NORTH AMERICAN P-51 MUSTANG ALTITUDE RECORD SETTING IN “The Rebel”

by Doug Matthews
22 MAY 2013
Indiantown, Florida, U.S.A.

“OH, WAY COOL!”

THE BACKGROUND

Since childhood I have been fascinated with aviation, with a special focus on military fighters.  Even while I was too young to fly, I studied WWI, WW II and Korean war fighters—it didn’t matter whose side they were on.  Each model, detail, area of operations, tactics, the whole nine yards!  I began my flying career at the minimum age requirement of 16. Somewhere along the line of accruing 20,000 hours, I researched national and world aviation records and how to set one. Actually, I didn’t stop at just one and now lay claim 112 of them! Recording and certification of aviation records falls under the responsibility of National Aeronautics Association (NAA) for U.S. records and the Federation Aeronatique Internationale (FAI) for world records. The primary category of records falls under “time-to-climb” (brake release to a certain altitude) and “point-to-point” (a time between two points on the earth). There are other categories as well, but I focused on these two. For example, I set the record for turbojets of a certain weight class from brake release to 10,000 feet (69 seconds) and to 40,000 feet (4 minutes and 12 seconds). Both of these were accomplished in a “stock” Learjet…the Learjet 24 was a heck of a plane!

Eventually I achieved 2000 hours of flying time in single-seat historic warbird fighters, 700 of which is in the 1944 North American P-51 Mustang. Reflecting on my records in other aircraft, I decided to attack the “time-to-climb” records for a reciprocating-powered aircraft of the P-51 weight class, along with the absolute records for altitude–sustained and momentary. My usual thorough (anal) research, with attention to detail and preparation for such a task, took one year.  My overall goal was to set this record utilizing the same “stock” configuration of the Mustang, just as if the record was being attempted in 1944.

My studies included publications and documents of North American Aviation (Flight testing history), the U.S. Army Air Corps (Acceptance tests), records and documents of the engine designer Rolls Royce Company and the engine manufacturer-Packard Motor Company. Armed with this knowledge, I then looked into documents of the NAA and the FAI, the USAF Flight Safety Center, the USN Safety center and the U.S. FAA. Finally, I consulted with good friends Col. Joe Kittinger (high-altitude record parachutist) and Bud Anderson (WW II Ace). I intended to fly quite high in an aircraft lacking any environmental systems: cabin pressurization, heat or air conditioning. Joe Kittinger and I discussed the problems of hypoxia and the “bends”. He suggested a regimen of 100% oxygen pre-breathing for several hours prior to the flight. Bud Anderson shared his 1949 USAF P-51 fight test research papers with me and coached me on the best performance profile.

THE PREPARATION

Personal flight equipment had to be collected and fitted. My typical flight gear already included a helmet and mask for my high-altitude cross-country flights (in jets, the P-51 and the F4U Corsair), a flight suit, boots and gloves.  For the harsh environmental conditions expected above FL230, I added extra clothing for extreme cold weather (-60°F at high altitudes), a pulse-oximeter (“Pulse Ox”) to monitor my blood level oxygen, and heat packs from skiing for my feet and hands.

Additional equipment for the flight included multiple video cameras (three Contour cameras, three GoPro cameras), camera moisture packs to combat both humid and extreme dry altitudes, video-recording sunglasses, and large 64 GB data cards. For supplemental audio recording, I added voice recorders; one each the P-51 and one in the chase plane (a Citation jet).  In order to have proper coverage of the record attempt routing, I also included an iPad with my special route displayed. Most important of all, we connected the NAA-required data link equipment. The latter would track and record my progress and report to the NAA observer on the ground.

Planning for optimal aircraft performance included considerations of Prop/RPM settings, mixture setting, climb schedule, fuel consumption, and fuel booster pump use. Regarding configuration, I wanted to duplicate the 1942 acceptance flights for “apples to apples” authenticity. I already lacked the higher-octane fuel they used (145 leaded octane back in the day versus 100 LL today). I left my guns and ammo onboard as well as the bomb racks.

Looking at the current records for “time-to-climb” to 20,000’, 30,000’ and 40,000’ in my weight class (“C-1. e, Group 1”), I felt I had a good chance of breaking those records by the required margin…that is IF I could make it that high at all! Now the big question–what would my altitude limit end up being? The Army Air Corps acceptance test flights listed the “Max Service Ceiling at 41,000”. But this was with a brand-new plane and engine, test conditions, high-octane fuel and a 25-year old test pilot! What would end up being my limiting factors? Would my almost 70-year old airframe fail or some system quit? (Not to mention my own personal ‘frame’ was way over 25 years!)  Would my Rolls Royce Packard V1650-9A engine just fail at high altitudes? Would the original oxygen system quit delivering vital oxygen at some point and I not notice? If so, would I drift off hypoxic and never recover? Will I pressure breathe correctly when needed? Would I get the bends so badly that I couldn’t perform? Would the harsh -60°F get to me so badly that I had to quit or freeze to death? Will I have good weather? In my attempt to stay light weight would I compromise my fuel requirements and cut myself short on fuel? Or most likely, would I worry so much about all these factors that I would simply decide that this was not an adventure I could survive?

