Messerschmitt Me P.1101 Jet-Powered Fighter Aircraft
The variable-wing Messerschmitt P.1101 never flew but its incomplete airframe was captured by the Allies and put under review in the United States, producing the Bell X-5.
Authored By Dan Alex; Content ©www.MilitaryFactory.com
The Messerschmitt Me P.1101 was a swept-wing, single-seat, single-engine jet-powered fighter aircraft under development for the German Luftwaffe in the closing years of World War 2. The aircraft was the first such design to feature variable-sweep wings, these being altered manually before flight while the aircraft was on the ground. Though in the process of having its first prototype nearing completion, the P.1101 program was halted when American ground forces arrived to secure the Messerschmitt facility. From there, the captured P.1101 underwent an evaluation period that furthered the next generation of jet-powered aircraft for other nations but its own. Had the P.1101 been completed in time, it is only left to the imagination what the aircraft would have done against even the latest prop-driven Allied fighters and bombers of the time.
While all major powers involved in World War 2 were, in some form or another, pursuing the technology of jet-powered aircraft, it was the Germans and the British that remained at the forefront of the new frontier. The Germans had more to lose in this race for their war had now become a wholly-defensive engagement, with Allied bombing raids weakening the German war-making infrastructure on a seemingly daily basis. The Reich Air Ministry (RLM) had all but given up on the production of bomber aircraft and had placed an emphasis on development and production of impressive - albeit technical - fighters of various makes and models. The RLM centered its sights on building fleets of jet-powered aircraft of which the likes of aerial combat had never before seen.
The Request Comes Down
With Germany on its heels, the Reich Air Ministry put forth Proposal 226/II on July 15th, 1944 under the collective initiative known as the "Emergency Fighter Competition". The specification called for 2nd generation jet-powered fighters to help in the defense of the Third Reich. These fighter proposals (with specifications continuously altered as time went on) would have to meet a top speed of 621 miles per hour at altitude, reach altitudes of nearly 46,000 feet with a pressurized cockpit, provide adequate armor protection for the pilot and supply an armament of at least 4 x MK 108 hard-hitting cannons. Power was to center around a single Heinkel-Hirth He S 011 series turbojet engine with a 264-gallon internal fuel capacity, supplying a flight time of at least a 1/2 hour.
The First Me P.1101
Work to fulfill the RLM requirement (and therefore obtain the potentially lucrative production contract thereafter) within the Messerschmitt firm began on July 24th, 1944. Messerschmitt engineer Hans Hornung began penciling out a design under the designation of "P.1101" as a stout, single-engine jet fighter with a "Vee" style tail arrangement, a fully-retractable tricycle landing gear system, swept-back wings and split side-mounted circular air intakes. The cockpit was held to the extreme forward of the tear-drop fuselage and was to offer up good visibility from out of the three-piece canopy. The wing leading edges were set at two different sweep angles (40- inboard and 26-degree outboard) while the trailing edge featured a consistent sweep with flap installations. Wings were mid-mounted along the sides of the oval fuselage which tapered at the rear. The rear held the "Vee" tail angled planes. The engine would have exhausted out at the base of the empennage, fitted at about 3/4 position of the fuselage underside. Armament was intended to be a pair of 30mm MK 108 series cannons fitted to each forward fuselage side. Provision was entertained for the carrying of a single bomb held under the fuselage center, with the bomb being placed in a semi-recessed enclosure.
The Second Me P.1101
A second P.1101 design emerged on paper on August 30th, 1944. This particular approach was more dart-like in appearance and made use of a sharp nose-cone assembly just ahead of the two-piece canopy system. The cockpit was situated further aft but still relatively forward in the design overall. The fuselage once again tapered into an extended boom mounting the Vee-style tail assembly. The powerplant was seated at the base of the fuselage and exhausted at the base of the empennage as in the previous design. The engine was aspirated via a pair of circular intakes fitted to either side of the cockpit. The wings were both equally swept and were essentially as those found on the Messerschmitt Me 262 jet-powered fighter-bomber. A tricycle undercarriage was once again the call of the day, though the shallower fuselage meant that the nose leg had to be rotated some 90-degrees to store itself flat in the forward bay. Proposed armament was to center around a pair of 30mm MK 108 series cannon OR - and this being perhaps somewhat optimistic - a pair of 55mm MK 112 cannons. Provisions were once again made for a single bomb to be carried under the fuselage.
