wheel-well fire??
It is surprising to me that most QRHs do not require a fire warning system test after completion of any fire drill.
Many years ago I experienced a momentary fire warning just after takeoff on a performance test flight in a brand new F27 that had only a few hours of ferry time. We were conducting 'hot and high' tests in temperatures approaching ISA plus 35.
The warning illuminated, but within a few seconds cancelled. Wrongly we assumed a false transient, caused we thought by the extremely hot ambient conditions. This was not uncommon in earlier versions of this aircraft type with the usual cure being to increase climb speed. Fortunately a deadheading pilot sitting in the passenger cabin saw the flames and yelled out to us.
After completing the drill and making an immediate landing we found that a combustion chamber had a faulty weld. This had opened up enough to allow hot flame to reach the fire wire and set off the warning. Then it opened more and became a blow torch which destroyed the complete loop system. The design was such that at that point the entire warning system was disabled. In the short time it had been burning through the combustion chamber, considerable damage had also been done to the engine control linkage for HP fuel.
So since then I have taught crews to conduct a fire test after any drill involving fire. If the system does not test, assume the worst and land RFN (right.......now)
Many years ago I experienced a momentary fire warning just after takeoff on a performance test flight in a brand new F27 that had only a few hours of ferry time. We were conducting 'hot and high' tests in temperatures approaching ISA plus 35.
The warning illuminated, but within a few seconds cancelled. Wrongly we assumed a false transient, caused we thought by the extremely hot ambient conditions. This was not uncommon in earlier versions of this aircraft type with the usual cure being to increase climb speed. Fortunately a deadheading pilot sitting in the passenger cabin saw the flames and yelled out to us.
After completing the drill and making an immediate landing we found that a combustion chamber had a faulty weld. This had opened up enough to allow hot flame to reach the fire wire and set off the warning. Then it opened more and became a blow torch which destroyed the complete loop system. The design was such that at that point the entire warning system was disabled. In the short time it had been burning through the combustion chamber, considerable damage had also been done to the engine control linkage for HP fuel.
So since then I have taught crews to conduct a fire test after any drill involving fire. If the system does not test, assume the worst and land RFN (right.......now)
Mexicana and Swissair were tire explosions, not wheelwell fires
Mexicana: The left main gear brake was overheated during the take-off run. When the aircraft had reached FL310 the heat caused a tyre on the left hand main gear to explode. Fuel and hydraulic lines were ruptured and electrical cables severed resulting in a cabin decompression. An emergency was declared, but spilt fuel ignited and caused a massive fire on board. Control was lost and the aircraft crashed into a mountain.
Swissair: The aircraft's brakes overheated due to the application of full engine power during taxiing. This caused the aluminum wheels to burst, one of them on the runway prior to departure. Upon retraction of the landing gear, the hydraulic lines in the gear bay were damaged. This was caused either by the wheels that had exploded, or the bursting of the other wheel rims during the climb. Subsequently, spilled hydraulic fluid ignited when it came in contact with the overheated landing gear rims. The fire damaged the gear bay, followed by the wing. Finally losing its hydraulic pressure, the aircraft became impossible to control. The cabin and the cockpit were filled with smoke, adding to the predicament of the crew. Control of the aircraft was lost totally, and the ensuing final dive and impact destroyed the aircraft.
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If there is an explosion on board, it is almost certain that the pilots will know from sound, feel, and indications of other system failures. In this case, there will likely be an immediate landing. Explosion scenario likely answers that question if you are lucky enough to remain in control.
For the scenario discussed earlier, we are talking about a wheel well fire indication only with no other indications of a problem after the gear was extended and with the fire indication extinguished. Should one head back and land immediately is the question.
For the scenario discussed earlier, we are talking about a wheel well fire indication only with no other indications of a problem after the gear was extended and with the fire indication extinguished. Should one head back and land immediately is the question.
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considering potency of the risks involved in a wheelwell fire...i would recommend having fire/overheat sensors in the wheels and pressure transducers in the tires to enable reject a take off...and Halon bottles in the wheelwell i believe would be a safer bet rather than just rely on ram air to extinguish a fire/overheat condition.am
In cases of a locked brake, there will eventually be an EICAS/ECAM warning generated (temperature limit reached), along with an immediate tendency to pull in the direction of the lock, but an RTO based on temps alone would be unlikely since the heat rise lags the physical event. Once airborne, lowering the gear is simple and effective in getting things cooled off. History has shown at or near V1 RTOs due to brakes or tires can lead to overruns.
am i missing something ?
Halon will not put out a magnesium fire and due to wheel wells being poorly closed compartments, the concentration levels needed for fire suppression would be difficult to sustain - the bottles would need to be very large. Halon also reacts poorly with hot metal, including that hot set of steel brake rotors and disks that most likely was the heat source for initiating the fire/overheat condition in the first place.
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The 737 is a very safe plane. It has three fire extinguishing bottles in the wheel well.
On a more serious note, I would get the thing on the ground as soon as possible.
Regardless of the state of the tires, I land anyway. You will figure that out after landing.
All this based on a real experience where on an A300 I burned away a tire during take off, resulting in a immediate , overweight landing and a complete bogey replacement later.
The discussion about it was held in a hotel with a coffee, not in a crippled burning plane in the sky at night.
