IAR 111

{{Short description|Supersonic mothership project}} {{Infobox aircraft | name = IAR-111 Excelsior | logo = | logo_size = | image = Haas 2 rocket with IAR 111 supersonic plane.jpg | alt = | caption = IAR-111 and [[Haas (rocket)#Haas 2|Haas 2]] rocket | long_caption = | other_names = | aircraft_type = Supersonic mothership | aim = | outcome = | related = | national_origin = Romania | manufacturer = [[ARCA Space Corporation|ARCA Space]] | design_group = | designer = [[ARCA Space Corporation|ARCA Space]] | builder = | issuer = | status = | owners = | primary_user = | more_users = | service = | major_applications = | proposals = | prototypes = | number_built = | construction_number = | civil_registration = | military_serial = | radio_code = | requirement = | aircraft_carried = | flights = | total_hours = | total_distance = | construction_date = | introduction = | retired = | first_flight = | initiated = | in_service = | last_flight = | expected = | developed_from = | variants = | developed_into = | preservation = | fate = | predecessors = | successors = | concluded = }}

The '''IAR-111 Excelsior''' was a cancelled [[supersonic]] [[Mother_ship#Spacecraft|mothership]] aircraft designed by the Romanian aerospace firm [[ARCA Space Corporation]]. It had ambitions of being the first supersonic aircraft produced by Romania.<ref name="arca-excelsior"/>

The IAR 111 was intended to replace ARCA's use of [[Balloon_(aeronautics)#Astronautics|carrier balloons]] for transporting rockets to orbit. Specifically, it was intended to transport a rocket payload up to {{convert|18000|m|ft|abbr=on}} as well as to support the wider development of technologies related to [[space tourism]]. The IAR was stated to be capable of Mach 1.5 at 16,000 meters while carrying the [[Haas (rocket)#Haas 2|Haas 2]] rocket, the IAR 111 was projected to be capable of attaining Mach 1.5 at 16,000 meters, and of Mach 2.6 at 30,000 meters while configured for space tourism development work. The cockpit, which was intended to accommodate a two-person crew in a [[tandem]] arrangement, was detachable and furnished with a pair of [[Drogue parachute|parachutes]] to slow its descent. As envisioned, the IAR 111 was to be constructed almost entirely from [[composite material]]s, powered by ARCA's in-house [[Executor (rocket engine)|Executor]] liquid-fuelled rocket engine, and was to be designed for take-off and landing from the sea surface.<ref name="111R1" />

The existence of the IAR 111 was announced in December 2010, although work had reportedly been underway for several years beforehand. By mid-2011, a pair of structures were being worked on, one of which was stated to be for low speed test flights while the other was reportedly for supersonic high-altitude flights. On 29 September 2011, a successful drop-test of the cockpit was carried out. In December 2011, it was reported that 60 percent of the fuselage of the first aircraft had been completed, and that an initial test flight was expected to occur sometime during mid-2012. By 2023, the project had been reportedly abandoned as a consequence of its high construction costs.<ref name = "thousand lives2023">{{Cite web |last=Bottlaender |first=Eric |date=29 January 2023 |title=Les mille et une vies d'ARCA Space : des fusées ou des arnaques ? |trans-title = The thousand and one lives of ARCA Space: rockets or scams? |url=https://www.clubic.com/mag/sciences/conquete-spatiale/dossier-455283-les-mille-et-une-vies-d-arcaspace-des-fusees-ou-des-arnaques.html |access-date=1 April 2023 |website=Clubic.com |language=fr}}</ref>

==History== The origins of the IAR 111 are closely linked with the founding of the Romanian aerospace firm [[ARCA Space Corporation]]. The design of the aircraft started before the successful launch of the [[ARCAspace#2005–2010:_Stabilo_and_Helen_rockets|Helen 2 rocket]]; early work on the project was carried out in secret throughout the 2000s.<ref name = "thousand lives2023"/> During December 2010, ARCA formally revealed the aircraft's existence to the general public via a press conference held at [[BRD – Groupe Société Générale|BRD]] headquarters in [[Bucharest]]. At the time of the reveal, the aircraft was still referred to by its initial name of ''E-111''.<ref name=111R1>{{cite news |url=http://www.gandul.info/magazin/cum-arata-primul-avion-supersonic-romanesc-inginerii-de-la-arca-lucreaza-la-prototip-vezi-aici-simulare-video-si-galerie-foto-cu-e-111-7839758 |title=Cum arată primul avion supersonic Românesc. Inginerii de la ARCA lucrează la prototip. Vezi aici simulare video şi galerie foto cu E-111 |trans-title=What the first Romanian supersonic aircraft looks like. ARCA engineers are working on the prototype. View this video simulation and photo gallery of the E-111 |work=[[Gândul]] |language=ro |first=Dan |last=Radu |date=22 December 2010 |access-date=18 March 2012}}</ref><ref name = "thousand lives2023"/> The aircraft was intended to replace the [[Balloon_(aeronautics)#Astronautics|carrier balloons]] that had been previously used by ARCA to transport rocket vehicles to sufficient altitude.<ref name="60structure dec2011"/>

