Can a modern IFR Instrument Panel be as SMALL as a glider instrument panel?

[Bearcat F8F]

Hi guys,

I am thinking of designing a glider, which can be transformed (relatively easily) into a personal jet aircraft. This is a university project (for now).

I would like to take a typical glider fuselage as a base to work with. Hence, I'm wondering if it's possible to create a relatively small glass cockpit that can be used for normal glider flying, but also for IFR flying when the a/c is converted into a jet? I'm guessing something like the G1000 is a bit big to fit into a normal glider panel.

I could move the pilot further back, creating a larger instrument panel. But should I?

Thanks

[CMM]

How do you plan on powering the avionics?

[Bearcat F8F]

Gah! I haven't thought about what will happen when the a/c is in the glider-config, without the engine. Is there a way round this without mounting any external ram props or solar panels?

The solution in that case would be to leave a back-up VSI, ASI and altimeter. This would however take up even more space on the panel, which is already small...

[LAHSO 06/03]

Interesting Engineering project.

My first idea would be: Flip out display!

Have a look in the car audio market, as car radio makers have also had to find a solution to overcome the limited dashboard space. Your requirements will not be met with a standard flip out system of course, but you can immediately see the benefit of having a flip out display that can go over the barometric instruments once there is power available from an engine driven generator.
You will have to solve some problems like doing the alignment preflight and so on, but concerning your space problem you definitely have to add the flip out display to your morphological diagram.

Cheers!

[Mark 1]

Look at instruments like the Dynon D10 and their engine monitor, they give you a full panel in 2 80mm instrument cut-outs. Add a Garmin GTN650 (with remote transponder) and even with back-ups, you can have a full IFR panel in a very small space.

OK the Dynons aren't TSO'd, but it show's what is possible, and that set-up would be IFR legal for a US experimental category aircraft. The Aspen EFIS is TSO'd and still pretty compact.

[Bearcat F8F]

Excellent. Thank you for the reply fellas.

The cockpit is actually the last concern I have. I am not going to go into it in too much detail. I will concentrate on the geometry and the technical problems which arise from doing such a "conversion". But it is important to know, that I can have the a/c equipped IFR using a relatively small instrument panel.

Thanks again

[Intruder]

"Equipped" for IFR and "suitable" for IFR may be 2 different animals...

While a set of certified "standby" instruments may be all that is required by the FAA, they may not be suitable for extended IFR flight as a powered airplane. Smaller instruments may induce eye strain and may not have the fidelity and quick-look capability that standard instruments have. OTOH, they may be fine for inadvertent IMC or emergency use (their intended purpose).

[alf5071h]

Bearcat F8F, don’t forget the adage that ‘form follows function’.
IMHO a small display (size) would not be suitable for a jet; a critical issue is the display resolution.
Whereas an instrument display can be created on a very small helmet mounted reflector, it is the angular resolution which enables usability. Thus the display size-to-viewing distance is an important relationship.

Also consider what has to be displayed. A small jet will probably have a much greater speed range than a glider, but still require the same speed resolution for accurate flight, thus the length of the speed scale should be greater, requiring a large dial circumference. Swept area is an important parameter for detecting change and rate of change; this could bias you to avoid tape speed displays as they could require additional supporting information such as speed trend vectors. The same would apply to altitude, but less so to VS as this is already a rate parameter.

Attitude flight might be more critical in the jet; consider the attitude-speed change relationship. This might warrant a larger attitude display to maintain resolution.
Navigation in a jet will be at higher speeds (both IAS and TAS), this requires a greater look-ahead capability, and this needs a larger display if resolution is not to be sacrificed. Don’t forget the clock.
Radio navigation is required for IFR operations, these require control-panel space; see cockpit remarks below.

Keep the design simple. Complex systems (design) can be acceptable, providing they avoid complexity (enabling simple use) by being easy to understand and providing timely relevant ‘information’, not just data.

The cockpit should be one of the first considerations as many airframe and system aspects could be dictated by cockpit size / space. Aircraft control column/stick lever arm and displacement could limit the control forces and thus change control surface size or system mechanical advantage – differences between gliders and jets - speed squared.
Panel space for additional navigational systems, radios, and engine system displays.
Don’t forget about night flying – IFR, lighting position and control.
Glareshield size/position must enable a good over-the-nose view and act as a sunshade. Consider sun reflection issues on instrument displays.
You may not be able to fix everything, but at least identify and consider critical items.
Good luck – ‘ s/he who makes no mistakes, makes nothing ’.

[Mark 1]

I think the OP is talking in terms more like this example (http://www.desertaerospace.com/).

Interesting as a project, but lots of obstacles to be overcome - noise, fuel consumption, Vne ...

Google the MC-15J and Sub-Sonex to see other peoples ideas in a similar vein.

Basic IFR isn't too difficult. All weather, FIKI, high altitude etc is another thing.

The GTN650 with remote transponder meets IFR nav/com requirements.

[Ka8 Flyer]

What about a HUD? Can that be IFR certified?
(Without the EFIS / Analog six pack)

[Bearcat F8F]

Thanks guys.

Mark1, I never knew someone already had the same idea as me. Although clearly it hasn't been built yet. I am aware of gliders which have jet turbines to launch them to altitude. However my idea assumes the creation of 2 intirely different aircraft in almost the same airframe. I am only interested in pushing forward this conceptual design so long, as it doesn't result in any significant compromise between the two different kinds of aircraft and their missions.

alf5071h, thanks for the info and suggestions. Yes the cockpit is one of the 1st considerations. I haven't even started the project yet and as you can see this is literally my 1st question for obvious reasons. Have you got any say on what Ka8 Flyer is asking? A HUD? Could that potentially work?

I may of course, for simplicity, design the jet variant as VFR only - just fly around and enjoy- type of thing, but obviously this is a huge chunk of a potential market cut off.