Starting off work on this project is easy, mainly because of some publicly available information as well as ATR being part of the Airbus Group. This helps in finalizing, with greater confidence, certain designs, and technologies which may find their way to the yet unnamed 90 seat turboprop: what we at The Flying Engineer call ATR9X.
This section deals with two main topics about the project: Section1: The anticipate workflow, and Section2: continuously updated repository of publicly available information regarding the 90 seat turboprop from ATR, Turboprop engine manufacturers like Pratt and Whitney, A400M’s design, and Airbus Technology. Section 1 deals with the approach. Section 2 deals with requirements capture.
Where possible, the sources shall be mentioned in Section 2.
Section 1: Workflow
To Be Updated.
Outline: Cabin Configuration Freeze, Fuselage Dimensions Freeze, Prelim Weight Estimate 01, Prelim Control Surface Design 01, Drag Analysis 01, Engine & Prop Diameter 01, 3-D model 01, Landing Gear Freeze, Weight Estimate 02, Control Surface Design Run 02, Drag Analysis 02, Engine & Prop estimate 02, 3-D model 02, Flight Simulator Model, Flight test & performance analysis, Evaluation of requirement for design Run 03, Conceptual Freeze.
Section 2: Requirements Capture
1. 90+ (90 to 92) seats with 30-inch seat pitch.(A1)
2. Cabin most likely will be 4-abreast for least drag profile, but adds aircraft length impacting landing gear and tail-strike considerations. Drag needs to be quantified. Option is 5-abreast. (A1)
6. Commonality with Airbus airplanes / philosophies (A1)
7. May have to consider under-floor cargo hold. Present ATR72 = 5.2f3 cargo volume per pax, while Embraer Jets, Q400 and Airbus single aisle ~ 7f3/pax. (A1)
1. Range: 800 – 1000NM with full payload. (Higher range opens up new market, but adds cost and economy penalty to aircraft, as jets best suited for 1000+NM) (A1)
2. Full Payload: 92 Pax X 102kg/Pax = 9,384kg (A1)
3. Speed: 300-325kts Cruise with 350kts Max Cruise  (A1)
Aircon / Press / Vent
1. Exploring the feasibility of Fly-By-Wire controls on such a large aircraft. (A1)
2. Controls may be hydraulically actuated and fly-by-wire controlled. (A1)
3. Possibility of side-stick controllers (Airbus Airliners & A400M), if FBW is adopted. Impact of sidestick / FBW on training commonality needs to be debated, considering aircraft is clean sheet and not a ATR72 stretch. (A1)
Ice & Rain Prot
1. Need effective anti-icing rather than de-icing system without performance penalty. (A1)
2. Electrical heaters an option, rather than bleed. (A1)
Ind & Rec Systems
1. Would like to explore the option of A400M-style LDG gear. (A1)
1. High use of LED, and HID lights for greater reliability. (A1)
1. Adequate requirement to allow the aircraft to operate above FL250 (A2) Oxygen masks will however add weight, and the higher cruise altitude may not be reached on short sectors. (A1)
1. Required to handle high air-conditioning demand on ground (A1)
2. “Hotel” mode on present ATRs is problematic. (A1)
3. Required for higher current draw for engine start. (A1)
1. Fwd and Rear Passenger Entry for QTA. (A1)
1. Cautious use of composites: High cycle aircraft: composites are difficult to detect for, and repair damages. (A1)
1. High cycle aircraft, susceptible to bird strike. Windows must be easily replaceable. (A1)
1. 8 Bladed Propeller (Source:ATR) (A1)2. 5000-7000SHP / Engine based on source . Independent analysis required. To be remembered that ATR 72 is underpowered in comparison to Q400, and this is responsible for best operating economy. (A1)3. May employ FADEC like in the A400M. (A1)
1. Not all chapters and sections may fall into the scope of this project.
2. Requirements Author: A1, A2, A3… are authors as listed under About ATR9X.