Section 10

 

Hot Air Subsystem Installation

 

01/03

Almost all hot air subsystems for no1 engine bay were removed after airframe disassembly. Most were removed correctly, though some were damaged, but have been replaced with spares.

 

All hot air pipes upstream and downstream of main engine bleeds are joined with flexi couplings and conoseals, and are sealed by stainless steel gaskets. These gaskets are normally used once.These gaskets will be reploaced and will be evaluated upon testing of the hot air circuits, with use of the main air palouste coupling. This will be done before installation of ECU’s. Small leaks can be ignored so long as hot air does not interfere with other subsystems. Couplings are normally coated with molybdenum powder before assembly when new. Since gaskets are already used, this should not be necessary.

 

All temperature control valves have been refurbished and function well. Both pressure relief valves and constant air valves are also good and can be re-used as normal.

Water extractor unit has undergone some refurbishment, mainly replacement of the mounting couplings and water bleed pipe. The internal condition of the water boiler is unknown, however unless it was drained and flushed correctly, some crystallisation is likely, and a pressure flush may be necessary. Heat exchanger requires no refurbishment, no corrosion is present and the matrix is in excellent condition.

 

The cold air unit is seized, however removal and subsequent freeing up will be simple to perform, completing the conditioning system for functional testing.

 

As with all zf579 subsystems, wiring will require re-connection too.

 

Once all air systems are installed and re-furbished, the system will be tested via the main air palouste connector. Before this can take place, the accessory drive gearbox will require refurbishment of the main turbine, which is currently seized.

 

 

 

05/03

 

Over the past 3 months, the main air systems have been re-installed into no1 engine bay, along with most of the conditioning and pressurisation valves. All piping went in without any hitches, though most needed re-adjustment after all were fitted, since some couplings were not true due to different torque settings. All conoseal clamps were in excellent condition, as were most pipes, though some pipes were replaced with better examples. The following list outlines all services and pipes that have been re-installed.

 

 

FMP/A/5100 *2          Cockpit temperature control valves

Ef3-75-3059                Air shut off valve assembly ee65 1317-1

Ef3-75-2987(a10)        starboard no1 engine bay main air duct

Ef3-75-957(a16)          hot air to cabin pressurisation pipe

Ef2-75-533 (f56)         hot air pipe

Ef2-75-309(a9)            branch air pipe

Ef3-75-2421                hot air pipe

Ef3-75-2423                hot air pipe

A17                             water extractor pipe

Pressure relief valve     rear and forward starboard

Ef3-75-2925                Air pipe reducing coupler

Ef2-75-163

Ef3-75-3247                pressure relief valve assembly

Main air pipe bypass to pressure relief valve (no part number available)

A14 and A15               hot air pipes

Water extractor assembly.

Forward bay constant pressure assembly.

Water extractor drain pipe.

 

 

Systems requiring further refurbishment

 

1)      Cockpit ram air valve assembly. Currently seized.

 

2)      Cockpit heat dispersal ducts. Condition unknown

 

3)      Equipment moisture extractors (replacement)

 

4)      Canopy heating ducts, rubber seals are hardened.

 

 

05/03

 

 

 

Above plate shows most air piping now installed.

 

 

 

 

 

 

 

 

 

Above: Aft air shut off valve and temp assembly for spine and equipment bay cooling.

 

 

Above: Main air duct and bypass pressure relief valve. Downstream of No2 NRV

 

 

 

 

Above: Refurbished shut off valves and temp control valves.

 

 

01/10/04

 

Expanding bellow joints frame 25S checked for measurements and adjusted as necessary to 0.09inch max.

 

Outstanding 20/02/04

 

1) Final torque up of all air piping in no1 engine bay.

 

2) Application of Teflon coating to sliding joints, no 1 engine bay.

 

3) Fire integrity checks for all high-risk areas, no1 engine bay, by way of hot air

palouste.

 

5)      Check all firewire gaps and implement fire wire test set.

 

 

 

09/2007

 

All hot air piping for no1 and no2 engine bays is now finished, just requiring a final leakage test. The last areas to be installed were No1 engine bay water extractor assembly and no1 engine hot air compressor bleed duct after refurbishment.

 

 

 

Above: no1 engine compressor bleed duct missing, whilst being refurbished.

 

 

 

Above. The same region, but with newly re-build compressor bleed duct installed. Completing the hot air system for no1 bay.

 

 

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