View Full Version : One Eng driven Gene remaining Airbus - Land ASAP or not?

6th Aug 2011, 16:14
Guys - I have this question for all ye airbus pilots - what's your take on this?

Boeing says land ASAP if you have one electrical source remaining - not quite the same with Airbus - Let's say you have only one Engine driven generator available (non-ETOPS flight), you don't have to land ASAP do you? Is that practical?

6th Aug 2011, 16:20
fire up the APU and continue, no big deal.:ok:

6th Aug 2011, 20:00
Having one electrical source remaining, and having only one engine driven generator available, is not the same thing.

If you have only one engine driven generator available you can still start the APU for electrical power.

If you only have one electrical source there is no second power source.

8th Aug 2011, 20:07
Sorry -Lemme clarify- I meant having only one engine driven generator available. NO APU, NO Standby Gene, the other generator Kaput!

Right Way Up
8th Aug 2011, 20:16

It is worth considering the Airbus has another layer of redundancy with the ram air turbine.

8th Aug 2011, 23:49
Hello guys,

I will divert... Yes you have the RAT but personally i d prefer to land asap.

I have made this same question to some instructors, some of them told me that they will continue, and other will land asap.

9th Aug 2011, 01:00
The 777 QRH says: Plan to land ASAP if:-

only one AC power source remains (main engine generator, APU generator, or backup power system [both generators])

Then there is the Standby Elec system powered by the batteries and a RAT.

The Airbus manual doesn't specify this, indeed the FCOM 3 doesn't contain a LAND ASAP for loss of a Elec gen. If you lose a Gen in flight it only says "consider APU use" I guess Airbus is happy for you to trundle along on only 1 Gen?

it comes down to your judgement on the day considering all factors.

Good luck. :ok:

9th Aug 2011, 01:33
Loss of the ramaining gen will put you in emer elec config, which is land asap red.

Diversion to appropriate airdrome nearby (consideration to commercial and operational factors can be taken into account).

9th Aug 2011, 08:37
Guys! Thank you for your valuable inputs - not all airbus RATs provide electrical power - a RAT on the 300s only provides Hydraulic power - so now with one engine generator and ONLY one gene remaining, Airbus does not say land ASAP like Boeing does. Is Boeing philosophy more conservative?

10th Aug 2011, 15:56
Continuing flight with only a single source of supply on any system is not a good idea. If you are down to one of any of the following, Hyd, Air, Elec, Eng (on a twin) then the land ASAP is a fairly straightforward decision, be it in the Airbus or the Boeing. You will have a hard time justifying otherwise. The APU has the same effect on the equation whichever type you fly.

10th Aug 2011, 16:12
I think a little common sense is required here. This sort of fault is covered by ECAM. However, ECAM has no idea if the APU is serviceable or not.

When I went through commercial training (years ago) a good maxim I was taught was: if your down to one of anything (eng, hyd, pilots, etc...) then it was to be considered an emergency.

Max Angle
10th Aug 2011, 18:12
Quite agree with the above, I would plan to be on the ground ASAP with only one main source of AC power remaining. Common sense I would say, can't expect the ECAM to spoon feed you all the time although it is curious that the Airbus don't specifically mention it in the way Boeing do.

10th Aug 2011, 18:42
with one bleed source remaining it's a GO, keep an eye on the remaining system though. :ok:

Teddy Robinson
10th Aug 2011, 22:46
Land and consider the problem on the ground.

Artificial Horizon
12th Aug 2011, 11:50
Funnily enough I had this exact scenario in one of my last sim checks. We had just departed and GEN 1 overheated and had to be disconnected. After the ECAM etc I got the FO to start the APU. Funnily enough the APU failed to start twice. At that point I elected to return to departure airfield as we were only 20 minutes out and still had 2 hours plus to destination. Checkie was not impressed, he could not understand why I went back considering I still had the RAT and the EMER GEN that could run off that as a back up to the one remaining GEN. I simply stated that after one GEN failing followed by the APU failing I felt the safest option was to let an engineer look at the aircraft, I also stated that I didn't consider the EMER GEN as 'another' GEN as it is there purely to get you out of the 'sh*t', not to allow you to continue normal ops. At the end of the day, this is a bit of a 'gut' call, I would still land at the nearest suitable and get this sorted out, the checkie would still carry on to destination happy to rely on the RAT.