SUPPORT TEAM

I based out of a remote grass strip in Indiantown, Florida, northwest of West Palm Beach. P-51 Mustang maintenance guru Glenn Wegman oversaw all the tedious preparations of pitot-static checks and last-minute weight and balance. The latter to certify the weight met the NAA requirements. He also connected the data link equipment. NAA observer Brian Utley was on hand to observe and certify all this and we were joined by the video/sound crew. The chase plane crew of Ted Stuckey and John Currenti were both ex-military jet jocks with the great (and current) formation skills needed for the chase plane. Not only did they have the second onboard audio recorder, but we outfitted them with another video recorder. This would prove invaluable as they shot the contrails at high altitude, a first in 50+ years! The Citation jet was serviced and ready at nearby North Palm Beach County airport (due to needing a paved runway). A radio frequency schedule card and route were briefed before they departed for “F45”.

THE MASTERPLAN

Aircraft Planning – The plan was to takeoff at max power (55” MAP) and as I climbed, try to keep it at 55” as long as possible. Eventually, I would be at max throttle but decreasing MAP. I would have to balance coolant temperature against coolant cooling door drag. Around 20,000’ I would need to shift to “HIGH” on the engine super-charger in order to obtain maximum power for continuing up to 40,000’. I would break through 10,000’ and 20,000’ “with vigor”. From there on up into the stratosphere, I wasn’t sure how much “vigor” the Rebel would exhibit! I would, hopefully, level off at an altitude above the previous record (33,000’) and meet the “Sustained Altitude” requirement-level for at least 90 seconds with the end speed greater than the entry speed. At the end of this phase, I would simply pull max back pressure on the stick and ‘pop up’ until I stall, thereby achieving the max momentary altitude. Post stall, I would fall off either direction and start my decent. I reckoned (correctly as it turned out) that it would take me longer to descend than to climb. This is due to the invariable condensation that would build up when my very cold windscreen met the Florida humidity at low altitudes. I also wanted to protect the engine by not reducing power to idle while diving and thus have the engine shocked or “propeller-driven”. Lastly, I didn’t want to dive back into normal atmospheric pressure and cause problems with ears or body parts unknown! Wearing an oxygen mask makes things difficult…

Physical Preparations – Physiological preparation for flight day included a high-fiber menu the day before, a good breakfast, pre-breathing 100% oxygen for hours, and hydrating in the hours before launch.  I practiced pressure breathing (which requires forced exhaling), reminding myself to check blood oxygen level during flight with the Pulse-Ox and report results to the chase plane. I also tried to get adequate rest in the days prior to the record attempt (as if I could sleep!).

Flight Planning/Preparations – I required a special routing and an unrestricted climb profile from the FAA. My requests were met at first with skepticism (what kind of plane to how high?!), but after some back-and-forth they eventually chipped in and handled me perfectly! I would be breaking through dense airline traffic corridors and the RVSM special airspace (FL 290). We agreed on the route: Originate at a grass strip (only fitting!) just northwest of Palm Beach, Florida. Head west to pass south of Lake Okeechobee towards Ft. Meyers. Cross the west coast of Florida at Ft. Meyers (where I would also be crossing through the high-level airline corridors!) and enter the off-shore Warning Area that would be dedicated to my flight (reserved normally for military and experimental tests). By this time, I reckoned I would achieve max altitude and reverse course back to base. Entering the very high-altitude phase (over 30,000’, where the really fun/serious problems could occur) out over water was a bit disconcerting, but there was no choice. Oh well, I’m former Navy and I was sure that there were multiple military, Coast Guard and civilian vessels afloat for rescue– assuming, of course, that my parachute worked and that I would remain conscious enough to use it! On top of that, a bailout with a 40,000’, descent and a free fall to below 15,000’–all with no oxygen—might not turn out so well! In case of engine failure, I limited my distance off shore to the computed engine-out glide distance factoring in the prevailing winds. Diversion fields were selected and alerted.

THE RECORDS

The flight started in clear weather and a light breeze. The NAA observer and film crew were there (the event to be shown on the History Channel, Military Channel and National Geographic). The required weight and balance was completed (8300 pounds), as was the pitot-static check (good to 50,000’!). The jet chase plane was in place at the nearby airport. With a thumbs-up from NAA observer Utley and power at max, brakes released and the clock and cameras started!

