Gull-wing door

This article is about the type of car door. For the aircraftwing shape, see Gull wing.

Gull-wing door is an automotive industry term de-

Mercedes-Benz 300SL Gullwing Coupé with its doors open

A Bricklin SV-1 with its doors open

scribing car doors that are hinged at the roof rather thanthe side, as pioneered by the 1952Mercedes-Benz 300SLrace car (W194) and its road-legal version (W198) intro-duced in 1954.Opening upwards, the doors evoke the image of aseagull's wings. In French they are portes papillon (but-terfly doors). The papillon door, slightly different inits architecture from a gullwing door – designed byJean Bugatti in 1939 Type 64,[1] fourteen years beforeMercedes-Benz produced its similar, famous 300SL gull-wing door – is a precursor, but is often overlooked when

A DeLorean DMC-12 with its doors open

A Cessna 350 light aircraft with its gull-wing doors open

discussing “Gull-wing” design.[2] Conventional car doorsare typically hinged at the front-facing edge of the doorand the door swings outward in a horizontal plane.Apart from the Mercedes-Benz 300SL of the mid-1950sand the experimental Mercedes-Benz C111 of the early1970s, the best-known examples of road-cars with gull-wing doors are the Bricklin SV-1 from the 1970s andthe DeLorean DMC-12 from the 1980s. Gull-wing doorshave also been used in aircraft designs, such as the four-seat single-engine Socata TB series built in France.[3]

1 Practical considerations

Despite the common misconception that the gull-wingdoors are mere stylistic affectations, the design is a verypractical one in a tight urban parking space. When

1

2 3 LIST OF AUTOMOBILES

properly designed and counterbalanced, they require lit-tle side-clearance to open (about 27.5 cm, or 11” in theDeLorean[4]) and allow much better entrance/egress thanconventional doors. The most obvious downside to hav-ing gull-wing doors is that, should the car roll over andcome to rest on its roof, exit by the doors would be im-possible, requiring a large windscreen opening to escape.A Volvo concept car (Volvo YCC) that was designed byand for women had gull-wing doors as part of a designmeant to be appealing from a woman’s perspective. Gull-wing doors to make it easier to lift a bag to store it be-hind the drivers seat, increases visibility over the driver’sshoulder, and makes it easier to get in and out of thevehicle.[5]

The Tesla Model X, first introduced in 2015, has gull-wing doors (called falcon-wing doors by Tesla). TheModel X has several design considerations to make thedoors more practical. The doors are double hinged. Thisallows them to open with less clearance (horizontal andvertical) than would otherwise be required. The vehiclealso has sensors to determine ceiling height and the pres-ence of potential obstacles. The vehicle then determineshow the hinges will operate to open the doors and avoidthe obstacles, if possible.[6]

2 Design challenges

Gull-wing doors have a somewhat questionable reputa-tion because of early examples like the Mercedes andthe Bricklin.[7] The 300 SL needed the door design as itstubular frame race car chassis design had a very high doorsill, which in combination with a low roof would make astandard door opening very low and small. TheMercedesengineers solved the problem by also opening a part of theroof. The Bricklin was a more conventionally sized doorbut the actuation system was problematic in day-to-dayuse and led to unreliable operation until an aftermarketair-door upgrade was installed in all Bricklins.[8] In ad-dition, there was some concern that in making the doorsas light as possible they wouldn't provide adequate pro-tection in side-impact accidents. There was, however, noindication that this concern was justified.The DeLorean solved these problems by using a solid-steel torsion bar (supplied by Grumman Aircraft Engi-neering Corporation) to counterbalance a full-sized doorand then used simple pneumatic struts similar to thosefound in hatchback cars to open the doors and damp theirmovement.Other disadvantages of the system were not so easy to ad-dress. For example, the gull-wing designmakes creating aconvertible version of the car harder, as the hinges wouldbe removed with the roof, and standard doors would beneeded for the convertible. Mercedes did so when replac-ing the gullwing coupe altogether with the 300SL road-ster in 1958. It was never a concern for DeLorean since

no convertible version was ever planned.It also makes sealing the car against water leaks more dif-ficult because of the shape andmovement path of the dooritself.

