View source for De Havilland Express

{{Short description|1934 four-engined passenger aircraft}}
{{Use dmy dates|date=May 2019}}
{{EngvarB|date=May 2019}}
{{lowercase title|de Havilland Express}}
{{Infobox aircraft
  |name = D.H.86 Express
  |image =File:De Havilland DH.86 1 AAU RAAF in flight c1942.jpg
  |caption = A D.H.86 air ambulance of the RAAF
  |type = Passenger transport / trainer
  |manufacturer = [[de Havilland]]
  |designer =
  |first_flight = 14 January 1934
  |introduction = 1934
  |retired =
  |status =
  |primary_users = [[Imperial Airways]]<br>[[Qantas]] <br>[[Union Airways]]<br>[[Royal Air Force]]<br>[[Royal Australian Air Force]]<br>[[Royal New Zealand Air Force]]
  |produced = 1934–1937
  |number_built = 62
  |unit cost =
  |variants =
}}

The '''de Havilland Express''', also known as the '''de Havilland D.H.86''', was a four-engined passenger aircraft manufactured by the [[de Havilland Aircraft Company]] between 1934 and 1937.

==Development==
[[File:Loila 'Australian National Airways' Sydney, 1937.jpg|thumb|VH-UUB Loila, 'Australian National Airways', Sydney, 1937]]
During 1933, talks between the governments of [[United Kingdom]], [[India]], [[British Malaya|Malaya]], the [[Straits Settlements]] and [[Australia]] resulted in an agreement to establish an [[Empire Air Mail Service]]. The Australian Government called for tenders on 22 September 1933 for the [[Singapore]]-Australia legs of the route, continuing as far south as [[Tasmania]]. On the following day [[Qantas]], anticipating success in contracting for the [[Singapore]]-[[Brisbane]] leg, placed an order with de Havilland for an as-yet non-existent aircraft to be designated the ''de Havilland 86'', the prototype to fly by the end of January 1934. This order was soon followed by one from [[Australian National Airways|Holyman's Airways]] of [[Launceston, Tasmania]] to operate the [[Bass Strait]] leg of the service. The D.H.86 was initially styled the ''Express'' or ''Express Air Liner'', although the name was soon discontinued.

The D.H.86 was conceptually a four-engined enlargement of the successful [[de Havilland Dragon]], but of more streamlined appearance with tapered wings and extensive use of metal fairings around struts and undercarriage. The most powerful engine made by de Havilland, the new 200&nbsp;[[horse power|hp]] (149&nbsp;kW) [[De Havilland Gipsy Six|Gipsy Six]], was selected. For long-range work the aircraft was to carry a single pilot in the streamlined nose, with a wireless operator behind. Maximum seating for ten passengers was provided in the long-range type; however, the short-range Holyman aircraft were fitted with twelve seats.

The prototype D.H.86 first flew on 14 January 1934, but the [[Qantas]] representative [[Lester Brain]] immediately rejected the single-pilot layout because he anticipated pilot [[fatigue (medical)|fatigue]] over long stretches, and the fuselage was promptly redesigned with a dual-pilot nose. Only four examples of the single-pilot D.H.86 were built, and of these the prototype was rebuilt as the dual-pilot prototype. When she entered service in October 1934 the first production aircraft, Holymans' single-pilot D.H.86 ''Miss Hobart'', was the fastest British-built passenger aircraft operating anywhere in the world. Despite de Havilland's predictions to the contrary, the dual pilot type with its lengthened nose proved to be even faster.

Investigations in 1936 following a series of fatal crashes resulted in late production aircraft being built with additional [[fin]] area in the shape of vertical "Zulu Shield" extensions to the tail planes to improve lateral stability – these aircraft were designated D.H.86B.

