FA/18 crash

[EtherealN]

What I read on AP was that he was still strapped in his harness, with first responders (some civilian locals, one of who was a retired paramedic) had to cut him loose. Might be confusion in the reporting about what exactly it was he was strapped into - possibly based on pictures of the seat lying on the ground. Does sound odd, but then again, if people have fallen several thousand meters from an aircraft without a chute and survived, stranger things have happened.

[159th_Viper]

Might also be a case of 'Chinese Whispers'. Until the official accident report is released, it's best to assume that all reports are just that: Assumptions and Speculation and of little or no value as to further insight of what actually transpired.

 

Oh yeah, for the record, eye-witness testimony is always the most unreliable testimony of all.

[EtherealN]

Oh hell yeah. Been a lot of interesting studies on just how extraordinarily bad humans are at remembering things that happened even just 10 minutes prior correctly.

 

Another interesting thing in that department is that most people that hear a factoid reported as false will remember it as being reported as fact. So if someone heard "he was not in his seat" they are very likely to remember it as being "he was in his seat". Human brains are epic fail, pretty much.

[Vekkinho]

Seems the engines were at different setting at the time of crash, possible failure of one or the 2.

 

Pilots were probably on final as plane crashed down the glideslope. They probably experienced some sort of failure just a few moments before ejection with no chance of hooking the plane in a nearby ocean direction. Pilot strapped in his seat is an indication that he problably ejected just few feet from the ground so I wonder if they had enought time to retard both throttles before ejection.

 

So looking at the engine nozzles of a plane in this state tells you nothing.

 

I'm glad there are only minor injuries mentioned so far.

[Phantom88]

I just heard through ABCNEWS that everyone at the apartment complex have been accounted for,Fantastic News!

[BIGNEWY]

I just heard through ABCNEWS that everyone at the apartment complex have been accounted for,Fantastic News!

 

great news !

[Jona33]

I just heard through ABCNEWS that everyone at the apartment complex have been accounted for,Fantastic News!

 

I'll wait for other sources before believing it.

[EtherealN]

Pilots were probably on final as plane crashed down the glideslope. They probably experienced some sort of failure just a few moments before ejection with no chance of hooking the plane in a nearby ocean direction.

 

This is what is reported over here:

"Enligt Mark Weisgerber, kapten i den amerikanska flottan, låg ett "katastrofalt, mekaniskt fel" bakom kraschen som skedde kort efter att planet lyft."

 

Translation:

According to Mark Weisgerber, captain in the american navy, the cause of the crash was a "catastrophic mechanical failure" which occured shortly after takeoff.

[lobo]

 

Notice engine nozzles...

 

Have a look at these two video's. 1st is a Mig-29 crash at Paris airshow. Note the commentary about the nozzle positions. Right eng failure due to bird ingestion.

 

http://www.youtube.com/watch?v=5MQk1yvsoKY

 

This next one is a CF-18 crash in Lethbridge alberta. Right eng failure. Note the nozzles.

 

 

Accident report preliminary for above CF-18

 

http://www.rcaf-arc.forces.gc.ca/dfs-dsv/nr-sp/index-eng.asp?id=11159

 

Moral of the story seems to be if you are slow at high AoA and have an engine failure in a Mig-29 or F-18 you can expect VMC controllabilty issues. I'm not saying this is what happened with the Virginia crash, but it is interesting to see that the nozzles were not symmetric in the wreckage pics.

[Frostiken]

Pilot strapped in his seat is an indication that he problably ejected just few feet from the ground so I wonder if they had enought time to retard both throttles before ejection.

 

So looking at the engine nozzles of a plane in this state tells you nothing.

 

Well they had plenty of time to dump fuel everywhere, so obviously whatever emergency they had took place over a long period of time.

 

I just heard through ABCNEWS that everyone at the apartment complex have been accounted for,Fantastic News!

 

Well apparently it was a retirement community so they were probably still driving back from the Early Bird Special at the Country Kitchen Buffet.

