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View Full Version : Air India at JFK...gone with the wind..!?


JanetFlight
16th Sep 2018, 17:36
Jesus Christ...almost everything gone...!!???

https://www.youtube.com/watch?v=5FTw9TQtw38

Incident: India B773 at New York on Sep 11th 2018, multiple instruments including localizer receivers lost (http://avherald.com/h?article=4bd8a3c1&opt=0)

BTW, amazing job by ATC and Crew !

B2N2
16th Sep 2018, 18:22
That first comment is very interesting.
Did they dispatch with the right IDG inop?

Sqwak7700
17th Sep 2018, 06:56
Sounds like a lot of confusion on the flight deck. No such thing as a VNAV approach. Their request was probably confusing the crap out of the controller. Sounds like the ATCO is a pilot or at least knows quite a bit about airplanes.

They where probably looking for an RNAV approach. Donít know what AICís capabilities and certification allow, but there are plenty of RNAV RNP approaches into JFK.

Flying the ILS in LNAV/VNAV to mŪnima would be an emergency only option, sort of like descending below minima. The ILS might have LOC only minima as an option, but that would still require the Localizer.

Again, very lucky to have an ATCO that was able to put together a plan for them and sort of declare a soft mayday for them in the background. Not familiar with 777 fuel figures, but 7200kg is not exactly critical. That seems like enough to make it to Logan and land with 2-3T.

Indeed, very strange and interesting incident. Happy that it all turned out well in the end. Well done to NY ATC for helping out.

Dufo
17th Sep 2018, 07:39
Good job by all. In some craphole this could have ended differently. It seems to me that crew were unwilling to declare panpan even though they were getting low on fuel and practically had loss of instrumentation. Perhaps busting the minima to save the aircraft is a criminal offence in Air India..
7200kg must be within minutes to final reserve fuel in 777.

ACMS
17th Sep 2018, 08:09
77W uses about 6T an hour at that late stage I’d guess so probably 72 mins left......luxury

FreezingDrizzle
17th Sep 2018, 08:11
7200 kg would be way more than final reserve fuel in a 777.

msbbarratt
17th Sep 2018, 08:29
Luxury it maybe, and we're all better off for them not having to eek that out to vapours / fresh air. Well done everyone involved for getting wheels on to tarmac with the rest of the airframe attached and in one piece.

Cloudtopper
17th Sep 2018, 11:57
An utterly poorly managed flight deck . Embarrassing to say the least.

Having said that , anytime I fly over or into India the standards I see / hear ( ATC) are just appalling.

Could they ( B777 crew ) not have made one clear transmission without all the gobble- gook and request a non precision approach and not over complicate the job of the ATCO who is not suppose to know all the terms you transmitted.


Lucky the controller done a great job in supporting you.

Wannabe Flyer
17th Sep 2018, 13:19
An utterly poorly managed flight deck . Embarrassing to say the least.

Having said that , anytime I fly over or into India the standards I see / hear ( ATC) are just appalling.

Could they ( B777 crew ) not have made one clear transmission without all the gobble- gook and request a non precision approach and not over complicate the job of the ATCO who is not suppose to know all the terms you transmitted.


Lucky the controller done a great job in supporting you.


I felt the communication was clear & the crew must have been under a lot of pressure & managed well enough. To me it seemed a good example of ATCO & crew resource management

aterpster
17th Sep 2018, 14:08
They where probably looking for an RNAV approach. Donít know what AICís capabilities and certification allow, but there are plenty of RNAV RNP approaches into JFK.
No need to go to RNP AR. JFK has six RNAV IAPs, all with LPV, LNAV/VNAV, and LNAV lines of minima.

aterpster
17th Sep 2018, 16:13
https://cimg5.ibsrv.net/gimg/pprune.org-vbulletin/600x1000/kewr_rnav_4_2a804838ff687e852c945fbc43241e9ceda27ff0.jpg

casablanca
17th Sep 2018, 16:39
Jfk has lots of Rnav/GPS approaches, but none with mda down to 200 feet.
min fuel is around 3 tons in 777W
however flying around at 2000 feet is going to burn little extra.
luckily weather improved and all ended well

Airbubba
17th Sep 2018, 16:54
That first comment is very interesting.
Did they dispatch with the right IDG inop?

Not sure but you can do 180 minute ETOPS on the Triple with an IDG MEL'ed under U.S. rules. But you need the APU generator.