The Finalized P.1101 Version
To help speed the project along, it was suggested that a flyable prototype be constructed alongside the ongoing data collection and evaluation testing. As such, work began on piecing together a new P.1101 design approach in late 1944, incorporating the culminated data for the project up to this point and utilizing whatever components were available from other existing aircraft. The new aircraft, designed by Willy Messerschmitt himself, would implement a unique ability to have its wing sweep adjusted manually while on the ground during pre-flight. This arrangement would allow for testing of the wing assembly at both 35- and 45-degree sweep as needed - something of a forerunner to the variable wing-sweep combat aircraft to follow decades later. Work was undertaken at the Messerschmitt facility at Oberammergau based in the mountains of Southern Germany. The target date for a first flight was penciled in for sometime in June of 1945.
The finalized P.1101 design form produced a relatively advanced turbojet-powered fighter. The single-seat platform sported a nose-mounted intake, aspirating the engine that was seated in the bowels of the lower fuselage. Like the previous P.1101 designs before it, the engine exhausted just past amidships under the boom empennage. The underside of the empennage was covered over in steel sheet to help protect the airframe from the hot jet exhaust. Unlike the previous P.1101 offerings, however, the new P.1101 design made use of a more traditional tail system mounting a single vertical tail fin and a pair of applicable horizontal planes mounted on the boom empennage (a "Vee" and "Tee" tail configuration were also in the works). All tail surfaces were constructed of wood. The fuselage was stout and deep to allow for adequate spacing for the intake ductwork, the engine compartment, radio equipment, the cockpit pressurization system and internal fuel stores. The fuselage was constructed out of duralumin.
Design of the P.1101 was such that a Junkers Jumo 004B jet engine would be used in the initial prototype but a relatively painless alteration to the more powerful Heinkel He S 011 turbojet could be made at a later time. The plywood-covered wings were shoulder-mounted assemblies on either side of the oblong fuselage and were lifted directly from the Messerschmitt Me 262 design. By this time, the new wings could sport three sweep angles of 30-, 40- and 45- degrees as needed. The undercarriage was, once again, of the tricycle arrangement and made up of a steerable single-wheeled nose landing gear leg and a pair of single-wheeled main landing gear legs attached to the same retraction device within the fuselage. The main landing gear was a modified form of the one as found on the Messerschmitt BF 109K fighter model. Armament was not to be fitted in the prototype for the time being though discussions ranged from a pair of 30mm MK 108 or a set of four 30mm MK 108 cannons for production forms. Pilot armoring was expected in the final production models as well but not exercised in the prototype. In perhaps a sign of the impending future, provision was also made to incorporate use of four X-4 wire-guided air-to-air missiles to be held underwing (two to each wing). In typical Messerschmitt fashion, the three-piece bubble canopy opened hinged to the starboard side of the aircraft.
Specifications were expected to be as follows for the prototype V1: A top speed of 534 miles per hour was envisioned along with a service ceiling of 32,808 feet while a climb rate of 39 feet per second was intended. An empty weight of 4,815lbs was expected along with a takeoff weight up to 7,066lbs with internal fuel making up 1,830lbs. As may be surmised, the production P.1101 (based on this prototype) was expected to showcase improved performance specifications that included a 612 mile-per-hour top speed and a service ceiling of 39,370 feet with a rate of climb equal to 73 feet per second. Range was listed at 932 miles.
At least on paper, the third vision of the P.1101 would have been quite the formidable opponent for Allied bombers and fighters alike.
The Program Comes to an Abrupt Close
While the Messerschmitt program moved along as best it could, inevitable delays caused by the relentless Allied bombing campaign soon began to take its toll on the facility at Oberammergau. Allied ground forces were finding success after success and claiming much of the previously-held German territory. Their warpath eventually brought them in the vicinity of the Oberammergau facility to which the Messerschmitt team began making future plans for the fate of their P.1101.
It should be noted here that, despite the Allied bombing campaigns wreaking havoc across Germany, the Oberammergau facility was as yet unknown to Allied war planners. As such, the facility operated without the disruptions inherent in sustained operations during constant aerial attack. While most other facilities across Germany suffered at the hands of the Allied bombers, Messerschmitt was allowed relatively unfettered progress in their Bavarian mountain location. At the very least, shipments of parts and components necessary to the survival of the P.1101 were some of what delayed the project but the Oberammergau facility was never targeted by Allied bombs. In fact, the Messerschmitt Oberammergau location came as something of a surprise to the Allies when they eventually stumbled upon it in the waning months of the European Theater.
