only known surviving example as you said.

[@jameslecka8085]

Great! I always wondered about the power to speed law for aircraft. 9:54 formula: [ (high speed hp / low speed hp) . take cube root . Multiply by the low speed mph = new high speed mph.] Makes general sense to me- you have to move a cubic volume of air out of the way, in a smaller unit time. This also matches in a general way to the observation that it takes a lot of increased hp for rather modest speed increases. I once asked a Skunk Works engineer. After hemming and hawing, and asking me why I wanted to know, he said "don't quote me but approximately cube law at less than mach." I explained that I was comparing it to ship design at less than hull speed, which is square law. Example for ships. Assume [shp = shaft horse power] 40 knots for 80,000 shp then 20 knots for 20,000 shp then 10 knots for 5000 shp then 5 knots for 2500 shp then 2.5 knots for 1250 shp the formula breaks down at about 3 knots or less. Notice that 1250 shp puts you in range of large outboard motors, ( or even sails, in some cases). Testing my understanding: ( low speed 80, hp 100),( hi speed =x, hp = 2700); 2700 / 100 = 27; cube root 27 = 3; 3 * 80 i = 240 speed high speed at hp = 2700. ??? This is an early biplane assuming NO changes to gross weight, air frame, balance, etc. So a bloody lot of hp to get to a mere 240 mph.

[@jeffussery4884]

I was aware of the Ki-84 Frank I never was aware of it's abilities. Sounds like if Japan had well built Franks in numbers. They would have given us a real bad time. Thanks for what you do, Merry Christmas, and Happy New Year.

[@dobridjordje]

They built roughly 3500 of them but the factories were pretty much devastated and lots hayates were built very poorly, but those that were built well and had amazing pilots, they were a force to be reckoned with for any US fighter during 44/45.

[@M80Ball]

@@dobridjordje 3500 is nothing.

[@AtomicBabel]

As materials got more scares, steel and wood started to replace sections of the wings and fuselage. Weight went up, performance dropped and quality .... well.

[@fafner1]

The Japanese were not only out of aircraft, they were out of fuel and out of pilots. The U.S. Navy had a surplus of pilots, courtesy of a ramp up of flight training after the heavy losses at Coral Sea and Midway, and was building aircraft like the F8F BEarcat and F2G Super Corsair if they were required.

[@dphalanx7465]

@@fafner1 Actually, if you read the book "Downfall" by Richard Frank (written 1999) he points out that the Japanese were actually "holding back" aircraft for the expected Invasion of Japan (which was beleived to be coming sometime after Aug. of '45.) Numbers were thought to be just ovrer 3000---with the required fuel to fly them. Which would have allowed the Japanese to seriously challenge Allied air superiority over the invasion beaches. For the first couple weeks, at least.

[@neurofiedyamato8763]

Excellent video as always. There is nothing else like this anywhere on youtube

[@dukecraig2402]

Merry Christmas Greg. I'll be saving this for tomorrow morning like a Christmas gift. Happy Holidays and all the best to you and your's.

[@HarryVoyager]

Trying out Flying Iron's F6F in MSFS has been a revelation. Just flying it an navigating it makes it extremely clear the first design priority was making the naval aviator's life easier and getting them there and back again in one piece. All out performance was a secondary consideration to consistency. I really get why so many of its pilots loved it, despite its raw numbers not being all that. Sort of the naval equivalent of the 190.

[@muskepticsometimes9133]

F6f had lowest top speed of any r2800 fighter But had huge impact in Pacific.

[@gt_grandtouring]

You keep outdoing yourself Greg on the videos. Info we didn't even know we wanted to know until you put it out there. Keep up the great work and Merry Christmas!

[@964cuplove]

Thx for this video, a happy Christmas and all the best for the new year !!

[@marcosfernandez7207]

Thank you for the Christmas gift, Greg!!! Very nice video, waiting for the next one on turning performance!!!! Kind regards from Brazil!!!

[@alairlibreinsfreie5785]

merry christmas to you and your family. thanks a lot for the highly interesting, well researched videos.

