Stucked in Sao Tome - Damaged Tyre

A trip to Sao Tome which is suppose to be just a turn around, end up as a night stop. During transit check found that one of the wheel have a multiple damaged beyond maintenance manual limit. There is few cut , thread chunking cut which pass through the cut protector and exposing the carcass ply, plus there is few more circumferential cuts that makes the wheel is good enough to ground the aircraft.


If we compare the damaged with reference to tyre nomenclature diagram below, it seem that the damaged is not that serious, however with the speed involved during take-off plus the effect of pressurization in flight, we have to consult the manufacturer first before decision made to release the aircraft.

No 5 Window Cracked

Came back from flight while performing the post flight check, i've notice inrregularities at the No 5 cockpit window. This window sometime been called "eyebrow window" located on top of cockpit crew head so it is hardly noticeable if there is a defect on it.

I've checked it & found that the cracked was in the middle layer as there is no feeling of the crack from outer as well as the inner surface of the window. There is three layer in this window, the middle layer that cracked is the vynil layer. This is the load bearing layer, the next fail safe is the inner layer which is made of glass.

Closer look at the edge of the window, there is a sign of overheated, the main probable cause for the crack to happen. This defect is beyond limit and the window replaced as soon after that.

Poor Maintenance Practices

I've found this while removing the right hand heat exchangers for cleaning. The clamp was"sitting" on top of the pneumatic duct.

It is posible that the ducts have been removed & reinstalled back with the top duct been normalised first, the lower duct then was reinstalled without the mechanic that done the installation aware of the contact.

All pneumatic, hydraulic, flight control cable must be inspected for interference with adjacent structures to eliminate unnecessary defect in the future. In the case above, due to vibration, crack can occur which will lead to pneumatic leakage and subsequent damage.

Cockpit Window Cracked

One of our BBJ aircraft came back with number 2 cockpit window cracked. No 2 window is the only window that can be opened, it slide backward. This is very dangerous situation where it might lead to rapid decompression however by knowing the construction of the window itself, we can be assured that the safety is not tolerated.






This window is a laminated assembly of layers of glass and vinyl or urethane. The structural inner glass pane carries pressure loads. The vinyl interlayer is structural for bird impact resistance and fail-safe pressure loads.

The current window manufactured by PPG has these layers: an non-structural outer glass pane, a non-structural urethane interlayer, a structural vinyl interlayer, a non-structural urethane interlayer and an structural inner glass pane.

A conductive film is located on the inner surface of the outer glass pane, which is a part of the window heat system that supplies the anti-fog and the anti-ice function.

Rest of the cockpit window have almost the same construction. The passanger window however in stuuctured in layers as well minus the heating element.

Few months earlier one of our Gulfstream had a similar incident where the number 1 cockpit window cracked during flight, from the sign of arcing at the top left corner of the window, overheated is the probable caused for the damaged.

Most Eventfull Flight - Morrocco - Benin - Angola - Libya

I just came back from the most "eventful" flight as quoted by maintenance controller to whom we consult incase of defect during line operation.

From Abu Dhabi to Al-Ain, landed with Air Traffic Controller no 2 failed, while fueling the fuel to Rabat, the fuel automatic cut-off once the center tank reach it maximum level also failed thus overflow from the underwing fuel tank vent outlet.

From Rabat, we go to Cotonou, Benin, then to Luanda, Angola and back to Cotonou. Then we go to Tripoli, Libya, on departure back to Cotonou we have Auxilliary Power Unit automatic shutdown, interrogate APU BITE (Built In Test Equipment) found autoshutdown due to high oil temperature, we departed with engine start using ground air starter. Before start there is CDS (Common Display Unit) fault messages, cycle the circuit breakers clear the defect.

Landed safely in Cotonou and opened APU cowl to check any abnormalities, found APU oil scavenge filter pop-out indicates filter is clogged, APU remained inoperative and will be repaired once aircraft returned back to base.

On departure back to Abu Dhabi, IRS (Initertial Reference System) ON DC fault light came on, found IRS circuit breaker pop-out, reset back and after 5 minutes IRS fault cleared, then we have both engine control ALT fault and TCAS came on as well, recycle ENG control switch & TCAS circuit breaker cleared both defects. I'm sure all this avionic defect related to less cooling as we dont have airconditioning during aircraft preparation as the APU is inoperative, as it get hot, the electronic units tend to failed and trip off to prevent further damaged.

I'm preparing this write-up from 37000 feet on the way back to base, long 8 days trip and of course with full of experience. From Africa with love.......

Birdstrike on radome.

Aircraft arrived back with sign of birdstrike on nose radome, inspected and tap test test to determine any delamination found nil damaged apart from paint flaking.

Further inspection carried out on landing gears, airconditioning intakes and engines show no secondary damaged. Checked with pilot for any changes in engines parameters found nil problem.

The impact area cleaned-up and aircraft is ready to fly back. Of course now we are waiting for replacement radome as it looks very unpleasant especially for a VIP aircraft.

Accident in Luton Airport

Mar 20th 2007 Luton Airport.

Mid size jet was parked infront of my aircraft after it has been placed at overnight parking bay. I was in impression that aircraft will be towed to taxiway and taxi out for takeoff however it is not, due to the jet blast from the engine start, the passanger step placed next to my aircraft was blown away and hit number 1 engines inlet lip.

