United Takeoff Aborted
 

On United flight from Newark to Zurich tonight leaving 6:15 PM takeoff aborted after reaching about fifty mph. Taxiing back to gate. Pilots said we are having problems with air systems on right engine. Not quite sure what that means but they are having maintenance come look at it.

Could be the air condition packs. These filter and prepare the air for the cabin. Depending on which type of aircraft you were on, if one of these was inoperable - then the flight could not depart. Were you delayed long?

Boeing 767-400. Had to change planes. Total delay 3.5 hours

No twin engine aircraft will depart with one air-con pack inoperative. I'd say that was the most likely reason but airlines tend not comment on exactly what happened. I sit to be corrected.

Wrong. ....

Perhaps paxboy meant to say to go ETOPS?? However, as you say Chesty, in general, wrong.

Some twins (for example certain 737 variants) are subject to altitude limitations if despatched with one pack inop.

TBH that could cover a multitude of problems.

Not familar with the 767 itself but sounds like the pilot was using a layman's description for the "bleed" air system that uses high pressure, very hot air tapped from the front end of the engine(s) to run (type dependent, but for example) not just air conditioning but a host of other things like leading edge flaps, anti-icing, various pumps (main and back up) and a whole host of other stuff buried away in the guts of the aircraft...

I guess it's possible the consequences of a subsequent loss of one of those subsystems might have been a reason to abandon, a perhaps much more compelling reason to stop would be a leak in the duct that carries the hot air around the air frame, OTOH maybe they did just lose a A/C pack and decided not to go, who knows? All the above could be described as "air system problems"!


As an aside as others have said dependent on type there are most definitely circumstances where you can despatch and/or continue to destination on some twins with just one pack, albeit possibly with restrictions, and even into/with ETOPS sectors on at least one twin.

I had indeed considered adding 'to cross the Atlantic' but sat to be corrected. Thanks for the info.

So to clarify AF twins can and do dispatch with one pack inop and at least one type can do so on ETOPS trans-Atlantic sectors.

Hi Chesty

If you're picking up on my comment about a specific twin then I should have been more clear. Under our Ops manual for the aircraft in question you cannot dispatch for ETOPS on one pack, but once you have dispatched if a pack then subsequently fails you can continue into ETOPS on the remaining pack, having gone through the appropriate checklist . Hope that's more clear.....

Seeing as this is a passenger forum, for any non-crew trying to follow this, especially the semantics: "Dispatch" occurs ( for us) when the aircraft powers away from the gate. So what the rule is saying is if you have a a/c pack problem prior to that point you must either re-plan the flight (e.g re-route) ,or get the pack fixed. Once you've got moving you're more committed to the original plan (especially from a fuel POV) so the safest course of action from that point on is to continue with plan A. There are similar rules for lots of similar minor unservicabilities...

Here Endeth the lesson..🤓

Roger!....