And that triple bus isolation on approach is famous for odd glitches with a generator out in my experience. I remember hours of ground school explanations of what should happen if you lost a remaining generator above 1500 feet, below 1500 feet, on alternate Thursday's etc. Bus tie locked open, closed, whatever.

Since they had one RA and no GS maybe the bus isolation did not go well on the first approach and a BTB stayed in ISLN after the missed. Of course, if they had some more MEL's on the GS, LOC and RA's as some have suggested on other forums it wouldn't have helped.

From a media report:

"Basically, we've got a single source radio altimeter, we have a Traffic Collision and Avoidance System failure", radioed in the Commander of the Air India 777-300 to Air Traffic Control in New York. "No Auto-land, no windshear systems, (no) Auto Speed Brake and the Auxillary Power Unit is unserviceable as well," he added.

And that was not all. All three Instrument Landing System (ILS) receivers on board the jet malfunctioned. ILS is the key system that helps pilots align the jet with the runway during landing in any weather condition, day and night.

https://www.ndtv.com/india-news/as-major-equipment-failed-how-air-india-pilots-landed-with-370-on-board-1917842

Listening to the tapes, my guess is that the pilots have spent much more time in New York than the controller has spent in India. It sounds to me like the controller couldn't understand a lot of the rapid AI 101 dialog but he was doing a great job trying. Some of us remember the first time we went into DEL or BOM trying to decipher thick Punjabi or Marathi accents. Or going into JFK listening to a Bronx accent for that matter.

glofish
17th Sep 2018, 17:09
Make the GA, ask for a holding area, determine your new status, ask for weather, check your options, decide where to go with what kind of approach, ask for respective clearance.
If wx, tech or fuel status, or clearance are unsatisfactory, declare fuel emergency/mayday and do the most appropriate approach to put the aircraft safely on ground irrespective of minimums or regulations.
Donít waste your and ATCs time with too much irrelevant babbel.

Lou Scannon
17th Sep 2018, 17:37
An unpleasant and unusual situation for both the crew and controllers. Disregard glofish's comment about "irrelevant babble". In this situation there is bound to be an amount of thinking aloud by both parties. Had they had 30 minutes notice of the failures the crew would have been able to give concise statements and requests and these would have been returned by the controllers with concise options and clearances.
My experience of Air India is that they only speak with an accent...they don't think with one. And as for the JFK and New York Controllers they were as helpful as I would expect them to be so well done everyone involved chaps!

MATELO
17th Sep 2018, 19:19
Disregard glofish's comment about "irrelevant babble". In this situation there is bound to be an amount of thinking aloud by both parties.

There has been enough accidents in the past when vital information hasn't been passed, both ways. Avianca Flight 52 in this neck of the woods springs to mind.

wiedehopf
17th Sep 2018, 19:30
No need to go to RNP AR. JFK has six RNAV IAPs, all with LPV, LNAV/VNAV, and LNAV lines of minima.

Don't think the big jets can do LPV, can they?

Zeffy
17th Sep 2018, 23:59
https://cimg4.ibsrv.net/gimg/pprune.org-vbulletin/1024x571/screen_20shot_202018_09_17_20at_206_52_04_20pm_zps2fx1ghi0_3 da4fd2e3690edd8ad2cbd16903dc65f366f80b6.png

Would an unserviceable APU indicate that electrical bus configurations may have been changed at some time during the flight?

Perhaps I'm assuming too much -- does ETOPS on a 777-300 require an operational APU for dispatch?

aterpster
18th Sep 2018, 01:45
Don't think the big jets can do LPV, can they?
Most cannot. My point is those procedures have LPV, LNAV/VNAV, and LNAV minimums.

Airbubba
18th Sep 2018, 01:56
Would an unserviceable APU indicate that electrical bus configurations may have been changed at some time during the flight?

Perhaps I'm assuming too much -- does ETOPS on a 777-300 require an operational APU for dispatch?

According to the FAA MMEL you can do 180 minute ETOPS on the 777 with an inop APU generator with both engine IDG's working and backup AC checked before every flight. Some of this MEL stuff is grandfathered from the 767 ETOPS certification three decades ago.

I've never been comfortable with generator inop dispatch on an ETOPS twin but there is indeed MEL relief in many cases.

I too am curious whether the APU was dispatched inop or was unable to start due to some electrical fault? Or was an IDG dispatched inop and some glitch propagated through the electrical system when a breaker opened or failed to close with a bus loss on the first approach?

