Concorde Unscheduled Maintenance Checks

THIS SECTION IS STILL BEING BUILT!


Unscheduled maintenance checks, generally resulting from unusual aircraft operating conditions, must be completed satisfactorily in accordance with the instructions given in the Flight Manual. They also include inspections required prior to a three-engine ferry flight, but do not include specific checks resulting from unsatisfactory operation of an individual power plant for which reference must be made to chapter 71 of the BA Flight Manual.

CHECKS FOLLOWING A FLIGHT IN THE RAIN – INSPECTIONS/CHECKS

In general no specific structural check are necessary for flight in rain within the subsonic speed envelope (M lower than 0.93) but is recommended after encounters with excessively heavy rain or for extensive periods in heavy rain.

Structural, checks are recommended after each flight in the rain at M greater than 0.93 in particular for TAS conditions greater than 560 Knots.

Checks (See the drawing below)

A.

The areas of the aircraft that must be checked are indicated on the following drawing below.

The sequence in which these areas should be checked is indicated and is related to their relative vulnerability to rain impact. Should no damage/erosion be evident in a particular area during the sequential check or if the damage/ erosion has not significantly increased from the previous check, then the remaining areas listed for check may be ignored.

B.

The most vulnerable areas are those manufactured from composite materials such as fin notch antennas/radome, followed by glazings – visor, windscreen, and collision warning lights, navigation lights, and finally structural items such as the wing leading edge and the fin leading edge.

Checks are also recommended for the external sensors fitted to the aircraft fuselage such as the pitot probes, angle of attack/sideslip vanes and the temperature probes and exposed repairs.

The type of damage which may be found is: Composite materials – paint erosion; followed by pitting of resin, and at the worst delaminating glazings – surface pitting, with at worst crazing of the outer laminate if the toughened layer is penetrated.

Structures – paint erosion, slight lifting of the rivet heads, external sensors and erosion of forward facing edges.

CHECKS FOLLOWING A TAIL WHEEL HARD TOUCHDOWN/OVER ROTATION

A.

A cursory visual inspection must be carried out following a report by the crew of a tail wheel hard touchdown/over rotation.

This can occur in conjunction with the following:

(1) A hard landing

(2) An incorrect approach attitude in pitch or roll, or

(3) Over rotation on take-off.

B.

A thorough inspection must be carried out whenever damage is observed during a cursory inspection.

Cursory Inspection/Check

Tail Landing Gear and Bay.

(1) Check the wheels and tyres for damage and loss of pressure.

(2) Inspect the Tail Landing Gear and attachment points for obvious damage.

Power Plant – Nozzles

Inspect the bottom surface of the twin secondary nozzles and lower thrust reverse buckets for impact damage.

Inspection Findings

If any damage is detected perform the appropriate thorough inspection/check as follows:

(1) If the damage is confined solely to the Tail Landing Gear or Bay, the thorough inspection/check may be limited to paragraph 3 A.

(2) If damage is detected on the bottom surface of the twin secondary nozzles/lower thrust reverse buckets perform the complete inspection/check described in paragraph 3.

Thorough Inspection/Check

The following items are additional to the cursory inspection/ check. Unless otherwise stated all inspections defined below are visual

A. Tail Landing Gear and Bay

Inspect the structure of the tail gear bay particularly at gear-to-bulkhead 88 attachment points for damage and distortion.

B. Power Plant

With engine bay doors open

(1) Engine Bay

Inspect the rear engine bay door latches and adjacent structure for damage and distortion both on the door and on the engine bay centre-wall and nozzle.

Operate and inspect the rear door-to-forward door/ secondary nozzle bodge bolts for evidence of distortion and damage.

Check engine bay centre-wall for evidence of movement. Inspect the Jet Pipe-to-Engine connection links for damage. Remove the covering heat shield and inspect the lower centre-wall link fittings for damage.

(2) Nozzles

Inspect the following for damage and distortion

(a) Complete exterior of twin secondary nozzle structure particularly in the region of the attachments to the wing and engine bay centre-wall

(b) Thrust Reverse Bucket Attachments.

Enter the twin secondary nozzle and jet pipe for the following checks.

  • Inspect the inner face of the jet pipe primary nozzle and convergent-divergent nozzle for damage and distortion.
  • Check for correct position of the reheat jet pipe
  • Check the primary nozzles petals for security and damage by measuring dimension ‘X’ (Ref. 78-12-01 Removal of the Installation in the BA Flight Manual)

Supplementary Checks

Depending on the degree and nature of the damage experienced the following additional checks should be carried out as appropriate to the aircraft.

Tail Landing Gear Functional Test

NOTE:

It is recommended that this test is performed following discovery of damage on the thrust reverse buckets even if no obvious damage has been sustained by the tail gear.

