View source for Engineering:Piper PA-30 Twin Comanche

{{short description|American twin-engined cabin monoplane built 1962–1972}}
{|{{Infobox aircraft begin
 |name= PA-30 Twin Comanche
 |image= File:N25PR_(44839824742).jpg
 |caption= 1967 Twin Comanche C/R
}}
{{Infobox aircraft type
 |type=Cabin monoplane
 |manufacturer=Piper Aircraft
 |national origin=United States
 |designer=
 |first flight= November 7, 1962<ref>{{Cite web|url=http://www.pilotfriend.com/aircraft%20performance/Piper/13.htm|title=Piper PA30 PA39 Twin Comanche Aircraft history performance and specifications|access-date=March 2, 2015|archive-date=December 3, 2010|archive-url=https://web.archive.org/web/20101203153837/http://www.pilotfriend.com/aircraft%20performance/Piper/13.htm|url-status=live}}</ref>
 |introduced=
 |retired=
 |status=
 |primary user=
 |more users=
 |produced=1961–1972
 |number built=PA-30: 2001<br>PA-39: 155
 |developed from= [[Engineering:Piper PA-24 Comanche|Piper PA-24 Comanche]]
 |variants with their own articles=
}}
|}
[[File:Piper PA-30 Twin Comanche C-FBDK 03.JPG|thumb|right|Turbo PA-30 with tip tanks and vortex generators installed]]
[[File:Piper PA-30 Twin Comanche C-FQPK 01.JPG|thumb|right|PA-30 Twin Comanche with modified dorsal fin and modified air intake in nacelles]]
[[File:PA-30-TwinComanche.jpg|thumb|PA-30 Twin Comanche]]

The '''Piper PA-30 Twin Comanche''' is an American twin-engined cabin monoplane designed and built by Piper Aircraft. It was a twin-engined development of the [[Engineering:Piper PA-24 Comanche|PA-24 Comanche]] single-engined aircraft. A variant with counter-rotating propellers was designated the '''Piper PA-39 Twin Comanche C/R'''.<ref name="guide">Murphy, Tom and Hans Halberstadt, ''Illustrated Piper Buyer's Guide,'' 1993, MBI Publishing / Motorbooks International, Osceola, Wisconsin</ref><ref name="9th_v2">Ibold, Ken, ed., ''Aviation Consumer's Used Aircraft Guide, 9th Edition,'' vol. 2, 2001, Belvoir Publications, Greenwich, Connecticut</ref><ref name="harris">Harris, Richard, [http://home.iwichita.com/rh1/hold/av/avhist/ppr/piper.htm "Piper Aircraft: a quick history,"] {{Webarchive|url=https://web.archive.org/web/20181208083442/http://home.iwichita.com/rh1/hold/av/avhist/ppr/piper.htm |date=December 8, 2018 }}''InFlight USA'' magazine, 2000–2001, as revised and expanded to 2014, on ''Aviation Answer-Man,'' website, retrieved May 11, 2017</ref>

==Development==
The Piper PA-30 Twin Comanche was designed as a twin-engined variant of the [[Engineering:Piper PA-24 Comanche|Piper PA-24 Comanche]].  A complex light twin, with retractable landing gear, seating 4 (in original models) to 6 (in later models), and cruise speeds ranging from 160–210&nbsp;mph on twin 150–160 horsepower engines, it competed with the more-powerful [[Engineering:Cessna 310|Cessna 310]] and Beech Baron, and later with Piper's other light twins.<ref name="guide" /><ref name="9th_v2" /><ref name="harris" />

The Twin Comanche was designed to replace the Piper Apache in the company's lineup of products.{{citation needed|date=October 2021}} The prototype was converted from the single-engined Comanche by Ed Swearingen who at the time operated a facility that specialized in the modification of production aircraft. A Comanche was modified with two 4-cylinder 160&nbsp;hp (120&nbsp;kW) Lycoming IO-320-B1A engines and first flew at San Antonio, Texas on 12 Apr 1961.<ref name="pepperell292-299">Peperell 2020, pp. 292–299</ref> The design was designated the PA-30 on the March 17, 1962 and named the Twin Comanche.<ref name="pepperell292-299" /> The prototype (registered N7000Y) was built at Lock Haven and first flew on November 7, 1962. FAA Type approval was awarded on February 5, 1963, the first production aircraft was completed on April 2, 1963 and the first delivery made on July 15, 1963.<ref name="pepperell292-299" />