In March 2011, ARCA received approval from [[Industria Aeronautică Română|IAR S.A. Brasov]] for the use of its initials on the aircraft, thus the E-111 was officially rebranded as the IAR 111. Work on the fuselage moulds started in early 2011 and were completed in September of that year, while the cockpit structure was completed in July. A pair of structures were under construction; while the first was intended to perform static tests as well as for low-altitude test flights, the second structure was stated to be capable of supersonic speeds and high altitude flight.<ref name="60structure dec2011"/>

In September 2011, the completion of [[computational fluid dynamics]] simulations for all possible flight configurations of the aircraft was announced. On 29 September 2011, a successful [[cockpit]] drop-test was carried out using a [[Mil Mi-17|Mi-17]] helicopter to lift the cockpit to {{convert|700|m|ft|abbr=on}} before dropping it to test the [[Ballistic parachute|parachute recovery system]].<ref name=111R2>{{cite news |url=http://adevarul.ro/news/eveniment/foto---video-cabina-primului-supersonic-romanesc-iar-111-testata-succes-zbor-pregatim-turism-spatial-1_50ad5e947c42d5a66393d73e/index.html |title=Cabina primului supersonic românesc IAR-111, testată cu succes în zbor. Ne pregătim pentru turism spaţial? |trans-title=The Cabin of the first Romanian supersonic IAR-111, successfully tested in flight. Preparing for space tourism? |work=[[Adevărul]] |language=ro |date=29 September 2011 |access-date=18 March 2012}}</ref><ref name = "droptest sep2011">{{cite web |url = https://www.antena3.ro/high-tech/supersonicul-romanesc-iar-111-la-primul-test-in-zbor-deasupra-marii-negre-138285.html |title = Supersonicul românesc IAR-111, la primul test în zbor, deasupra Mării Negre |trans-title = The Romanian supersonic IAR-111, at the first flight test, over the Black Sea |language=ro |date= 28 September 2011}}</ref> In December 2011, it was reported that the first two fuselage sections of the aircraft had been completed and had undergone preliminary assembly.<ref name="60structure dec2011">{{cite news |url=http://www.mediafax.ro/stiinta-sanatate/primul-avion-supersonic-romanesc-aproape-de-finalizare-60-din-structura-iar-111-realizata-9056182 |title=Primul avion supersonic românesc, aproape de finalizare: 60% din structura IAR-111, realizată |trans-title=First Romanian supersonic aircraft nearing completion: 60% of the structure of IAR-111 achieved |work=[[Mediafax]] |language=ro |date=13 December 2011 |access-date=18 March 2012}}</ref> At the time, an ARCA spokesperson stated that the IAR 111's final structure would be completed within the following three months, and that the aircraft would undergoing testing towards a flight, in collaboration with multiple state institutions, during mid-2012.<ref name="60structure dec2011"/> In March 2012, it was reported that ARCA has completed work on the first combustion chamber and nozzle of the first [[Executor (rocket engine)|Executor]] [[liquid-fuelled rocket|iquid-fuelled rocket engine]], which was intended to power the IAR 111.<ref name=executor_rtv> {{cite web |title=Avionul supersonic românesc: Vezi progresele făcute în construcţia motorului Executor FOTO |trans-title=The Romanian supersonic plane: See the progress made in the construction of the Executor engine |date=5 March 2012 |publisher=[[România TV|RTV]] |url=http://www.rtv.net/avionul-supersonic-romanesc-vezi-progresele-facute-in-constructia-motorului-executor-foto_19265.html |language=ro |access-date=20 March 2012}}</ref>

By 2023, no known flight of the IAR 111 had taken place and ARCA was seemingly concentrating on other projects, leading to media speculation that the project had been quietly abandoned.<ref name = "thousand lives2023"/>

==Design==

===Features=== The IAR 111 was designed to both take-off from, and land upon, the surface of the sea.<ref name="111R1" /> ARCA decided to use this approach to eliminate the need for [[landing gear]] and thus reduce the cost of the aircraft. Another factor that went into the decision was that [[Romania]] has no unpopulated areas above which to safely test the aircraft to high altitude flights.{{citation needed|date=April 2026}} The envisioned mission profile for the IAR 111 consisted of its take-off from the sea surface, followed by a horizontal acceleration phase from low subsonic speeds before a rapid ascent that would reach 48,000 feet within approximately two minutes, to the altitude of 48,000 feet before releasing the [[Haas (rocket)#Haas 2|Haas 2]] rocket, after which the aircraft would descend for a water-based landing.<ref name="arca-excelsior"/> While carrying the Haas 2 rocket, the IAR 111 was projected to be capable of attaining Mach 1.5 at 16,000 meters; in its alternate space tourism development platform configuration, it was stated to be capable of reaching Mach 2.6 at 30,000 meters.<ref name="arca-excelsior"/>

The aircraft was designed with diamond-shaped wings that reportedly both reduce weight and lower [[Drag_(physics)#Aerodynamics|drag]] during high speed flight. A "V" tail configuration was selected to avoid contact with the water on take-off and landing. For [[buoyancy]], the IAR 111 was to be provisioned with a pair of [[Float (nautical)|float]]s between which the payload would be positioned, which would also function as a third float.{{citation needed|date=April 2026}} The payload would have either been the Haas 2 rocket or an external fuel tank.