Years ago I took a non-ETOPS 757 with an IDG inop. There was an unusual pause before the legacy CRT screens came back up after the first engine start, maybe some relay clicked out of sequence. Airborne the heading bug on the EHSI became unsynced with the HDG window on the MCP. We were in VNAV and it didn't look right so we tried FLCH and then both lights were illuminated. It was the old days and a short leg so we popped off the autopilot and flew the plane to the destination without the benefit of autoflight (oh, the horror ;)). On the ground the mechanics removed all power from the plane and restarted, it seemed to reboot the FCC's and we handed the aircraft to another crew.

fdr
19th Sep 2018, 02:51
Yikes.

There was a power loss in the system, I cannot recall offhand the common architecture for these systems, however eventually on the downwind the crew advise that they have no LLZ displays (ILS later noted). On a bad day on the east coast that is going to make for a busy cockpit. ATC maintained calm throughout as they developed understanding of the issue.

Having identified within the first 10 minutes or less that they were getting a repeat of the first event, then the crew response is calm, probably too calm. At that point they need to be taking immediate action to preserve their fuel status and increase their options as more information is gained on the tactical situation. Flying around at 2000' is not healthy. The crew did propose Stewart, which never seemed to be resolved. At around this time, KPIT was suggested by ATC, and that is 295nm away, but was VFR. At that point, the aircraft was approaching minimum fuel to divert to KPIT, and would have been down in the 3T remaining or so if proceeding there. An immediate emergency declaration on finding a repeat of the same instrument indications would have set up for a divert to a VFR airport. The aircraft instead travelled on various headings, East and otherwise for a period, and then a GPS based approach was flown to KEWR 04R. At the time the LPV/LNAV/VNAV approach was flown, the aircraft probably broke out at or above minima. It would not have had an alternate at that point, it was already on the divert however, so the OPSPEC would come into play to determine if the flight remained in a fuel emergency or not. I would suspect that it did.

Stewart used to have PRA capability, so if you have an ADI, heading etc, you can shoot an approach, assuming that you have some level of familiarity to the approach type. The LNAV/VNAV approach, would have placed the aircraft almost every time more reliably in the position of the final approach compared to an ILS that is not CAT II/III.

An interesting CRM exercise in a LOFT, and an event that many airlines can learn from.

Being too quiet about your issues may be great on the read backs, but being in a critical corner, and burning options out the exhaust from politeness may not help the reliability of the safe outcome.

The crew did a good job in trying circumstances, ATC did an excellent job. Once the wheels fall off the wagon, then what the crew do is up to their command judgement. Once you are in an emergency condition, all bets are off, and the only requirement is to minimise the risk to the outcome. At the time of the failure of the primary navigation system, and assuming that it could not be fault found and corrected with the QRH (which is highly likely, the ELEC, and INST sections of the B777 NNCL are brief, some knowledge of the bus architecture goes some way, as does talking to company engineers, or via them to the manufacturer), thereafter the viability of a SBAS/GPS LPV/LNAV/VNAV approach becomes seriously important. This was an emergency at that time, and the non ILS approach has the capability to achieve same or better performance than the ILS.

Perhaps as a professional group, we do not fly enough approaches using the alternative to ILS. I routinely would fly an ILS approach using the LNAV/VNAV tracking in the B744 and the B777. It does an excellent job. Even without any of those aids, flying a track and FPA (its a B777... easy to do) from a known distance or fix will keep the plane on the approach within normal tolerances. Yes, we used to demonstrate that routinely as well. Do I recommend flying that as a primary method? Nope, but having some faith in the systems capabilities at least gives some options to be followed when the wheels fall off the wagon. Having formated large aircraft on other small and large aircraft, there are always some options that may be considered, depending on background and how big a hole the operation is in. A similar event occurred and ended badly in another part of the world, where the crew of a jet did an approach and missed at minima, and lost the alternate at that time. an hour later, they parked their jet in the water, and survived. They were conducting approaches in an emergency condition, with some excellent capability, but never transitioned into an emergency authority frame of mind. After going around at PUBLISHED minima on multiple occasions, they parked the plane in the water. Many years before, at the same airport, my plane had the same situation. We declared an emergency, descended out over the water to visual conditions, and tracked on the available precision navaid (not so precise... doppler and airborne radar) back to the airport (1,050' below the minima for the approach). We had to climb back into the cloud to cross the cliff, and then sighted the runway threshold, and dumped the sorry bird on the ground. We had already briefed for a ditching as a potential outcome. Once you are in an emergency, your options change. Today, we have better tools, and the options may be easier.

