Tyre Fire Risk

[bodstrup]

We have had a couple of 'emergency landings' as the press like to call it here in Copenhagen recently.

Currently the press is critisising the airlines for not supplying crisis aid for scared passengers.

One was an Avro landing with no flaps - at high speed, the second a SIA 777 who apparently had to shut down an engine after a turbine or fan blade seperation.

This leads to a question. How great is the risk of a tyre fire spreading to the cabin ? (gear down..)

On the 777 the tyres appear to be well away from the hull, but the Avro family like many other high-wing aircraft has the tyres close to the hull.

In the Avro incident, passengers complained about a smell of burned rubber and fear of fire.

Fire services was there and I would think that any tyre fire would quickly die and the brakes cool, when subjected to a burst of high pressure water fog.


Regards
Michael

[lomapaseo]

This strikes me as a technical question.

Tyre fires are assumed under the FAR/JARS more particularly under max breaking conditions. Even with a tyre fire the airplane manufacturer must show by testing that the fuselage will not be penetrated for a finite period of time (time for the passengers to egress).

[cirrus01]

Recently BA had an Avro RJ main wheel tyre burst on T/O.

Tyre debris took out parts of the U/C door , damaged the flaps, and hit,but not penetrated the Pax windows.

Took about 10 days to fix...........but that could be because BA have a shortage of skilled Engineers !

[Eboy]

I recall seeing a television documentary (on the U.S. PBS network) on designing and testing the 777. One of the final flight tests was landing and stopping only by applying full brakes. The plane stops in a short distance and the hot brakes ignite the tires, which are allowed to burn. Thermal plugs pop out of the hubs and deflate the tires gradually before they burst. The tires burn to cinders and the plane is sitting on the hubs. And that's it. The fire does not spread. As I recall, this test is an FAA requirement.

[411A]

Yes, most definately an FAA requirement, and the fire services cannot intervene for (if memory serves) five minutes after the aeroplane comes to a complete stop.

[bodstrup]

Thanks for the answers.

The radio had an interview with a lady who 'thought they all would die' - because the had to land at high speed with no flaps.


Apparently the SN crew did not inform the passengers about what was going to happen and the cabin crew were very tense when instructing how to assume the crash position.

A bit of information can cure a lot of worry.

What would the Vref and landing length be for an Avro (assumed fully loaded with pax) on a dry runway with flaps up ?

Regards
Michael

[Fokker-Jock]

Avro I don't know, but for my bird a DHC8-Q400 the ref speed would be with full load 156 kts, and in icing conditions 176 kts. The landing distance required would be in 0 wind and ISA conditions: 1984m and 2777m

[Herod]

It's digging a bit into the memory but I think the Vref for a 146-300 at max weight flapless was 189 kts. Well within the tyre speeds, but I think it was normal pracice to scrap the tyres after a flapless landing.