[@chrischiampo7647]

Merry Christmas Greg 😀😊😀❤️😀😊👍🏼

[@Ebergerud]

Good video on a very good looking IJAAF fighter. There was one in the online WWII Sim Aces High: decent bird, but the wings could collapse if you went into a steep dive. I'm not sure how many fighter engagements there were with US planes, but those used for home defense I think would have run into Mustangs most often - there were a lot of them after Iwo was taken. Methinks the KI-84 would have run into 5th AF P-38Ls. The IJAAF had a very large force on Luzon when the Leyte landings were made in October 1944. As was normal, the Japanese did not sink or damage very many ships but they launched enough attacks to scare the Americans. (Ironically, the huge US fleet gathered for the Leyte landings had largely dispersed because of these air attacks a couple of days before the Japanese Fleet arrived for the slugfest at Leyte Gulf. So even if the IJN had done better at Samar, pickings would have been pretty slim off the Leyte beaches - and had they gone there, every Japanese ship would have been sunk by Halsey's returning CVs and the arming of the other CVEs with torpedoes for their Avengers. Anyway, FEAF (figure 5th Air Force) set up a fighter base at Tacloban on Leyte where the experienced fighter jockeys of the famous fighter groups got their last chance to shoot at Japanese aircraft. Tacloban could not have held many planes but the IJAAF did keep some planes operating in the Clark Field area for several weeks before all that could left for Japan. I'd guess the 38s would have done very well - the pilot quality was so radically on the American side, that any US fighter would have prevailed normally.

[@icewaterslim7260]

It appears Takeo Doi's Ki 61 and the resulting Ki100 are the divers in the Japanese line with three spars in each side of the wing. I don't know if the middle one is continuous or not. Or the others for that matter. Reading pilots combat accounts seems to indicate that when the wing begins to flutter pulling out of dives is when they come apart. I've never heard about the dive restriction on the Ki 84 but Greg did mention a restriction on snap rolls in the Frank's pilot manual. Saburu Sakai said there was a dive speed restriction in the A6M manual.

[@icewaterslim7260]

One interesting thing about Thomas McGuire's reported crashing on Negros Island in the Philippines, was the discrepancy that was revealed after declassification of the two surviving P38 Pilots after action reports. One said that McGuire crashed with his drop tanks on while attempting to save one of his formation from a Ki43 III on his tail. The other report was classed as missing but I guess they referenced their commander's summary. It said that McGuire went down "due to enemy action". The Ki 84 that shot down McGuire's third wingman was said in the official version to have shown up after McGuire's crash. But the organization that documents and sometimes recovers Pacific wrecks found a 20mm fragment of an HEI round in McGuire's wreckage. Seems there were 3 types of HEI ordinance for the HO5 cannon that equipped the Ki 84. No variant of operational Ki43 used any cannon. Both IJA pilots were instructors with a great many hours in their respective aircraft and both were combat veterans. The Ki 43 pilot was killed by Philippine Guerrillas upon crash landing his damaged aircraft. The Ki 84 pilot was credited in the reports with shooting down Major Jack Rittemayor who was seeking a 5th kill. Whatever happened it sounds like another case of someone competing in the "Ace Race" either getting surprised or just taking risks outside his aircraft's performance envelope.

[@Jareers-ef8hp]

I can’t wait for part 4 🎉

[@MichaelLlaneza]

Good stuff Greg, keep it coming, especially the deep dives.

[@martinryan2370]

Brilliant work really detailed study. Take care 👍

[@sadwingsraging3044]

**statistical math** 🤯 **speed at altitude chart** NOW we're talking!🤩 Wish there had been a Lightning in that comparison.😔

[@WildBillCox13]

Hi Greg. Great content. USAAF/USN ground crews +2 in all environments (+1 Training, +1 Logistical advantage) IJN/IJA ground crews -1 in all environments (-1 Logistical disadvantage) It appears that both Germany and Japan felt the pressure of the strategic bombing campaign and naval blockade. This is best illustrated by the exigencies forced upon both Axis partners in terms of alloys and quality of fuels. This is despite the almost perfect lack of accuracy demonstrated by Allied bomber streams. Bombing from high altitude, few bombs fell within a kilometer of target. Bombing from low altitude increased accuracy to roughly 300m CEP, but brought bombers within range of enemy FlaK and low/mid altitude interceptors. This was less of an issue against Japan, where the lack of industry severely limited production of any and all artillery, armor, aircraft, and ships. B29s suffered from heavy attrition-not so much due to enemy action, but an artifact of operational losses due to engine fires and other failures/infarctions. In effect, we killed more bomber crews than the Japanese did. In balance, hasty production and nasty/hasty solutions to otherwise insurmountable problems probably killed almost as many IJN/IJA pilots in the late war as Allies gunnery did. Total War sucks*. *Unless you're Ford or Krupp or the Uralmash Zavod. Or Sony. Sony's is a story worth reading. Worst rice cooker ever . . . and it saved the Japanese economy.

