Hypothetical question.
 

You are 10 miles out on final to SFO. Between you and SFO there is a storm system with embedded lightning.

There is conflicting traffic from OAK so you can't divert. You have two choices.

1) You could go into a holding pattern until the storm system passes but in doing so you lose your spot at the gate.

2) You can penetrate the storm system.

Which would you chose?

Or, is there an alternative?

PS I'm not a pilot so please excuse the possibility of errors in my assumptions.


:E :E

Oddly enough Lu, had this same situation develop at KSFO years ago in a B707 enroute from PHNL.

I diverted to KSMF, as this was the company designated alternate for handling/refueling.
The expected hold at OSI was 1hr30min...ugh!

Still had to buy however. We had no INS, only Bendix doppler and a navigator, and I had bet the guy a fish dinner at Fishermans Wharf that he could not get within 5nm of BEBOP, then the oceanic gateway.
Radar fix was at 2nm....I never bet against navigators again, ever. :sad:

Getting to Frisco
 

Lu
Insurance companies take risks and they usually indulge themselves initially in declinature - to escape their predicaments. I don't take risks so I indulge myself with inclinature (i.e. I am always inclined to bog off away from a thunderstorm because I have the greatest respect for Mother Nature's right to rip me limb from limb if I invade her cosmic orgasm). Nothing is ever quite as cut and dried as you've portrayed it. If I had enough gas I'd be inclined to slope off into a holding pattern and entertain the pax with war stories (nothing like a captive audience that's already in thrall duer to the lightning in the middle distance). That's my entitlement. If I had sufficient gas and things were starting to shut down all around due weather I'd not waste that gas holding - I'd go somewhere else. I'd expect some sensible suggestions from ATC and my OPS on that score. If I didn't have enough gas I'd blame the F/O and Flt Eng for allowing me to be so stupid in the prevailing weather/season. Only then would I be in a corner and forced to make the harder decisions. Trapped rats never think clearly and that's why it's always best to avoid that scenario.

Losing a spot at a gate? Hardly consequential methinks. There are always alternatives. Conflicting traffic? So I'll do TWO long-way round turns and keep talking until they slot me in. Weighing the alternatives, fast talking, declaring your fuel state as a factor and always coming up with the right answer (or reply) is why captaincy gets you the big bucks.

OVERTALK
OVERTALK

Fuel shouldn't be a problem.
Go into the hold if the wx system is moving through reasonably quickly. You don't have to hold where it says on the chart although that makes things tidy ;) You can hold where ever it's safe from wx (and clear of restricted airspace, terrain etc)
Yes, there is an alternative and that is the divert. Holding and diverts to the alternate(s) are planned on the ground :D and reviewed when airborne. As you've noticed, things change.
Slot on the ground won't be a drama, if the wx's stuffing you up, it's stuffing every one up.

Penetrating an active cell isn't the wisest thing to do. The least you'll do is spill the drinks and spook some of the pax. The worst you'll do is much worse.... :uhoh:

You just ruined my day
 

I really appreciate your input but you just blew the storyline of the book I am writing. There must be some cases where an aircraft is struck by lightning as the possibilities of this occurring are quite high which means that the aircraft has penetrated a storm system. In fact I was in a MD-80 that had a lightning attachment near Syracuse, NY several years ago.

This is the scenario I am looking for. The aircraft is set up for landing or then again it is taking off. In either case the slats are partially extended and there is a lightning attachment on the partially extended slat. The lightning flashes over to the slat jack and then into the fuel tank blowing the outer wing off. On this particular aircraft the slats (and flaps) are not bonded to the airframe. Although the accident is pure fiction the probability of it occurring is very real.

Now, I will rephrase my original question asking for technical input as to when, and under what conditions, the aircraft with partially extended slats can be struck by lightning.

If you want I can give attribution for the technical assistance.


:E :E

Charting the Plot
 

Seek your inspiration here Lu

http://www.pprune.org/forums/showthr...hreadid=123867

Build yourself a causal chain. Accident Circumstances are woven from happenstance, make-do, misunderstandings, misanthropy, meander and minor deviations. We are all destined to end up behind the eight-ball sometimes. It's how we cope wiith what's on our plate that sorts the men from the boys and the copulators from the cadavers.

"...The copulators and the cadavers"
 

In my case, that fits beautifully:

"The Quick and the Dead"

Scenario is fanciful to say the least-I don't believe there is a certified passenger aircraft flying that can be taken down by a lightning strike. I've had 3 strikes so far in my career, and though dramatic, they are relatively benign. You don't have to be in the middle of a storm cell to get one. If I thought that there was a possibility of a strike bringing me down, I'd enjoy my job a lot less.

Waldo, there's more interesting side effects to thunderstorms than lightning (although the cost of a compass swing, ADF fix and minor/skin paint damage, plus the aircraft down time are sufficient reason to avoid even a lightning strike).

Have a look at http://afsafety.af.mil/magazine/htdo...98/tstorms.htm



I'd hold clear until the storm, with it's associated potentially severe dangers, had passed.

