Correct. My understanding, from reading the NACA report and the OTL effects of adding the filleting to the P-38, is that the filleting reduced the sensation of the "tail flutter" and associated instabilities but had no real effect on the mach tuck aka. Compressibility stall.
Yes, the fact that NACA didn't develop the boundary layer scoop (aka NACA Duct or NACA Scoop) until 1945 puts a bit of a nail in the coffin of using one on the early P-38Also, thanks for "streamlining" the booms; those scoops always had me wondering what Johnson was thinking... (Then again, boundary layer scoops didn't exist yet...)
Not likely for the XP-49. The V-3420 was simply too big and heavy for the XP-49. The engine installation and booms would need to be redesigned and the entire airplane would need to be re-balanced to accommodate the massive CoG shift. It is, however, the engine that ended up being used in the XP-58 when it finally flew on...yeah...June 6th, 1944 (it seems a lot happened on that day).
I also wonder if the 3420 would have worked in something like the P-47 or F4U. Of course, the R-4360 Wasp Major that was put in the XP-72 (based on the P-47) was even more power dense (and considerably more powerful) than the V-3420.
It seems odd that both the XP-49 and the XP-58 flew with the same airfoil as the P-38, without the inconvenience of interrupted production schedules being a hindrance.
The original XP-80 flew with jet intakes in boundary air, which created a big booming noise, corrected with a boundary air bleed system. NAA didn't wait for NACA to create a stand-off scoop for ram effect in undisturbed air. The NACA scoop doesn't separate boundary layer air, and doesn't benefit from ram air. It just sucks.
The original XP-80 flew with jet intakes in boundary air, which created a big booming noise, corrected with a boundary air bleed system. NAA didn't wait for NACA to create a stand-off scoop for ram effect in undisturbed air. The NACA scoop doesn't separate boundary layer air, and doesn't benefit from ram air. It just sucks.
There I go again, not considering all the implications...
Yeah, by the time you want it, it stops being competitive. (There were a small number of F2Gs with the R4360 built, at least one with a turbo, which I'd adopt just for sheer coolness.
) An R4360-powered *XP-58 is an interesting WI...but I'm at a loss to imagine what you'd want it for.So the idea wasn't as far down the road as I imagined. (I was actually thinking of the flush-mounted inlets.)
A lot of war-time designs ran into that problem. By the time the bugs were mostly worked out the need was no longer there or Jets were already being developed to supplant them. The XP-73, and the F2G are both good examples as is the F8F.Yeah, by the time you want it, it stops being competitive. (There were a small number of F2Gs with the R4360 built, at least one with a turbo, which I'd adopt just for sheer coolness.
I presume you mean XP-72, not the ephemeral P-73. The P-75 Eagle was one of those late-comers that ran into in-service aircraft that were already there, even with the V-3420.
The new P-38 with the NACA modifications will only have the intercooler fitted in each engine nacelle under the engine. I would think that would provide another opportunity to improve the streamlining as the cooling air intake opening required for the intercooler would I think be smaller than the size of intake needed for the 2 oil coolers on the pre-J version models.
To avoid the OTL problems with the chin mounted intercooler that worked a little too well the new intercooler design would have to provide a wide cooling range from tropical low level flights at high boost to long duration stratospheric -50C flying at fuel saving engine settings and still keep the charge temperature within acceptable limits. What type of cowling design could provide such a large dynamic range from full as possible charge cooling to almost none at all. Would some kind of front flap or door at the nacelle intercooler intake be required to close off the cooling air to the intercooler completely?
To avoid the OTL problems with the chin mounted intercooler that worked a little too well the new intercooler design would have to provide a wide cooling range from tropical low level flights at high boost to long duration stratospheric -50C flying at fuel saving engine settings and still keep the charge temperature within acceptable limits. What type of cowling design could provide such a large dynamic range from full as possible charge cooling to almost none at all. Would some kind of front flap or door at the nacelle intercooler intake be required to close off the cooling air to the intercooler completely?
Indeed. "Fat fingered" as they say.
@Draconis I am looking into the intercooler installations shortly. I was going to put it off until installation of the F5 engines (in the F) or even until after combat experiences in the "G" with the F10 engine but I recently discovered an Acceptance Performance Test for the P-38E (#41-1983) from December of 1941 that already mentions insufficient carburetor air cooling so I am thinking I can justify the exploration of better intercoolers during the F model development in early winter 1942. Most likely, the early models will use the same cowling design as the OTL early P-38's but open the dual ducts into a single. There is also the possibility that the F17 engines or F30 engines may be tested with a redesigned intercooler intake that will meet more of the requirements you mention. Whether or not these improved designs ever see production in TTL is going to largely depend on their complexity and extent of modification needed for the design(s) I come up with.
I've done modifications far beyond what Lockheed would seem to take an inkling in performing, but a separate intercooler in a broader chord outer wing bearing the 66 airfoil seems logical to me, allowing for a larger prestone cooler, with oil coolers untouched. In for a penny...
