Perlan Project: Difference between revisions

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{{Infobox company

|name = The Perlan Project, Inc.

|image = Windward Performance Perlan II N901EE 01.jpg

|image_caption = Perlan II

|foundation = 1992

|founder = [[Einar Enevoldson]]

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Prior to the 4 September 2017 flight, the glider absolute world [[flight altitude record|altitude record]] stood at 15,460 meters (50,727 feet), which is the altitude reached by [[Steve Fossett]] and [[Einar Enevoldson]] during Perlan Mission I. The previous record was 14,938 meters (49,009 feet). It was set in 1986 by Robert R. Harris, flying from [[California City]] and reaching his record height over [[Mount Whitney]], California.<ref>*[http://records.fai.org/gliding/history.asp?id1=DO&id2=1&id3=98 Official FAI Gliding Open Class Absolute Altitude World Record] {{webarchive|url=https://web.archive.org/web/20050219015448/http://records.fai.org/gliding/history.asp?id1=DO&id2=1&id3=98 |date=19 February 2005 }}</ref> This may be near the limit for standing mountain waves in temperate latitudes, although in unusual meteorological conditions much higher altitudes may be achievable.

Standing waves normally do not extend above the tropopause at temperate latitudes. A strong west wind usually decreases above the tropopause, which has been shown to cap or prevent the upward propagation of standing mountain waves. However, at the outer boundary of the [[polar vortex]], in winter, the stratospheric [[polar night jet]] exists. Its wind field can join with the wind field of the polar [[jet stream]]. The result is a wind which increases with altitude through the [[tropopause]] and upward to 100,000 feet or above. When this conjunction of winds occurs over a barrier mountain, standing mountain waves will propagate through that entire altitude range. [[Einar Enevoldson]], former [[NASA]] test pilot, sought to demonstrate the feasibility of riding these stratospheric standing mountain waves. The weather conditions favorable, although not in every case required to exist simultaneously for a climb into the stratospheric waves, are not exceptional. The following list of requirements for record attempts was given in an article published in 2014:<ref name=":0">{{CitationCite news needed|date=July2014-11-01 2015|title=Airbus Perlan Mission II |url=https://issuu.com/mccawmedia/docs/soaringissue39_web_backissue |access-date=2024-09-20 |work=SoaringNZ |pages=27}}</ref>

*Prefrontal conditions

*The stratospheric polar night jet overhead (occurring in near-polar latitudes during the late winter and early spring),{{Citation needed|date=July 2015}}

*Ridge top winds ≥ 40 knots

*Pre-frontal conditions,{{Citation needed|date=July 2015}}

*Winds within 30 degrees of perpendicular to ridgeline

*A gradual increase in wind speed with altitude,{{Citation needed|date=July 2015}}

*Strong low-level winds

*Wind direction within 30° of perpendicular to the mountain ridgeline,{{Citation needed|date=July 2015}}

*Strong low-altitude winds in aA stable atmosphere,{{Citation needed|date=July 2015}}

*A gradual wind increase in altitude

*Ridge-top winds of at least 20 knots.{{Citation needed|date=July 2015}}

*A weak tropopause

These conditions often occur during late winter and early spring over the southern Andes and Scandinavia.<ref name=":0" />

These conditions are likely to occur in the southern region of Patagonia three to four times per year between mid-August and mid-October. They probably occur in New Zealand, but less frequently; over the Antarctic Peninsula more frequently; and at several locations in the northern hemisphere, but closer to the North Pole at latitudes above 60° north.{{Citation needed|date=July 2015}}

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A great deal of design work has been done by Greg Cole of [[Windward Performance]] to show that a sailplane for 90,000 feet is relatively straightforward, while 100,000 feet is possible, although more difficult and expensive. Windward Performance would build the sailplane of high performance pre-preg in production-quality tooling. The sailplane required relatively high-end design, analysis, and construction to be flutter-safe at very high true air speeds, and strong enough for the potentially heavy turbulence that could be encountered at 90,000 feet. It must also have well-proven, fail-safe pressurization and cabin air re-cycling systems.

