Airbus configuration question

[FN FAL]

I was riding on an airbus today and something wierd happened.

The pilots did one of those long taxis followed by a non-stop turn-out on to the runway. While on the roll, they powered up for takeoff and as abruptly as power was coming up, they jerked the thrust levers back to idle. We were on the takeoff roll for at least 2 seconds.

They taxied on the runway for a bit and then took an exit to taxi back to the end of the runway. They said something on the PA about a sticky brake causing all of this. Keep in mind we entered the runway from a roll and never stopped all the way from the gate and we taxied for at least 10 minutes.

As we exited the runway I heard something like a starting and stoping hydraulic pump whiring away really loud. In fact, loud enough to be heard loudly throughout the plane.

As we were taxiing for the departure end again, I started getting a feeling that we were not in configuration for take off, during the first attempt to get off.

I seem to remember one of the AVRO runway checks was a push of the "configuration" button. I also seem to remember that if you pushed up the thrust levers and if the plane was out of configuration that you would get an alarm.

Correct me if I am wrong, I am not an expert on this stuff...

But could it have been possible that the airbus pilots could have pushed up the throttles and got a "configuration" warning, so they aborted?

 

[DorkProp]

Sounds likely. In the Dornier that loud alarm is a convenient reminder that the taxi checks were forgotten.

 

[Big Duke Six]

Hard to say...

I'm fairly new to the airplane, but from what I know, it could have been a brake temp problem. I don't know which model you were on, but the 318/319 taxis like a madman, even at idle, with both engines going. The recommended procedure is to wait till the aircraft gets to 30 knots, then use one brake application to get the speed down to 15 knots, and repeat. This can result in brake temps approaching the max limit for takeoff if you're not careful. Some companies opt for the brake fans, which help somewhat, but we don't have them. I've seen some airplanes where you will get a significantly higher brake temp on one wheel than the others, probably due to a draggy brake on that wheel. I've heard they cool fairly quickly on their own. It is possible that they got a brake overheat just as they started the takeoff roll.

I would be really surprised if it was a configuration problem, but I have no explanation for the sounds you heard. If the airplane is not configured, there is a big memo staring you in the face telling you it's not ready. Of course, anything is possible, but they would have had to miss a flow, a briefing item (with confirmation) and a checklist to put themselves in that position.

 

[FN FAL]

Ok...thanks for the info Duke six and Dork Prop...I would feel better if it was a brake overheat light, as opposed to what they said to us over the intercom...which was that a brake had "hung" up and was now "unstuck".

It gave me the impression they were covering up something, because it's not like any MEL I know of, to let pilots "fix" brakes from the cockpit.

The overheat thing makes sense, and I do remember the BAC RJ85 as having quite the elaborate brake temperature indicating system. It makes sense that you would want to have your temps in limit for take off, incase of the need to abort on the runway.

Yea, it was a 319 Airbus.

And congratulations on your success at finding a job flying the larger aircraft Big Duke.

And also congratulations to you Dork Prop on your landing a position flying the Dornier.

I know it's a little late to be congratulating both of you, but none the less...

 

[UPS Capt]

I seriously doubt it had anything to do with hot brakes. Unless the aircraft was "quick turned" for the next flight the brakes should have cooled sufficiently enough. Also, the crew would have been well aware of the brake temps prior to taking the active for t/o as the wheel page (with brake temps) on the ECAM is staring you in the face. The A300 brake overheat warning comes on at 300C. Those are temps you'd see after landing. If the brakes had overheated than why would they abort a takeoff (heating them up even more) and then return for another t/o soon after?

The takeoff configuration warning looks at a multitude of items and sounds when t/o power is applied. If we were to speculate, it would be easier for me to believe it was something like a trim setting out of whack or a a mis-programmed rwy in the FMC giving a position error when TOGA was pressed than a brake temp problem.

 

[Skank]

Brakes are hard to keep cool on a long taxi if you start with a high temp (quick turn) and don't have brake fans. But you should have noticed this before attempting to takeoff!? The T/O Config button checks most items. The only items that will generate a warning with the application of power (if the T/O config button was pushed at the appropriate time in the before T/O checklist) are Parking Brake set, and Flex Temp not set.

It is possible that they had a brake temperature differential that bothered them that they didn't notice until they were about to takeoff. I know, not likely, but who knows.

 

[side stick-n]

Reading your description of the event, it would seem that there was a hot brake issue. A long taxi can indeed heat the brakes up very quick especially with a light airplane or a condition requiring ground idle to be higher than normal (A/C, Engine A/I, ect).

However, I am perplexed by your statement concerning the loud start and stop noise you heard after clearing the runway. This sound would have been the PTU and should have NOT been operating if both G and Y hydraulic systems were operating normally. The PTU operates when there is a difference of >500psi between the two systems. We don't hear that noise from the cockpit but I can't recall of a "normal" situation where you would hear the PTU during or immediately after the takeoff phase of flight. It could have been a fault with either Hyd pump right at power up. This would have caused a slow speed abort and would have resulted in the PTU activation. Clearing the runway, it may be possible to reset the pump and return it to normal operation. The brake excuse would be easier to explain than the hyd pump fault, not that I agree with doing that.

Any other thoughts?

 

[JayDub]

For quite some time, I've made it a personal policy to complete an "After Landing Check" whenever I clear a runway. I also run a complete "Before Takeoff Check" before taking the runway again. All of this due to an SOP from two companies ago. It's possible the unmentioned airline you were on has the same policy, and you merely heard the flaps cycling. 100% speculation, though.

JayDub