The Oberammergau Facility Falls
As American ground forces moved in, Messerschmitt employees gathered up documents related to the P.1101 development. This included amassed data as well as schematic drawings. The information was transferred to microfilm and hidden throughout the surrounding villages in the area while the P.1101 was tucked away in a neighboring tunnel. The area soon fell to an American ground force on April 29th, 1945 and led to the discovery and subsequent capture of the P.1101 airframe. The prototype was not yet flyable though some 80% of the aircraft had indeed been finished by this time. After some days of foraging by the Americans and obtaining other company documents at the facility, Messerschmitt employees soon gave up the existence of the microfilm data to the Americans. However, French ground forces had already moved into the surrounding area and uncovered the valuable data, inevitably sending them back to France for further evaluation. American researchers later arrived at Oberammergau to study the existing P.1101 V1 prototype up close.
The French Dare Say No
Though a joint effort was made on the part of Bell Aircraft's Robert Woods (part of the American evaluation team) and Messerschmitt chief designer Woldemar Voight to finish the P.1101 V1 as planned, this proved insurmountable because of the missing data now in French hands. The French - for whatever reason - were not in the interest of sharing their new-found trophy. One could suppose that, considering the circumstances of the German invasion of France years earlier, French authorities were in no mood to listen to anything a German had to say. As such, the Americans were left with just the incomplete P.1101 airframe and little else. The P.1101 was scrutinized "as is" with its remains ultimately sent stateside for further research.
Bell Aircraft Kicks the Tires and Lights the Fires
Bell Aircraft Works of Buffalo was the proud recipient of the P.1101 V1 prototype, the prize arriving sometime in August if 1948. By now, the prototype proved to be in a sad physical shape for it had been exposed to the elements of Southern Germany and transported across Europe. It also suffered at the hands of those rough-handling American GI's bent on photographing the trophy whenever possible. In one final stroke of fate, the unfinished prototype was dropped from its transport railcar, further diminishing the prospect that the airframe could actually be completed and flown someday. However, Bell Aircraft took the P.1101 under their microscopes and still garnered quite a bit from the Messerschmitt experiment. The original P.1101 was mated with an American Allison J35 turbojet engine and had mock cannon armament fitted to her. Some ground testing of the system occurred and even more data collection ensued.
The Bell Aircraft X-5
Bell Aircraft eventually began a new project all their own - based highly on the P.1101 - and developed the experimental Bell X-5 jet-powered fighter. The new aircraft resembled the P.1101 almost to a tee. The X-5 became the first aircraft to feature variable sweep wings. Whereas the P.1101 depended upon technicians to change the wing sweep while the aircraft was at rest on the ground, the X-5 had the uncanny ability to vary this sweep "on-the-fly" while in the air. The variable wing sweep allowed the operator to change-up wing drag based on the current action at hand (landing, take-off, cruise) in effect making each action more efficient and somewhat controlled. The Bell X-5 first took to the air on June 20th, 1951. While two examples were eventually produced and successfully test flown, one was later lost to a crash on October 13th, 1953 after falling into an irrecoverable spin. Its wings were set to 60-degrees sweepback just before the accident ensued. The National Museum of the United States Air Force took on delivery of the sole existing Bell X-5 in March of 1958 - a place where the aircraft still resides to this day.
Variable wing-sweep eventually became the basis for future combat aircraft designs that included the Grumman F-14 Tomcat, General Dynamics F-111 Aardvark, Rockwell B1 Lancer, Mikoyan MiG-23/MiG-27 "Flogger", Tupolev Tu-22 "Backfire" and the Panavia Tornado. All proved successful in one form or another, proving the validity of variable wing sweep design and then some.
The Fate of P.1101 V1
The actual P.1101 V1 prototype airframe was used up as far as it could go and eventually handed over to the scrapman's torch sometime in the 1950s. While the direct legacy of the P.1101 was effectively over, the P.1101 lineage lived on for a time through the development of the Bell X-5. The Cold War-era Saab 29 "Tunnan" jet-powered fighter also shared some external similarities to the P.1101 design.