[@wauweau]

You should make a video on the different air wars of each theater of ww2! The western front, the eastern front, and the pacific, as well as how the circumstances of each theater affected how aircraft were designed

[@TempusFugit1159]

Hi Greg, I came across something interesting when looking at the Wright Field T-2 Report on Frank 1, released Nov. 1946. Page 2 of the report gives detailed data on speeds and climb rates at various altitudes. However Page 8 describing the actual flight test states "Climb seems very good, NO performance climbs were attempted due to flying time restrictions." When describing handling and response at various speeds there is NO speed mentioned higher than 350 IAS. Not sure why flight time was limited, unless it was due to the amount of time needed to do maintenance on engine and hydraulics! Let me wish you and yours a safe and peaceful Holiday, too.

[@kannony5393]

TAIC didn't do any performance testing unless they specifically indicated it in the report. Everything is calculated. However, they did issue a seperate report that was just on the Homare 21 engine. The report contained detailed benchmarks, measurements, and other data that was obtained through a laborious dissection of the engine and its capabilities. I suspect that they use calculated speeds because it's easier to standardize such data across different airframes because of how variances in how atmospheric pressure, wind, and temperature can make big differences in indicated airspeed. By doing bench tests on engines under controlled conditions, TAIC could generate more useful data for pilots and engineers.

[@TempusFugit1159]

@@kannony5393 My point was that many people are under the impression that the actual test aircraft flew at 427 mph (as Wikipedia and other sources claim). As our good friend Chuck Yeager pointed out in his book, flying a full performance test card on an aircraft is complicated and there is no evidence that they took the time to do it with the Frank.

[@arthurli406]

It would be great if you could look into the Ki 83 's performance. It's a plane that is not much known, but I feel that it would be interesting!

[@libertycosworth8675]

Another great video Greg!

[@KekusMagnus]

I was looking at top-speed and climb-rate graphs for the Ki-84 and even in perfect condition, they seem on the low side given its high power to weight ratio. It has a much smaller propeller diameter than comparable fighters which leads me to believe the propeller on the Ki-84 was undersized and inefficient. There were prototypes with different engine/prop configurations but info on them is very scarce, they make for interesting what-if scenarios It's hard to believe that despite all these limitations, it still gave the best WW2 fighters a serious run for their money. The engineers truly out-did themselves

[@googoodatte]

1:10 There are 3 conversion errors from IAS to TAS in this table. ALT. IAS TAS 3370 502 594 4000 488 591 591 → 597 4900 452 584 584 → 580 5000 454 580 580 → 586 6000 448 610 In the revised table, the speed of altitude 4000m will be faster than the speed of altitude 3370m, so I am confused. I think the speed of 4000m is wrong. And 4000m and 4900m are 1st speed. The rated altitude of the engine is shown in the table of 3:04 , the rising value of the 1st and 2nd rated altitude is too different. 1st. 3370 - 2000 = +1370m 2nd. 6550 - 5700 = +850m I think the 1st rated altitude is 2500m to 2600m correct. Because the pressure difference between altitude 5700m and 6550m is about 60% of the ram pressure when flying at 624km/h at altitude 6550m, but the pressure difference between altitude 3370m and 2000m exceeds the ram pressure when flying at 594km/h at altitude 3370m. So if the rated altitude is 2000m, the manifold pressure of +250mm cannot be maintained at an altitude of 3370m. 3:04 I don't think this graph is correct. The altitude horsepower is calculated from the horsepower measured on the ground, but there is a high possibility that the calculation method was wrong. The only reliable horsepower is the two numbers in the upper right table. Rated S.L. Hp. are a measurement value, so I can trust them. But Rated Altitude and Rated Hp. @Rated Alt. are calculated value, so I can't trust them. 2:15 In Japan, the boost pressure of take-off horsepower was not used except for take-off. However, at the end of the war, it was allowed to use it for a short time, following the emergency war power of the United States.

[@chuckdegoal3264]

Great stuff! Merry Christmas!

[@jaym8027]

Merry Christmas Greg, and thank you for another great video. Reading some of the comments, I don't know how you suffer some of these fools so gladly. Good luck and God Bless you and your family in the New Year.

[@GregsAirplanesandAutomobiles]

Thanks Jay. I try to stay patient and not just bring out the ban hammer, but it's hard sometimes.

[@muskepticsometimes9133]

wow that P47 November is a monster, esp at high altitude.

