Taiwan Air Force orders additional Hush-Houses

Citation

(1998), "Taiwan Air Force orders additional Hush-Houses", Aircraft Engineering and Aerospace Technology, Vol. 70 No. 1. https://doi.org/10.1108/aeat.1998.12770aaf.007

Taiwan Air Force orders additional Hush-Houses

Taiwan Air Force orders additional Hush-Houses

The Republic of China Taiwan Air Force has contracted with Industrial Acoustics Company to supply two engine/aircraft test facilities with noise suppressors. This coincidentally follows the successful demonstration and acceptance by the ROC Air Force of an IAC Hush-House for their Chiayi Air Base.

The new installations will include adaptations of the IAC Standard Jet Aircraft Hush-Houses and IAC Power-FIow® Jet Engine Test Cells to test engines out of the airframe. In addition, an engine preparation shop will be provided. The Hush-Houses incorporate design modifications for increased noise reductions that were used successfully with IAC Noise Suppressors for the Korean Air Force.

The noise reduction capability of the Standard IAC Hush-Houses will be enhanced by means of a Secondary Power-Flow Exhaust Silencer 7.32 meters (24 feet) square in cross-section and 8.53 meters (28 feet)long. Sound level measurements at existing installations, with and without a similar silencer, confirm that such a silencer reduces noise by an additional 10dB(A).

The following outlines some of the features of the completed Chiayi AFB IAC Hush-House, many of which will be included in the two new engine/aircraft test facilities.

Under contract to the United States Air Force's (USAF) San Antonio Air Logistic Command's Directorate of Aerospace Management (SA-ALC/LD), Industrial Acoustics Company delivered the first of two IAC Jet Aircraft Hush-House Noise Suppressors to the ROC Taiwan Air Force (TAF) at their Chiayi Air Base. The second system is currently being installed at Hualien Air Base and is scheduled to be turned over to the TAF later this year.

An F-16A aircraft being checked inside an IAC Hush-House, recently installed at the Taiwan Air Force's Chaiyi Air Base

These Hush-Houses are identical to the more than 70 standard systems IAC has supplied to USAF for their worldwide bases. Designed to support ground run-up operations for any fighter aircraft in the Air Force's inventory, standard Hush-Houses satisfy most local community noise ordinances. TAF's multi-purpose Hush-Houses will support overhaul and maintenance operations to keep their new fleet of F-16s air-worthy.

Chiayi F-16 aircraft noise was reduced to 80 dB(A) or below, at a distance of 250 ft (76 m) from the Hush-House. At critical forward locations, the Hush-House suppresses the noise generated to below 75 dB(A) at the same distance.

The facility includes a Noishield® Control Room to observe engine test routines. This room is acoustically isolated to allow operational personnel to run engines up to full power in comfort and safety. While an F-16 at maximum after-burner power emits noise levels of over 140dB(A), just a few meters away, inside the control room, they are below 70dB(A). The room also includes a thermostatically controlled air-conditioning and heating system.

The aircraft/engine test area of the Hush-House is 25 meters (82 feet) long by 20 meters (65.6 feet) wide and 8.25 meters (27 feet) high. Walls and ceilings are faced with stainless steel Noishield Sound Absorbers for maximum noise reduction and corrosion resistance. Large bi-parting, electrically operated Noise-Lock® Doors provide ingress and egress for both aircraft and engines. Other Hush-House features include a storage area, rest room and toilets.

Eight Power-Flow Air Intake Silencers (four in each of the opposite side walls) allow cooling and engine air to be drawn into the cell. The two forward intakes have electrically operated vanes to minimize flow vortices by directing air towards the intake of the engine under test.

In the rear wall of the cell, an Absorptive Resonator Power-Flow Augmentor Tube Silencer, 6.1 meters (20 feet) in diameter and over 24.4 meters (80 feet) long, collects and disperses engine exhaust gases. Built in ten separate sections, the tube's interior is protected against the jet engine blast by perforated, corrugated stainless steel liners designed to expand and contract with temperature changes. While the temperature inside the exhaust silencer might reach 450 degrees Celsius (842š F) at maximum after burner power, the exterior is cool to the touch.

IAC Hush-Houses, in addition to testing F-4 and F-16 aircraft and their engines will accommodate other aircraft, including the A-7, A-10, F-5, F-18, F-111, Tornado and Mirage; they offer flexible solutions to the maintenance and overhaul of aircraft and engines.

Industrial Acoustics Company has provided Hush-Houses, Aircraft Ground Run-Up Pens and Engine Test Cells for both military and commercial operations in Canada, Germany, Holland, Japan, Kuwait, Korea, Italy, Pakistan, Portugal, Taiwan, the USA and the UK.

IAC Air-Cooled Engine Test Cells with Noise Suppressors are utilized for maintenance and overhaul of aircraft engines mounted on stationary thrust stands when removed from the aircraft. Modular Power-Flow® Demountable Test Cells are supplied in three models for testing of all fighter aircraft and most transport aircraft utilized by the military forces.

In addition to the Taiwan Air Force's current four F-16 projects, IAC Hush-Houses were selected recently by the United States (USAF) and German Air Forces (GAF) to support the USAF special missions at Aviano Air Base in Italy and the GAF Tornado Pilot Training Program at Holloman Air Base in New Mexico.

Details from Industrial Acoustics Co. Inc., 1160 Commerce Avenue, Bronx, New York, 10462, USA. Tel: 718 931 8000; Fax: 718 430 4590; e-mail: info@industrialacoustics. com