The first Twin Commanche B was announced on September 2, 1965 with deliveries starting in November 1965.<ref name="pepperell292-299" /> The aircraft had minor changes with two additional seats and an extra cabin window on each side.<ref name="pepperell292-299" /> A turbocharged variant of the Twin Comanche B was available with 160&nbsp;hp (120&nbsp;kW) Lycoming IO-320-C1A engines.<ref name="pepperell292-299" />

In 1966, the PA-30-200 was developed with two 200&nbsp;hp engines, the prototype first flew on January 16, 1967 but Piper decided not to put the variant into production.<ref name="pepperell292-299" /> Following the cancellation of the PA-30-200, the company introduced the Twin Comanche C. It had a new interior, a different external paint scheme, and a higher cruise speed.<ref name="pepperell292-299" /> First deliveries of the Twin Comanche C were made in November 1968.<ref name="pepperell292-299" /> The last PA-30 was completed at Lock Haven on November 5, 1969 when it was replaced on the line by the PA-39.<ref name="pepperell292-299" />

During 1969, a number of developments to improve the flight characteristics of the PA-30 were tested which resulted in the Twin Comanche D with counter-rotating engines, the prototype first flying on September 23, 1969.<ref name="pepperell410-411">Peperell 2020, pp. 410–411</ref> For marketing reasons, the type was re-designated the PA-39 and received FAA Type Approval on November 28, 1969. The first production aircraft was completed on December 23, 1969.<ref name="pepperell410-411" />

The Twin Comanche was produced on the same Lock Haven, Pennsylvania, production line as its single-engined cousin; production ceased when the factory was flooded in 1972.  Piper chose at that time to focus on its equally popular Cherokee 140/180/235/Arrow line, manufactured in Florida, and its highly popular twin-engined [[Engineering:Piper PA-34 Seneca|Seneca]], which is essentially a Twin [[Engineering:Piper PA-32|Cherokee Six]]. The [[Engineering:Piper PA-40 Arapaho|Piper PA-40 Arapaho]] had been scheduled to replace the PA-39 in the 1973–74 timeframe. Three were manufactured, and the aircraft was already fully certified when the decision was made not to proceed with the manufacture.

==Design==
The Twin Comanche is a low-wing cantilever monoplane with a retractable tricycle landing gear. With tip tanks, the aircraft holds 120 gallons (454 L) of fuel. Fuel burn at typical cruise settings is approximately 16 gal/h (58.7 L/h) with a cruise speed of 165 kn. It easily climbs to 18,000 feet (5,500 m) when desired (24,000 feet (7,300 m), if turbocharged). When compared with the Seminole, the Twin Comanche goes faster, carries more, burns less fuel, climbs more rapidly and ultimately higher, is quieter. When compared to the Seneca, which is really quite a different aircraft, the more noticeable differences are in handling. Another contemporary competitor to the Twin Comanche was the [[Engineering:Beechcraft Travel Air|Beechcraft Travel Air]]. A similar airplane in form and function was the [[Engineering:Gulfstream American GA-7 Cougar|Gulfstream American GA-7 Cougar]], which went into production after the Twin Comanche's production run ended.