==Operational history==
[[File:De Havilland DH86 Express ZK-AEG over Dunedin, NZ.JPG|thumb|right|A [[Union Airways of New Zealand]] de Havilland D.H.86 flies over [[Dunedin]].]]
[[File:DH.86 Express G-ADVJ Bond Air Services.jpg|thumb|right|DH.86B G-ADVJ of charter airline Bond Air Services at Liverpool (Speke) Airport in March 1950. Note the "Zulu Shield" extensions to the tail planes]]

Early proving flights were flown in 1934 by [[Railway Air Services]] which had three of the first four single-pilot aircraft built.<ref name="jackson87">{{harvnb|Jackson|1987|pp=341–350}}</ref> The third aircraft built, G-ACVY ''Mercury'', started flying between [[Croydon Airport]], [[Castle Bromwich]], Barton, Belfast and Renfrew on 20 August 1934.<ref name="jackson87" /> The third aircraft built was shipped to Australia for [[Holyman's Airways]] to operate the Empire air route between Melbourne and [[Hobart]] in Tasmania.<ref name="jackson87" />

Dual-pilot D.H.86s were built for [[Imperial Airways]] and given the class name ''Diana''. They were used on [[Europe]]an and [[British Empire|Empire]] air routes including the run from [[Khartoum]] to [[Lagos]].

[[Railway Air Services]] (RAS) operated a fleet of seven Expresses between 1934 and 1946. RAS used the aircraft on their UK scheduled flight network including their trunk route from London Croydon via Birmingham, Manchester/Liverpool to Glasgow.

D.H.86s were also built for [[New Zealand]]'s [[Union Airways]], flying between [[Auckland]], [[Palmerston North]] and [[Wellington]]. During World War II, the New Zealand aircraft were fitted with bomb racks and used by the [[Royal New Zealand Air Force]] to hunt German raiders and Japanese shipping.

A total of 15 D.H.86s, D.H.86As and D.H.86Bs operated commercially within Australia and [[New Guinea]] up to the outbreak of [[World War II]]. Eight D.H.86A and D.H.86B aircraft were impressed into the [[Royal Australian Air Force]] and served as A31-1 to A31-8 during the War. Some served as air ambulances in the [[Middle East]], while others did sterling work as transport aircraft and air ambulances in Australia and New Guinea.<ref>[http://www.adf-serials.com/2a31.shtml ADF Serials D.H.86 page] {{Webarchive|url=https://web.archive.org/web/20071111051614/http://www.adf-serials.com/2a31.shtml |date=11 November 2007 }} retrieved on 2007-09-13.</ref>

A total of 62 D.H.86s of all types were built. Most of those still flying in Europe at the start of World War II, except for the Railway Air Services aircraft, were taken into military service, mostly for communications and radio navigational training. A few Expresses survived the war and were used by UK [[air charter]] operators until the last example was burnt out in 1958.

==Technical deficiencies==<!-- This section is linked from [[Qantas fatal accidents]] -->

Seriously lacking in directional stability, the D.H.86s were frequently in trouble. On 19 October 1934 Holyman's VH-URN ''Miss Hobart'' was lost in the [[Bass Strait]] with no survivors. [[Flotsam]] that may have been wreckage from the aircraft was seen from the air three days later but surface ships failed to locate it in rough seas; the aircraft had effectively vanished. At the time ''Miss Hobart'' disappeared it was thought that an accident may have occurred when Captain Jenkins and the wireless operator/assistant pilot Victor Holyman (one of the proprietors of [[Holyman's Airways]]) were swapping seats midflight. However, following the loss of Qantas' VH-USG near [[Longreach, Queensland|Longreach]] four weeks later while on its delivery flight, it was found that the fin bias mechanisms of the crashed aircraft and at least one other were faulty, although it is doubtful that this had any direct bearing on the accidents other than perhaps adding to the aircraft's lack of inherent stability. Further investigation revealed that VH-USG had been loaded with a spare engine in the rear of the cabin, and that one of the crew members was in the lavatory in the extreme aft of the cabin when control was lost. It was theorised that the [[centre of gravity]] was so far aft that it resulted in loss of control at an altitude too low for the pilot to recover (the aircraft was at an estimated height of {{convert|1000|ft|m|abbr=on}} prior to the crash).<ref>This section is largely sourced from the book ''Air Crash, Volume One'' by Macarthur Job. {{Cite book| author=Job, Macarthur| title=Air Crash, Volume One| edition=1991| publisher=Aerospace Publications | location=Canberra| year=1991 }}</ref>

On 2 October 1935 Holyman's VH-URT ''Loina'' was also lost in Bass Strait, again with no survivors. This time a significant amount of wreckage was recovered from the sea and from beaches on [[Flinders Island]]. Investigation of the wreckage revealed a section of charred carpet on a piece of cabin flooring from just ahead of the lavatory door. It was thought possible that a small fire from a dropped cigarette had led to someone running aft suddenly to stamp it out – a sudden change in weight distribution that could lead to fatal loss of directional control while the aircraft was on a low-speed landing approach.