The mods were performed in Burbank Factory B-6, while the drop-tank stations were being installed. Meanwhile, a model was constructed for testing at the NACA 8' HST, by John Stark.
I like it and think that combining the coolant and intercoolers into the open leading edges of a 66-115 wing may be ideal in some ways I would be concerned about how extensive the re-design / modification would be (perhaps to the point of requiring a new type?). The reason NACA recommended the 0.2c Leading Edge extension over the 66-115 laminar flow wing is because the change in the center of pressure for the .2c extension required a change in weight distribution thereby justifying the move of the radiators forward whereas the CoP for the 66-115 wing is nearly the same as the original 23016 wing. Moving the weight forward with this wing would require some added weight aft. Ballast is an idea, as is additional fuel tanks; but, in the latter case there would be the same CoG issue the Mustang experienced when the tank runs low/dry. The other reason the 0.2c extension is more desirable--at least to the Army and Lockheed execs--is because the modification can use the existing wing structures for the most part. Only the leading edge needs to be re-designed. The main spar and trailing spar as well as the fuel tanks and fowler flaps can all remain un-changed.
I think this solution would be better suited to the XP-49 since it is not yet in production and is still in the design and development stage.
Whatever you think Lockheed would change is fine with me. Whatever efforts are spent on the XP-49 are a waste of time. Lockheed took 14 months to implement a dive flap, while the B-6 and Love Field modification centers were doing something else, I suppose.
The Gloster E-28/39 received a complete new wing from British research at RA&AE's NPL, and returned better numbers. Lockheed's own P-80 received a new wing, for better performance, but mods to the P-38, such as the 'K's cowling mod were deemed too much trouble. The Fig 7 drawing and Fig. 8 photo in the NACA blurb seem to indicate the fitting of a full 66 airfoil which extends chord front and aft of original with the extended fuselage. That would suit me fine, with the addition of the outer wings following suit, but that's just me.
Another thing, the entire story of the P-38 is full of contradictions, so nothing is for sure.
The Gloster E-28/39 received a complete new wing from British research at RA&AE's NPL, and returned better numbers. Lockheed's own P-80 received a new wing, for better performance, but mods to the P-38, such as the 'K's cowling mod were deemed too much trouble. The Fig 7 drawing and Fig. 8 photo in the NACA blurb seem to indicate the fitting of a full 66 airfoil which extends chord front and aft of original with the extended fuselage. That would suit me fine, with the addition of the outer wings following suit, but that's just me.
Another thing, the entire story of the P-38 is full of contradictions, so nothing is for sure.
I agree that Just Leo's mods would be better suited for the XP-49. Seeing a P-38 with wing tip tanks is a personal first though. And I think the intercooler location in the under engine location is fine. Reduces the ducting too.
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[
Another thing, the entire story of the P-38 is full of contradictions, so nothing is for sure.[/QUOTE]
It is a complicated and puzzling story. Just Leo would you like to take a crack at drawing EverKings' vision of the NACA P-38? Maybe with a bubble canopy and the inner wing only intakes. I'd do it but I don't know how.
Another thing, the entire story of the P-38 is full of contradictions, so nothing is for sure.[/QUOTE]
It is a complicated and puzzling story. Just Leo would you like to take a crack at drawing EverKings' vision of the NACA P-38? Maybe with a bubble canopy and the inner wing only intakes. I'd do it but I don't know how.
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Ideally, I would like to see a full 66-115 wing with matching outer wings. It is certainly possible to do this but I am really trying to stick to plausibilty rather than possibility. From a purely practical stance if you can get most of the performance gain from the .2c extension for only a fraction of the effort I think it far more reasonable that they would go in that direction.
Now, if we were to back off an additional 6 months or even 12, so the NACA study comes out 3/31/41 or 9/30/40 then I think there may be time and desire for a full re-wing.
Wishful thinking, though. Again, I would love to see it but for TTL with the limits I have given myself I just don't know I can justifiably do it. :-(
Now, if we were to back off an additional 6 months or even 12, so the NACA study comes out 3/31/41 or 9/30/40 then I think there may be time and desire for a full re-wing.
Wishful thinking, though. Again, I would love to see it but for TTL with the limits I have given myself I just don't know I can justifiably do it. :-(
EverKing because this is such an interesting subject for propellor heads like me you've gotten plenty of suggestions and requests. I hope that you will stick to what you think is best by your own judgement and not be unduly influenced by the eager audience. Going by your first two narrative posts you have made an excellent start with the creative writing and your intent to be historical plausible just makes this an even more interesting and absorbing story. Thanks for your efforts and looking forward to the next installment.
Some people have nothing better to do.
The drop tanks were a personal affectation based on historical adaptation of tip-tanks to reduce induced drag, on a previous night fighter Lockheed Swordfish that used leading edge rads which impinged on the full capacity of the original reserve tanks.
