De Havilland D.H.99

[Boogey]

I chequed by the forum search machine ... No word about this aircraft.
De Havilland D.H.99
The De Havilland's project agreed with the British Government ( Ministry of Aircraft Industry )
in 7 Juni 1941 with projected Halford H.1 jet engine of 12.89 kN.
- span : 12,20 m ;
- wing area : 24,19 m2 ;
- lenght : 9,46 m ;
- height : 2,44 m ;
- max. weight : 3.615 kg ;
- projected speed : 715 km/h at 0 m ;
- projected speed : 755 km/h at 13.700 m ;
- climbing : 26,15 m/sec.
In 8 december 1941 the Ministry offered the proposal under designation E.6/41
and the D.H.99 became D.H.100 Spider Crab
and our beloved D.H.100 Vampire in the end.

 

[Jos Heyman]

I believe DH.99 was also a high-speed high-altitude unarmed bomber based on the DH.87 to meet the Spec. B.11/41 requirements. Not built.

 

[steelpillow]

Kelsey Media published an Aeroplane Icons Vampire special in 2014. The first piece, by Martyn Chorlton and Tony Buttler, tells the well-illustrated story of the DH.99, DH.100, "Spider Crab", "Vampire" and E.6/41 designations and the designs behind them. The '99 was the original all-metal high altitude fighter proposal. Following the crystallisation of Ministry Specification E.6/41 and a consequent move to mixed construction, the new design became the '100. Outward changes were minimal, the main ones being structural. It was named Spider Crab just before its first flight and the three prototypes flew under this name. The type was renamed the Vampire shortly before the first production order was placed.

The publication also covers the later derivatives; the DH.108 Swallow, DH.112 Venom and the French Mistral and Aquilon.

 

[hesham]

Hi,


it is very close to DH-102.

 

[toura]

Hi all

Sorry ! I don't remenber where I've foud this !

 

[steelpillow]

Sorry ! I don't remenber where I've foud this !

Chorlton and Buttler reproduce a copy of it, cleaned-up and slightly simplified. They attribute it to "De Havilland via Aeroplane".

They also reproduce an original manufacturer's design drawing from 1941, obtained from the National Archives. It shows small differences, such as a slight forward weep to the tail plane trailing edge (deepest chord in the middle), low forward extensions of the tailbooms with what might be additional guns fitted, and a longer rear cockpit canopy/fairing. Has the same rather tall leaf-like tail fins as the wind tunnel model.

I cannot help but wonder what the provenance of the twin piston-engined fast bomber design is said to be. DH were apt to produce a new type number at the drop of a hat, would they really have re-used the same number for wholly different projects?

 

[lark]

To make it a bit more complicated:

DH.99 project for a twin engined light civil aircraft
DH.99 re-allocated to project for DH.98 development with Napier Sabre N.S.19 engines

DH.100 project for civil aircraft,C of A application made on May 27 1940
DH.100 Vampire single seat jet fighter

From : De Havilland - Donnald Hannah . Flypast Library