On 13 December 1935, another Holyman DH86, ''Lepina'', forced-landed on Hunter Island off northern Tasmania with the lower port interplane strut having "vibrated loose".  An investigation by the Australian Civil Aviation Board using stop-motion film of the wing in flight resulted in identification of wing distortion and failure under certain flight conditions.  Australian authorities in December 1935 required the installation on all Australian DH86 aircraft of a complete set of lift bracing in the wing rear spar and redesign of the bracing on the tail unit to provide greater redundancy.<ref>P Ewer, ':Wounded Eagle'', New Holland Sydney 2009 p.74</ref>

The [[Royal Air Force]]'s [[Aeroplane and Armament Experimental Establishment]] tested the D.H.86A design in 1936 following three fatal crashes in Europe. It would be forty years before the report was published. The D.H.86 had been rushed from design concept to test flight in a record four months to meet the deadlines set by the Australian airmail contracts, and a lot of attention to detail had been ignored. It was a big aircraft for its power, and as a result very lightly built. There was poor response to control movements in certain speed ranges, the wings were inclined to twist badly if the ailerons were used coarsely and, most seriously, the vertical tail surface was of inadequate area. The result was an aircraft that, although quite safe under normal conditions, could rapidly get out of control under certain flight regimes.

[[File:VH-USE.jpg|right|thumb|de Havilland VH-USE crashed at Brisbane on 20 February 1942.]]
Although the control problems were overcome on later-manufactured D.H.86Bs by the fitting of a new spring in the elevator control and the fitting of auxiliary fins, the results of these tests do not appear to have been communicated to Australia so the D.H.86s already in use in Australia were never modified to improve their safety. This lack of communication may have caused a number of later accidents, including at least one of two fatal accidents in commercial service. The mid-air break-up of Qantas' VH-USE ''Sydney'' in a thunderstorm near [[Brisbane]] on 20 February 1942 with the loss of nine lives, was possibly unavoidable; however, the fin was found almost a mile away from the main wreckage which had been burnt. The accident involving [[MacRobertson Miller Airlines]]' ex-Qantas aircraft VH-USF at [[Geraldton]] on 24 June 1945 most likely was entirely avoidable had the AaAEE report been communicated to Australia.<ref>''Air Crash Vol. II'' pp107-111.</ref> On its first commercial flight for its new owners after military service, the pilot and a passenger were killed in a classic loss-of-control accident while taking off with a heavy load in gusty conditions.

Another D.H.86, VH-USW (the former Holyman's Airways ''Lepena''), was bought by MacRobertson Miller Airlines at much the same time as VH-USF and was the last of the type to fly in Australia. MMA sold the eleven-year-old aircraft to an English company late in 1946; it was abandoned in [[India]] in an "unsafe state" while on its delivery flight. Edgar Johnston, the Assistant Director General of the [[Airservices Australia|Australian Department of Civil Aviation]], then had it scrapped at Australian Government expense to make sure that it never flew again.<ref>''Air Crash Vol. II'' p111.</ref><ref>''The Historic Civil Aircraft Register of Australia'' VH-USW entry.</ref>

==Political and commercial consequences==
Following the first three fatal Australian D.H.86 accidents, and a forced landing by VH-USW ''Lepena'' on 13 December 1935 when the pilot believed his aircraft was about to break up in mid-air,<ref>It was later found that only a metal fairing had worked loose and was fluttering in the airflow, but this incident demonstrates the lack of confidence in the design held within the Australian aviation industry at the time.{{citation needed|date=June 2020}}</ref> the Australian Government temporarily suspended the type's [[Certificate of Airworthiness]]. This caused outrage in Britain as it reflected on the whole British aircraft industry. The D.H.86 had approached the limits to which traditional "plywood and canvas" aircraft construction could be taken,{{Citation needed|date=October 2012}} and was obsolete compared to all-aluminium stressed-skin aircraft like the [[Boeing 247]] and the [[Douglas DC-1]] that were already flying before it was even designed, and the [[Douglas DC-3]] that had its first flight just four days after the forced-landing of VH-USW. Under pressure from Holymans and other companies, in 1936 the Australian Government rescinded its ban on the import of American aircraft, and from then on, large airliners used in Australia were mostly of American manufacture.{{citation needed|date=March 2025}}