My views are not a criticism of the flight crew, they did a good job. They could have had less stress if they had declared the emergency, and dealt with it as a real emergency at that time. From a training point, understanding the capability of the systems and what backup you may have at least gives a quick set of options to consider, which makes the decision making process less traumatic.

ATC-Cockpit communications were really pretty good in the circumstances.

Overall, good outcome, potential good training value to other crews for SA and ADM/NDM heuristics. I would fly with the crew. I would also buy the ATCO a beer.

bud leon
19th Sep 2018, 09:39
Actually it appears they were monitoring the situation well and made a decision well before fuel remaining became a critical factor, and the situation was successfully resolved. All we have are the radio transmissions which may not even be complete and which are one part of the largely opaque picture.

beeps
24th Sep 2018, 16:38
Lot of comments about using a different approach and minima but the issue was that all NPAs had obviously higher minimal and with the low ceilings almost everywhere the choices were fairly limited.

Great job by the crew in stating their requirements vis a vis ceiling requirements to make an approach and to the ATCO for being totally calm and helpful in finding an airport with weather for a possible approach. Also his knowledge of the avionics was also very good considering that most Airbus pilots would not totally understand the Boeing terminology and vice versa.

Well done all

Elephant and Castle
25th Sep 2018, 07:01
I don't fly the 777 but I am guessing that double RA failure means the autopilot will not couple to the ILS. What is wrong with a manually flown ILS though?

nike
25th Sep 2018, 13:26
Exactly.

Raw data ILS.

172_driver
25th Sep 2018, 13:38
I don't fly the 777 but I am guessing that double RA failure means the autopilot will not couple to the ILS. What is wrong with a manually flown ILS though?

Both LOC receivers had failed.

Hence the need for the LNAV/VNAV approach.

Elephant and Castle
25th Sep 2018, 16:28
They said "every time we try to lock on to the localised the instrumentation does not allow us to do that" that sounds like the loc was indicating but the autopilot/ flight director would not lock on, which is consistent with a double ra failure.

vilas
28th Sep 2018, 23:53
The main problem was the cloud ceiling which was low at JFK for an NPA and they couldn't do ILS. The other failures like APU, autoland, double RA are not significant. They chose their regular alternate EWR as the ceiling there improved 400ft.and trend showed further improvement. EWR has LNAV/VNAV approaches on both sides of the runway with 400ft. Ceiling. Once committed it's natural to feel anxious about the actual ceiling prevailing and whether they would see runway environment at minimum. Possibly they busted the minimum. With GPS PRIMARY should not be that hazardous.

Elephant and Castle
29th Sep 2018, 06:14
Possibly they busted the minimum. With GPS PRIMARY should not be that hazardous.

That says it all really

Long Haul
29th Sep 2018, 18:42
I don't fly the 777 but I am guessing that double RA failure means the autopilot will not couple to the ILS. What is wrong with a manually flown ILS though?


I donít recall what the RVRs were, but I read somewhere that the vis was 1/4 sm, so maybe below CAT I mins, which requires an autoland at my company.

wiedehopf
30th Sep 2018, 07:48
I donít recall what the RVRs were, but I read somewhere that the vis was 1/4 sm, so maybe below CAT I mins, which requires an autoland at my company.
RVRs around 3000 ft

Anyway EWR was much better vis so they could have done a manual ILS there at least.

arketip
30th Sep 2018, 09:29
Anyway EWR was much better vis so they could have done a manual ILS there at least.

Without localizer receiver? How do you do that?

wiedehopf
30th Sep 2018, 16:15
Without localizer receiver? How do you do that?

Please see the speculation above: Both RA faulty therefore the autopilot won't couple to the approach or something along those lines.

Thus the discussion ensued. Not saying it's a likely scenario was just pointing out weather conditions.

crwkunt roll
1st Oct 2018, 01:24
It sounds to me like the controller couldn't understand a lot of the rapid AI 101 dialog but he was doing a great job trying.
Normally the situation is reversed after a 15 hour long haul into JFK.
Don't forget these guys have been working too long, probably with little rest onboard, and as usual when stuff gets busy and the feeling of overload occurs, you look for the easiest way out. Nit pick later.
7200kg is about 30 minutes of holding/diverting fuel, before you land with final reserve. (Not 72 minutes!)