The [[flight control surface]]s would have been actuated using [[hydraulics|hydraulic]] power, and control would have been exercised via a [[fly-by-wire]] arrangement. The aircraft was to have been powered by ARCA's in-house [[Executor (rocket engine)|Executor]] liquid-fuelled rocket engine; it would have used [[kerosene]] as fuel and [[liquid oxygen]] as an [[Oxidizing agent|oxidizer]].<ref name="arca-executor">{{cite web |url=http://www.arcaspace.com/en/executor.htm |title=Executor Rocket Engine |publisher=ARCA Space Corporation |archiveurl=https://web.archive.org/web/20141009042218/http://www.arcaspace.com/en/executor.htm |archive-date=9 October 2014}}</ref>

===Cockpit=== The cockpit was have accommodated two people - the pilot and navigator - arranged in a [[tandem]] seating configuration.<ref name = "droptest sep2011"/> The forward position, intended for the pilot, would have been provided with a central console featuring [[Analog device|analogue]] navigation equipment along with [[GPS]] and a panoramic screen for a [[high-definition television]] to give greater visibility for assisting in the take-off and landing phases, while the sides would have populated by the [[radio]] communication apparatus, along with the various controls necessary for handling the aircraft. The rear position, occupied by the navigator, would have had their own console to display the various operating parameters of the aircraft, along with radio communication, navigation, [[passive radar]], and TV visuals for monitoring of the aircraft.<ref name = "droptest sep2011"/>

The cockpit walls and windows are very thick, able to withstand an engine explosion in case of failure of the rocket. Additionally, the cockpit is detachable and is equipped with a pair of rocket-propelled parachutes slow and stabilise its descent.<ref name = "droptest sep2011"/> The detach mechanism was to use a [[pneumatics|pneumatic]] system.<ref name="60structure dec2011"/> The aircraft will have a very large recovery parachute and a smaller [[anti-stall parachute]].<ref name="111R1" /> Mission 6 tested the safety systems with a drop test from {{convert|700|m|ft|abbr=on}}, during which one of the parachutes was opened to test the explosive bolts. This test was reported to be a success and that the cabin had been recovered in good condition.<ref name="111R2" /><ref name="arca-excelsior"/>

==Specifications== The specifications released to date are approximate design goals, and include:

{{Aircraft specs | ref = ''ARCA Space Corporation''<ref name="arca-excelsior">{{cite web |url=http://www.arcaspace.com/en/iar111.htm |title=IAR-111 Excelsior |publisher=ARCA Space Corporation |accessdate=30 January 2016 |archive-date=28 September 2013 |archive-url=https://web.archive.org/web/20130928155643/http://www.arcaspace.com/en/iar111.htm |url-status=dead }}</ref> |prime units?= met  |crew= 2 |capacity= |length m= 24 |length note= |span m= 12 |span note= |height m= 5 |height note= |wing area sqm= 100 |wing area note= |aspect ratio= |airfoil= |empty weight kg= 7,200 |empty weight note= |gross weight kg= 19,000 |gross weight note= |max takeoff weight kg= 23,000 |max takeoff weight note= |fuel capacity= |more general=  |eng1 number= 1 |eng1 name= [[Executor (rocket engine)|Executor]] |eng1 type= [[liquid-fuelled rocket|iquid-fuelled rocket engine]] |eng1 lbf= 44,000 |eng1 note=

|max speed kmh= |max speed note= |max speed mach= 2.6 |cruise speed kmh= |cruise speed note= |stall speed kmh= |stall speed note= |never exceed speed kmh= |never exceed speed note= |minimum control speed kmh= |minimum control speed note= |range km= |range note= |combat range km= |combat range note= |ferry range km= |ferry range note= |endurance= |ceiling m= 100,000 |ceiling note= |climb rate ms= 250 |climb rate note= |time to altitude= |wing loading kg/m2= 230 |wing loading note= |fuel consumption kg/km= |power/mass= |thrust/weight= 2.316 |more performance= |avionics= }}

==See also== * [[Northrop YF-23]], similar wing and tail shape * [[North American X-15|Boeing NB-52 & North American X-15]] * [[Pegasus (rocket)]] * [[Shuttle Carrier Aircraft]] * [[SpaceShipOne]]

==References== {{reflist}}

[[Category:Private spaceflight]] [[Category:Experimental aircraft]] [[Category:Rocket-powered aircraft]] [[Category:ARCAspace]]