690A Twin Commander

Specifications & Performance

The 690A, first produced in 1973, represented a significant advancement for turboprop Twin Commander aircraft. This model used the more powerful 251K variant of the AiResearch TPE331 power plant and Hartzell propellers. Airframe changes included an increase of 30 inches at the center wing section, increased rudder area, enlarged dorsal fin and longer tail cone. These changes allowed for a gross weight rating of 9,600 and baggage capacity of 600 lbs., the highest for a Twin Commander. Other changes such as the addition of a heated windshield, increased cabin pressure differential and standard de-icing equipment, changed the maximum ceiling rating from 25,000 feet to 31,000 feet.

Specifications

Dimensions

Wing span 46.55′ 14.19m
Length 44.35′ 13.52m
Height 14.95′ 4.56m
Tread 15.42′ 4.70m
Cabin Entry Door 2. 21’ x 3.92’ .67 x 1.19m
Cabin Height (Inside Interior) 4.47′ 1.36m
Cabin Length 14.25′ 4.34m
Cabin Width (Inside Interior) 4.01′ 1.22m
Cabin Volume 224 ft³ 6.34m³
Baggage compartment height 3.81′ 1.16m
Baggage compartment width 3.50′ 1.07m
Baggage compartment length 4.83′ 1.47m
Baggage compartment volume 46.5 ft³ 1.32 m³
Baggage door height 2.60′ .79m
Baggage door width 1.64′ .50m
Baggage compartment load limit 600 lbs 272 kg

Propellers

Hartzell 3 blade, constant speed, full feathering and reversible

Power Plant

Honeywell TPE-331-5-251 single-shaft turbo-prop with integral gearbox, two-stage centrifugal compressor, three-stage axial turbine and single annular combustion chamber.

Weights - Aircraft

Ramp Weight: 10,300 lbs/4,672 kg
Take-off Weight: 10,250 lbs/4,649 kg
Landing Weight: 9,600 lbs/4,355 kg
Standard Empty Weight: 6,126 lbs/2,779 kg
Useful Load: 4,174 lbs/1,418 kg
Zero Fuel Weight: 8,750 lbs/3,969 kg
Baggage: 600 lbs/272 kg

Performance

Operating Speed

Maximum Cruise
(100% 12,000 ft.TAS@ 10,325 lbs/4,683 kg) 328mph/285kts
Normal Cruise Speed
(96%20,000 ft.TAS@ 10,325 lbs/4,683 kg): 321mph/279kts
Twin Engine Best Rate of Climb Speed (CAS): 161mph/140kts
Twin Engine Best Angle of Climb Speed (CAS): 133mph/116kts
Single Engine Best Rate of Climb Speed (CAS): 132mph/115kts
Single Engine Best Angle of Climb Speed (CAS): 126mph/109kts
Minimum Control Speed (CAS): 99mph/86kts
Stall Speed, Clean (CAS): 94mph/82kts
Stall Speed, Gear and Flaps Down (CAS): 89mph/77kts

Cruising Ranges

Long range cruise at 288mph/250.3kts/463.4kmh (TAS) average at 31,000 ft., 9,449 meters, (96% rpm) with 45 min. fuel reserve: 1,693 SM/ 1,471 NM, 2,724 KM

High speed cruise range at 320mph/278kts/515kmh (TAS) average at 25,000 ft., 7,620 meters (96% rpm) with 45 min. fuel reserve: 1,458 SM/1,266 NM/2,346 KM