Edited April 7, 2012 by Frostiken

[Vekkinho]

Have a look at these two video's. 1st is a Mig-29 crash at Paris airshow. Note the commentary about the nozzle positions. Right eng failure due to bird ingestion.

 

http://www.youtube.com/watch?v=5MQk1yvsoKY

 

This next one is a CF-18 crash in Lethbridge alberta. Right eng failure. Note the nozzles.

 

 

Accident report preliminary for above CF-18

 

http://www.rcaf-arc.forces.gc.ca/dfs-dsv/nr-sp/index-eng.asp?id=11159

 

Moral of the story seems to be if you are slow at high AoA and have an engine failure in a Mig-29 or F-18 you can expect VMC controllabilty issues. I'm not saying this is what happened with the Virginia crash, but it is interesting to see that the nozzles were not symmetric in the wreckage pics.

 

 

These videos are all showing nozzles of aircraft before they hit the ground and desintegrate. Throttle lever position is the only thing that can tell investigators real engine settings.

[aaron886]

...VMC controllabilty issues. I'm not saying this is what happened with the Virginia crash, but it is interesting to see that the nozzles were not symmetric in the wreckage pics.

 

Probably the best assumption. That or a multi-channel hydraulic/FCS failure. What caused the crash will come out, but the reason the jet is in an apartment complex is the point of contention. The reason is that the building was underneath the path of landing aircraft at NAS Oceana... something of an accepted risk when you live there. (The military makes no secret that there is an increased "risk" where fast jets are flying slow and low.)

 

Whether or not the nozzles are symmetric is largely irrelevant, except to determine the failure of one engine or the responsible hydraulic system or its mechanical linkage or its fuel control or its power lever or... etc.

 

Throttle lever position is the only thing that can tell investigators real engine settings.

 

Wrong, interestingly enough. They have some sneaky methods to get close. ;) (Like examining compressor blade conditions, debris patterns, damage to cowl/casing, etc.) Either way, the position of the thrust lever doesn't necessarily correspond to the condition of the engine.

Edited April 7, 2012 by aaron886

[Frostiken]

These videos are all showing nozzles of aircraft before they hit the ground and desintegrate. Throttle lever position is the only thing that can tell investigators real engine settings.

The properties of the engine flexshafts isn't going to cause the nozzle to change position when it hits the ground. Also, as mentioned, throttle doesn't have the effect on the nozzles you may think it does, especially since in the crash the throttles are more likely to shift than anything else. Throttles don't take much to move and it's just a lever connected to a cable.

 

Other things they can use: all engines have downloadable memory units on the engine controller which will tell you a surprising amount of things to include aircraft flight parameters and every little thing wrong with the engine with frightening degrees of accuracy. Plus, has anyone forgotten the most useful tool, the flight data recorder? It's a D-model so it might not have had one, but still.

Edited April 7, 2012 by Frostiken

[aaron886]

Also, as mentioned, throttle doesn't have the effect on the nozzles you may think it does

 

To be fair, just to balance this out... the Legacy Hornet does not have FADEC engines. It's a plain-old fuel control on a pushrod. (Pretty much.) So in some ways the position of the throttles is a lot more relevant than it might be in another aircraft.

 

in the crash the throttles are more likely to shift than anything else.

 

I'd contend that point. :D

[Frostiken]

To be fair, just to balance this out... the Legacy Hornet does not have FADEC engines. It's a plain-old fuel control on a pushrod. (Pretty much.) So in some ways the position of the throttles is a lot more relevant than it might be in another aircraft.

 

I find it hard to believe there isn't a computer of some sort involved down the line that isn't constantly monitoring the engine. Anyway, I was implying a major abnormality could slam the engine into secondary power mode which will move the nozzle as well.

Edited April 7, 2012 by Frostiken

[aaron886]

FADEC engine controls are a surprisingly recent introduction. The tried and true mechanical fuel control is generally free of problems. In the Hornet, an electrically-powered lever connected to the throttle pushrods acts as a booster but can put in place some scheduled limitations as well. In that way, you could say there's a computer involved.