Inspect the following items for damage and distortion.

(1) Thrust Struts (Remove Lower part of heat shield.

(2) Drag Struts (Removal of heat shield unnecessary unless (1) is damaged).

(3) Centre-wall upper link fittings (remove heat shields as required and view from inboard or outboard side only).

If lower rear corner of centre-wall shows evidence of ground contact remove heat shields and inspect restraint bracing struts to wing at Spar 68 on engine bay rear centre-wall. – LH & RH Nacelles.

NOTE:

If the engines are not scheduled for removal carry out inspection at next main base engine removal.

Check upper part of Spar 72 in region of secondary nozzle attachments and adjacent wing skin for damage and distortion.

CHECKS FOLLOWING A LIGHTNING STRIKE OR ELECTRICAL DISCHARGE

The lightning strike phenomenon can be described through the effects it brings about in its various phases:

A. Fields and arcs produced by high electric voltages

B. Magnetic forces produced by high currents

C. Blast and heat effects produced by high energy intermediate currents

D. Metal erosion induced by weaker and longer duration currents following the high energy phase

When Concorde has been struck by lightning or has undergone electric discharges, a general check must be carried out before the next take-off.

Structural Check

A.

An external visual examination of the aircraft structure has to be carried out, with special attention being paid to the flying control surfaces and the primary bonding leads, which should be inspected for breakage or blackening due to overheating.

An operational test must follow the inspection of flight control surfaces. Furthermore, a visual examination, together with an operational test, must be carried out on the landing gear hinge fittings in so far as these areas show evidence of strike contact.

B.

With the structural components, make certain that there are no stains, paint discoloration, pitting and burn marks, particularly on heads of fasteners.

Navigation and Communication Systems

A. Visual Check

A visual check has to be carried out to the following components for lightning strike deterioration:

Pitot heads

Angle-of-attack sensors

Sideslip sensors

Total temperature sensors

Nose probe

Radome and lightning Strips

Weather radar antenna

VHFI antenna

VHF2 antenna

ADF antenna and flux valve fairings

Static dischargers:

VOR-LOC antenna in case of damage, refer to the corresponding chapter of the maintenance manual for repair.

B. Tests

After a reported lightning strike, operational tests have to be carried out on the following:

High Frequency (HF) Adjustment/Test

Very High Frequency (VHF) Adjustment/Test

Air Data System Adjustment/Test

Compass Coupler Adjustment/Test

Marker Adjustment/Test

Instrument Landing System Adjustment/Test

Weather Radar System Adjustment/Test

Radio Altimeter Adjustment/Test

Distance Measuring Equipment Adjustment/Test

Automatic Direction Finder (ADF) – Adjustment/Test.

VHF/Omnirange (VOR) – Adjustment/Test.

On all cases:

Check the operation of the Standby Compass by comparing its reading to that of Compass Couplers. In the case of difference greater than 10° refer to Maintenance Manual Adjustment/Test procedure

Lighting

Perform operational tests for each of the following systems:

Navigation lights – Adjustment/Test

Anti-collision lights – Adjustment/Test

Landing lights:

-Main – Adjustment/Test

-Taxi and turn – Adjustment/Test

Miscellaneous

Check ice detector head located in the area known as zone 111. If any damage is found, then refer to the Maintenance Manual for Removal/Installation and Adjustment/ Test.

Perform self-test of fuel quantity indication – Adjustment/Test.

Perform external-visual check and functional test on visor window static discharge units and windshield static discharge units – Adjustment/Test).

CHECKS FOLLOWING A FLIGHT IN TURBULENT AIR

Checks must be performed after a flight in turbulence involving excessive acceleration.

Checks must be effected when motivated either by the Captain’s report or by results of routine flight recorder data analysis.

A flight in excessive turbulence is defined by an acceleration resulting in a load factor n, such that:

n greater than 2.5

or n smaller than – 1

NOTE:

The manufacturer must be informed of any flight configuration involving acceleration in excess of the quoted values, and should be provided with the following parameters:

Acceleration recorded

Altitude

Speed

Aircraft weight

CG position

Fuel weight

Fuel distribution

Structural Check

Fuselage

Visually check the exterior surface of the fuselage between stringers 6 left and right, frames 41, 46 and 54 for loose or missing fasteners, cracks or distortion.

Visually check the exterior surface of the fuselage top skin between stringers 5 left and right and at all frames 29 to 42 inclusively for loose or missing fasteners,.

Check all the doors and access panels for security of attachment, paying particular attention to those which are retained by quick release fasteners.

Visually check the exterior of tank 11 between frames 81 and 88 for evidence of fuel leakage.

Visually check the exterior of tank 9 between frames 38 and 41 for evidence of fuel leakage.