Thanks, but it's still not perfect. Ralph Virden reported that it ran hot on auto-lean and required the flaps opened and a switch to auto-rich. I know how to fix that, but it's apparently not going to happen. It's like the Hawker Henley all over again.
Ch.3 - War! & Second Test (Dec 1941)
Well, I decided not to belabor the US entrance into the war and the reaction to Pearl Harbor. I was going to make it more of a personal scene but I realized it really had no bearing on the P-38 and only served to slow the important parts of the ATL. So...without further ado...
8 December 1941
Throughout the Nation, USA
The President’s voice buzzed through the radio speakers.
“As Commander in Chief of the Army and Navy I have directed that all measures be taken for our defense.
“But always will our whole Nation remember the character of the onslaught against us.
“No matter how long it may take us to overcome this premeditated invasion, the American people in their righteous might will win through to absolute victory. I believe that I interpret the will of the Congress and of the people when I assert that we will not only defend ourselves to the uttermost but will make it very certain that this form of treachery shall never again endanger us.
“Hostilities exist. There is no blinking at the fact that our people, our territory, and our interests are in grave danger.
“With confidence in our armed forces—with the unbounding determination of our people—we will gain the inevitable triumph- so help us God.
“I ask that the Congress declare that since the unprovoked and dastardly attack by Japan on Sunday, December 7, 1941, a state of war has existed between the United States and the Japanese Empire.”
Burbank, California, USA
Executive of the Board, Courtlandt S. Gross, switched off the radio. The hissing applause clicked off and the room fell into complete silence. Gathered today were all of Lockheed’s chief officers. The news from the previous day of the sudden Japanese attack on the Navy and Army installations in Hawai’i had stopped everyone cold and there was no return to “business as normal” on this Monday morning as everyone tuned in to listen to the President’s response in his speech to Congress.
As a military contractor they fully expected to receive new demands and updates from the War Department now that the nation would soon be starting full mobilization. The executives needed to ensure that everything was proceeding as it should and ordered each bureau and project team provide complete updates on the status of research, development, design, and production. The board had to have their priorities in order for the Army.
Most of the company efforts had of late been in building Hudsons—Super-Electras modified as maritime patrol craft and bombers—for the RAF and RCAF and in getting the first production P-38’s delivered for the USAAF. In addition there was still the trouble with the Model 322, the P-38’s built for the British which they named the “Lightning,” a name which had taken hold in popular parlance for the entire Model 22 family. The British had wanted the Lightning to use the same engines as the P-40’s they received and so the aircraft was effectively neutered. Between the poor performance and the issues the past summer with supposed tail-flutter, the British had canceled the order before the P-38 Improvement Program had started causing no end of consternation for the Board and the lawyers who fought to get the contract fulfilled. Then the RAF had changed the majority of the order, over 500 aircraft, to be standard production P-38’s as “Lightning II’s” but whether or not they were going to honor the contract was in doubt.
Then there were the development projects. The P-38 Improvement Project as well as the related XP-49 and the stalled XP-58 would need to be prioritized by the military now that the US was entering the war. The future of Lockheed, though, was in the TWA airliner model 049. The prototype mock-up was sitting in the hanger and 80 airplanes had already been ordered and authorized to be built. The entire board and the chief designers, including both Hall Hibbard and Kelly Johnson, had hoped the US could stay out of the war long enough the Constellation to be delivered and guarantee a strong future for the Lockheed Corporation.
Chairman of the Board, Robert E. Gross, Courtlandt’s brother, broke the silence after a moment, “Gentlemen, it appears we are out of time.”
18 December 1941
Burbank, California, USA
Reorganization and re prioritization for the war effort had progressed quickly at Lockheed following the US entrance into the War. The fear of a Japanese attack on the west coast prompted the USAAF to immediately lay claim to the British Lightning I’s waiting in Burbank. Forty of these Lightnings were already patrolling up and down the Pacific coast ready for any sign of a Japanese invasion.
The Air Corps, responsible for logistics for the Army Air Forces, had also already stepped in to take over the rest of the British order, thereby ending the on-going legal struggle between RAF procurement and Lockheed. As soon as each batch of aircraft became ready they were to be delivered directly to the Air Forces for modification and readiness assessment. Army test pilot Major Ben Kelsey—who, contrary to Air Corps doctrine, had pushed for Lockheed to add provisions for external fuel tanks on the P-38--was also advocating a modification to the P-38 for its use as a photo-reconnaissance aircraft in preference to the British built Mosquito which General Hap Arnold was backing.
With the desire to build up the Air Forces as quickly as possible the War Department was considering using aircraft currently available in favor of newly or as-yet undeveloped aircraft, which meant that Kelly Johnson’s P-38 Improvement Program was getting preference over the XP-49.