 

secondary power mode which will move the nozzle as well.

No clue what that's supposed to refer to...

[Vekkinho]

To be fair, just to balance this out... the Legacy Hornet does not have FADEC engines. It's a plain-old fuel control on a pushrod. (Pretty much.) So in some ways the position of the throttles is a lot more relevant than it might be in another aircraft.

 

 

However there's the IECMS with GEF404 monitoring and recording engine malfunctions that can say more on this matter.

 

But making any conclusions on the engine state by looking at the nozzle photo of an aircraft that crashed and burned makes no sense. Nozzle position might have changed after impact... what did it look like before plane hit the ground is another story.

[Yurgon]

It never seizes to amaze me how many opinions are given and wild theories stated on single eye witness reports and some such. As others have said before, we won't know anything for sure unless an (official) preliminary report comes out.

 

But let's try to look at some of the sources that were all quoted in this thread prior to this post.

 

1. Runway and crash site alignment

 

According to Google Maps, the crash site at Fleming Circle, Virginia Beach is in almost perfect alignment with runway 5R of NAS Oceana (linked map centered on the crash site).

 

Also have another look at the article linked in post #1. They've added a photo showing this very well, just click on the top image and then ahead twice.

 

(On the satellite/aerial imagery, construction work is being done on this particular runway. But I didn't find any info on when those images were taken. Does anyone know if 5R is currently available for flight ops?)

 

I couldn't find any reference to the runway the aircraft actually took off from. But if it was 5R, there are some conclusions that can be drawn a little down the road.

 

2. Damage at crash site

 

Look at the actual crash site.

 

 

(src).

 

Cross reference with Google Maps.

 

It looks to me like the buildings on the western end of the crash site (in direct extension of runway 5R) were damaged both in a physical way and by fire. I'd make this the most probable point of impact.

 

The buildings on the other side of the complex look very much burned down, especially the roofs, upper most floor and side walls show obvious signs of heavy fire. These also seem to be the buildings where the firefighters used their heaviest equipment. I'd make this the main direction of a jet fuel fireball that instantly and heavily ignited those houses.

 

Aircraft debris

 

We've all seen one or two pictures of the aircraft's tail with the ominous nozzle settings. How is this tail positioned in regard to the crash site? The best clue so far comes from video footage published by the BBC (first video on the page). At 00:08 we can clearly see the tail from the same perspective the photos were taken from.

 

The footage can only have been taken from the north side of the complex (at 00:16, the camera pans to the left where you can see the heavily burnings roofs mentioned earlier).

 

Apparently, the tail points somewhat south south easterly (by which I mean: if the aircraft was complete, its nose would point SSE. When looking at the wreckage from the north, we look almost straight into the engine exhaust nozzles).

 

I can only theorize that when the aircraft broke apart during the crash, the tail section (including engines and vertical stabilizers) separated from the rest of the fuselage and was torn around.

 

Dumping fuel

 

According to multiple sources, the crash occurred moments after take off, BBC says one minute after take off. After almost an hour of googling I've given up on finding a near accurate fuel dump rate for the F/A-18 (or any other aircraft, for that matter). It appears to be consensus that dumping a full internal fuel load takes quite some time, let's say >10 minutes.

 

Link 1 (yes, a car maniac forum turned up #1 on Google), Link 2 (navy pilot, seems legit) Link 3 (F-15E info site. Screw those imperials units, I'm too tired to calculate how long it takes gallons to be dumped at pounds/second).

 

I think it's fairly safe to say that if the crew did in fact dump fuel, it had nothing to do with alleviating the upcoming inferno at the crash site, it was simply a matter of reducing aircraft weight in order to help the aircraft stay airborne in an emergency condition and make an emergency landing a little easier. The most probable such condition would be (single or dual) engine failure.

 

Observations

 

• The aircraft was piloted by a student pilot, with an instructor pilot in the back seat.
  