==Other accidents and incidents==
[[File:De Havilland DH.86 VH-USG wreckage.jpg|thumb|right|Remains of Qantas D.H.86 VH-USG (c/n 2311) displayed in the Qantas Founders Museum, Longreach (Qld.). This is all that remains of the sixty-two D.H.86 aircraft that were built.]]
* On 12 August 1936 G-ADEB of British Airways crashed near Altenkirchen, Germany.
* On 15 September 1936 G-ADYF of British Airways crashed during a night take off from Gatwick Airport, England.
* On the night of 15/16 March 1937 G-ACVZ ''Jupiter'' of Railway Air Services, carrying [[Charles Wolley-Dod]], crashed at Elsdorf near Cologne, Germany.<ref name=CT1937>{{cite news |title=Disaster in Germany; discovery by woodcutter|work= Croydon Times |date=20 March 1937|page=1|url=https://www.britishnewspaperarchive.co.uk/viewer/bl/0004277/19370320/014/0001|via=British Newspaper Archive|url-access=subscription}}</ref>
* On 9 May 1938, G-AENR of [[Isle of Man Air Services]] crashed on landing at [[Ronaldsway Airport]], [[Isle of Man]]. The aircraft was operating a mail flight from [[Speke Airport]], [[Liverpool]], [[Lancashire]]. Despite substantial damage to the port lower wing and both port engines, the aircraft was repaired and returned to service.{{sfn|Poole|1999|pp=14–15}}
* On 14 September 1938, G-ADVK of Isle of Man Air Services lost the starboard inner propeller in flight whilst operating a flight from Speke to Ronaldsway. The propeller embedded itself in the fuselage of the aircraft. A successful landing was made at Ronaldsway.{{sfn|Poole|1999|p=15}}
* 4 November 1938: DH.86 G-ACZN ''St. Catherine's Bay'' crashed at St. Peter's shortly after take-off from Jersey airport, en route to Southampton. All 13 occupants were killed in addition to one person on the ground.<ref>[https://jerseyeveningpost.com/news/2009/11/09/air-disaster-of-1938/ Air disaster of 1938]</ref>

==Variants==
;D.H.86: Four-engined medium-transport biplane. First production version, 32 built, the first four with a single-pilot cockpit.
;D.H.86A: Improved version with pneumatic landing gear, metal rudder and modified widescreen. 20 built, all converted to DH.86B standard.
;D.H.86B: Fitted with auxiliary "Zulu-Shield" endplate fins to the tailplane. 10 built.