[@GregsAirplanesandAutomobiles]

It really is.

[@williamromine5715]

@@GregsAirplanesandAutomobiles The P47 was one hell of a plane. It didn't get the publicity of the Spitfire and Mustang because it wasn't as pretty. Kind of like the B24 and B17. Thank you for your efforts in producing these videos, especially this one on Christmas Eve here in the USA. Have a Happy and Prosperous New Year. (Didn't know you are ill, hope it's not serious.)

[@yoseipilot]

@@GregsAirplanesandAutomobiles There’s is any version from Ki-84 that was not built yet, especially like with Turbocharger and even 2.500 hp engine but both doesn’t exist. And I wonder what would have speed and range then?

[@PaulieLDP]

Loving this Ki-84 series, very interesting.

[@isolinear9836]

Merry Christmas to your and your family, Greg.

[@beachboy0505]

Excellent video 📹 The only American 🇺🇸 person who says good things about late war Japanese fighter planes.

[@givenfirstnamefamilyfirstn3935]

The B-29 crews took them very seriously. Bombing at night at medium altitude they were vulnerable.

[@X8X8X8X8X8X8X8X8X8X]

Merry Christmas, Greg!

[@Colt45hatchback]

Excellent video as always, thanks for the Christmas gift, hope you have a great one Greg (shakes hand)

[@hugo8851]

Could you please make a similar video of the Kawanishi N1k2? There is a lot of debate about the real speed of that fighter.

[@ogaugeclockwork4407]

Ki-84 Christmas video! Thanks!!

[@neoconshooter]

My uncle told me that they used both 115-150 grade fuel and ADI injection in very late war Mustangs with "Dash nine" engines from Iwo Jima to Japan. He should know since he flew them. Not a ask for performance charting, just Info. PS. My other uncle was an Ace in his P-38 and claimed that with the 1800 HP engines, he could out fly anything. Do not know how much of that is bravado and how much is just my faulty memory? Love all your vids! Yours is the only one I can afford to support. Vets Comp VS Inflation!

[@GregsAirplanesandAutomobiles]

Hi Stewart. The P-51H Mustang did in fact use ADI. However it never saw combat. All other P-51s ran without it.

[@SearTrip]

Merry Christmas to everyone and as a gift for the algorithm.

[@rudywoodcraft9553]

Very interesting series on the Frank!

[@richardlincoln8438]

Merry Christmas and a Happy New Year to You, Your Family and Friends Greg.

[@fredsalfa]

My dad flew P51Ds near the end of the war. He said there were no more Japanese planes left in the sky in 1945. But if he had met a Frank he would have been in for a match

[@steveproctor1748]

The Ki 84 was a beautiful fighter airplane.

[@ottovangogh9477]

At last! Greg offers a Frank Discussion! Frankly speaking... 🤣🤯🏴‍☠️🔧🤣

[@tekboyg]

Amazing content as always! Wishing you a healthy, happy Christmas season!

[@mryhdy6266]

00

[@charlesmitz5239]

Merry Christmas to you and yours Greg

[@Token_Civilian]

👍👍👍👍👍👍👍👍👍👍 - Great stuff. Loving these vids on the Frank.

[@peterconnan5631]

Merry Christmas Greg!

[@davidbatinich1528]

The same thing happened with US testing of captured. George's(Inflated US testing for various reasons) I E higher speeds , climb rates etc etc

[@kenneth9874]

Various reasons being build quality and better fuel....

[@Punisher9419]

I wander what happened to the rebuilt Ki-84?

[@GregsAirplanesandAutomobiles]

I think there were two, one was crashed, I think the other is in Japan, but I'm not sure about that.

[@Punisher9419]

@@GregsAirplanesandAutomobiles Shame it crashed. At least one survived. Considering there where thousands of these built there would still be a lot around today but I guess a lot where destroyed and scrapped. Should really make a policy of keeping a few examples of everything and just leave them in a nice storage facility.

[@dphalanx7465]

Your guess on post-war testing of the Hayate is correct. I have read that the tested Hayate had a cleaned-up engine with _American_ replacement sparkplugs, as well as 115-octane US gas. Standard wartime Japanese gas was in the high-80s for octane rating (low-90s for special test flights). According to some sources, the Hayate with those "power-ups" out-flew a P-51D, LOL!

[@GregsAirplanesandAutomobiles]

No, it was tested with US 96 octane fuel. They didn't say it out flew the 51, but it's performance was comparable in some areas, and even superior in a few.

