WACO AIRCRAFT COMPANY
MODELS: Waco UKS-7, VKS-7 (Army UC-72D), VKS-7F
T.C. NUMBER: 648
I - Model UKS-7, 5 PCL-SB (Approved 6/8/37)
(Same as UKS-6, ATC 528, except wing fittings, landing gear moved forward 4 inches,
fixed trim tab added to rudder, miscellaneous changes in fuselage and controls)
Engine Continental W670K or W670K1
Fuel 65 minimum octane aviation gasoline
Engine limits Maximum, except take-off
2175 rpm (225 hp) (K); or 2200 rpm (230 hp) (K1)
Take-off (one minute)
2175 rpm (225 hp) (K); or 2200 rpm (230 hp) (K1)
Airspeed limits Level flight or climb - 140 mph True Ind.
Glide or dive - 168 mph True Ind.
Propeller limits Maximum permissible diameter 102 inches
C.G. range Landplane (-14.4) to (-2.5)
Seaplane (-12.7) to (-3.7)
Maximum weight Landplane 3250 lbs.
Seaplane 3540 lbs.
No. seats 5 (2 at -3), (3 to +27)
Maximum baggage 100 lbs. (+45)
Fuel capacity 70 gallons (two 35 gallon tanks in upper wing) (-11.5)
Oil capacity 5 gallons (-44)
Control surface
movement Not available
Serial numbers eligible 4551 and up
Required equipment Landplane:
Items 101(a), 102, 103(a), 104(a), 105(a), 106,
107, 108(a), 109, 110.
Seaplane:
Items 101(a), 102, 103(a), 104(a), 107, 108(a),
110, 151, 152.
II - MODEL VKS-7 (Army UC-72D), 5 PCL-SB (Approved 6/8/37)
(Same as UKS-7 except engine installation)
Engine Continental W670M or W670M1
Fuel 80 minimum octane aviation gasoline
Engine limits Maximum, except take-off
2200 rpm (240 hp) (M); or 2200 rpm (250 hp) (M1)
Take-off (one minute)
2200 rpm (240 hp) (M) or 2200 rpm (250 hp) (M1)
Airspeed limits Level flight or climb - 140 mph True Ind.
Glide or dive - 168 mph True Ind.
Propeller limits Maximum permissible diameter 102 inches
C.G. range Landplane (-14.4) to (-2.5)
Seaplane (-12.7) to (-3.7)
Maximum weight Landplane 3250 lbs.
Seaplane 3540 lbs.
No. seats 5 (2 at -3), (3 at +27)
Maximum baggage 100 lbs. (+45)
Fuel capacity 70 gallons (two 35 gallon tanks in upper wing) (-11.5)
Oil capacity 5 gallons (-44)
Control surface
movements Not available
Serial numbers eligible 4551 and up and all AAF numbers of Model UC-72D.
Use manufacturer's number when available.
Required equipment Landplane:
Items 101(a), 102, 103(a), 104(a), 105(a), 106, 107,
108(a), 109, 110.
Seaplane:
Items 101(a), 102, 103(a), 104(a), 107, 108(a),
110, 151, 152.
III - MODEL VKS-7F, 5 PCLB (Approved 7/28/42)
(Same as VKS-7 except addition of split flaps on lower surface of upper wing,
Flettner rudder tab, miscellaneous changes to structure and control system)
Engine Continental W670M
Fuel 80 minimum octane aviation gasoline
Engine limits Maximum except take-off
-- in. Hg., 2200 rpm (240 hp)
Take-off (one minute)
-- in. Hg., 2200 rpm (240 hp)
Airspeed limits Level flight or climb - 140 mph True Ind.
Glide or dive - 168 mph True Ind.
Flaps extended - 102 mph True Ind.
Propeller limits Maximum permissible diameter 102 inches
C.G. range (-14.5) to (- 3.6)
Maximum weight 3250 lbs.
No. seats 5 (2 at -3), (3 at +27)
Maximum baggage 100 lbs. (+45)
Fuel capacity 70 gallons (two 35 gallon tanks in upper wing) (-11.5)
Oil capacity 3-1/2 gallons (-44)
Control surface
movement Not available
Serial numbers eligible 5279 and 6101 and up
Required equipment Items 101(b), 102, 103(b), 104(b), 105(b), 106, 107, ,7,
108(a), 109, 110 and 111
SPECIFICATIONS PERTINENT TO ALL MODELS:
Datum Leading edge of lower wing
Leveling means Lower surface of upper wing at strut points must be
level
Certification 1,3.E;is Type Certificate No. 648 (Aero. Bulletin 7A)
Production basis None (See NOTE A)
Export eligibility Eligible for export as follows, subject to inspection
for equipment specified in MOP 2-4:
(a) Canada
- Landplane
- Seaplane (UKS-7 and VKS-7 only) - Maximum
weight 3430 lbs.
- Skiplane - Not eligible. However, structure
complies with Canadian requirements for
ski installation when equipped with special
axle per Waco Drawing 20243.
(b) All other countries except Australia and
New Zealand.
EQUIPMENT:
Propellers and Propeller Accessories
108. Propeller - Curtiss Model 55501
Diameter 8'0" maximum, 7'10"
minimum. (Must be installed with blades
at right angles to engine crankthrow
(either 90 or 270 degree position).
Restrict engine operation to 2000 rpm
maximum and placard tachometer
accordingly.) 51 lbs. (-79)
305. (a) Adjustable metal propeller +27 lbs. (-79)
(b) Hamilton Standard propeller, hub
2B20, blades 6135A-6 or 6135A-7.
Diameter 8'6-1/8" maximum, 8'3-7/8"
minimum. Pitch range 10 degrees
to 14.5 degrees.) (VKS-7F only) +51 lbs. (-79)
Engine and Engine Accessories - Fuel and Oil System
101. (a) Engine ring cowl 27 lbs. (-63)
101 or
317. (b) Engine ring cowl (Drawing 21992) 34 lbs. (-63)
102. Starter (Eclipse E-80) 20 lbs. (-51)
107. Oil cooker 5 lbs. (-65)
201. Large starter +10 lbs. maximum (-53)
204. Oil heater 3 lbs.
208. 15 gallon fuel tank (1 or 2 in lower
wing) 17 lbs. each
209. (a) 6-1/2 gallon oil tank (UKS-7 or
VKS-7 only) No weight change
(b) 5 gallon oil tank (VKS-7F only) No weight change
309. Engine shielding 11 lbs. (-75)
Landing Gear and Floats
105. 7.50-10 wheels Hayes 750M) with
(a) 8.50-10 4-ply tires (Models
UKS-7 and VKS-7 only) 63 lbs. (-28)
320. or
105. (b) 7.50-10 4-ply tires only) (Surface Combustion Co. Model
AGU-15N-L2) (See Waco Drawing 23719) +15 lbs. (+27)
152. Seaplane type vertical tail surface
(replacing landplane type) (UKS-7 or
VKS-7 only) +10 lbs. (+185)
210. Extra door and wing walk +16 lbs. (+19)
212. Airbrakes (UKS-7 or VKS-7 only) +10 lbs.
321. Bonding (VKS-7F only) 6 lbs. (-3)
NOTE A. Each aircraft manufactured subsequent to 1/11/49, must prior to original
certification, satisfactorily pass:
(a) An inspection for workmanship, materials and conformity during
construction.
(b) A final inspection of the completed aircraft.
(c) Check of flight characteristics.