==Operators==
♠ Original operators

===Civil operators===
{{AUS}}
* [[Australian National Airways]]<ref name="jackson87" />
* [[Holyman's Airways]]<ref name="jackson87" /> ♠
* [[MacRobertson Miller Airlines]]<ref name="jackson87" />
* [[Qantas]]<ref name="jackson87" /> ♠
* W.R. Carpenter<ref name="jackson87" /> ♠
{{BHR}}
* [[Gulf Aviation]]<ref name="jackson87" />
{{EGY}}
* [[EgyptAir#Early years: Misr Airwork (1932–1949)|Misr Airwork]]<ref name="jackson87" /> ♠
{{IND}}
* [[Tata Airlines]]<ref name="jackson87" />
{{IRL}}
* [[Aer Lingus]]<ref name="jackson87" />
{{NZL}}
* [[Union Airways of New Zealand]]<ref name="jackson87" /> ♠
* [[New Zealand National Airways Corporation|National Airways Corporation]]
{{NGR}}
* [[Elders Colonial Airways]]<ref name="guttery">{{Cite book|last=Guttery|first=Ben R.|title=Encyclopedia of African airlines|publisher=Ben Guttery|year=1998|page=140|isbn=0-7864-0495-7|url=https://books.google.com/books?id=KBmGpaD36cMC|access-date=2010-01-17}}</ref>
{{SIN}}
* Wearne Brothers Limited.<ref name="jackson87" />
{{TUR}}
* [[Turkish Airlines]] Turkish State Airlines (Devlet Hava Yollari) <ref name="jackson87" />♠
{{UK}}
* [[Allied Airways]]<ref name="jackson87" /> ♠
* [[Blackpool and West Coast Air Services]]<ref name="jackson87" /> ♠
* [[British Airways Ltd|British Airways]]<ref name="jackson87" /> ♠
* [[Hillman's Airways]]<ref>{{harvnb|Arthur|1992|p=23}}</ref>
* [[Imperial Airways]]<ref name="jackson87" /> ♠
* [[Jersey Airways]]<ref name="jackson87" /> ♠
* [[Lancashire Aircraft Corporation]]<ref name="jackson87" />
* Peacock Air Charter<ref name="jackson87" />
* [[Railway Air Services]]<ref name="jackson87" /> ♠
* Skytravel<ref name="jackson87" />
* [[Western Airways]]<ref name="jackson87" />
* Wrightways<ref name="jackson87" />
{{URY}}
* [[PLUNA]]<ref name="jackson87" />

===Military operators===
{{AUS}}
* [[Royal Australian Air Force]]<ref name="jackson87" />
{{FIN}}
* [[Finnish Air Force]]
{{NZL}}
* [[Royal New Zealand Air Force]]<ref name="jackson87" />
** [[No. 2 Squadron RNZAF]]
** [[No. 4 Squadron RNZAF]]
** [[No. 42 Squadron RNZAF]]
{{UK}}
* [[Royal Air Force]]<ref name="jackson87" />
** [[No. 24 Squadron RAF]]
** [[No. 117 Squadron RAF]]
** [[No. 216 Squadron RAF]]
* [[Royal Navy]] – [[Fleet Air Arm]]<ref name="jackson87" />
** [[782 Naval Air Squadron]]<ref name="jackson87" />

==Specifications (D.H.86A)==
[[File:De Havilland DH.86 3-view NACA-AC-189.png|thumb|De Havilland DH.86 3-view drawing from NACA-AC-189]]
{{Aircraft specs
|ref=''De Havilland Aircraft since 1909,<ref name="jackdehav p347">{{harvnb|Jackson|1987|p= 347}}</ref> and Jane's All the World's Aircraft 1938''<ref name=JAWA1938>{{cite book |title=Jane's All the World's Aircraft 1938 |editor1-last=Grey |editor1-first=C.G. |year=1938 |publisher=Sampson Low, Marston & company, ltd |location=London |editor2-last=Bridgman |editor2-first=Leonard |pages=30c–31c}}</ref>
|prime units?=imp
<!--
        General characteristics
-->
|crew=2 (pilot and co-pilot)
|capacity= 10–16 passengers
|length ft=46
|length in=1.25
|length note=
|span ft=64
|span in=6
|span note=
|height ft=13
|height in=0
|height note=
|wing area sqft=641
|wing area note=
|aspect ratio=12.3
|airfoil=RAF 34 modified<ref name="Selig">{{cite web |last1=Lednicer |first1=David |title=The Incomplete Guide to Airfoil Usage |url=https://m-selig.ae.illinois.edu/ads/aircraft.html |website=m-selig.ae.illinois.edu |access-date=16 April 2019}}</ref>
|empty weight lb=6140
|empty weight note=
|gross weight lb=10250
|gross weight note=
|max takeoff weight lb=
|max takeoff weight note=
|fuel capacity={{cvt|1145|impgal|USgal l|0}} in two undercarriage fairing tanks
|more general=
<!--
        Powerplant
-->
|eng1 number=4
|eng1 name=[[de Havilland Gipsy Six I]]
|eng1 type=6-cylinder air-cooled inverted in-line piston engines
|eng1 hp=200
|eng1 note=

