Lufthansa A333 at Mumbai burst 4 main tyres on landing
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Lufthansa A333 at Mumbai burst 4 main tyres on landing
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LH467 Tyres burst at landing at BOM
Don't know the causes about this incident, happened few hours ago at BOM. LH764 flight MUN-BOM Aircraft A333 D-AIKR
Last edited by mingocr83; 14th May 2016 at 18:51. Reason: Adding Aircraft Info and correcting flight number
Are the front wheels on both sides on one anti-skid system and the rear wheels on both sides on a second one?
No, the anti-skid system controls all eight brakes equally. Also, the parking brake applies to all eight brakes.
A bogie "pitch trim" system tilts the bogie at takeoff and for landing to provide additional tail clearance. The tilt mechanism levels the bogies for retraction, and the shock strut is "shortened" by another mechanism so the gear fits into the gear bay on retraction.
Touchdown is always on the rear bogies first; the tilt system "lowers", (sometimes drops!...) the forward bogies as aircraft de-rotation occurs. That's the small secondary bump one feels in an A330/A340, (some have mistaken this for the centre landing gear touchdown, but the A330 doesn't have this gear and I can assure anyone that it still "bumps"...).
The wheels are numbered, 1,2 - 3,4 across the front bogies, and 5,6 - 7,8 across the rear bogies.
Not sure what would cause just the rear bogies to lock and remain locked but the scenario (all four evenly destroyed), fits a "signal-to-a-system" vice any mechanical/physical impediment (frozen, etc), that prevented all four from rotating.
I believe if the park brake is set to "ON" prior touchdown, park-brake pressure would be applied to the main gear at touchdown. Placing the Park Brake selector to ON isolates the main and alternate braking systems and provides Blue system pressure @ ~2500psi.
The AOM states:
CAUTION
As long as the handle is not in the «ON» position, the parking brake is not applied.
If the park brake is selected ON in flight phases 6 & 7, (above 1500, to touchdown), an amber ECAM warning, PARK BRAKE ON, is presented, associated with a single chime.
There is some discussion on PPRuNe on this exact question, but is inconclusive. But the statement above seems pretty clear - if the handle is OFF, then the brakes aren't SET - otherwise, they're ON, period.
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An upset at touchdown resulting in a large lateral load on the tyres during spin-up could potentially take out the 4 rear tyres. They might get away with a bogie change, but the dressings on the main gear and the underside of the flaps will have taken a beating.
Busbert, wind was essentially LV - we don't know of course, but I doubt if there were extraordinary lateral loads on the landing, and there is no other apparent reason for rudder input, either.
Besides, the exciting internet is full of crosswind landings with considerable drift angles, as well as crosswind landing tests, (B777) and no tires were lost, let alone 4.
VABB 131800Z 33005KT 3500 HZ SCT020 SCT025 30/26 Q1008 NOSIG
VABB 131730Z 34005KT 3500 HZ SCT020 SCT025 30/26 Q1008 NOSIG
Besides, the exciting internet is full of crosswind landings with considerable drift angles, as well as crosswind landing tests, (B777) and no tires were lost, let alone 4.
VABB 131800Z 33005KT 3500 HZ SCT020 SCT025 30/26 Q1008 NOSIG
VABB 131730Z 34005KT 3500 HZ SCT020 SCT025 30/26 Q1008 NOSIG
OK465;
Interesting. I flew the -500 - shorter fuselage, same engines. I found it thumped less than either the A333 or A343. Those could produce a very benign settling or a real positive thump that bordered on 'hard' depending on how fast the tilt mechanism unloaded the bogies.
I don't have a theory either. The arrangement of the hydraulic manifold that services the brakes is one single unit which, while the four individual ports serve different brakes on the left & right bogie respectively, there does not a appear to be condition in which normal pressure would not be available to all brakes, and of course that is as it ought to be. So this may lend credence to the notion that it is a braking-system logic matter or a park-brake matter. Pure conjecture, though.
clark y, re "residual brake pressure", no, the BSCU, (Brake Steering Control Unit) does a residual pressure check and sends an ECAM message indicating "RESIDUAL BRAKE PRESSURE". I believe from the descriptions in the AMM that when/if the park brake is set to "OFF", pressure is bled off via the return lines.
Interesting. I flew the -500 - shorter fuselage, same engines. I found it thumped less than either the A333 or A343. Those could produce a very benign settling or a real positive thump that bordered on 'hard' depending on how fast the tilt mechanism unloaded the bogies.
I don't have a theory either. The arrangement of the hydraulic manifold that services the brakes is one single unit which, while the four individual ports serve different brakes on the left & right bogie respectively, there does not a appear to be condition in which normal pressure would not be available to all brakes, and of course that is as it ought to be. So this may lend credence to the notion that it is a braking-system logic matter or a park-brake matter. Pure conjecture, though.
clark y, re "residual brake pressure", no, the BSCU, (Brake Steering Control Unit) does a residual pressure check and sends an ECAM message indicating "RESIDUAL BRAKE PRESSURE". I believe from the descriptions in the AMM that when/if the park brake is set to "OFF", pressure is bled off via the return lines.
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This could happen if MAX was selected on the Autobrakes for landing.
LOW and MED are the only settings valid for landing and MAX is only valid for takeoff/RTO, however, l believe it is still possible to select MAX for landing. I have seen it done in the SIM, no warning was generated and multiple tyres burst on landing.
LOW and MED are the only settings valid for landing and MAX is only valid for takeoff/RTO, however, l believe it is still possible to select MAX for landing. I have seen it done in the SIM, no warning was generated and multiple tyres burst on landing.
Tangan, #12 "This could happen if MAX was selected on the Autobrakes for landing."
Incorrect.
As per #13, anti skid should be available and applied equally to all wheel brakes.
MAX brake is certificated for use in all situations as required for a safe operation. Only in rare circumstances, e.g. max energy RTO, it is possible that the tyres might deflate.
Incorrect.
As per #13, anti skid should be available and applied equally to all wheel brakes.
MAX brake is certificated for use in all situations as required for a safe operation. Only in rare circumstances, e.g. max energy RTO, it is possible that the tyres might deflate.
clark y, re, "PJ2, There is a note in the A320 QRH residual brake pressure abnormal checklist that mentions deflated/damaged tires. I can only assume the A330 is similar." Yes, same for the A330/A340. Agree, any time there is residual brake pressure, (alternate system, as indicated on the gauge, ECAM caution/single chime), there is risk of tire deflation.
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Residual brake pressure gives dragging brake and overheated rims hence deflation.
This is all 4 locked although it looks like there was a little rotation after initial skid on one of them. (number 6)
This is all 4 locked although it looks like there was a little rotation after initial skid on one of them. (number 6)
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No, the anti-skid system controls all eight brakes equally.
Many antiskid systems have a primary purpose of controlling the wheel brakes independently, but do have secondary protection which controls wheel brakes in pairs (however, not on a different landing gear).
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BBC NEWS | UK | England | West Yorkshire | Tyre burst pilot 'was distracted'
Possible to have this and only blow up the rear tyres?
Possible to have this and only blow up the rear tyres?
Had the aircraft just been on maintenance?
I had an A300 burst 2 and flat one on landing due to in correct anti-skid wiring on first landing after gear change.
I had an A300 burst 2 and flat one on landing due to in correct anti-skid wiring on first landing after gear change.