Tyre failure during take off -continue at V1 minus 20 knots.
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Tyre failure during take off -continue at V1 minus 20 knots.
McDonnell Douglas Corporation published a All Operator Letter No 4 recommending not rejecting a take off for a suspected tyre failure at speeds above V1 minus 20 knots. The subject was aired in previous Pprune discussions several months ago but I am unable to locate it. Does anyone have a copy of the full contents of the All Operator Letter No 4?
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It sounds a bit questionable! What about the difficulty of making a positive ID of tyre failure? Not many types have tyre pressure indication. At some stage, you still have to land on it anyway, maybe at a lighter weight, but at that stage before V1, with very little time to decide, is it worth stopping anyway? I'd be interested in the thinking behind it.
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The subject was aired in previous PPRuNe discussions several months ago
The B737-300 simulator I operate has a instructor panel page labelled Landing Gear (malfunctions) and it gives several choices of tyre burst on outboard and inboard of both main landing gears. Selection of left outboard on take off and landing gives an obvious heavy vibration accompanied by "wobbling" similar to flat tyre on a car.
There is no guidance to instructors in the applicable manuals, so from reading various accident reports over the years involving tyre bursts on take off it becomes almost self evident that it is best to keep on going if the tyre bursts at high speed and at speeds above V1 minus 20 knots. Somewhere in Pprune up comes a reader who quoted this McDonnell Douglas letter which confirms the V1-minus 20 knots figure.
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I too recall it, Cent, and I even think it may be buried in one of the Boeing papers too, although I don't recall B saying '-20', just that 'performance' stopping with degraded wheels is by no means assured and equates to a 'reduced V1' in many ways. I have never heard it covered in a take-off brief other than the need to stop for only 'confirmed' engine failure ie a bang is not enough (as the actress.........................
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As for A320 we have the same recommendation in FCOM3: rather to continue than make RTO in case of tire failure between V1 and V1-20 unless that caused engine anomalies. More in case of NLG vibration above 100 - far better to go.
All these aims to reduce load to have lower speeds and extend RWY length for stopping to deccelarate slower.
I has had both cases prooved me the above. During take off there was serious tyre failure - we made no RTO but actually debris caused engine problems and we had to shutdown it later. The second occured when I used to fly 737 - during take off we expierenced severe NLG vibration actually after 100 and we made CTO to destination for smooth landing with national football team aboard. During vacating the RW we stopped due to the fact that one of the NLG wheels were successfully off - later investigation found not proper maintenence fixing of a new wheel.
All these aims to reduce load to have lower speeds and extend RWY length for stopping to deccelarate slower.
I has had both cases prooved me the above. During take off there was serious tyre failure - we made no RTO but actually debris caused engine problems and we had to shutdown it later. The second occured when I used to fly 737 - during take off we expierenced severe NLG vibration actually after 100 and we made CTO to destination for smooth landing with national football team aboard. During vacating the RW we stopped due to the fact that one of the NLG wheels were successfully off - later investigation found not proper maintenence fixing of a new wheel.
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Many airlines follow the principle of not stopping after 100 knots except for Fire, Engine Failure or Control Jamming. Better to take the problem airborne, sort it out and plan a controlled landing - dumping fuel - selecting a longer runway - improved weather/wind conditions etc.
Better a landing with reducing speed rather than a rejected take-off from an accelerating condition.
Better a landing with reducing speed rather than a rejected take-off from an accelerating condition.
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Yes....
Yes, Airbus says the same thing.....
And, one more caveat....unless you need the climb gradient, leave the gear down after liftoff. Don't risk jamming damaged tires/gear in the wheel well. Leave the gear down, if you can, burn off fuel (maybe have
lunch in a holding pattern), and land at a relatively light weight, all of
the runway ahead of you, emergency equipment already standing by, etc., etc.
The problem is not really a problem if your takeoff weight is light (low V-speeds) and you have a long runway. But, these days, you're usually pretty heavy (i.e. high speeds)....and runway, well, who knows with some of the airports we serve.....
Yes, the Airbus SOP for rejected takeoffs above 100 KIAS is pretty explicit. There are six listings in the FCOM....In essence:
1. Any fire,
2. Any "Severe Damage",
3. Sudden Loss of Thrust,
4. Any RED ECAM Warning,
5. ONLY the following AMBER ECAM Caution:
a. F/CTL Sidestick Fault,
b. ENG Fail,
c. ENG REV Fault,
d. ENG REV Unlocked.
6. Perception the Aircraft is Unsafe to Fly. ("Unambiguous Indications")
FCOM 3.02.10 P2 (REV 42) also talks about tire failure.....as BORODA so well stated.
Statistically, very few acccidents have occurred when takeoffs were continued after a malfunction. At the same time, many accidents have occurred when the decision to reject was made.
Fly safe,
PantLoad
And, one more caveat....unless you need the climb gradient, leave the gear down after liftoff. Don't risk jamming damaged tires/gear in the wheel well. Leave the gear down, if you can, burn off fuel (maybe have
lunch in a holding pattern), and land at a relatively light weight, all of
the runway ahead of you, emergency equipment already standing by, etc., etc.
The problem is not really a problem if your takeoff weight is light (low V-speeds) and you have a long runway. But, these days, you're usually pretty heavy (i.e. high speeds)....and runway, well, who knows with some of the airports we serve.....
Yes, the Airbus SOP for rejected takeoffs above 100 KIAS is pretty explicit. There are six listings in the FCOM....In essence:
1. Any fire,
2. Any "Severe Damage",
3. Sudden Loss of Thrust,
4. Any RED ECAM Warning,
5. ONLY the following AMBER ECAM Caution:
a. F/CTL Sidestick Fault,
b. ENG Fail,
c. ENG REV Fault,
d. ENG REV Unlocked.
6. Perception the Aircraft is Unsafe to Fly. ("Unambiguous Indications")
FCOM 3.02.10 P2 (REV 42) also talks about tire failure.....as BORODA so well stated.
Statistically, very few acccidents have occurred when takeoffs were continued after a malfunction. At the same time, many accidents have occurred when the decision to reject was made.
Fly safe,
PantLoad
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You all might like to think about this one.
You cannot dictate some things out of books!!
We had a tire burst just below V1, followed by another, and the 4 wheel truck ended up digging into the runway. It was the front RH front wheels. Our speed dropped dramatically, as shown on the recorded later, and we would never have got airborne. As it was we were almost at the "piano keys' at the end when we got it stopped. The recorder also showed our reaction time which was just under 3 secs from the first tire burst.
At the time our manuals said not to reject for a tire burst, and they were changed in the light of our experience.
The cause was Firestone remolds that were discontinued after that.
It was a max weight take-off in an L1011-1 at Daharan, SA. at 1am.
You cannot dictate some things out of books!!
We had a tire burst just below V1, followed by another, and the 4 wheel truck ended up digging into the runway. It was the front RH front wheels. Our speed dropped dramatically, as shown on the recorded later, and we would never have got airborne. As it was we were almost at the "piano keys' at the end when we got it stopped. The recorder also showed our reaction time which was just under 3 secs from the first tire burst.
At the time our manuals said not to reject for a tire burst, and they were changed in the light of our experience.
The cause was Firestone remolds that were discontinued after that.
It was a max weight take-off in an L1011-1 at Daharan, SA. at 1am.
Thread Starter
You cannot dictate some things out of books!!