|prop blade number=2
|prop name=fixed-pitch propellers
|prop dia ft=<!-- propeller aircraft -->
|prop dia in=<!-- propeller aircraft -->
|prop dia note=
<!--
        Performance
-->
|max speed mph=166
|max speed note=at sea level
|cruise speed mph=142
|cruise speed note=at {{cvt|1000|ft}}
|stall speed mph=
|stall speed note=
|never exceed speed mph=
|never exceed speed note=
|minimum control speed mph=
|minimum control speed note=
|range miles=760
|range note=
|ferry range miles=
|ferry range note=
|endurance=<!-- if range unknown -->
|ceiling ft=17400
|ceiling note=
* '''Absolute ceiling:''' {{cvt|19500|ft}}
* '''Absolute ceiling with one engine inoperative:''' {{cvt|13000|ft}}
* '''Absolute ceiling with two engines inoperative:''' {{cvt|2000|-|4000|ft}} depending on combination
|glide ratio=<!-- sailplanes -->
|climb rate ftmin=925
|climb rate note=
|time to altitude=<br>
::*{{cvt|5000|ft}} in 6 minutes 30 seconds
::*{{cvt|10000|ft}} in 15 minutes
|lift to drag=
|wing loading lb/sqft=
|wing loading note=
|fuel consumption lb/mi=
|power/mass=
|more performance=
|avionics=
}}

==See also==
{{Aircontent
|related=
* [[de Havilland Dragon]]
* [[de Havilland Dragon Rapide]]
|similar aircraft=
|lists=
* [[List of aircraft of the Royal Air Force]]
|see also=
}}

==Notes==
{{Reflist}}

==Bibliography==
* {{cite magazine |last=Arthur |first=Robin |title=Pre-War Airliner Fleets: I. Hillman's Airways Ltd |magazine=Archive |publisher=[[Air-Britain]] |year=1992 |issue=1 |pages=23–24 |issn=0262-4923}}
* {{cite journal |last1=Comas|first1=Matthieu|title=So British!: 1939–1940, les avions britanniques dans l'Armée de l'Air|journal=Avions |date=September–October 2020 |issue=236 |pages=38–61 |trans-title=So British!: British Aircraft in the French Air Force 1939–1940|language=French |issn=1243-8650}}
* Cookson, Bert. ''The Historic Civil Aircraft Register of Australia (Pre War) G-AUAA to VH-UZZ''. 1996, Toombul, Queensland: AustairData (privately published).
* {{Cite book| author=Jackson, A. J.| title=British Civil Aircraft 1919–1972: Volume II| edition=1988| publisher=Putnam (Conway Maritime Press)| location=London| year=1988 }}
* {{Cite book|last=Jackson|first=A.J|title=De Havilland Aircraft since 1909|year=1987|publisher=Putnam|location=London|isbn=0-85177-802-X}}
* {{Cite book| author=Job, Macarthur| author-link=Macarthur Job| title=Air Crash, Volume Two| edition=1992| publisher=Aerospace Publications | location=Canberra| year=1992 }}
* {{cite magazine|last1=Lumsden|first1=Alec|last2=Heffernan|first2=Terry|title=Probe Probare: No. 3: D.H. 86|magazine=Aeroplane Monthly|date=April 1984|volume=12|issue=4|pages=180–185}}
* {{cite magazine|last=Prins|first=François|title=Pioneering Spirit: The QANTAS Story |magazine=[[Air Enthusiast]] |date=Spring 1994|issue=53 |pages=24–32 |issn=0143-5450}}
* {{Cite book | first = Stephen| last = Poole| year = 1999| title = Rough Landing or Fatal Flight | publisher=Amulree Publications| location = Douglas| isbn = 1-901508-03-X }}

==External links==
{{Commons category|De Havilland DH.86 Express}}

{{de Havilland aircraft}}
{{ADF aircraft designations}}
{{Authority control}}

[[Category:De Havilland aircraft|Express]]
[[Category:1930s British airliners]]
[[Category:Four-engined tractor aircraft]]
[[Category:Biplanes]]
[[Category:Aircraft first flown in 1934]]
[[Category:Four-engined piston aircraft]]
[[Category:Aircraft with fixed conventional landing gear]]