3 List of automobiles

Gumpert Apollo

Melkus RS 1000

Tesla Model X

The following is a (partial) list of production and kit au-tomobiles with gull-wing doors:

3

3.1 Production cars• Autozam AZ-1 (Suzuki Cara)• Bricklin SV-1• Bristol Fighter• DeLorean DMC-12• De Tomaso Mangusta (engine compartment)• Gumpert Apollo• Hofstetter Turbo• Isdera Commendatore 112i• Melkus RS 1000• Melkus RS 2000• Mercedes-Benz 300SL• Mercedes-Benz SLS AMG• Pagani Huayra• (NSU) Thurner RS• Tesla Model X (rear passenger doors only)• Quant E• Quant F• Bugatti atlantic type 64

3.2 Kit cars

Gullwing doors are common in kit cars and many weremade that are not included on this list. They were almostalways one of the most mechanically problematic parts ofthese vehicles.

• AMT Piranha• Bradley GTII• Dare DZ• Eagle SS Mk1• Elite Enterprises Laser 917, inspired by the Porsche917

• Fiberfab Aztec 7, a loose replica of the Alfa RomeoCarabo concept car (which has scissor doors).

• Fiberfab Caribee/Banshee• Innes Lee Scorpion K19• Pelland Sports• Replicar Cursor• RPB GT• Burton Car Company hardtop• Siva S160 Spyder

4 Aircraft• Cessna 350

• Socata TB

5 See also• List of cars with unusual door designs

• Suicide doors

• Scissor doors

• Butterfly doors

• Sliding doors

• Canopy door

• Car door

6 References[1] http://www.bugatti.com/en/tradition/bugatti-models/

t64.html

[2] “Papillon and gull-wing door”

[3] “Socata Trinidad GT: A beautiful little French retractablewith a certain je ne sais quoi”, Plane & Pilot retrieved 3August 2011

[4] Knut Grimsrud. “DeLorean Frequently Asked Questions- Technical Information”. Dmcnews.com. Retrieved2009-12-08.

[5] “Volvo Concept Car”. Volvo Car France. RetrievedMarch 2, 2004.

[6] “Inside Tesla’s freaky Falcon Wing doors”.

[7] “Why Don't More Cars Have Gullwing Doors?". PopularMechanics.

[8] “Bricklin Specifications”. Saintjohn.nbcc.nb.ca. Re-trieved 2011-11-26.

