"Brakes Hot" Ecam Msg [Archive]

CONF iture

28th Dec 2006, 15:11

McAero

28th Dec 2006, 16:54

Quick answer is yes and yes. On the 777, brake temperatures can be monitored on the "gear" synoptic displayed on one of the DU's. Not sure of anything similar on 737's or the likes though.

SMOC

28th Dec 2006, 17:47

Airbus doesn't use a wheel well fire detection system, so therefore use the brake temp as a limitation, while Boeing use a wheel well fire detection system so therefore have no brake temp limitation.

spannersatcx

28th Dec 2006, 20:44

The 747 has brake temp indicators.

vapilot2004

28th Dec 2006, 23:22

All Boeing aircraft with the exception of the inherited MD-95 (717) have wheel well fire detection systems. Widebodies include brake temp monitoring.

717 & MD-90 - Brake Temp Monitoring - Gauge on MD-90

727, 737 & 757 - Wheel well fire detection system. No Brake Temp readout***

747-all models, 767 & 777 - Both wheel well fire detection system & Brake Temp Monitoring

No aircraft (Airbus or Boeing/McD) have wheel well fire suppression installed. Usual procedure is to hang your feet out to cool.

***An Option - see more enlightened posts below.

relax.jet

29th Dec 2006, 07:14

The 737NG can have brake temperature monitoring, if you pay extra for it :}

late developer

29th Dec 2006, 12:23

...but please say ABS is standard, right?:\

Piper19

29th Dec 2006, 15:40

All Boeing aircraft with the exception of the inherited MD-95 (717) have wheel well fire detection systems. Widebodies include brake temp monitoring.

717 & MD-90 - Brake Temp Monitoring - Gauge on MD-90

727, 737 & 757 - Wheel well fire detection system. No Brake Temp readout

747-all models, 767 & 777 - Both wheel well fire detection system & Brake Temp Monitoring

No aircraft (Airbus or Boeing/McD) have wheel well fire suppression installed. Usual procedure is to hang your feet out to cool.

757's can have a temp readout (we have, as did british airways). It's a cutomer option and shows on Eicas together with hyd press, oxy press, apu rpm etc. It shows numbers in eight boxes ranging from 0 to 10. The numbers turn red when passing a certain value.

late developer

29th Dec 2006, 18:47

No aircraft (Airbus or Boeing/McD) have wheel well fire suppression installed. Usual procedure is to hang your feet out to cool.On a more serious note than my last post...I have long been aware of the hang your feet out to cool requirement for certain fast-turnaround conditions but despite having ridden in the back of quite some number of fast turnaround flights, I have never been aware of the undercarriage being relowered after the initial climbout. To take just one type, what percentage of fast turnaround 737 landings are heavy braked and what percentage of those go out again in under say 53 minutes? Does the 53 mins apply to NG's? Any ideas?

CONF iture

29th Dec 2006, 20:22

It shows numbers in eight boxes ranging from 0 to 10. The numbers turn red when passing a certain value.
I would be interested if you have these values.

Also, if you have some documentation on WHEEL WELL FIRE detection.
How many detectors by wheel bay ?
What's the conditions to trigger a warning ?
Can a high brake temp trigger a fire warning as well ?

Thanks

SMOC

29th Dec 2006, 21:29

747 Classic.

One continuous fire detector loop is installed with detector elements in each of the main landing gear wheel wells. A fire or overheat condition in one of the wheel wells will initiate a fire warning.
The detector system is similar to the nacelle and APU fire detection systems except there is no discriminator. With an electrical short (detector failure) or a fire condition causing a short, the warning will be locked on. With a fire condition causing an open loop, the wheel well fire warning light will remain illuminated but will extinguish when the overheat condition has ceased.
With an open circuit in the detector loop the system will not respond to test. The brake temperature monitor module on the F/E’s panel provides a means of monitoring the wheels for an overheat condition.

I have some Boeing notes somewhere which say that hot brakes will not generate a fire warning.

vapilot2004

30th Dec 2006, 03:21

The 737NG can have brake temperature monitoring, if you pay extra for it :}

757's can have a temp readout (we have, as did british airways). It's a cutomer option and shows on Eicas together with hyd press, oxy press, apu rpm etc. It shows numbers in eight boxes ranging from 0 to 10. The numbers turn red when passing a certain value.

I was not aware of this and have not seen an NB Boeing so equipped here in the states - yet.
I thank you both.

.......To take just one type, what percentage of fast turnaround 737 landings are heavy braked and what percentage of those go out again in under say 53 minutes? Does the 53 mins apply to NG's? Any ideas?

