It certainly would give a GV spotter a bit more bite than the Storch's smoke marker.
Specifications (U-2)
Поликарпов По-2.svg
General characteristics
Crew: 1, pilot/instructor
Capacity: 1, passenger/student
Length: 8.17 m (26 ft 10 in)
Wingspan: 11.40 m (37 ft 5 in)
Height: 3.10 m (10 ft 2 in)
Wing area: 33.2 m² (357 ft²)
Empty weight: 770 kg (1,698 lb)
Loaded weight: 1,030 kg (2,271 lb)
Useful load: 260 kg (573 lb)
Max. takeoff weight: 1,350 kg (2,976 lb)
Powerplant: 1 × Shvetsov M-11D 5-cylinder radial engine, 93 kW (125 hp)
Performance
Maximum speed: 152 km/h (82 kn, 94 mph)
Cruise speed: 110 km/h (59 kn, 68 mph)
Range: 630 km (340 nmi, 391 mi)
Service ceiling: 3,000 m (9,843 ft)
Rate of climb: 2.78 m/s (546 ft/min)
Wing loading: 41 kg/m² (8.35 lb/ft²)
Power/mass: 60 W/kg (0.04 hp/lb)
Armament
(U-2VS / LNB only)
Guns: 1 × 7.62 mm (0.30 in) ShKAS machine gun
Bombs: 6 × 50 kg (110 lb) bombs