On a more serious note, I would get the thing on the ground as soon as possible.
Regardless of the state of the tires, I land anyway. You will figure that out after landing.
All this based on a real experience where on an A300 I burned away a tire during take off, resulting in a immediate , overweight landing and a complete bogey replacement later.
The discussion about it was held in a hotel with a coffee, not in a crippled burning plane in the sky at night.
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Nationair's first indication of a problem once airborne was a flight attendant report of a lot of smoke in the back. An immediate landing is required(I don't believe they had a wheelwell fire detection system).
In none of these cases used as wheelwell fire examples, was there was a delay in pilot intent to try to get safely back on the ground and in none of these cases was the scenario what has been discussed(wheelwell fire indication that has extinguished after the gear is lowered with no further anomalies noted).
It seems that there is a tendency to create a panic return when a procedure has been done and a warning has ended for the most likely cause.
For those that flew King Air's with engine fire indicators based on detection of light instead of heat, there could be occasional dual engine fire warnings when the sunlight was just at the proper angle entering the cowls. Turn a little bit and the warnings disappear. Or should the panic land immediately idea take over because maybe the sensors on each engine burnt out and therefore landing on that extremely short nearby runway somehow has become the only option.
After all...we are on fire.
Last edited by JammedStab; 30th Apr 2015 at 03:51.
latetonite,
Indeed the 737 is a very safe aircraft, but of all the 737's that I have operated on, they have only ever had two firex bottles in the wheel well in the upper aft l/h corner. Your outfit may have a different bottle configuration. These bottles are the engine firex bottles and have absolutely nothing to do with the wheel wells apart from where they are located.
Indeed the 737 is a very safe aircraft, but of all the 737's that I have operated on, they have only ever had two firex bottles in the wheel well in the upper aft l/h corner. Your outfit may have a different bottle configuration. These bottles are the engine firex bottles and have absolutely nothing to do with the wheel wells apart from where they are located.
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On a more serious note, I would get the thing on the ground as soon as possible.
Regardless of the state of the tires, I land anyway. You will figure that out after landing.
All this based on a real experience where on an A300 I burned away a tire during take off, resulting in a immediate , overweight landing and a complete bogey replacement later.
The discussion about it was held in a hotel with a coffee, not in a crippled burning plane in the sky at night.
Regardless of the state of the tires, I land anyway. You will figure that out after landing.
All this based on a real experience where on an A300 I burned away a tire during take off, resulting in a immediate , overweight landing and a complete bogey replacement later.
The discussion about it was held in a hotel with a coffee, not in a crippled burning plane in the sky at night.
I suspect in the case you experienced, you were fortunate to have a nice long runway.
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To Jammed Stab:
Was the plane burning? An Air France on approach reported me to be on fire, tower relied to me the same. To me in the cockpit, I could not see the extend of the fire, nor predict how much would be on fire in the next ten minutes.
Overweight? Yes. Max TO weight for a five hr sector. Fuel dumping on a fire? No.
And I do not need to be lucky to know that if CDG does not cut it, where else in your Jeppesen would you go?
Was the plane burning? An Air France on approach reported me to be on fire, tower relied to me the same. To me in the cockpit, I could not see the extend of the fire, nor predict how much would be on fire in the next ten minutes.
Overweight? Yes. Max TO weight for a five hr sector. Fuel dumping on a fire? No.
And I do not need to be lucky to know that if CDG does not cut it, where else in your Jeppesen would you go?
Megan
Where did you get that from?
I recall quite a few more details leading to lessons learned.
Mexicana: The left main gear brake was overheated during the take-off run. When the aircraft had reached FL310 the heat caused a tyre on the left hand main gear to explode. Fuel and hydraulic lines were ruptured and electrical cables severed resulting in a cabin decompression. An emergency was declared, but spilt fuel ignited and caused a massive fire on board. Control was lost and the aircraft crashed into a mountain.
I recall quite a few more details leading to lessons learned.
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BOEING 737 QRH is concise about the matter regardless if the fire had extinguished or not, and if the gear is left extended or retracted after the Wheel Well light has extinguished after the 20 minute period.
As I recall, it was the same for the 727, 757, and 767.
As I recall, it was the same for the 727, 757, and 767.
Plan to land at the nearest suitable airport.
oh for fudges sake haven't we learned from previous, have a fire indication treat it as real and get on the ground....... on average 8-12 minutes before your done. had a groundcrew signal an engine fire, captain shut them both down, and fired the bottles as per sop. we were called on the carpet as to why we fired both bottles for a stack fire. " because thats the way you wrote the SOPs".
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Hi,
Rigpiggy,
What I understand from your post is that the captain used both bottles after the ground crew informed you about the engine fire. If this is true, then you had engine tailpipe fire (internal fire) and not engine fire (external fire).
Did you have engine fire alarm in the cockpit?
Feedback appreciated.
Regards
Rigpiggy,
oh for fudges sake haven't we learned from previous, have a fire indication treat it as real and get on the ground....... on average 8-12 minutes before your done. had a groundcrew signal an engine fire, captain shut them both down, and fired the bottles as per sop. we were called on the carpet as to why we fired both bottles for a stack fire. " because thats the way you wrote the SOPs
Did you have engine fire alarm in the cockpit?
Feedback appreciated.
Regards