I am stating the obvious here.... the percentage would depend on load, airport served, weather and company SOPs. Regarding quick turn around capabilities, the 737 is among the best in the fleet.

CONF iture

2nd Jan 2007, 03:07

747 Classic.
I have some Boeing notes somewhere which say that hot brakes will not generate a fire warning.
Thank you .
Now, if, for any reason, after gear retraction, heat continues to built up to a certain value, would you have a checklist requesting to select gear down again ?

Zeke

2nd Jan 2007, 03:41

That one is for Airbus since a brake temp has reached 300C.
And it could come up on the ground as well as in flight.

Is there an equivalent message on a Boeing product ?
Are the brakes temp always monitored, and visible on request ?
How works the "WHEEL WELL FIRE" EICAS ?

Thanks

On the 330/340/380 they have wheel well fire detection, just the mini bus missed out as standard. I am not sure, it may even be an option for them.

SMOC

2nd Jan 2007, 10:05

Thank you .
Now, if, for any reason, after gear retraction, heat continues to built up to a certain value, would you have a checklist requesting to select gear down again ?

Yes. On the classic the F/E will do a panel scan some time after TO which includes the brake temps, depending on the temp you may go into the alternate procedures and select the gear down to bring the temp within the normal range.

On glass A/C an EICAS/ECAM message would lead you to the QRH or procedure to put the gear down.

On the 330/340/380 they have wheel well fire detection, just the mini bus missed out as standard. I am not sure, it may even be an option for them.

I don't think the A330/340 have wheel well fire detection, which is why they have the 300C limitation.

Zeke

2nd Jan 2007, 10:49

I don't think the A330/340 have wheel well fire detection, which is why they have the 300C limitation.

FCOM 1.26.58, Main landing gear fire and overheat detection & FCOM 3.02.26 MLG BAY FIRE DET FAULT, MLG BAY FIRE LOOP A(B) FAULT, MLG BAY FIRE IN FLIGHT, MLG BAY FIRE ON GROUND, still with 300 deg limit for takeoff.

Maybe your aircraft do not have them installed.

SMOC

2nd Jan 2007, 10:56

Cheers Zeke, You're right the 330/340 I flew didn't have it, I never would have thought wheel well fire detection was an option, you learn something new every day!

Piper19

2nd Jan 2007, 17:25

I would be interested if you have these values.

Also, if you have some documentation on WHEEL WELL FIRE detection.
How many detectors by wheel bay ?
What's the conditions to trigger a warning ?
Can a high brake temp trigger a fire warning as well ?

Thanks
According to the 757 maintenance training manual, the figures go from 0 to 9 (not 10 as I mentioned earlier). This resembles a range from 0 to 690°C. There are three colors available on the lower EICAS display. When a brake reaches value "5" (or approx. 500°C) there is a color change, together with a "brake" light, next to the three greens and the "door" light. Every single brake has a temp probe and these 8 signals go to a brake monitoring computer. A photo with the blocks on the EICAS and the brake light: http://www.airliners.net/open.file/0529570/M/ (http://www.airliners.net/open.file/0529570/M/)
If I have time I will look up the fire warning issue.

CONF iture

3rd Jan 2007, 16:21

According to the 757 maintenance training manual, the figures go from 0 to 9 (not 10 as I mentioned earlier). This resembles a range from 0 to 690°C. There are three colors available on the lower EICAS display. When a brake reaches value "5" (or approx. 500°C) there is a color change, together with a "brake" light, next to the three greens and the "door" light. Every single brake has a temp probe and these 8 signals go to a brake monitoring computer. A photo with the blocks on the EICAS and the brake light: http://www.airliners.net/open.file/0529570/M/ (http://www.airliners.net/open.file/0529570/M/)
If I have time I will look up the fire warning issue.
OK, great ... so, without talking of WHEEL WELL FIRE warning, is it fair to say that an EICAS caution or warning, or a QRH procedure requesting to lower the gears, would not come up as long as one brake temp did not reach that 500C equivalent value ?

SMOC, do you agree with that value, or is it somewhat different on 747 Classic or any Boeing product ?

I was also surprised to learn that wheel well fire detection was available on option for 330/340, thank you Zeke.
Would you know which percentage of 330/340 fleet is equipped with that option ?

vapilot2004

3rd Jan 2007, 21:09

I was also surprised to learn that wheel well fire detection was available on option for 330/340, thank you Zeke.
Would you know which percentage of 330/340 fleet is equipped with that option ?