==Operational history==
The Twin Comanche suffered a number of [[Physics:V speeds#Regulatory V-speeds|V<sub>MC</sub>]] ([[Physics:Minimum control speeds|Velocity Minimum Controllable]]) loss-of-control crashes in the 1960s and early 1970s.  Initially, focus was placed on the aircraft design and the FAA reacted by issuing an airworthiness directive changing the V<sub>MC</sub> speed, though there was no change in the aerodynamics.  At the time, well known aviation journalist, Richard L. Collins, was highly critical of the FAA's multiengine training standards which encouraged unsafe V<sub>MC</sub> demonstrations at low altitude.<ref>Collins, Richard, "What about the Twin Comanche?", Flying, March 1969, p. 46.</ref> Collins pointed out in another article that year that one FBO had suffered four fatal V<sub>MC</sub> roll-over spins. Two were in a Twin Comanche, One in a Beech Travel Air and one in a Beech Baron.<ref>Collins, Richard, "Safety check", Flying, October 1969, p. 96.</ref>  It is not surprising that the Twin Comanche had a higher number of such crashes as it was used more often as a training aircraft.  The FAA performed a series of flight tests on the Twin Comanche and NASA conducted wind tunnel tests and found no unusual tendency to spin beyond what would normally be expected given the airflow of the normally rotating propellers.<ref>Winter, Kristin, "The Twin Comanche: "Safety facts and best practices", ''Piper Flyer'', March 2016, p. 50.</ref>

In the 1970s, the FAA changed its training standards and required flight instructors to obtain a separate rating to teach in multiengine aircraft. The V<sub>MC</sub> crashes dissipated dramatically. In 1997, the Aircraft Owners and Pilots Association (AOPA) Air Safety Institute published a safety review of the Comanche series aircraft and concluded that the Twin Comanche showed no greater tendency for V<sub>MC</sub> roll-over spins than comparable aircraft.<ref>Air Safety Institute, Piper Comanche Safety Review, November 1, 1997.</ref> Kristin Winter, a long time Twin Comanche instructor, operator, and trained accident investigator, reviewed the NTSB records for a ten-year period ending in 2014 and concluded that the Air Safety Institute's report was correct in its conclusions. Of the six single engine loss of control crashes, most resulted from inexperienced pilots and substandard training.<ref>Winter, The Twin Comanche, p. 51</ref>

Prince William of Gloucester bought a Twin Comanche and used it as his personal aircraft for several years in the 1960s. He flew it from the United Kingdom to Nigeria, where he held a diplomatic post; then later returned in it to the United Kingdom and flew it to Japan when he took up a diplomatic post in that country.<ref>[http://www.flightglobal.com/pdfarchive/view/1972/1972%20-%202414.html "HRH Prince William of Gloucester", ''Flight International'', September 7, 1972, p.341a (online archive version)] {{Webarchive|url=https://web.archive.org/web/20160306222709/https://www.flightglobal.com/pdfarchive/view/1972/1972%20-%202414.html |date=March 6, 2016 }} retrieved August 13, 2012</ref>

A Twin Comanche was flown in the 1992 and 1994 French Arc en Ciel air races. It is the only US aircraft to have raced twice around the world. In the pilot-skilled races, 1992 pilot and Pioneer Hall of Fame enshrinee and 100 Aviation Hero for the First Century of Flight, Marion P. Jayne and her daughter Nancy Palozola placed second. In 1994 Jayne and her daughter, Patricia Jayne (Pat) Keefer won the FAI Gold Medal in what, so far, is the longest race in history at over 21,000 miles flown May 1–24, 1994. With FAA approval the twin carried a total of 252 gallons in 11 tanks and at maximum power went over 2,100 miles nonstop between Marrakech, Morocco and Istanbul, Turkey in 11:19 hours.<ref name="Jayne">{{Cite web|url = http://www.firstflightcentennial.org/100_Aviation_Heroes.html|title = Honoring 100 Aviation Heroes Tuesday, December 16|access-date = December 18, 2010|last = First Flight Foundation|date = December 2003|url-status = dead|archive-url = https://web.archive.org/web/20101214203724/http://firstflightcentennial.org/100_Aviation_Heroes.html|archive-date = December 14, 2010|df = mdy-all}}</ref>

All Twin Comanche engines have long times between overhaul (2000 hours for the B1A, 1800 for the IO-320-C1A)<ref>Lycoming Service Instruction 1009AV, dated July 13, 2013.</ref> and have developed a reputation for reliability.