P-38E-1-LO #41-2009 (serial number 222-5227) had been extensively modified after it came off the production line. Being fully armored but with without guns, it was being operated by Lockheed as a registered AAF aircraft. Aircraft 009 was the first to have the NACA wing extensions installed using pre-production dies with the new custom built Prestone radiators from Allison and dual can-type oil radiators in the leading edge. The fabrication team had just completed the three foot fuselage extension and had fitted a more gradually curved, less extremely peaked, canopy from DuPont. Although the designers had considered redesigning the lower engine nacelles, where the oil radiators used to be installed, to tighten the engine fitment and possibly improve the aerodynamics, they had instead smoothly faired them over to keep their original aerodynamic profile for simplicity’s sake. The modification team was hoping to test it with the new Allison V-1710-F5 engines but they had not yet arrived at the factory so the initial flight testing would take place using the current production F2 engines.
Once again, it was left to Lockheed’s best test pilot, Ralph Virden, to give the newly modified aircraft a workout.
At first glance, 009 was of similar shape to YP-38 689 he had tested six weeks earlier except it was in full olive drab over grey paint with the yellow tail number “12009” and the bold black letters reading “ARMY” under the wings. The most obvious difference in form was the rear of the central nacelle, which was now extended beyond the trailing edge of the inner-wing assembly.
Ralph found this made mounting the aircraft far easier since it meant he no longer had to contort himself around the wing and instead needed simply to step up onto the wing from ladder. Getting into the airplane was also easier with the new larger canopy opening—which had the added benefit of the top hood now being hinged at the rear rather than on a bar to the right. It was still a little clumsy having the three different pieces to close in order to completely seal the cockpit, but it was at least some sign of progress.
From the seat he noted that the forward windscreen sloped farther away and he was slightly dismayed at the curved lensing effect the forward quarters had on his view in front of the broad inner-wings. Kelly Johnson had warned him of this problem and assured him they were hard at work developing a solution. Nevertheless, he made a note of it in the spirit of thoroughness.
Pre-flight and engine start was the same as before but without the benefit of the battery cart. He found the on-board battery had no challenge spinning up the inertial starters and engaging the engines.
Taxiing was made difficult with the skewed perspective through the new windscreen. He ended up having to crank the left window down and unbuckle so he could navigate the turns by peeking his head outside. This was definitely a problem that needed to be fixed.
Roll out and take were otherwise uneventful. Once he had climbed to the testing altitude and double checked that he was back on the main tanks he started the series of preliminary handling tests, just as he had done in 689. His overall impression was that the airplane was an absolute marvel to fly, even more sore than the roughly modified 689 had been.
The rearward extension of the central nacelle was mostly balanced by the slightly larger coolant radiators which had been installed. In all, the net shift in the center of gravity was only a few percent of the mean aerodynamic chord to the rear so the general behavior in flight was unchanged.
The new bespoke Prestone radiators were wonderful at maintaining the coolant temperatures and Ralph noted that he never had any unexpected coolant temperatures throughout the first portion of the flight. The issues 689 had with the hastily adapted radiators from a P-39 were completely absent with the larger radiators how sitting in the wings.
Once again he took the aircraft through a series of dives, once again beginning from 25,000 feet.
More confident that he had been in 689 he pushed the aircraft down to 15,000 feet on his first attempt, reaching a final indicated speed of 418 miles per hour at just above 18,000 before starting his slow pull out. The control surfaces were a little heavy but there was no indication of shudder or tail flutter.
The second dive followed nearly the same profile but with full throttle he carried it past an IAS of 440 mph at 16,000 feet. It was a feat he repeated with the third and fourth dives, each progressively lower and faster: indicating 450 at 15,000 feet and 455 at 14,500 respectively. With each dive the airplane was stable and steady displaying no tendency to tuck under but Ralph noted that the ailerons became extremely heavy and stopped responding altogether at just above the old dive limit speeds of the unmodified aircraft.
He left the throttles open as he climbed for his fifth power dive, circling back to his starting altitude as the turbos spun past 20,000 revolutions to maintain 40.6 inches of intake manifold pressure. As it passed 24,800 feet, oh-oh-nine caught a turbulent updraft under the left wing which Ralph perceived as little more than small bump and slight roll to the right, easily corrected with the ailerons. Unknown to Ralph, the torsion of the outer left wing strained the hot-side intercooler ducting seal on that side. A rush of hot air pressurized to more than twice the ambient air pressure burst the seal and leaked into the wing.
The automatic manifold pressure regulator on the Allison V-1710-F2L engine registered the resulting drop in carburetor air pressure and the vacuum system immediately fully closed the exhaust waste-gate. The resulting increase in exhaust pressure spun the B-2 turbo-supercharger past its 24,000 rpm limit but all of the additional pressure was lost through the leaking duct seal preventing the manifold pressure from increasing.