Visually check the nose gear uplocks and doors for freedom from distortion or damage.

Fin and Flight Control Surfaces

Visually check the fin fuselage attachments for freedom from distortion or cracks.

Visually check the exterior surface of the fin for 1oose or missing fasteners, cracks or distortion.

Perform an operational test of the flight control surfaces

Wing

Forward wing to fuselage attachments at frames 28, 31, 34, 38; visually check the spherical adjustable eye-end junction fittings and integral attach fittings for freedom from damage or distortion.

Visually check the main landing gear doors and uplocks for freedom from distortion or damage.

Variable Aerodynamic Fairings

Visually check the droop nose uplocks and the radome latches for freedom from damage and distortion.

Visually check the visor and droop nose mechanisms for freedom from damage and distortion.

Perform an operational test of the visor and droop nose system

Aircraft Interior

Check the passenger and crew member seats, electronics racks, and galley and toilet attachments for security of attachment.

Visually check the interior of both baggage compartments, for possible damage caused by freight or securing equipment.

NOTE:

If there are any anomalies found during the checks performed, then the Airframe Manufacturer must be notified.

CHECKS FOLLOWING A HARD OR OVER-GROSS LANDING

MANDATORY INSPECTION

CAUTION: ALL AIRCRAFT ARE TO HAVE NDT INSPECTION TO K53-U-74 CARRIED OUT FOLLOWING A HARD LANDING OR PRIOR TO THE

EXPIRY OF FIVE REFERENCE FLIGHTS FROM THE HARD LANDING OCCURRING. THIS IS A COMBINED MANDATORY AND QSD REQUIREMENT.

A cursory inspection must be carried out immediately following a report by the crew of any of the following:

A hard landing

An over-gross landing:

  • Aircraft weight greater than 130 Tonnes (286598 lb).
  • Aircraft weight greater than MLW but not more than 130 Tonnes (286598 lb) unless operating in the special overweight landing configuration as defined in the Flight Manual.

NOTE:

Landings carried out at weights greater than MLW but not more than 130 Tonnes (286598 lb), using the special configuration referred to above, will be recorded in the technical log and identified as “fuel saving landings”.

A nose wheel hard touch-down (i.e., when the nose wheel is lowered onto the runway with high vertical velocity).

NOTE:

In the case of a nose wheel hard touch-down the inspection may be confined initially to the nose landing gear and bay.

Following a tail wheel hard touch-down/over rotation, a thorough inspection must be carried out whenever:

Damage is observed during a cursory inspection or, the analysis of the flight recorder data indicated that the aircraft has been subjected to load factors/pitch rates equal to or greater than those defined below.

For hard or over-gross landing load factors. (Ref. See the picture below)

Nose Wheel Hard Touch-Down

This condition can occur in conjunction with a hard or normal main wheel landing followed by a rapid pitch-down of the nose producing a vertical velocity of 6 ft/sec or more. For inspection purposes a vertical velocity of 6 ft/sec can be considered as a pitch rate of 6 ft degrees/see.

NOTE:

Inspection findings should be transmitted to the Manufacturer.

Cursory Inspection/Check

This involves carrying out a NDT inspection to technique K53-U-74.

The inspections that are defined below are visual ones

Fuselage

The following items must be inspected for damage and distortion:

The droop nose exterior as visible from the ground.

Lower fuselage skin exterior from Frames 18 to 20 between stringers 26 and 32 (LH and RH sides).

Lower fuselage skin from Frames 35 to 42 between the left and right hand wing lower fillets.

Upper fuselage skin exterior from Frames 35 to 60 between stringers 6LH and 6RH, with particular attention to skin panel joints at Frames 41, 54 and 60.

Lower fuselage internal structure from Frames 18 to 20 between pressure deck and nose landing gear door surround approximately between stringers 26 and 32 (LH and RH sides).

Operate the droop nose and visor to ensure correct operation of mechanism and indicators

Nose Landing Gear and Bay (Applicable for Nose Wheel Hard Touch-Down only)

  • Check the wheels and tyres for damage and loss of pressure.
  • Check shock absorber for normal extension.
  • Inspect the following items for obvious damage
  • (Nose Landing Gear doors open).
  • Nose landing gear and attach points.
  • The structure of the Nose Landing gear bay particularly at lateral brace strut and the telescopic drag strut attach points.

Main Landing Gear and Bays

Check the wheels and tyres for damage and loss of pressure.

Check shock absorbers for normal extension.

Inspect the following items for damage and distortion (Main Landing Gear Doors open).

Main landing gears and attach points.

Main landing gear secondary doors particularly at door-to-gear attach points. The structure of the main landing gear bays particularly in the vicinity of the main gear trunnion bearings and at telescopic brace strut attach points.