[@FiveCentsPlease]

@@GregsAirplanesandAutomobiles The Allies had captured stocks of German and Japanese aviation fuel. I suspect they tested captured aircraft with both for comparison, but I'd have to read the test documents. (Also the Germans saved fuel out of crashed Allied aircraft for lab analysis and for flying captured examples.)

[@dphalanx7465]

@@GregsAirplanesandAutomobiles Thanks for the info; I had heard that it used the same fuel that standard fighters got, hence the assumption.

[@dragonflyfx6968]

I know data is very limited if non but I'll love to see A7M in future videos

[@apfelsnutz]

Haven't seen the video but i'm sure the manuverability would go to the Ki-84. However, being a pilot I would worry about strength at speed, and I'm sure this would be a problem. Thank you very much, i certainly love the Ki-84 and would have no problem fighting in it...

[@givenfirstnamefamilyfirstn3935]

Gosh you are very dedicated to the late Emperor Hirohito and The Greater East Asia Co-Prosperity Sphere! Unfortunately you have missed all the actual fighting, perhaps you could do some voluntary work for Japanese charities or your local Japanese Embassy or Consulate? Is this an _Axis_ thing?

[@jamesjanssen8252]

@@givenfirstnamefamilyfirstn3935 what the heck!!! 😳

[@scottgiles7546]

Going to try asking early so Greg might see it. How fast could a propeller driven aircraft go? Not a WWII aircraft with their straight wings and ICE engines but one that could be a clean sheet design with current airframe knowledge and with turboprop power where 5K-10K HP seems common? Certainly someone has researched this.

[@kenneth9874]

With a prop aircraft you get to a point of diminished returns rather quickly, Greg has a bit to say on the subject, I believe it's in a video comparing hp to thrust

[@davidellis2021]

The TU-95 can go over 600 mph. It's also very noisy.

[@kiwidiesel]

Regardless of power it all comes down to using that power and the tool that does this is the propeller. The more power you have the larger the propeller needs to be. You can't spin a propeller any faster than they have been since WW2 because after a point the tips of the propellers exceed the speed of sound, at this point the thrust from that propeller drops drastically. That leaves you with propeller blade length, chord and number of them. That then leads into things like the corsair faced with propeller clearance against the ground and there is the can of worms you open after that, bigger propeller means bigger plane means more power needed etc. The current Beechcraft T6 Texans and the like are a good example of what you can do with modern practices and small gas turbine engines in a light frame.

[@scottgiles7546]

Did a bit of a search and found this. It's an old NASA document, from 1980 and that's old even for me, about high speed turboprops. While planning on reading it through I am still in the early pages. It's focus is on extending the MACH number turboprops can efficiently operate as they are more efficient at lower speeds than fan jets. They quickly bring up MACH.8, which translated to about 593 mph (if you trust the internet). Well. it's a start. ntrs.nasa.gov/api/citations/19800012800/downloads/19800012800.pdf

[@paulslevinsky580]

Very interesting!!! It would be nice to know which aircraft bleeds less energy when turning at altitude. The Jug is faaast, but can it turn with so much all-up weight?

[@jamespinkerton7534]

How fast was a Frank? Fast enough to be really hard to catch.

[@demetridar506]

And fast enough to be hard to run away from it!

[@4toes1nose]

Thank you

[@p99t0013]

Really disappointed that you didn't include the P-38J or L. These would be a very common opponent of the Ki-84.

[@rickriede2166]

@ Greg's Airplanes and Automobiles. We see a lot of emphasis put on absolute speed in comparing combat aircraft. I'm curios. Strictly speaking, as a non pilot. How important is that factor in real combat situations relative to say climb rate, max dive speed and acceleration? Ps I'd be happy to wait for the full video. Thx and Seasons Greetings.

[@GregsAirplanesandAutomobiles]

Hi Rick, a lot of those other factors are in the next video. No single performance factor will make a good fighter plane.

[@js14a]

Pierre Clostermann reported an engagement with a Do335 while piloting his Hawker Tempest V. Despite being in one of the fastest aircraft of the war at low level, Clostermann couldn't catch the Dornier, because of its superior speed. Had he caught up to it, the Tempest would likely have have made quick work of the Dornier, which was inferior in most if not all other performance measures.

[@givenfirstnamefamilyfirstn3935]

@@js14a Pierre only broke the throttle gate limit-wire once in his Tempest, he couldn’t lose 3 FW190s on his tail so he more or less sacrificed his engine to get clean away. The Dornier pilot might have had the same idea, ….. especially with a tail propellor and the deadly cockpit jettison handles (German mountaineer joke ‘look no Hans’).