Damaged assesment found it is out of Structural Repair Manual limit for normal flight, measurement taken and forwarded to Boeing for evaluation. Boeing granted approval for 1 ferry flight and 1 revenue flight.

Depart next day to Agadir as ferry, night stop for 8 hrs and head back to Riyadh next day as revenue flight.

Lucky it was only a dent, if it a puncture, for sure i have to stay in Luton at least for 1 week. Nice place to stay but with very temperature almost 0 deg Celcius, back home is much better.

Hydraulic Pressure Module Leakage

I was in Kuwait for 2 days trip, after landed and parked infront of VIP terminal in Kuwait Airport, i've noticed hydraulic fluid accumulated below system B hydraulic pressure module, from my observation i suspect it is from System B Hydraulic Electrical Pump pressure transmitter however it cannot be confirmed even with pump turned on , I've cleaned the area and wipe it dry, ready to be verified on next flight.

The next day after flight back to base, confirmed the leakage was from the transmitter base, as per IPC (Illustrated part catalog) there is a seal inbetween. Ordered and replaced the seal, ground check no leak as well on subsequent flight... problem solved...

Landing Gear Shock Strut Leakage.

During all this years i'm working on B737 NG, leakage on the main and nose landing gear strut is common on all aircrafts that i've worked with either Mastar or on current fleet.






I'm sure if someone unfamiliar with this situation will thinked that the this landing gear is having a problem of leakage however it is not.






As per Boeing Maintenance Tip document, this is because of new design on new 737 landing gear, thin layer of oil presence everytime the shock strut extended and this layer plus dirts that have sticked to it has been push down by a scraper seal as the shock strut compressed.


A follow-up maintenance action have to be carry-out after few hundred hours of aircraft operation, this is to ensure sufficient amount of fluid remain in the shock strut itself.

Nose Gear Low Extension

I was in Seoul, Korea from 9 Feb to 15 Feb 07, upon arrival in Incheon Airport during my walkaround check found nose gear strut with very low extension. Only 1 inch of the chrome part visible. Since tired of long 11 hours flight from Riyadh to Seoul i decided to return back to aircraft after few days.

On 12 Feb, I've made arrangement with Korea Business Airport Service (KBAS) representative, our ground handler for me to visit the aircraft to check the aircraft condition before our departure on 15th. This is a norm in VIP service as we don't want any surprise on departure date.

Miss Son from KBAS escort me to the aircraft from the terminal, security is very tight, the airport security did not allow me to bring my camera inside. Well no problem so we headed to the aircraft.

I've requested the maintenance support personnel to be there to assist me rectify the nose landing gear low extension problem. As per the maintenance manual, we are allowed to top up the nitrogen for the strut to bring it up to the specified length as per the chart in the MM as well as at the nose wheel well left hand bulkhead.

So i top up the nitrogen for the strut and got the required extension. Walkaround check found aircraft is in good condition. Headed back to the hotel after that.. long journey... 1 hr drive... no problem because they provide me nice big hyundai limo...

Thanks to Miss Son for the picture below, she shot it with her phone and email it to me.

Display Unit Goes Blank

I was preparing the aircraft for early morning departure and noticed the center upper DU goes blank. Aircaft is heading for Geneva and will fly back on the tonight.

I've reset the circuit breaker CB at P18 behind pilot seat nil joy, swapped it with lower center DU found defect transfered so confirmed the defect was the DU itself.

Check with Minimum Equipment List (MEL) found faulty lower DU is despatchable with cat C MEL.

My supervisor came onboard and double check the DU. He noticed a blink on the DU when he pull push the CB so he decided to do the ground test from FMC CDU maint page, walla.. sudddenly it come back to normal, so it is intermittent. However this is the sign that it gonna fail soon. So getting the spare in advance will be a good idea.

Hydraulic Leaking

This happened 2 years ago but i still have the photo to share, massive hydraulic leaks around both main landing gear. Aircraft has been brought to maintenance facility for retraction test to confirmed the leak from main landing gear actuator however after 5 complete retaction cycle there is no sign of leak from either MLG actuator.

Here is the photo taken in Heathrow, after 8 hrs flight from base to pick-up VIP from London. It is difficult to make decision from where it leak when ground check unable to confirm it. Multiple theory was brought up by my work-mate such as it could be from ground spoiler, i'm insist on it is from the MLG even though ground check unable to confirm it.

Lucky for us the aircraft heading for hangar check and part of the package was to replaced the MLG actuator as called out by SB. Since then everything is back to normal so it prove that the culprit is the MLG actuator even though the ground retraction unable to proof it. Probably it need load from airflow when the aircraft take-off and approach to induce the leak.

R/H Boost Pump Wire Burned.

Last week, mission from Riyadh to Melbourne, transit stop in Kuala Lumpur for 1 hr after 7 hrs flight. 2 hrs after airborne, the pilot called me to the cockpit and informed me that R/H aft boostpump Low Pressure light came on. As per crew checklist boost pump switch to be kept off.

Upon landing in Melbourne, noticed that the boost pump CB's in P62 PDP popped-out. Inspected the boost pump looks normal, however when i traced the wiring found burned wire about 1 ft from the pump itself. Defect put under MEL cat C, upon return to base, damaged wire repaired per Standard Wiring Practice Manual.

It is quite mysterious how the wires got burned, lightning strike? Landing was retracted as it happen 2 hrs after airborne. I noticed adjacent bolt to the burn area, probably arcing could be the caused.