Perhaps I'm assuming too much -- does ETOPS on a 777-300 require an operational APU for dispatch?
The 777 doesn't need much for EDTO. Most failures, including APU, allow 180 minutes.

Wild blue yonder
1st Oct 2018, 04:21
I felt the communication was clear & the crew must have been under a lot of pressure & managed well enough. To me it seemed a good example of ATCO & crew resource management
Agree.Easy to criticize from an armchair. Not an easy situation to be grammatically correct in. You just had to be there. The old saying applies..." People in glass houses shouldn't throw stones"....

Yaw String
1st Oct 2018, 06:32
Any criticism of these guys,and their handling of the unusual,after having flown a longhaul sector,just shows what a miserable bunch we can be,
FGS!

wiggy
1st Oct 2018, 08:50
Yaw String..very much agree, I actually think it sounded like both ATC and the crew did a good job handling an unusual non-normal... :ok:

That said I’m still waiting for they “should have brought their “A game”...

glofish
1st Oct 2018, 09:00
Yaw String

So you want nothing but applause on this site. Fair enough but hardly professional.

I am used to hear a lot that did not go perfectly well and could be improved after each sim session. Discussion allowed!
On this particular event i stand by my earlier quote that there was too much irrelevant babble wasting precious time, call me miserable or not.

Derfred
1st Oct 2018, 12:22
I donít come here to criticise, I come here to learn. I think I have learned a few things from this thread, which makes it worthwhile.

I first listened to the video when the thread started. My immediate reaction was that the pilots should have been more specific about what they needed: eg ďWe are unable ILS, we need an RNAV approachĒ.

But I didnít say anything, because who am I to criticise? Iím glad I did because I have subsequently listened to it again, and now have a completely different conclusion.

Itís easy to criticise when you are sitting in an airchair, and donít have a rapidly dwindling 7200kgs in your tanks, and possibly donít fully understand what is wrong with your aircraft, although superior systems knowledge could help with that.

I think it turned out that they ended up happy to fly an ILS (Cat I) approach in LNAV and VNAV. They may have worked out that if they didnít attempt to couple the ILS to the autopilot, that they could actually fly a legal and safe ILS approach, provided the minima were above CAT I.

It appears that that is what they did. And perfectly legal (and sensible). There may be some who will state ďyou canít fly an ILS in LNAV/VNAVĒ. To those, I preemptively suggest that you have a think about that.

I therefore reject all the comments on this thread about ďthey should have flown an RNAVĒ. I also reject any suggestion that a PAN or MAYDAY was required.

They ended up flying an ILS approach in raw data using an autopilot coupled to LNAV and VNAV. That is surely the safest outcome, and Iíve had a couple of weeks to come up with that decision, these guys only had minutes.

So, yes, I say congratulations to both the pilots and ATC, and Iíve learned a lot from it.

Regards all, Fred.

vilas
1st Oct 2018, 12:39
[Any criticism of these guys,and their handling of the unusual,after having flown a longhaul sector,just shows what a miserable bunch we can be] Shouldn't professional discussion explore what really happened, what was done and whether there was better option? Otherwise it's like any number of comments that are written below the news. All emotional outbursts of the ignorant praising or criticizing but not worth wasting time reading.

misd-agin
2nd Oct 2018, 15:21
Did they always have the raw data ILS available? If yes the story should be much less thrilling.

A comment about climbing to save gas while holding - the gas you burn to climb is often greater than you’ll save at the higher altitudes. Performance charts show a savings of of roughly 120-200 lbs/hr per hour by climbing from 5,000to 10,000. That’s roughly 25-40 lbs/hr saved for each 1000’ of climb. Based on simple observations from enroute climbs the fuel burned (300-400 lbs for 2000’??) to move the airplane 2000’ higher would take hours and hours to recuperate.

The old thinking of staying high to ‘save gas’ in holding is frequently inappropriate. A 777-300 most efficient holding altitude is around 15,000’. Other jets are similar.

JW411
2nd Oct 2018, 17:01
As a rule of thumb, we used to reckon (on the DC-10) that if you were contemplating a 2,000 foot step climb, you would have to be up there for at least one hour to actually save any fuel. Incidentally, I was based at JFK for 3 years and I think that the crew and ATC both did a good job.

misd-agin
2nd Oct 2018, 21:58
JW - Iíve timed the fuel flow before and after the climb, checked the performance pages, noted the average fuel burn during the climb, timed the climb, etc.