I would have enough fuel for such messing around, because I'd have seen the thunderstorms on the TAFs and added destination holding fuel. 30 mins minimum also covers any need for dog-legs during the flight. Yes, I really do do that in practice, I'm not just saying it.

In other words, I'd have covered the situation in the briefing room before departure.

Well, people may not think about it very much, but there's a pretty large air carrier airport just south-east of SFO. As long as your jet is a 777 or smaller, SJC is just fine as a divert. You might not be able to deplane (Customs), but you can wait out the weather on the ground. If the s**t really hits the fan at both SFO and OAK, then they suddenly notice SJC.

Waldo Pepper
 

USAF study excerpt (published BASJ - Volume 7):

QUOTE

The following lightning-caused damages are from 773 documented USAF strike mishaps:

? Pilot disorientation/blinding
? Instrument failure
? Flight control failure
? Fuel tank burnout/explosions
? Engine flameout, electrical failure
? Non-metallic helicopter rotor blade failure
? Aircraft structure deformation/burnout
? Acoustic shock/magnetic forces
? Non-metallic aircraft surface components

You may be surprised that lightning strikes cause more than half the weather-related USAF mishaps. From 1975 through 1985 these cost nearly $80 million damage, 10 aircraft and eight lives.

UNQUOTE

In 1994 I suffered a lightning strike in Southerna Africa that deleted the No. 2 EADC, burnt a 2 inch hole in the left wingtip and blew off the entire trailing edge of the elevator. Fanciful? I suggest not!

:}

126.9

Ah, but you made it home, didn't you?

I agree that lightning can be extremely dangerous, but the point is that civil operations lack the imperative of military ones...the primary objective is to get safely on the ground rather than complete the mission. It follows that military aircraft are likely to venture into skies that civil aircraft wouldn't.

As such, a well planned passenger flight would be unlikely to encounter the extreme conditions to which the USAF quote refers...should it do so, the chances of having a wing blown off are remote, though as you correctly assert, some damage is likely.

Since it's hard for me to think of many situations that would involve a civilian aircraft encountering the above scenario, I still think it's a bit fanciful, by which I mean very unlikely.

Which is which?
 

To: Waldo Pepper

I appreciate your input especially the part about planning your route to avoid thunderstorms. Yet in another post you indicate you were hit several times. In my case I have to reverse engineer the situation to make the story line work. In the case of Wings of Wax the aircraft is hit with a lightning strike which attaches to a partially extended slat. Because there is no bonding of the slat system to the airframe the lightning arcs to the path of least resistance which is a slat jack. The lightning then arcs to the fuel tank causing the explosion. In the process of doing this the lightning also causes a disconnect in the slat drive system.

That is why I asked the questions. With all of the answers I got I will have to stick with the three innocuous cumulous clouds below and parallel to the landing path. I have to get a lightning strike otherwise there is no story.

Although extremely improbable it is possible on the two subject airliners


:E :E

Some confusion reigns !

Clear message. (I hope !)

Since pilots of all experience levels read this forum (and I'm not suggesting vast levels on my part, BTW) I've really got to insist that thunderstorms are dangerous and should be avoided using the prescribed methods*.

I don't fly military aircraft on vital missions, as financed by the taxpayer, so I won't comment in that respect (don't tempt me).

I'm talking from the point of view of someone who wishes to minimise injury and death, not to mention damage and maintenance delays on commercial aircraft attempting to fly for profit.


*Try www.google.com and type in --- thunderstorms flying dangers.

Lu
Does the script require the aircraft to enter the cell or just receive a lightning strike?

Lightning can occur a surprising distance ahead of the cell.

In answer to your question.....
 

To: CoodaShooda

Answer to the first part: No

Answer to the second part: Yes

That is why I asked the question. It seems from the responses to my original question there is a lot of wiggle room. Some pilots responded that proper flight planning and judicious fuel consumption and or loading you could avoid the thunderstorms. Others have responded that they have been struck by lightning.

I hope the above is not too confusing.




:E :E

Lu, there was a Herc that got hit out of Hunter ANG Base in SAV some years ago. I'm trying to think of the exact sequence of events, but I'm pretty sure he didn't penetrate the cell. It blew the wing off, outboard of #4 engine, or something equally catastrophic.

Didn't a lightning strike bring down an Iranian Air Force 747 a few years back? Hit the wing and ignited the fuel, if my grey matter's not mistaken...

BTW a lightning strike from inside an aircraft isn't what you imagine from watching the movies. The noise it makes is a kind of 'flum' noise, a bit like an old fashioned camera flashbulb.

I'd a lightning strike on the approach. One of the biggest bangs I've heard (and I'm ex artillery - TA REME LAD attached) It's the one Arthur Whitlock refers to in 'Behind the Cockpit Door' - I was his FO. We'd negligible damage.
Saw an RAF Hastings with a little puncture in the nose and a fist size hole in the tail. ooh - er :ooh:

p.s. I wasn't the one Arthur said wanted to step into his shoes, I think it was the P3 - at least that's what he said when I asked him :O