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Sikorsky S-70C(M) Thunderhawk Specifications Service History Images Fleet Information
Information on this page is kindly provided by Jason Tu.

The ROCN S-70C(M)-1 and S-70C(M)-2 helicopters (also referred to as Lot 1 and Lot 2, respectively) are configured with a single four-blade main rotor, a 20-degree canted tail rotor, a fully controllable stabilator, conventional fixed landing gear, emergency flotation, a rescue hoist, and weapons pylons for carrying and launching external stores. The S-70C(M)-1 is powered by two CT7-2D-1 turbine engines, while the S-70C(M)-2 is powered by two T700-GE-401C. In addition, both S-70C(M) models are equipped with a T-62-T40-2 auxiliary power unit to provide pneumatic power for starting the engines, operating the environmental control system, and electrical power for ground functional check and blade fold.

The flight control systems are hydraulically power-boosted mechanical control system. Two hydraulic modules driven by transmission power the flight control system, and one hydraulic module driven by electric motor provides emergency backup power to either module and provides maintenance necessary on ground. Another hydraulic module driven by transmission actuates sonar system and rescue hoist. The automatic flight control system assists the pilot in maneuvering and heading the helicopter. It is composed of the stability augmentation system, stabilator system, and digital automatic flight control system that provide dynamic stability and maintain desired altitude, speed, and heading.

The AN/APS-143(V)3 search radar system is used to detect and track surface and air targets over a wide range of sea surface up to a range of 200 nautical miles and can be used for weather detection. The AN/AQS-18(V)3 sonar provides detecting, tracking, and classifying of underwater targets. It can be operated as either a dipping passive/active sonar or an acoustic processor for real-time display of data from passive/active sonobouy sensors, and also provides underwater voice communications and bathythermographic recordings. Other onboard systems include the AN/ASN-150 tactical navigation system, AN/ALR-606(V)-2 ESM gear, and one or two ARR-84 99-channel sonobuoy receivers.

There are three external stores/suspended bomb racks located at the helicopter left and right external stores stations. External stores may consist of torpedoes or auxiliary fuel tanks. The Mk46 torpedo can be suspended from all bomb racks while 120-gallon droppable auxiliary fuel tanks may be suspended from the two inboard bomb racks only.

Although the primary mission the S-70C(M) is anti-submarine warfare, it can be easily converted for alternative missions of vertical replenishment, medical evacuation, and search and rescue. Aircrew consists of pilot, copilot, acoustic sensor operator, tactical sensor operator, and plane captain if necessary. It is designed to operate at sea aboard aircraft carriers, frigates, destroyers or cruisers with installation of RAST system. Also, the foldable main rotor blade, tail pylon, stabilator and extended weapon pylon are designed to fit narrow space on ships.


Aircraft dimensions
  Operation length 19.76 m
  Operation height 5.18 m
  Main rotor diameter 16.36 m
  Folded length 12.47 m
  Folded height 4.04 m
  Folded height 3.26 m
  Take-off gross weight 21,768 lb (Lot 1)
21,706 lb (Lot 2)
  Vmax 150 kts
  Service ceiling 12,467 ft (Lot 1)
12,562 ft (Lot 2)
  Best rate of climb 1,395 ft/min (Lot 1)
1,410 ft/min (Lot 2)
  Time on task (100 nm from base) 2.6 hrs (Lot 1)
2.34 hrs (Lot 2)
Power ratings (in hp)
  Max continuous shaft 1,595 (CT7-2D1)
1,662 (T700-GE-401C)
  Intermediate 1 1,625 (CT7-2D1)
1,800 (T700-GE-401C)
  Selectable contingency 2 1,940 (CT7-2D1)
1,940 (T700-GE-401C)
1:30 minutes
2:2.5 minutes at sea level and 59 degrees F

Service History

Badge of 701st Helicopter Squadron (Light)
701st Helicopter Squadron (Light)
Badge of 702nd Helicopter Squadron (Light)
702nd Helicopter Squadron (Light)
The first S-70C(M)-1 was officially handed over to ROCN in US on July 19, 1990. In January 1991, the S-70C(M)-1 were sent to Florida to join the 16 pilots and 32 maitenance crew who received training there. After returning to Taiwan in June 1991, these helicopters were assigned to the newly commissioned 701st HSL under the auspice of the Fleet Helicopter Group. The 701st HSL immediately began the conversion training, which lasted until the end of 1992 and was followed by intensive operational training. It reached the IOC status in March 1994.