Minutes of flight from brake release:

1+05: Passing through 3,000’, the jet chase plane joins in close formation and we climb out under ATC control. Ground temperature is 70 degrees F, but it cools off quickly in the climb. We head west and UP.

9+30: Climbing through 20,000’ we note a new record! (We would later be told that the data link had a temporary failure and the videos had glare from the sun over my shoulder so-no official record accepted!). -10 degrees C, 185 IAS, MAP 43”, 2800 RPM, Induction temperature 70, Oil temp 70, ROC 1900 fpm. More than 50% of the earth’s atmosphere is below me and I am a bit stressed contemplating what lies ahead.

11+05: At 23,000’, manifold pressure needs a boost and I switch to “high blower”. Tighten oxygen mask straps!

16+10: Around 26,000’, my knees start to hurt, reminding me of the bends. Coolant is hot-adjust climb speed and coolant door angle! Press on!

18+00: 30,000’- Chase plane announces a new record.! I am excited! Even if I cannot go farther, I have a new and great record and in a P-51 Mustang! We press on! From here on out the situation gets really “interesting”! It is getting extremely cold now -35 degrees C. I am still climbing at 1100 fpm as my oxygen system switches to 100%! I keep the chase plane updated with onboard parameters: -35 degrees C, IAS 165 mph, ROC 1100 fpm, MAP 42”, induction temp 80 degrees, coolant temp 100 degrees, Oximeter 94, TAS 268, RPM 2700, pain level- “tolerable”.

19+17: ATC denies climb request from nearby airliner “Unable due to conflict with military mission”! My flight controls begin to get sluggish. This is the onset of the lubricant freezing I was warned about. Within a minute, I am reduced to perhaps a one-inch movement of the control stick and rudder in any direction! I try to get help from the trim system with marginal benefit. My knee pain increases and is joined by pain in my shoulders.

20+15: 32,500’: The chase plane is unable to keep up with me and drops back and announces that maybe for the first time since WW II, a P-51 is “conning”! A P-51 vapor contrail against a clear blue sky reminding me of Goering’s statement in WW II- “When I saw P-51’s over Berlin, I knew the jig is up!”.

24+30: 35,000’: I am keeping wings level mainly with rudder and I am now rethinking the sensibility my ultimate “pop-up” maneuver strategy! After the completion of the sustained altitude portion, I intended to just pop up (pull back on the stick) and stall at the max achievable altitude. But a stall at over 40,000’ with no ability to make large flight control inputs post-stall would result in the aircraft entering a spin and with me as the “passenger”! The spin would continue at high speed vertically until the wings come off at over 505 mph which is ideally not how I want this to end! If I were still conscious (unlikely), I would be unable to bail out. I report to chase: -40 degrees C, IAS 165, TAS 268, MAP 39”, RPM 2700, ROC 600 fpm, etc.

25+25: 39,000’. ATC gives me a traffic call, a B-737 at my right. Upon further reflection, the “pop up” thing is definitely out! I am now pressure breathing, a very uncomfortable process. Breathing is opposite normal! I must forcefully exhale with great effort into the mask, and when I relax my lungs fill quickly, ballooning to full! Repeat as necessary! Avoid hyperventilating! As if!

27+20: As I cross the west coast of Florida near Ft. Meyers, a major airline route, ATC denies the descent request from Delta flight number 1366, an Airbus. “Unable your request, traffic your one o’clock, climbing through your altitude, a WW II fighter” There is a pause and the airliner pilot replies: “Say the type aircraft?”. Miami Center responds, “Ah, it’s a North American P-51 military fighter”. A long pause follows during which I spot the airliner’s contrails off my right wing. The pilot replies:” Oh, way cool!”. I am trying to imagine cruising in the Airbus cockpit at FL390 and being told that a WW II prop fighter is climbing through my altitude!

31+00: 40,000’! Another record for the Mustang and me! Whoo hoo! I am ecstatic! I report to chase: “-55degrees C, IAS 170, TAS 297, RPM 2600, ROC 400 fpm, Oximeter 96. I am really cold now but totally distracted. While I have been as high as 51,000’ in various jets and have seen the curvature of the earth come into sight, it still is amazing! This, especially when I realize that there is no pressurization or environmental protection! All that separates me from the air just outside my cockpit is a thin plexiglass canopy! The sky is dark blue and cloudless, the engine noise somewhat muffled by the thinner air and an air-starved engine producing power at a much lower level than its capabilities.

