The A-10 Thunderbolt II by Andy Ko February 11, 2000

1. The A-10 Thunderbolt IIby Andy KoFebruary 11, 2000 http://www.geocities.com/CapeCanaveral/Hall/5777/A-10.html

2. History • Lessons learned from Korea and Vietnam War • Need for close air support • Model the A-1 Skyraider • AX Program • June 1966 - • USAF send RFP to 21 companies • Parallel Paid Study Contract • 1970 - Requirements finalized, bidding starts • Northtrop & Fairchild Republic selected for fly-off • 1972 - Fly-off begins • Jan 1973 - Fairchild’s A-10 announced to be the winner http://skyraider.org/skyassn/otherpics/mignard/602sos/602sos.htm

3. Requirements • Speed: 350-400 kts. • 250 nm. operational radius with: • 9500 lbs external stores and internal ammunition • Field Length = 4000 ft. at Max TOGW • Simplicity • Only proven/off-the-shelf technology • Exception: High BPR turbofans • Survivability • Redundancy • Cheap • $3.02 Million (F-16 ,F-18, Harrier) • F-16, $9.5 - $12.8 Million • F-18, $24 Million • AV-8B, $23.7 Million http://www.af.mil/news/factsheets/A_10_OA_10_Thunderbolt_II.html

4. Dimensions Wing span 57ft 6in Length overall 53ft 4in Height overall 14ft 8in Weights Operating empty 24959lbs Basic design weight 30384lbs Internal fuel 10700lbs Max external load 16000lbs Take-off weights Maximum 50000lbs CAS mission 47094lbs Anti-armour mission 42071lbs Ferry 49774lbs Never-exceed speed 450kts Max level speed at sea level, clean 381kts Combat speed at 5000ft with six 380kts Mk82 bombs Cruising speed at sea level 300kts Sea-level rate of climb at design weight 6000ft/min Service ceiling 45000ft Anti-armour configuration, 30min combat, 252nm 40nm penetration and exit CAS configuration, 1.88hr single-engine 250nm loiter at 5000ft, 10min combat Ferry range, 50kt headwinds, 2240nm 20 min reserve Performance Combat radii Graphics from Dana Bell, “A-10 Warthog in detail & Scale”,

5. Configuration • Cantilever Low wing • Airfoils • NACA 6716 on centerline, NACA 6713 at tip • Provides low wing loading (92.14 lb/sq ft) • Wide Chords • Mean wing chord = 8ft 11.32in • 2 segment, 3 position Fowler flaps • No leading edge devices • Wide span ailerons • Dual upper and lower surfaces for airbrakes • SAS (Stability Augmentation System) • H-Tail • No deep stall • Spin resistance Graphics from Dana Bell, “A-10 Warthog in detail & Scale”,

6. Configuration (Cont’d) • Little Sweep • Mach number no greater than 0.68 • Aspect Ratio = 6.54 • Taper ratio = 0.65 • Engines • TF34-GE-100 (6.2 BPR) • 9065 lbs. Static thrust • Turbofan vs. Turboprop vs. Turbojet? • Placement • Nozzles are canted 9º upward • Landing Gear • Forward retracting • Exposed wheels when retracted http://www.a-10.org/photos/photos5.html http://www.a-10.org/photos/photos6.html

7. Improvements / Fixes • Stall problem • Initially a fixed slat was installed, later changed to a movable slat • Stall strip added to the leading edge • Wing root modified with a fillet • Forward projecting strakes • Drag improvements • Increased wing-span by 30 in. • Hoerner wingtips • Induced drag • Aileron effectiveness • Canopy and windscreen shapes refined • Pylons shortened and streamlined • Reduced landing gear pod cross section http://www.a-10.org/photos/photos7.html http://www.a-10.org/photos/photos.html

8. Comparison with other Attack Aircraft * With combat load ** With external fuel tanks (tanks retained)

9. Survivability and Lethality • Redundant control system • 2 hydraulic controls (separated) and 1 cable manual reversion • H-tail provides 2 separated control surfaces • Redundant structure • Titanium bathtub for pilot • 1.5 in thick bulletproof canopy • Weapon loads • GAU-8/A Avenger 30mm seven barrel gun • 1350 rounds at 2100 or 4200 rounds/min • 11 store pylons with max external load of 16000 lbs Smithsonian Air & Space Magazine, March 1999, pg 27