[@calebfogler2145]

Merry Christmas!

[@sebekglab]

Merry Christmas🎄🎄🎄🎄

[@aurosan750AU]

when the americans had recognized the speed abilities of Hayate in the late time of pacific war they often did not scramble when some or a Single Ki84 came in for reconnaisance. The common speech at the radio was: "Forget it its a frank"

[@davewolfy2906]

Watchable - as usual Interesting - as usual You really are have to go some to raise the average.

[@stephaniem3580]

This is like a total aside. It's great to weigh your channel sticks to its documentary format. A lot of documentary channels. Once they get a little success, it becomes an opportunity for FaceTime for the creator. I'm sure you're very good looking, but I appreciate the fact that you have not evolved your channel into a talk show.

[@jcwoodman5285]

I wonder what became of the blue printed ki 84? Do any ki 84 examples exist today?

[@GregsAirplanesandAutomobiles]

I think there were two, one was crashed and I think the other in in Japan.

[@Colt45hatchback]

I recall watching a video of it post war at a japanese airshow, the story that went along with it was that some wealthy ki84 pilot post war bought it from the americans and used to fly it often and maintain it, then when he got too old to fly or died (i cant remember which) his family donated it to a small museum which did not have space to store it correctly (in the writers words, had no business having such an aircraft) and it was left outside, parts were stolen from it, and it became not airworthy due to corrosion and missing components, if i recall its now stored somewhere else indoors.

[@Colt45hatchback]

kzbin.info/www/bejne/bJ6xhJ-gn9t1bMU heres the link to that ki84 and the story along with it, that channel also has some japanese ace interviews n1k2, g4m, ki43 etc, very good stuff.

[@M.R.0662]

Hi Greg! Compared to the Fw 190 how good was the cockpit of the F4u-4 corsair?

[@GregsAirplanesandAutomobiles]

Hi Matt, I have just the video for you: kzbin.info/www/bejne/n2PEoph3gayKgpo

[@TheHarvHR]

Personally I'm not aware of the F4U-4 having cannons during WWII, I thought that begun with the F4U-4B which was post-war no?

[@khaccanhle1930]

I've read first hand accounts of pilots using -4 corsairs with cannons. One pilot mentions how on one mission, three of his cannons jammed, leaving him only one to fight with. It was not a common fighter, but some were available in 45.

[@givenfirstnamefamilyfirstn3935]

American manufactured Hispanos were out of tolerance until after the war.

[@pac1fic055]

Spoke to a veteran Corsair ww2 pilot some years ago. Mentioned his preference of the 50 cal armed Corsair over the 20 mm cannon version.

[@TheHarvHR]

@@khaccanhle1930 Can you find them? Because I still cannot find any information on cannon armed F4U-4Bs in 1945. As far as I can see the vast majority of -4 went to the Marines, and I haven't found any photographic or memoir evidence of any without the 6 50 cal. Are you sure that account wasn't Korea or referring to the very rare F4U-1C?

[@TheHarvHR]

@@pac1fic055 Yeah, the F4U-1C wasn't particularly popular and suffered issues with the cannons at least for the beginning of its life, but only 200 were made.

[@thomaslubben8559]

Your cube root rule is what I found for published speeds of similar motorcycles. It holds very well there as well, except that I found that the best-fit curve was the 2.8th root, not 3rd root. Since this is empirical, I wonder if you used that, or better yet, plotted known values from a variety of aircraft for which you have similar tests, and fit the plot using a non-linear regression method, whether you might find even better fits between your predicted and actual numbers. After all, there is no reason the fit has to be to an even number root.

[@GregsAirplanesandAutomobiles]

I didn't choose that number at random. Power power required varies as the cube of velocity. Source AFNA page 97. Now I'm sure you're right, in some cases 2.8 or 3.1 will be better for the root, but in all cases I have found with WW2 airplanes using the cube root results in numbers that are within the normal plane to plane, test to test variations.

[@daneshivers2921]

Might be me picking a sore spot, but was the "perfect" Frank armed? Lack of weight might need to be considered, just a thought. Thanks, Dane

[@robdow6348]

My Uncle was P51 pilot in the pacific. He shot down a Frank. Documented in Kearbys Thunderbolts.

[@sakai_2]

And my grandfather, Magome Mitsue was a KI-84 Pilot, shot down 3 mustangs over the Philippines in 1944.