When the S-2T were transferred from ROCAF to ROCN in 1999, the Fleet Helicopter Group was redesignated the 2nd Aviation Group. The 701st HSL remained with this Group.

The 702nd HSL was commsioned on March 1, 2000, also under the auspice of the 2nd Aviation Group, in anticipation of the newly ordered S-70C(M)-2. Deliveries of S-70C(M)-2 began in April 2000. From March 1, 2001 to June 20, 2001, the 702nd HSL underwent operational training. It was declared operational on July 9, 2001.

During the first quarter of 2004, the S-70C operated by both the Air Force and Navy surpassed the 100,000 flight hour milestone. But unfortunately two S-70C(M) have been lost in accidents:

  1. On January 12, 1994. S-70C(M)-1 2311 crashed into sea while taking off from the PFG-2 class frigate Cheng Kung (PFG1101) on the Southwest coast. One crew member was killed.
  2. When conducting joint training with the frigate Tzu I (PFG1107) on the evening of October 19, 2005, S-70C(M)-2 2316 crashed into the sea off Tsoying with three onboard. The body of the co-pilot was recovered in half an hour. However, the other two crew and the helicopter were never located.


All photo by Jason Tu unless noted otherwise.
S-70C(M)-1 2301 S-70C(M)-1 2301 (Photo by Wei-Bin Chang) S-70C(M)-1 2305 (Photo by Jason Tu) S-70C(M)-1 2305 S-70C(M)-1 2309 (Photo by Jason Tu) S-70C(M)-1 2309 S-70C(M)-1 2311 (Photo by Jason Tu) S-70C(M)-1 2311
S-70C(M)-2 2312 (Photo by Jason Tu) S-70C(M)-2 2312 S-70C(M)-2 2317 (Photo by Jason Tu) S-70C(M)-2 2317 S-70C(M)-2 2323 S-70C(M)-2 2323 (Photo by Wei-Bin Chang) S-70C(M)-2 2325 S-70C(M)-2 2325 (Photo by Wei-Bin Chang)
S-70C(M)-2 2326 S-70C(M)-2 2326 (Photo by Wei-Bin Chang)
S-70C(M) (Photo by Jason Tu) S-70C(M) (Photo by Jason Tu) S-70C(M) (Photo by Jason Tu) S-70C(M) (Photo by Jason Tu)
S-70C(M) (Photo by Jason Tu) S-70C(M) (Photo by Jason Tu) S-70C(M) (Photo by Jason Tu) S-70C(M) (Photo by Jason Tu)
S-70C(M) (Photo by Jason Tu) S-70C(M) (Photo by Jason Tu) S-70C(M) (Photo by Jason Tu)

Fleet Information

Tail No. Constr. No. Remark
2301 701634 S-70C(M)-1
2302 701558 S-70C(M)-1
2303 701568 S-70C(M)-1
2305 701574 S-70C(M)-1
2306 701580 S-70C(M)-1
2307 701582 S-70C(M)-1
2308 701586 S-70C(M)-1
2309 701671 S-70C(M)-1
2310 701673 S-70C(M)-1
2311 S-70C(M)-1; w/o 01/12/94
Tail No. Constr. No. Remark
2312 702530 S-70C(M)-2
2315 702562 S-70C(M)-2
2316 702555 S-70C(M)-2; w/o 10/19/05
2317 702554 S-70C(M)-2
2319 702564 S-70C(M)-2
2320 702568 S-70C(M)-2
2321 702574 S-70C(M)-2
2322 702579 S-70C(M)-2
2323 702603 S-70C(M)-2
2325 702605 S-70C(M)-2
2326 702630 S-70C(M)-2

 Last update: 05/03/11 TaiwanAirPower > Navy > Top