Following a string of crashes involving pilot loss-of-control in single-engine flight (due to engine failure, or in pilot training for engine-failure conditions), Piper sought to alter the plane's single-engine behavior at low airspeeds (such as takeoff and landing). The resulting '''PA-39 Twin Comanche C/R''' was a modified version with counter-rotating engines (to eliminate the "[[Engineering:Critical engine|critical engine]]" which, when failed, created the greatest risk of loss-of-control). The PA-39 replaced the PA-30 in the early 1970s. At least one comparative study of U.S. crash rates for the PA-30 and PA-39 indicated that crash rates for the counter-rotating PA-39 were only one-third of those for the conventional PA-30. Piper subsequently expanded the counter-rotating engine development to its other light twins.<ref name="harris"/><ref name="guide" /><ref name="9th_v2" /><ref name="failures_1979ntsb">[http://libraryonline.erau.edu/online-full-text/ntsb/aviation-special-studies/AAS79-02.pdf Special Study: "Light Twin-Engine Aircraft Accidents Following Engine Failures, 1972–1976,"] {{Webarchive|url=https://web.archive.org/web/20210609102039/http://libraryonline.erau.edu/online-full-text/ntsb/aviation-special-studies/AAS79-02.pdf |date=June 9, 2021 }} NTSB-AAS-79-2, 1979, National Transportation Safety Board, [[Place:Washington, D.C.|Washington, D.C.]], as retrieved from ERAU Library, May 16, 2017</ref>

As of November 3, 2019, 80 PA-39's remain on the Federal Aviation Administration (FAA) registry.<ref name="FAAReg2">{{cite web|url = https://registry.faa.gov/aircraftinquiry/Mms_results.aspx?Mmstxt=7103902&conVal=0&PageNo=1|title = PA-39 Make / Model Inquiry Results|access-date = November 3, 2019|publisher = Federal Aviation Administration|date = November 3, 2019}}{{Dead link|date=December 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

==Variants==
Three versions of the PA30 were produced: the original, a B model, and a C model. The B and C models can carry six passengers and can be identified by the additional side windows. Factory turbocharged engines became available with the B model. Turbo models can be identified by the presence of vents on the nacelle sides. These use Rajay turbochargers with manual wastegates operated by twin knobs under the throttle quadrant. They are properly termed "turbonormalized" since the compression ratio and maximum manifold pressure remained unchanged. Pilots are required to use care to avoid overboosting at low altitudes, since no overboost popoff valves are used. Since there is no accompanying power increase, the B/C models simply give owners a fuel vs. passenger tradeoff. The two rearmost seats, occupying the baggage compartment, are quite small.

;PA-30 Twin Comanche
:Four-seat twin-engined cabin aircraft powered by two 160&nbsp;hp (119&nbsp;kW) Lycoming IO-320-B1A engines in wing-mounted nacelles. The aircraft was available in five levels of equipment fit:

::Standard.
::Custom – additional instruments
::Executive – additional instruments and radio equipment
::Sportsman – Palm Beach interior and exterior and AltiMaticII autopilot
::Professional – full IFR panel
;PA-30 Twin Comanche B
:PA-30 with a third cabin window on each side and an optional fifth or sixth seat
;PA-30 Turbo Twin Comanche
:Turbonormalized version of the PA-30B Twin Comanche, powered by two Rajay turbonormalized IO-320-C1A piston engines
;PA-30 Twin Comanche C
:Twin Comanche B with new instrument panel, switches, and other minor variations. Optional turbonormalized version.
;PA-30-200
:Experimental variant with two 200&nbsp;hp Lycoming engines, one built
;PA-30-290
:Experimental variant with two 290&nbsp;hp Lycoming IO-540-G engines, one converted from PA-30 prototype
;PA-30 Twin Comanche D
:Original designation for the PA-39.
;PA-39 Twin Comanche C/R
:PA-30 with counter-rotating 160&nbsp;hp Lycoming IO-320-B1A engines and modified wing leading edges
;PA-39 Turbo Twin Comanche C/R
:Turbocharged version of the PA-39 Twin Comanche C/R
;[[Engineering:Piper PA-40 Arapaho|Piper PA-40 Arapaho]]
:Developed and fully certified version of PA-39 with entirely different wing and extensive fuselage modifications. Three prototypes only.