At 40,100’, I figure I am about as high as I can get on this low-octane fuel and still sustain the required level flight. I ease what back pressure I have on the stick plus do a bit of nose-down trim to maintain 40,100’. I must maintain this altitude for a minimum of ninety seconds and my end speed must exceed my entry speed. The last thing I want is for me to misjudge my time and be disallowed for only lasting 89 seconds! So, I hold it for a full 2+ minutes! The chase plane is asking me if I’m ok. They worry that I have passed the 90-second point with no action. This also allows me more time to rethink my pop up! After over two minutes, I have the record and I pull and trim as hard as I can! As speed decreases to under 100 mph, the better part of valor takes over and I ease the nose over as best I can while hitting 42,534’! Holy cow! I let the wing fall off to the left and start down.

I am now in a great hurry to get the heck down to earth…preferably conscious, dry, and in one-piece! I pull the throttle back half way as I get the nose down and…. the engine quits! Yikes! I am 50 miles to sea. Well, an old axiom in single-pilot cockpits is: “If you move something (switch, lever, control) and you don’t like the results, “re”-move it! I jam the throttle forward to 30 inches MAP and decide to make smaller changes! I start down towards home to the east. As I descend, I need to protect the engine with my power selections, plus, not exceed a reasonable airspeed. I keep the manifold pressure higher than 35 inches when I can and slowly retard the prop RPM to 2100. I decide to limit my IAS to 300 mph and just accept what decent rate I get! Passing through 18,000’ my canopy and windscreen fog over, as expected. The extreme cold air has cooled the canopy so that when it reaches the warm, moist Florida air, I get socked in with dense, continuous and opaque foggy glass! I fly instruments all the way to home field (making up my own instrument approach and with chase-plane help!) and land with the canopy cranked open and my head stuck into the wind (looking like a dog on a great car ride!). The landing, while “acceptable” was, nonetheless, “exhilarating”! It took maybe 35 or so minutes to get to 42,534’ and almost 45 minutes to get back down!

AFTERTHOUGHTS

For me, setting these records was simply fantastic! I was especially pleased that all the preparation yielded such good results. Why do pilots seek to make or break such records? There is no gain of any type-monetary, personal, financial or glory. What is it that drives pilots to do such things, especially when much of it can be dangerous? I’d like to think that it is an intrinsic part of the human spirit, the thrill of an adventure. For me, it was simply the consummation of my love affair with the P-51 Mustang. I guess I wanted to prove to myself and share with the world how truly great this aircraft design was—in any era. What a magnificent example from the early 1940’s –truly a design-breaking achievement. It was the creation of a then perfect fighter design that had such an incredible impact on WW II, especially in Europe. For the first time, bombers had fighter escort all the way to Berlin and back.

Over 15,500 P-51’s would be made in three years of the war. Today, perhaps 250 are still in existence worldwide, with about 130 in flying condition.

I’m fortunate to be currently living in a private aero community and I often wander into my hangar next to my house and just stare at “my P-51”. However, I am but the current custodian of an historic aviation artifact. Someday, this plane will rest in a museum with the rest and I wonder if visitors will ever appreciate and comprehend where the greatness of this design resides in the lineage of fighter design. I wonder if they will even process the era in which it flew and the hardship of piloting back then? Will anyone know the total fright of those young men taking off in the early morning darkness from English grass/mud fields on cold winter mornings in order to climb through a very thick overcast and hopefully rendezvous with their wing mates, while having no navaids? Will anyone comprehend an eight-hour flight in this small cockpit, with no heat except what the engine throws off, with no autopilot, through terrible weather, escorting bombers, waiting for the flak to commence and the enemy fighters attacking to kill them? Can anyone think about how a mission could end-shot down, killed or maimed, crashing due to mechanical failure or fuel starvation or surviving it all only to be made a prisoner of war for years? These were not the nostalgic “good ol’ days” but days of disasters, lost lives and loves, of cities destroyed in a single night, of the sacrifice of what would predominantly be young lives. But to be sure, I am thankful that the P-51 Mustang was on our side. I’m just sorry I wasn’t with them.

The Rebel is a P-51D Mustang, serial number 44-84933, made by North American Aviation at their Dallas plant in 1944. It did not make the war in time and was initially stored straight from the factory. In 1947 the Army Air Corps became the U.S. Air Force and 44-84933 was called to active duty, where it served until 1957. Along with many P-51’s, it was sold to the civilian market for but a few thousand dollars. I acquired it in 2007 and in late 2008 I placed it into a restoration which would last 3+ years! The finishing touch was the paint scheme applied to replicate that of Captain Joe Joiner of the 4^th Fighter Group, an American hero. In April 2011, The Rebel won EAA Grand Champion (WW II, Sun n Fun). In May 2011, retired USAF Colonel Joe Joiner flew in The Rebel.

Thanks to the folks at the NAA, Joe Kittinger, Bud Anderson, my chase crew of Ted Stuckey/John Currenti and Fighter Enterprises!