For Ralph, everything seemed to happen at once. The airplane start to yaw as the left engine lost several hundred horsepower. He kicked the rudder to the right to even the yaw as a small glow lamp on the instrument panel flickered, warning him that the left turbo-supercharger had passed 25,600 rpm overspeed. He had just registered the light before it glowed steady as the turbo reached its peak 26,400 rpm. Ralph lifted his left hand off the yoke and was reaching for the throttle when a series of metallic pops almost sounding like gunfire made him flinch.
The flinch delayed his reaction enough that the turbo spun out of control. The bearings disintegrated, causing the turbine to explosively come apart. It burst in its housing like an artillery shell and peppered the entire left side of the aircraft with shrapnel and debris, tearing through the sheet aluminum like it was paper. Ralph heard the pieces impacting around and passing through the cockpit with whistles and zips. One of the impeller blades flew forward, severing one of the oil lines for the left engine before burying itself in the the number 2R cylinder head. More debris sped aft through both oxygen cylinders but mercifully sparing the battery.
The force of the bursting turbo caused the left wing to drop even as it yawed further against the rudder. Ralph counter-rolled with ailerons and nosed the airplane over seeking denser air as he kept up a hard right rudder. He made it three minutes and down to 19,300 feet before the left engine started to cough and wheeze as it spewed brown smoke from the hole where the turbo used to be. He knew it would not make it much longer.
He pulled the left throttle back to IDLE CUT-OFF and moved the propeller feathering switch to feather the propeller. As soon as the engine was dead his voltmeter and ammeter dropped to zero as the only electrical generator was on that engine. He moved the right propeller lever to FIXED PITCH and reduced throttle and RPMs before switching the battery OFF to save what little electrical power he had left.
Once he was sure he was still flying and in control of the airplane he took the time to close off the fuel to the left side, turn on the left fuel booster pumps, and ensure the radiator and oil flaps were completely closed. Ralph trimmed the rudder and aileron tabs to ease up the load of having to manhandle the airplane quite so roughly. Comfortable that the immediate emergency was under control he checked the rest of the instruments and made a visual inspection of the airplane.
The first thing Ralph noticed was the burning sensation in his right leg. He reached down to inspect it with his fingers and felt a twisted piece of still hot metal protruding from the inside of his calf. He gingerly tried to move it to get a feel for how deep it may be but an electrical jolt of pain shot through his entire leg and he decided it was deep enough. He felt around it some more before lifting his gloved hand back up to see there was surprisingly little blood. He decided to leave the shrapnel for the doctors on the ground to take care of.
His oxygen pressure was low, but holding. He could only assume he lost both bottles out of the left boom and was now flying only on the reserve bottle in the right boom. He was continuing to descend at a few thousand feet per minute. He was aiming to get down below 10,000 feet so the low O2 would not be a problem. At the current rate he should be there in just four minutes.
Ralph was relieved to see that the Hydraulic system was unscathed, registering at just under 1200 psi--well within the normal range. He had no inclination to pump the hydraulics by hand to lower the flaps or landing gear when the time came.
The right engine seemed to be running fine and strong at 2600 RPM and about 33 inches of mercury manifold pressure. Oil and fuel pressures were good. Carburetor air temperature was adequate as was both oil and coolant temperatures. It was holding more that enough speed considering his continued down-ward slope so at the moment he had no worries of stalling out.
Looking to the left past the dead and still smoking engine he noticed that one of the outer wing panels was slightly bulged and part of it had come lose, the rivets had popped and it now shuddered in the airflow. Ralph mused, that must have been the source of the "popping" sound he heard before the turbo blew.
The plexiglas was peppered with a half-dozen or so holes from the exploding debris. One piece had planted itself in the rear of engine control box just above the landing gear lever and another was jammed in the canopy frame where the upper hood meets the right window. That piece, Ralph realized, must have missed his head by inches at most.
Now below 10,000 feet, he removed his oxygen mask and closed off the regulator but continued down albeit at a slower rate of decent.
He took a few minutes to orient himself and get his bearings from some of the landmarks below. He was able to recognize the Santa Clara River and figured that the mountains to his left must be the San Gabriels. Looking south past the hills he could two distant airstrips with the growing sprawl of Los Angeles beyond them. The more distant and southerly airstrip would be Glendale's Grand Central Airport. The closer one would be the Lockheed Air Terminal in Burbank and his destination.
Continuing his descent past the mountains he switched his battery back on for a moment so he could radio the tower to declare his emergency and get the current altimeter reading. After confirming the information he switched it back off and dialed in the new air pressure at the airport.
At 500 feet above the airport and only a mile out he turned the batter on again, this time for good. The Curtiss propellers relied on electrical power for their automated pitch control and when coming in on one engine it was always Ralph's policy to make engine control as easy as possible. He moved the right propeller control out of the FIXED PITCH position and back to AUTO CONSTANT SPEED.
At 140 mph indicated, he dropped the Fowler Flaps. Shortly after, now certain he was lined up and steady, he lowered the landing gear. The airplane shimmied as the right tire dropped into the propeller wash but Ralph held 009 true, steadily reducing his airspeed.