==Specifications (PA-39)==
[[File:Piper PA-30 Twin Comanche B 3-view line drawing.png|frameless|right|3-view line drawing of the Piper PA-30 Twin Comanche B]]

{{Aircraft specs
|ref=Jane's All The World's Aircraft 1971–72<ref name="jawa71p389">{{Harvnb|Taylor|1971|p=389}}</ref>
|prime units?=imp
|genhide=
|crew=
|capacity=4–6
|length m=
|length ft=25
|length in=2
|length note=
|span m=
|span ft=36
|span in=9+1/2
|span note=(including tip tanks)
|height m=
|height ft=8
|height in=3
|height note=
|wing area sqm=
|wing area sqft=178.0
|wing area note=
|aspect ratio=7.28:1
|airfoil=NACA 64<sub>2</sub>A215
|empty weight kg=
|empty weight lb=2270
|empty weight note=
|gross weight kg=
|gross weight lb=
|gross weight note=
|max takeoff weight kg=
|max takeoff weight lb=3725
|max takeoff weight note=
|fuel capacity={{convert|120|USgal|impgal L|abbr=on}} (with tip tanks)
|more general=
<!--
        Powerplant
-->
|eng1 number=2
|eng1 name=Lycoming IO-320-B1A
|eng1 type=air-cooled flat-four
|eng1 kw=<!-- prop engines -->
|eng1 hp=160<!-- prop engines -->
|prop blade number=2<!-- propeller aircraft -->
|prop name=Hartzell HC-E2YL-27663-4
|prop dia m=<!-- propeller aircraft -->
|prop dia ft=6<!-- propeller aircraft -->
|prop dia in=0<!-- propeller aircraft -->
|prop dia note=(counter-rotating)
<!--
        Performance
-->
|perfhide=

|max speed kmh=
|max speed mph=205
|max speed kts=
|max speed note=
|max speed mach=<!-- supersonic aircraft -->
|cruise speed kmh=
|cruise speed mph=178
|cruise speed kts=
|cruise speed note=(long range cruise)
|stall speed kmh=
|stall speed mph=70
|stall speed kts=
|stall speed note=(flaps down, power off)
|never exceed speed kmh=
|never exceed speed mph=272
|never exceed speed kts=
|never exceed speed note=
|minimum control speed kmh=
|minimum control speed mph=
|minimum control speed kts=
|minimum control speed note=
|range km=
|range miles=1200
|range nmi=
|range note=
|endurance=<!-- if range unknown -->
|ceiling m=
|ceiling ft=20000
|ceiling note=
|climb rate ms=
|climb rate ftmin=1460
|climb rate note=
|time to altitude=
|more performance=*'''Take-off run to 50ft (15m):''' {{convert|1530|ft|m|abbr=on}}
* '''Landing run from 50 ft (15 m):''' {{convert|1870|ft|m|abbr=on}}

|avionics=
}}

==See also==
{{aircontent
<!-- include as many lines are appropriate. additional lines/entries with carriage return. -->
|see also=
|related=<!-- related developments -->
* [[Engineering:Piper PA-24 Comanche|Piper PA-24 Comanche]]
|similar aircraft=<!-- similar or comparable aircraft -->
|lists=<!-- related lists -->
}}

==References==
;Notes
{{reflist|30em}}
;Bibliography
* The Illustrated Encyclopedia of Aircraft (Part Work 1982–1985), 1985, Orbis Publishing
* {{cite book|last=Peperell|first=Roger W.|title=Piper Aircraft – Freedom of Flight|year=2020|publisher=[[Engineering:Air-Britain|Air-Britain]]|isbn=978-0-85130-524-0}}
* {{cite book|editor-last=Taylor|editor-first=John W. R.|title=Jane's All the World's Aircraft 1971–72|year=1971|publisher=Sampson Low Marston & Co. Ltd|isbn=0-354-00094-2}}

==External links==


[[Category:Low-wing aircraft]]
[[Category:Twin piston-engined tractor aircraft]]

{{Sourceattribution|Piper PA-30 Twin Comanche}}