Just as I was equally surprised to find 757 and 737 brake temp readouts as an option. :)

I know that both Korean Air A330s and Air Canada's fleet do not have wheel well fire detection. Anyone know of a carrier operating the Airbus A330 or A340 with this option? Perhaps Northwest or BA?

Piper19

3rd Jan 2007, 22:37

OK, great ... so, without talking of WHEEL WELL FIRE warning, is it fair to say that an EICAS caution or warning, or a QRH procedure requesting to lower the gears, would not come up as long as one brake temp did not reach that 500C equivalent value ?

SMOC, do you agree with that value, or is it somewhat different on 747 Classic or any Boeing product ?

I was also surprised to learn that wheel well fire detection was available on option for 330/340, thank you Zeke.
Would you know which percentage of 330/340 fleet is equipped with that option ?

I cannot say much about QRH procedures here, since I am the guy in the cockpit with grease on his hands:O . A 757 driver can give better answers.
As for 757 wheel well fire, fairly simple. That same manual says there are two loops (one each wheel well) with sensors that trigger when temperatures reach 200°C. There is an EICAS message "Wheel Well Fire" and a "fire" light just underneath the light "brake temp" and next to the three greens. At the same time the master warning signal and lights go on. There is also a test button at the lower right pedestal corner.

Surprises me that brakes can go to 500° without warnings, and well temps can go to 200°. So there must be something requesting the wheels to stay lowered. In real, I've never seen a 757 brake going above figure "2" on EICAS.
I looked up some cockpit pictures on the net, and almost every airline has the brake temp option installed.

SMOC

4th Jan 2007, 11:33

Bolty McBolt

5th Jan 2007, 04:01

I know that both Korean Air A330s and Air Canada's fleet do not have wheel well fire detection. Anyone know of a carrier operating the Airbus A330 or A340 with this option? Perhaps Northwest or BA?
On the CX and QF fleets the A330 have no fire detect sys in the wheel well either.
The 300 deg C brake temp discussed in this thread is related to a performance limitation for an RTO.
The reason this "hot brake" ecam message can be generated in the air and on the ground could be for crew info to action via FCOM etc.
EG a dragging brake/s on take off roll raises brake temp above 300 deg, after flight phase inhibit for this message is removed "DING" ecam msg HOT Brakes . I dont have an FCOM in front of me but I suspect the gear would be lowered until brake temp fell to an acceptable level
:ok:

I will haveto dig out my notes on the Boeing wheel well detection but memory says single loop "graviner" detector ????

Fournier Boy

5th Jan 2007, 16:24

Just as I was equally surprised to find 757 and 737 brake temp readouts as an option. :)
I know that both Korean Air A330s and Air Canada's fleet do not have wheel well fire detection. Anyone know of a carrier operating the Airbus A330 or A340 with this option? Perhaps Northwest or BA?

Virgin Atlantic has fire detection fitted to its entire airbus fleet, single loops 340-300, double loops 340-600 (one loop either side of the keel beams for the centre gear). Took both Airbus courses last year and there was no mention of Fire detect being fitted as an option - TPIS, thats an option.

CONF iture

6th Jan 2007, 01:33

Virgin Atlantic has fire detection fitted to its entire airbus fleet, single loops 340-300, double loops 340-600 (one loop either side of the keel beams for the centre gear).
With that type of equipment installed, do you know if the ECAM requesting lo lower the gear in case of brake temp above 300C is still active, or the corresponding brake temp value is higher for such an ECAM ?

Fournier Boy

6th Jan 2007, 11:14

With that type of equipment installed, do you know if the ECAM requesting lo lower the gear in case of brake temp above 300C is still active, or the corresponding brake temp value is higher for such an ECAM ?

My notes don't give a temperature threshold i'm afraid, after all we fix them, we don't fly them! FCOM might be usefull there. As with most Airbus systems, it will only give a fire message if both loops, and therefore all four LG Bay detectors detect an overheat in their area (nothing to do with brake temp). The FDU microprocessor will then filter the data with AND logic and if all channels indicate fire, a message will pass to the FWC and on to the EWD. MLG fire will also call for a speed limit of 250kts (to enable gear to be dropped), Gear down, ATC notify, and LANDASAP.

The only info I have relating to brake temp as a system states that all brake temp info is sent to the BTMU for each braked pair. This amplifies the signal to the BSCU and the info is then displayed on ECAM via the normal routes. If brake fans are fitted (Virgin don't) then the BSCU will also light up HOT on the BRK FAN PB/SW. The brake fans only run on ground with inputs from the switch and the LGCIU in command.