At a mere 85 miles per hour the beating and brused duo of pilot and airplane settled onto the runway and rolled to smooth and gradual stop.
Ralph was sure this plane was trying to kill him.
8 December 1941
Throughout the Nation, USA
The President’s voice buzzed through the radio speakers.
“As Commander in Chief of the Army and Navy I have directed that all measures be taken for our defense.
“But always will our whole Nation remember the character of the onslaught against us.
“No matter how long it may take us to overcome this premeditated invasion, the American people in their righteous might will win through to absolute victory. I believe that I interpret the will of the Congress and of the people when I assert that we will not only defend ourselves to the uttermost but will make it very certain that this form of treachery shall never again endanger us.
“Hostilities exist. There is no blinking at the fact that our people, our territory, and our interests are in grave danger.
“With confidence in our armed forces—with the unbounding determination of our people—we will gain the inevitable triumph- so help us God.
“I ask that the Congress declare that since the unprovoked and dastardly attack by Japan on Sunday, December 7, 1941, a state of war has existed between the United States and the Japanese Empire.”
Burbank, California, USA
Executive of the Board, Courtlandt S. Gross, switched off the radio. The hissing applause clicked off and the room fell into complete silence. Gathered today were all of Lockheed’s chief officers. The news from the previous day of the sudden Japanese attack on the Navy and Army installations in Hawai’i had stopped everyone cold and there was no return to “business as normal” on this Monday morning as everyone tuned in to listen to the President’s response in his speech to Congress.
As a military contractor they fully expected to receive new demands and updates from the War Department now that the nation would soon be starting full mobilization. The executives needed to ensure that everything was proceeding as it should and ordered each bureau and project team provide complete updates on the status of research, development, design, and production. The board had to have their priorities in order for the Army.
Most of the company efforts had of late been in building Hudsons—Super-Electras modified as maritime patrol craft and bombers—for the RAF and RCAF and in getting the first production P-38’s delivered for the USAAF. In addition there was still the trouble with the Model 322, the P-38’s built for the British which they named the “Lightning,” a name which had taken hold in popular parlance for the entire Model 22 family. The British had wanted the Lightning to use the same engines as the P-40’s they received and so the aircraft was effectively neutered. Between the poor performance and the issues the past summer with supposed tail-flutter, the British had canceled the order before the P-38 Improvement Program had started causing no end of consternation for the Board and the lawyers who fought to get the contract fulfilled. Then the RAF had changed the majority of the order, over 500 aircraft, to be standard production P-38’s as “Lightning II’s” but whether or not they were going to honor the contract was in doubt.
Then there were the development projects. The P-38 Improvement Project as well as the related XP-49 and the stalled XP-58 would need to be prioritized by the military now that the US was entering the war. The future of Lockheed, though, was in the TWA airliner model 049. The prototype mock-up was sitting in the hanger and 80 airplanes had already been ordered and authorized to be built. The entire board and the chief designers, including both Hall Hibbard and Kelly Johnson, had hoped the US could stay out of the war long enough the Constellation to be delivered and guarantee a strong future for the Lockheed Corporation.
Chairman of the Board, Robert E. Gross, Courtlandt’s brother, broke the silence after a moment, “Gentlemen, it appears we are out of time.”
18 December 1941
Burbank, California, USA
Reorganization and re prioritization for the war effort had progressed quickly at Lockheed following the US entrance into the War. The fear of a Japanese attack on the west coast prompted the USAAF to immediately lay claim to the British Lightning I’s waiting in Burbank. Forty of these Lightnings were already patrolling up and down the Pacific coast ready for any sign of a Japanese invasion.
The Air Corps, responsible for logistics for the Army Air Forces, had also already stepped in to take over the rest of the British order, thereby ending the on-going legal struggle between RAF procurement and Lockheed. As soon as each batch of aircraft became ready they were to be delivered directly to the Air Forces for modification and readiness assessment. Army test pilot Major Ben Kelsey—who, contrary to Air Corps doctrine, had pushed for Lockheed to add provisions for external fuel tanks on the P-38--was also advocating a modification to the P-38 for its use as a photo-reconnaissance aircraft in preference to the British built Mosquito which General Hap Arnold was backing.
With the desire to build up the Air Forces as quickly as possible the War Department was considering using aircraft currently available in favor of newly or as-yet undeveloped aircraft, which meant that Kelly Johnson’s P-38 Improvement Program was getting preference over the XP-49.