I estinated the time to payoff is about 45 minutes. So weíre in the same ball park.

Derfred
3rd Oct 2018, 12:35
Did they always have the raw data ILS available? If yes the story should be much less thrilling.

I donít think we do know, but we have two pieces of evidence that that may have been the case:

1. They made a comment along the lines that it would not ďlock onĒ, and

2. They reported 2 RAís failed.

Join those dots.

Eric Janson
5th Oct 2018, 14:47
I donít think we do know, but we have two pieces of evidence that that may have been the case:

1. They made a comment along the lines that it would not ďlock onĒ, and

2. They reported 2 RAís failed.

Join those dots.

If this does indeed turn out to be the case - have standards really deteriorated to the point that people can no longer fly an approach using basic modes or even fly a raw data approach?

Quite disturbing.

wiedehopf
5th Oct 2018, 16:09
If anyone cares: The webtrak clearly showed they did a step down approach with level-offs consistent with an LNAV approach.
(webtrak with noise monitors showing radar data of the new york area: http://webtrak5.bksv.com/panynj)

What he probably meant they flew a LNAV/VNAV approach crosschecking with the ILS readings.

glofish
8th Oct 2018, 06:29
Level-offs on a VNAV approach with a T7 ... !
Give me a break! We are in 2018.
If true and fellow pros still talk about a job well done then good night.

beeps
8th Oct 2018, 15:38
The low cloud ceiling was the issue and thats why they were apparently unable to conduct an ILS approach down to landing. Not a question of raw data but the fact that with the low ceilings they needed to conduct an auto land and with the failures on board they were unable to do that and hence were looking for a place to approach where the ceiling was better so that they could possibly sight the runway at minima and continue to a safe landing.

misd-agin
9th Oct 2018, 01:53
RVRs around 3000 ft

Anyway EWR was much better vis so they could have done a manual ILS there at least.

A hand flown approach with 3000 RVR shouldnít be an emergency. Or even warrant a go-around on the first attempt.

Derfred
9th Oct 2018, 12:16
What he probably meant they flew a LNAV/VNAV approach crosschecking with the ILS readings.

Maybe they did, but my take from the ATC recordings is that they ended up doing an ILS approach, presumably autocoupled to LNAV/VNAV.

And there is nothing wrong with that (to CAT I) providing the raw data is monitored.

Now, maybe Iím being biased by what I would do in that circumstance, because that is certainly what I would do in that failure scenario!

ILS in LNAV/VNAV will get you lower than any other RNAV approach. Yes, you could fly it manually in raw data, but why?

aterpster
9th Oct 2018, 16:15
ILS in LNAV/VNAV will get you lower than any other RNAV approach. Yes, you could fly it manually in raw data, but why?
Many of the GA crowd has SBAS RNAV, which gets them LPV minimums. LPV is usually the same as ILS CAT I to a given runway. It is with 4R at KJFK, but not with 4R at KEWR.

pilotguy1222
10th Oct 2018, 09:40
What do we have?
What do we need?

If something else IS needed, How do we get it?

A raw data, hand flown ILS seems the consensus here, so nothing else was “needed”, though I am sure it was wanted.

Hi_Tech
12th Oct 2018, 12:41
According to the FAA MMEL you can do 180 minute ETOPS on the 777 with an inop APU generator with both engine IDG's working and backup AC checked before every flight. Some of this MEL stuff is grandfathered from the 767 ETOPS certification three decades ago.

I've never been comfortable with generator inop dispatch on an ETOPS twin but there is indeed MEL relief in many cases.

I too am curious whether the APU was dispatched inop or was unable to start due to some electrical fault? Or was an IDG dispatched inop and some glitch propagated through the electrical system when a breaker opened or failed to close with a bus loss on the first approach?

Years ago I took a non-ETOPS 757 with an IDG inop. There was an unusual pause before the legacy CRT screens came back up after the first engine start, maybe some relay clicked out of sequence. Airborne the heading bug on the EHSI became unsynced with the HDG window on the MCP. We were in VNAV and it didn't look right so we tried FLCH and then both lights were illuminated. It was the old days and a short leg so we popped off the autopilot and flew the plane to the destination without the benefit of autoflight (oh, the horror ;)). On the ground the mechanics removed all power from the plane and restarted, it seemed to reboot the FCC's and we handed the aircraft to another crew.

Any info on what was found on ground that caused this compound defect?. What was done to get the aircraft back in the air?