Dornier Do 228 AEW

[Voltzz]

I found an article in the Dornier Post about their ideas for a small, relatively cheap AEW aircraft based on the Do228. The radar they chose was the Thorn EMI Skymaster mounted in 2 different version, either in the nose or in a radome on top of the aircraft.
Do-Post_88-2

 

[CJGibson]

Interesting, similar to the B-N Defender.

Thanks

Chris

 

[CJGibson]

I might have a go at the Pilzradom next.

Chris

 

[SteveO]

Any idea which radar position provided better coverage? Nose mounted looks neater anyway!

 

[CJGibson]

Here ye go, as promised. dorsal probably better coverage, but aerodynamic and structural considerations would need addressed.

Chris

 

[Foo Fighter]

Wedgetail type would be the current style but where would that fall in ability/aerodynamic cost?

 

[yasotay]

@CJGibson - I wonder if the height of the radome (moment arm I think) and it being behind(?) what appears to be the aircraft CG might create some stability issues. A wedgetail might be better aerodynamically, but I think there might be a significant weight penalty associated with it.

 

[Foo Fighter]

That spherical widget looks like it would introduce a pitch up tendency.

 

[aim9xray]

Looks very ripe for von Kármán vortex street or von Kármán vortices. Couple that with a nearby airframe resonance mode, and you will very soon have a load of scrap aluminum flying in close formation in a descending trajectory.

 

[CJGibson]

@CJGibson - I wonder if the height of the radome (moment arm I think) and it being behind(?) what appears to be the aircraft CG might create some stability issues. A wedgetail might be better aerodynamically, but I think there might be a significant weight penalty associated with it.

Dunno, to paraphrase Oddball, I just draw 'em, I don't know how they work.

View: https://youtu.be/TzsNh3-FnHQ


Chris

 

[Nik]

If they can put spiral 'spoilers' on skinny tubular masts, factory chimneys, oil-rig legs etc etc, perhaps there's an equivalent for 'egg-shaped' ??

 

[riggerrob]

If they can put spiral 'spoilers' on skinny tubular masts, factory chimneys, oil-rig legs etc etc, perhaps there's an equivalent for 'egg-shaped' ??

Those spiral spoilers defeat von Karman Waves from every angle.
Spoilers for an AWACS only need to discourage turbulence from one angle: dead a head.
The simplest cure for AWACS legs/struts is teardrop shaped struts with a chord to length ratio of 1:3 or greater.

 

[riggerrob]

I might have a go at the Pilzradom next.

Chris

View attachment 690637

That bulbous nose radome reminds us of a similar installation on a British Army Britten-Norman Islander/Defender. The Islander needed an extended nosewheel strut to prevent the radome from dragging on the runway.

 

[RavenOne]

That bulbous nose radome reminds us of a similar installation on a British Army Britten-Norman Islander/Defender. The Islander needed an extended nosewheel strut to prevent the radome from dragging on the runway.

the abandoned CASTOR project for battlefield surveillance ....

cheers

 

[Scott Kenny]

Any idea which radar position provided better coverage? Nose mounted looks neater anyway!

Dorsal gives the option of a 360 sweep in one radar unit.

You would need to get a bit creative with your rear fairing to have it the same transparency to radar as the front fairing. IIRC that's why the E3 AWACS has the whole dome rotate, but the older E1 Tracer did not rotate the entire dome and instead had a huge teardrop shape that tied into the vertical stabilizer at the tail. Not sure about the E2 Hawkeyes, those may be electronically swept.