P-38E-1-LO #41-2009 (serial number 222-5227) had been extensively modified after it came off the production line. Being fully armored but with without guns, it was being operated by Lockheed as a registered AAF aircraft. Aircraft 009 was the first to have the NACA wing extensions installed using pre-production dies with the new custom built Prestone radiators from Allison and dual can-type oil radiators in the leading edge. The fabrication team had just completed the three foot fuselage extension and had fitted a more gradually curved, less extremely peaked, canopy from DuPont. Although the designers had considered redesigning the lower engine nacelles, where the oil radiators used to be installed, to tighten the engine fitment and possibly improve the aerodynamics, they had instead smoothly faired them over to keep their original aerodynamic profile for simplicity’s sake. The modification team was hoping to test it with the new Allison V-1710-F5 engines but they had not yet arrived at the factory so the initial flight testing would take place using the current production F2 engines.
Once again, it was left to Lockheed’s best test pilot, Ralph Virden, to give the newly modified aircraft a workout.
At first glance, 009 was of similar shape to YP-38 689 he had tested six weeks earlier except it was in full olive drab over grey paint with the yellow tail number “12009” and the bold black letters reading “ARMY” under the wings. The most obvious difference in form was the rear of the central nacelle, which was now extended beyond the trailing edge of the inner-wing assembly.
Ralph found this made mounting the aircraft far easier since it meant he no longer had to contort himself around the wing and instead needed simply to step up onto the wing from ladder. Getting into the airplane was also easier with the new larger canopy opening—which had the added benefit of the top hood now being hinged at the rear rather than on a bar to the right. It was still a little clumsy having the three different pieces to close in order to completely seal the cockpit, but it was at least some sign of progress.
From the seat he noted that the forward windscreen sloped farther away and he was slightly dismayed at the curved lensing effect the forward quarters had on his view in front of the broad inner-wings. Kelly Johnson had warned him of this problem and assured him they were hard at work developing a solution. Nevertheless, he made a note of it in the spirit of thoroughness.
Pre-flight and engine start was the same as before but without the benefit of the battery cart. He found the on-board battery had no challenge spinning up the inertial starters and engaging the engines.
Taxiing was made difficult with the skewed perspective through the new windscreen. He ended up having to crank the left window down and unbuckle so he could navigate the turns by peeking his head outside. This was definitely a problem that needed to be fixed.
Roll out and take were otherwise uneventful. Once he had climbed to the testing altitude and double checked that he was back on the main tanks he started the series of preliminary handling tests, just as he had done in 689. His overall impression was that the airplane was an absolute marvel to fly, even more sore than the roughly modified 689 had been.
The rearward extension of the central nacelle was mostly balanced by the slightly larger coolant radiators which had been installed. In all, the net shift in the center of gravity was only a few percent of the mean aerodynamic chord to the rear so the general behavior in flight was unchanged.
The new bespoke Prestone radiators were wonderful at maintaining the coolant temperatures and Ralph noted that he never had any unexpected coolant temperatures throughout the first portion of the flight. The issues 689 had with the hastily adapted radiators from a P-39 were completely absent with the larger radiators how sitting in the wings.
Once again he took the aircraft through a series of dives, once again beginning from 25,000 feet.
More confident that he had been in 689 he pushed the aircraft down to 15,000 feet on his first attempt, reaching a final indicated speed of 418 miles per hour at just above 18,000 before starting his slow pull out. The control surfaces were a little heavy but there was no indication of shudder or tail flutter.
The second dive followed nearly the same profile but with full throttle he carried it past an IAS of 440 mph at 16,000 feet. It was a feat he repeated with the third and fourth dives, each progressively lower and faster: indicating 450 at 15,000 feet and 455 at 14,500 respectively. With each dive the airplane was stable and steady displaying no tendency to tuck under but Ralph noted that the ailerons became extremely heavy and stopped responding altogether at just above the old dive limit speeds of the unmodified aircraft.
He left the throttles open as he climbed for his fifth power dive, circling back to his starting altitude as the turbos spun past 20,000 revolutions to maintain 40.6 inches of intake manifold pressure. As it passed 24,800 feet, oh-oh-nine caught a turbulent updraft under the left wing which Ralph perceived as little more than small bump and slight roll to the right, easily corrected with the ailerons. Unknown to Ralph, the torsion of the outer left wing strained the hot-side intercooler ducting seal on that side. A rush of hot air pressurized to more than twice the ambient air pressure burst the seal and leaked into the wing.
The automatic manifold pressure regulator on the Allison V-1710-F2L engine registered the resulting drop in carburetor air pressure and the vacuum system immediately fully closed the exhaust waste-gate. The resulting increase in exhaust pressure spun the B-2 turbo-supercharger past its 24,000 rpm limit but all of the additional pressure was lost through the leaking duct seal preventing the manifold pressure from increasing.
For Ralph, everything seemed to happen at once. The airplane start to yaw as the left engine lost several hundred horsepower. He kicked the rudder to the right to even the yaw as a small glow lamp on the instrument panel flickered, warning him that the left turbo-supercharger had passed 25,600 rpm overspeed. He had just registered the light before it glowed steady as the turbo reached its peak 26,400 rpm. Ralph lifted his left hand off the yoke and was reaching for the throttle when a series of metallic pops almost sounding like gunfire made him flinch.