• Witnesses didn't say anything about the landing gear. That indicates that the landing gear was properly retracted.
  
• Theory: Left engine failure caused by compressor stall.
  
• The aircraft had already covered about half of the distance to the Atlantic ocean where a crash would have left civilians (most probably) unharmed
  
• Right in front of the crash site, a large riverbed unfolds to the left (north), where a crash would have been much less likely to put anyone outside the aircraft in danger
  

 

Conclusions

 

We'll have to see what will be revealed about the crash in the days and months to come.

 

From a preliminary look at some of the available sources, I would theorize that:

• The aircraft took off from NAS Oceana, runway 5R
  
• After becoming airborne, the aircraft continued on heading 050 (+/- a few degress)
  
• At an unknown time (but within a 0 to 55 seconds window after takeoff), the left engine failed
  
• The crew started to drop fuel in response to the engine failure
  
• The crew ejected only moments before the aircraft crashed into a highly populated area
  
• The aircraft had not altered its heading one bit throughout the whole flight
  
• IMHO, that leaves two possible reasons for crashing into a populated area:
  • Complete failure of flight controls
    
  • The crew underestimated the emergency situation or did not react in time to stear clear of a populated area
    

[IvanK]

Quoted Dump rate FA18A is 600-1000lbs per min and 1300lbs min for the E/F. I don't think this is really relevant though. A clean Hornet suffering a single engine failure will easily be able to climb away on one engine ... no real need to dump fuel to reduce weight. Secondly they were only airborne (if the figure is correct for 55secs). In the scheme of things not a long time to be considering Duel dump etc ... flight path control would have been the prime concern. Only the front seater can initiate Fuel Dump in the A-C Hornets.

 

I think the "Fuel" seen may have been as a result of a major failure rupturing fuel tank s .. like an uncontained engine failure.

 

Like all these events though best to await the actual crash investigation.

Edited April 8, 2012 by IvanK

[vanir]

Reported on our local news station (ABC radio, our version of BBC), eyewitnesses said the flames were coming from the inner wing, not the engine.

"Eyewitnesses said flames were coming from underneath the wing..." is what they said yesterday.

 

*shrug*

[Frostiken]

• Theory: Left engine failure caused by compressor stall.
  

From that site:

 

Image of the crashed VFA-106 Hornet shows right engine nozzle fully open, and left nozzle closed: this could be a sign that, while the right engine was working properly providing max thrust, the left one was not (hence the closed engine nozzle).

I find it hard to believe any site apparently full of aviation enthusiasts has any credibility whatsoever when they can't understand the basic fact that when an engine is shut down the nozzle opens all the way, and it only closes when it's under power (opens for afterburner too). Additionally, they attribute the F/A-18 crash in San Diego to a compressor stall, when it wasn't, it failed because of a series of major maintenance ****-ups. Edited April 8, 2012 by Frostiken

[Eddie]

Since when did aviation 'enthusiasts' have the first clue how aircraft actually work?

[Frostiken]

Since when did aviation 'enthusiasts' have the first clue how aircraft actually work?

 

I would imagine through sheer chance you'd end up with about as much knowledge as the schmucks on this forum :P

[Vekkinho]

From that site:

 

I find it hard to believe any site apparently full of aviation enthusiasts has any credibility whatsoever when they can't understand the basic fact that when an engine is shut down the nozzle opens all the way, and it only closes when it's under power (opens for afterburner too). Additionally, they attribute the F/A-18 crash in San Diego to a compressor stall, when it wasn't, it failed because of a series of major maintenance ****-ups.

 

I'm sorry Frostiken but these enthusiasts are right about nozzles. Pictured here is RAAF F/A-18C and cold GE F404-400 engines look like this:

 

 

Nozzles are closed not open!

[Vekkinho]

I was very sad to hear it was a VFA 106 Gladiators F/A-18D. I've got VFA 106 1:72 scale model by Italeri in Wild Weasel config and of all kits I've assembled this one turned so damn good and became my favorite.