Check fuel tank walls for unusual leakage or an increase in flow from existing recorded permissible leakage

Tail Landing Gear and Bay

Check the wheels and tyres for damage and loss of pressure.

Inspect the tail landing gear and attach points for obvious damage and distortion.

Wing

Inspect the under surface of the wing for signs of unusual fuel leakage or an increase in flow from existing recorded permissible leakage.

Power Plant

Engine and Nacelle:

Observe appropriate safety precautions and prepare access to engine air intakes

WARNING:

DO NOT ENTER THE ENGINE AIR INTAKES WHILST THE AIRCRAFT HYDRAULIC SYSTEM IS PRESSURIZED.

From inside the engine air intake:

Check LP rotor for free rotation. Check first stages of LP compressor for damage.

With engine bay doors closed:

Inspect engine bay doors for damage and distortion particularly at the skin panel joints.

With the engine bay doors open:

Inspect the fuel pipes and connections for damage check the magnetic plugs

Check that the QAD (quick attach/detach) couplings are firmly tightened. (Ref. Maintenance Manual

Nozzles.

Inspect the bottom surface of the twin secondary nozzles and lower thrust reverse buckets for impact and damage.

Hydraulic System

Using ground rigs, or with the engines running, carry out external hydraulic leakage checks in accordance with the Flight Manual.

Inspection Findings

If the foregoing Inspection/Checks disclose no damage, proceed with run-up and operational checks described in the manual

If any damage is detected, perform the complete thorough Inspection/Check described in the manual

Thorough Inspection/Check the following items which are additional to the cursory Inspection/Check. Unless otherwise stated, all inspections defined below are visual.

Fuselage

  • Inspect the following items for damage and distortion.
  • Radome attachments (forward radome)
  • Droop nose jack attach points

Nose Landing Gear and Bay

  • Check shock absorber for correct pressure

Main Landing Gears and Bays

  • Check shock absorbers for correct pressure

Tail Landing Gear and Bay

  • Inspect the structure of the tail gear bay for damage and distortion particularly at gear-to-bulkhead 88 attach points.

Wing

Inspect the following items for damage and distortion.

Web of rib 21 between spars 54 and 60 (MLG Doors open).

Web of spar 59 (MLG Doors open).

Joints of upper and lower surface skin panels in the vicinity of the landing gear trunnion bearings at spars 56 and 59.

Web of spar 54 between ribs 21 and 27. (Requires entry into fuel tank)

Web of spar 60 between ribs 21 and 27. (Requires entry into fuel tank)

Power Plant

Engine and Nacelle with engine bay doors open:

Check the air intake casing vanes for distortion with a straight edge

Carry out an optical check of the HP compressor 4th and 5th stage blades through the 4th stage

Check for excessive discoloration and for burring at the blade tips.

Check the turbine exhaust diffuser casing vanes with a straight edge, for bending and buckling

Nozzles.

Check for correct position of the reheat jet pipe by measuring dimension ‘X’

NOTE:

If dimension ~x~ is outside tolerances check for condition of reheat jet pipe/ spherical flange adaptor connecting link and angular positioning stop.

Remove air intake units and restore system to operating condition.

Engine running.

Start engine and carry out a ground run with a slow acceleration deceleration up to maximum continuous and check that No.1 bearing vibration is within acceptable limits. During the run, examine the engine for excessive breathing and oil and fuel leaks.

Carry out engine run-down checks

After shut down, examine bearing vents for excessive oiliness and the outside of the engine for signs of leaks.

Check the magnetic plugs

After restoration to flyable status and closing of engine bay doors, perform the following checks.

During the next flight, the oil consumption must be recorded and checked against the consumption prior to the heavy landing. An increase in consumption indicates internal damage.

NOTE:

An increase in oil consumption should also be confirmed by inspection of the magnetic plugs.

Alignment Checks

If analysis of flight recorded data indicates that during landing the aircraft has been subjected to a vertical load factor in excess of 3g up to Maximum Landing Weight or in excess of 2.2g at weights between MLW and Maximum Take-off

Weight, check the Main Landing Gear forward trunnion spherical bearing for distortion.Depending on the degree and nature of the damage evidenced, as a result of “cursory” and “thorough” inspections, the following additional checks may be carried out as appropriate:

Level the aircraft and check the Z-axis dimensions

Check landing gears for alignment

Internal visual inspection of upper joints at Frames 46, 54 and 60 from stringer 4RH.

Visual inspection for distortion of (tunnel) lower and upper brace rods, fuselage stringer, stringer 4LH to centre beam at Frames 54A and 9 – upper brace

Internal visual inspection of wing lower longitudinal detail parts: stiffeners and ribs between spars 35 and 46 over a width of approximately 1 metre (40 inch) from inboard tank wall for damage and distortion.

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