12th Aug 2011, 12:52
Artificial Horizon......I agree with you. Maybe the "Checkie" wanted to see you continue to destination and may have entered the "APU failed to start" fault by mistake. Ask him if he recorded his thoughts in your training file..!!

12th Aug 2011, 12:53
Joesoap------The A330 RAT will provide 3.5 kva if required via the Emerg Gen. Not a lot but enough to get you down ASAP with no Eng/Apu Gen or Green Hyd power for the Emerg Gen.

So in the Airbus if you lose Both Eng Gens and the Apu Gen you still have the Emerg Gen available at either 8.6 kva or 3.5 kva.

On the 777 if you lose both Eng Gens and the Apu Gen you still have the backup Gen system and then the Rat Gen as well.

12th Aug 2011, 13:02
Were you wrong to go back? I can't say you were but I don't know the status of the Airport you went back to.

Would you be wrong to go on? I can't say you would be as if you lost the remaining Eng Gen then you'd still have the Emerg Gen at 8.6 kva or if the Green Hyd also failed 3.5 kva ( via the RAT ) to get to the nearest Airport.

I can see how a commercial operator would prefer you continue but at the end of the day if you can JUSTIFY YOUR DECISION then do whatever you are comfortable with. :ok:

Sometimes these things are deliberately left in a grey area to give the Commander some wiggle room in his decision making. i.e its up to you to exercise good command judgement and decision making on the day. :ok:

13th Aug 2011, 10:29
Hi guys,

I apply procedures as from 2


14th Aug 2011, 09:42
I don't think anyone would criticise you if you land at nearest suitable airport in real life if you are down to 1 elec source.

tea and biscuits or not...im landing it at the nearest suitable airport, dunno bout u...

23rd Aug 2011, 11:13
Artificial Horizon;

I brought up the scenario with some of my instructors. One of them a former Airbus test pilot. They would all turn back unless past ETP. It's just too close to the edge for comfort. Think of it in terms of the famous Swiss cheese; You have passed 2/3 holes. Pass the last one (remaining GEN inop) and you'll be in deep...

23rd Aug 2011, 18:27
I had a real life situation. Departed with one gen inop (MEL said it was OK) Left the APU gen on for the flight (2 gens ops). On the return (at night) the APU did an "auto shutdown". Now we are down to one gen. We landed within 30 minutes.
There is no way I would continue to fly on one. This aircraft (A320) is very dependent on electrics and hydraulic power to operate. You just don't want to be in a situation where if you lost the last gen ( maybe had to shut down the engine with the good gen for whatever reason) you would have to resort to a RAT power, emergency landing. Common sense.

berraies mondher
28th Aug 2011, 11:25
especially at night

sudden Winds
28th Aug 2011, 17:51
If you have one source of electrical power remaining you are one generator short of full emergency, and if that happens you're now 30 (or 60) minutes short of a nightmare. Now, if you're returning back home, daylight vfr and your distance to destination, where full maintenance support is waiting for you, is slightly (only slightly) higher than an enroute alternate airport with less maintenance, whether your company serves it or not, I might consider flying a bit faster and heading home, but anything different from the scenario described above would mean a landing at the nearest suitable airport. Of course I'd try my best to choose an airport served by my company, a place I have approach plates for, with at least the minimun fire service category for the airplane I fly, etc.

29th Aug 2011, 09:11
........and if you continue and then lose your remaining source you are down to the RAT (hydraulic driven) Emer Gen which will put you into the Emer Elec Config.

From A320 200 Series QRH 2.32, the Ldg Dist Factor is 3.15 times a working reference figure (from QRH 4.03) of around 900m so you are now scratching around looking for a 3300m runway (including a factor of 15% wriggle room). Better perhaps to have stuck it on the ground when you still had that 1 main source?