The flinch delayed his reaction enough that the turbo spun out of control. The bearings disintegrated, causing the turbine to explosively come apart. It burst in its housing like an artillery shell and peppered the entire left side of the aircraft with shrapnel and debris, tearing through the sheet aluminum like it was paper. Ralph heard the pieces impacting around and passing through the cockpit with whistles and zips. One of the impeller blades flew forward, severing one of the oil lines for the left engine before burying itself in the the number 2R cylinder head. More debris sped aft through both oxygen cylinders but mercifully sparing the battery.
The force of the bursting turbo caused the left wing to drop even as it yawed further against the rudder. Ralph counter-rolled with ailerons and nosed the airplane over seeking denser air as he kept up a hard right rudder. He made it three minutes and down to 19,300 feet before the left engine started to cough and wheeze as it spewed brown smoke from the hole where the turbo used to be. He knew it would not make it much longer.
He pulled the left throttle back to IDLE CUT-OFF and moved the propeller feathering switch to feather the propeller. As soon as the engine was dead his voltmeter and ammeter dropped to zero as the only electrical generator was on that engine. He moved the right propeller lever to FIXED PITCH and reduced throttle and RPMs before switching the battery OFF to save what little electrical power he had left.
Once he was sure he was still flying and in control of the airplane he took the time to close off the fuel to the left side, turn on the left fuel booster pumps, and ensure the radiator and oil flaps were completely closed. Ralph trimmed the rudder and aileron tabs to ease up the load of having to manhandle the airplane quite so roughly. Comfortable that the immediate emergency was under control he checked the rest of the instruments and made a visual inspection of the airplane.
The first thing Ralph noticed was the burning sensation in his right leg. He reached down to inspect it with his fingers and felt a twisted piece of still hot metal protruding from the inside of his calf. He gingerly tried to move it to get a feel for how deep it may be but an electrical jolt of pain shot through his entire leg and he decided it was deep enough. He felt around it some more before lifting his gloved hand back up to see there was surprisingly little blood. He decided to leave the shrapnel for the doctors on the ground to take care of.
His oxygen pressure was low, but holding. He could only assume he lost both bottles out of the left boom and was now flying only on the reserve bottle in the right boom. He was continuing to descend at a few thousand feet per minute. He was aiming to get down below 10,000 feet so the low O2 would not be a problem. At the current rate he should be there in just four minutes.
Ralph was relieved to see that the Hydraulic system was unscathed, registering at just under 1200 psi--well within the normal range. He had no inclination to pump the hydraulics by hand to lower the flaps or landing gear when the time came.
The right engine seemed to be running fine and strong at 2600 RPM and about 33 inches of mercury manifold pressure. Oil and fuel pressures were good. Carburetor air temperature was adequate as was both oil and coolant temperatures. It was holding more that enough speed considering his continued down-ward slope so at the moment he had no worries of stalling out.
Looking to the left past the dead and still smoking engine he noticed that one of the outer wing panels was slightly bulged and part of it had come lose, the rivets had popped and it now shuddered in the airflow. Ralph mused, that must have been the source of the "popping" sound he heard before the turbo blew.
The plexiglas was peppered with a half-dozen or so holes from the exploding debris. One piece had planted itself in the rear of engine control box just above the landing gear lever and another was jammed in the canopy frame where the upper hood meets the right window. That piece, Ralph realized, must have missed his head by inches at most.
Now below 10,000 feet, he removed his oxygen mask and closed off the regulator but continued down albeit at a slower rate of decent.
He took a few minutes to orient himself and get his bearings from some of the landmarks below. He was able to recognize the Santa Clara River and figured that the mountains to his left must be the San Gabriels. Looking south past the hills he could two distant airstrips with the growing sprawl of Los Angeles beyond them. The more distant and southerly airstrip would be Glendale's Grand Central Airport. The closer one would be the Lockheed Air Terminal in Burbank and his destination.
Continuing his descent past the mountains he switched his battery back on for a moment so he could radio the tower to declare his emergency and get the current altimeter reading. After confirming the information he switched it back off and dialed in the new air pressure at the airport.
At 500 feet above the airport and only a mile out he turned the batter on again, this time for good. The Curtiss propellers relied on electrical power for their automated pitch control and when coming in on one engine it was always Ralph's policy to make engine control as easy as possible. He moved the right propeller control out of the FIXED PITCH position and back to AUTO CONSTANT SPEED.
At 140 mph indicated, he dropped the Fowler Flaps. Shortly after, now certain he was lined up and steady, he lowered the landing gear. The airplane shimmied as the right tire dropped into the propeller wash but Ralph held 009 true, steadily reducing his airspeed.
At a mere 85 miles per hour the beating and brused duo of pilot and airplane settled onto the runway and rolled to smooth and gradual stop.
Ralph was sure this plane was trying to kill him.
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