The A-10 Thunderbolt II
by Andy Ko
February 11, 2000
http://www.geocities.com/CapeCanaveral/Hall/5777/A-10.html
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
http://skyraider.org/skyassn/otherpics/mignard/602sos/602sos.htm
– 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
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
Dimensions
Wing span
Length overall
Height overall
Weights
Operating empty
Basic design weight
Internal fuel
Max external load
Performance
57ft 6in
53ft 4in
14ft 8in
24959lbs
30384lbs
10700lbs
16000lbs
Take-off weights
Maximum
CAS mission
Anti-armour mission
Ferry
Graphics from Dana Bell, “A-10 Warthog in detail & Scale”,
50000lbs
47094lbs
42071lbs
49774lbs
Never-exceed speed
Max level speed at sea level, clean
Combat speed at 5000ft with six
Mk82 bombs
Cruising speed at sea level
Sea-level rate of climb at design weight
Service ceiling
Combat radii
Anti-armour configuration, 30min combat,
40nm penetration and exit
CAS configuration, 1.88hr single-engine
loiter at 5000ft, 10min combat
Ferry range, 50kt headwinds,
20 min reserve
450kts
381kts
380kts
300kts
6000ft/min
45000ft
252nm
250nm
2240nm
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”,
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
http://www.a-10.org/photos/photos5.html
• Nozzles are canted 9º upward
• Landing Gear
– Forward retracting
– Exposed wheels when retracted
http://www.a-10.org/photos/photos6.html
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
http://www.a-10.org/photos/photos7.html
• 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/photos.html
Comparison with other Attack Aircraft
A-10
Thunderbolt
II
SU-25
Frogfoot
Max T/O Weight (lbs)
47400
38800
14061
60400
Max Speed at S/L (kts)
390
526
575
560
Max Range (nmi)
2300
675*
1700
2380**
4500
3935
1700
4560
92.14
95.87
129.87
114.2
0.6
0.511
1.03
0.346
T/O Distance at Max T/O
Weight (ft)
Max Wing Loading
(lb/sq ft)
T/W Ratio
AV-8B Harrier
A-6 Intruder
II
* With combat load
** With external fuel tanks (tanks retained)
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