7 External links

4 8 TEXT AND IMAGE SOURCES, CONTRIBUTORS, AND LICENSES

8 Text and image sources, contributors, and licenses

8.1 Text• Gull-wing door Source: https://en.wikipedia.org/wiki/Gull-wing_door?oldid=716431054 Contributors: Liftarn, Gbleem, Anobo, Arteitle,Furrykef, Aleph4, AlainV, Litefantastic, Niteowlneils, Matthead, Mateuszica, SamH, Andy Christ, Ericg, Twinxor, Milkmandan, Bobo192,JonGwynne, Hooperbloob, Nsaa, A strolling player, Vuo, Klparrot, Kelly Martin, Vanished User 3388458, Mikebabb, Yrithinnd, Clearedas filed, Cadillac, Rwxrwxrwx, Pil56, Jason Vanderhill, Crystallina, SmackBot, DTM, Pedrose, Xaosflux, Armeria, Chris the speller, Blue-bot, BabuBhatt, OrphanBot, SpinyNorman, Morio, Jwplumley, Zero10one, Carnby, WikiABG~enwiki, Earthlyreason, Ntsimp, Peripitus,SpeedyJ, EdJogg, Zchris87v, MrFlit, Y2kcrazyjoker4, Mdoc7, Clausewitz01, Soulbot, Randy G, Lihui912, CommonsDelinker, Aliaz-imi, 72Dino, Peppergrower, Prahanormal, Jimlanza, GTHO, Typ932, Cryonic07, SieBot, Swaq, Warren Whyte, Oxymoron83, Dino246,Regushee, YSSYguy, Chump Manbear, Mariordo, Wraithful, Zach4636, DineshAdv, Rynoshark, Romaine, Private Pilot, Addbot, Ghet-toblaster, ,ماني Luckas-bot, Yobot, Bunnyhop11, Amirobot, AnomieBOT, Snowrail, DSisyphBot, Mr.choppers, FrescoBot, Yamomwa3,TGCP, John of Reading, Bravo Foxtrot, ZéroBot, Wayne Slam, ClueBot NG, Elroygoh02, Matthiaspaul, BG19bot, Pvanhoesen, Matty.007,Caffeyw, Suzukiluke, Lemmons138, KH-1, Sandul666, Optrimes, Kitcarguy, Nigautam and Anonymous: 62

8.2 Images• File:1955_Mercedes-Benz_300SL_Gullwing_Coupe_34.jpg Source: https://upload.wikimedia.org/wikipedia/commons/a/a9/1955_Mercedes-Benz_300SL_Gullwing_Coupe_34.jpg License: CC-BY-SA-3.0 Contributors: ? Original artist: ?

• File:Bricklin_SV-1.jpg Source: https://upload.wikimedia.org/wikipedia/commons/5/5a/Bricklin_SV-1.jpg License: Public domain Con-tributors: public domain en:User talk:JonGwynne#Image source Original artist: User JonGwynne on en.wikipedia

• File:Cessna350N2546W02.jpg Source: https://upload.wikimedia.org/wikipedia/commons/1/1e/Cessna350N2546W02.jpg License:Public domain Contributors: Own work Original artist: Ahunt at English Wikipedia

• File:Commons-logo.svg Source: https://upload.wikimedia.org/wikipedia/en/4/4a/Commons-logo.svg License: CC-BY-SA-3.0 Contribu-tors: ? Original artist: ?

• File:DeLorean_DMC-12_with_doors_open.jpg Source: https://upload.wikimedia.org/wikipedia/commons/8/86/DeLorean_DMC-12_with_doors_open.jpg License: CC-BY-SA-3.0 Contributors: Wikipedia en Original artist: en:user:Grenex

• File:Folder_Hexagonal_Icon.svg Source: https://upload.wikimedia.org/wikipedia/en/4/48/Folder_Hexagonal_Icon.svg License: Cc-by-sa-3.0 Contributors: ? Original artist: ?

• File:Gumpert_Apollo_Dubai.jpg Source: https://upload.wikimedia.org/wikipedia/commons/c/c9/Gumpert_Apollo_Dubai.jpg License:CC-BY-SA-3.0 Contributors: GUMPERT Sportwagenmanufaktur GmbH Original artist: GUMPERT Sportwagenmanufaktur GmbH

• File:Melkus_RS1000.JPG Source: https://upload.wikimedia.org/wikipedia/commons/6/64/Melkus_RS1000.JPG License: CC-BY-SA-3.0 Contributors: Own work Original artist: Thomas doerfer

• File:Model_X_vs._DeLorean.jpg Source: https://upload.wikimedia.org/wikipedia/commons/2/29/Model_X_vs._DeLorean.jpg Li-cense: CC BY 2.0 Contributors: https://www.flickr.com/photos/jurvetson/21916454200/ Original artist: Steve Jurvetson

• File:Portal-puzzle.svg Source: https://upload.wikimedia.org/wikipedia/en/f/fd/Portal-puzzle.svg License: Public domain Contributors: ?Original artist: ?

8.3 Content license• Creative Commons Attribution-Share Alike 3.0