In 2014, [[Airbus]] agreed to become the title sponsor, and provide sufficient funding for completion of the aircraft, flight testing and the altitude flights. The mission aswas renamed the [[Airbus Perlan Mission II]].

[[RDD Enterprises]], an aviation research, design and development company based in [[Redmond, Oregon]], took over the manufacture of the [[Windward Performance Perlan II|Perlan 2]].

===Flight campaigns===

[[File:Windward Performance Perlan II N901EE 02.jpg|thumb|Perlan II N901EE at EAA AirVenture Oshkosh in 2022]]

The aircraft was completed in the summer of 2015, with first flight scheduled for 7 September. Windy conditions that day prevented the flight, which finally occurred on 23 September.<ref>[http://www.opb.org/news/article/experimental-glider-flies-for-first-time-in-redmond/ "Experimental Glider Flies for the First Time in Redmond"]</ref> Flight testing started in [[Minden, NV]] in fall and winter of 2015, using a new hangar donated by Tito.<ref>{{cite web | url=http://www.flyingmag.com/perlan-2-glider-preps-for-flight-tests | title=Perlan 2 Glider Preps for Flight Tests | date=17 December 2015 }}</ref> The first attempts to reach 90,000 feet will be launched from [[El Calafate]], [[Argentina]], deep in the south of [[Patagonia]], in the [[Southern Hemisphere]] soon afterwards in summer of 2016.<!--use month, as summer is January in South-->

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The 2018 season was again based at El Calafate. The project acquired a [[Grob G 520|Grob G 520 Egrett]] turboprop aircraft for use as a tow plane. This enabled Perlan II to be towed to {{cvt|44,000|ft|0}} <ref>{{cite web|url=http://www.perlanproject.org/blog/stratospheric-tow-perlan-2-egrett|title=Stratospheric tow of Perlan 2 by Egrett}}</ref> This seems to be the highest glider tow, although such records are not registered.

[[File:Windward Performance Perlan II N901EE 03.jpg|thumb|Perlan II's list of actual and hoped-for records as of 2022]]

On 26 August 2018 Jim Payne and Morgan Sandercock reached an altitude of {{cvt|18,492|m}}.<ref name=Airbus3sep2018 /><ref name=altituderecords>{{cite web|url=https://www.fai.org/records?f%5B0%5D=field_record_sport%3A2019&f%5B1%5D=field_type_of_record%3A504|title=FAI Absolute Altitude Records : Gliding}}</ref>

This was followed by {{cvt|19,439|m}} with Jim Payne and Miguel Iturmendi on 28 August 2018.<ref name=altituderecords />

On 2 September 2018, Jim Payne and Tim Gardner reached an altitude of {{cvt|22,646657|m}},<ref name=altituderecords /> surpassing the {{cvt|73,737|feet}} attained by Jerry Hoyt on 17 April 1989 in a [[Lockheed U-2]]: the highest manned, heavier -than -air, subsonic flight.<!--<ref name=Airbus3sep2018>-->

The Perlan 2 could fly to {{cvt|90,000|feet}} if conditions allow, higher than the manned level flight altitude record of the [[SR-71 Blackbird]] at {{cvt|85,069|feet}}.<ref name=Airbus3sep2018>{{cite press release |url= https://www.airbus.com/newsroom/press-releases/en/2018/09/airbus-perlan-mission-ii-glider-soars-to-76-000-feet-to-break-ow.html |title= Airbus Perlan Mission II glider soars to 76,000 feet to break own altitude record, surpassing even U-2 reconnaissance plane |date= 3 September 2018 |publisher= Airbus}}</ref>

Previous records were measured with [[pressure altitude]]; high altitude soaring records now require [[GPS]] data.<ref>{{cite news |url= http://www.perlanproject.org/blog/world-record-claim-above-60000-feet-august-26-2018 |date= 27 August 2018 |title= World Record Claim Above 60,000 Feet on August 26, 2018 |publisher= Perlan Project}}</ref>

==Notes==

{{reflist|group=note}}

==References==