Broward County accident...

[wrench1]

https://twitter.com/i/status/1696155128494014575 ​​​​​​​

https://wsvn.com/news/local/broward/2-hospitalized-after-bso-fire-rescue-helicopter-crashes-in-pompano-beach/
​​​​​​​ (https://wsvn.com/news/local/broward/2-hospitalized-after-bso-fire-rescue-helicopter-crashes-in-pompano-beach/)

[Cabby]

Video of crash. 3 POB.

https://www.dailymail.co.uk/news/article-12453331/Air-rescue-helicopter-crashes-apartment-building-Florida-losing-tail.html

[ShyTorque]

That looks like a fire causing structural failure. Horrendous. It’s a miracle that anyone involved survived.

[FiveBlades]

2 pax, not seriously injured.Unbelievably lucky, imagine if they were in a robbi!

[EDLB]

Unbelievable lucky. Surviving structural failure in a heli does not happen often.

[wrench1]

Update: 2 dead, 6 injured. Was about a mile out of airport when turned back.
https://wsvn.com/news/local/broward/2-dead-6-injured-after-bso-fire-rescue-helicopter-crashes-in-pompano-beach-triplex/

[Bell_ringer]

Wonder if they knew the severity of the problem? Dropping it into the first safe space (if there was one) would have been worth the paperwork vs trying to return to base and not making it.
Miracle anyone survived, feel for the unsuspecting folks who had it drop into their home.
All things considered, very lucky all round.

[212man]

Wonder if they knew the severity of the problem? Dropping it into the first safe space (if there was one) would have been worth the paperwork vs trying to return to base and not making it.
Miracle anyone survived, feel for the unsuspecting folks who had it drop into their home.
All things considered, very lucky all round.

There is an ATC recording where they tell Pompano TWR they had an engine failure and request priority runway landing. I don’t know why they didn’t have a fire warning?

[hepkat]

Dropping it into the first safe space (if there was one) would have been worth the paperwork vs trying to return to base and not making it.

Found the guy with zero multi-time.

[Cabby]

Sky news. Different camera footage.

https://news.sky.com/story/two-killed-after-helicopter-crashes-into-apartment-building-in-florida-12949832

[Bell_ringer]

Found the guy with zero multi-time.

Did you try apply your mind or did you just leap into sarcasm?
In this case, that second engine really paid for itself when the tailboom failed.
One size thinking doesn't fit all.

[brogul]

Found the guy with zero multi-time.

There's a lot of difference between an engine failure and an uncontained failure with a large fire, which is what it looks like here. The only question I have is whether the pilot could see or otherwise knew the severity of the situation. There's an extended video of this where you can see the chopper flying for well over a minute with an obviously serious fire. Apparently the pilot has survived so he'll be able to answer all those questions.

[wrench1]

I don’t know why they didn’t have a fire warning?
The fire detectors are mounted in front under the ST/GEN and under the combustion can. If the fire was aft and on the deck quite possible never hit the trigger temps for the detectors. Seems if he had a warning he would have blown the fire bottle or at least commented to ATC is was on fire?

[Lonewolf_50]

Ouch, can you imagine sitting in your home and having a helicopter fall through the roof?
https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/1600x900/skynews_helicopter_crash_florida_6266084_10bb5c5fb85cb564f05 006a973a30151043d7047.jpg
That's just not something you expect on a given day.
Very sorry to learn of the two fatalities. :suspect:

[DogTailRed2]

Found the guy with zero multi-time.
You don't need to be a heli pilot or indeed a pilot to know it's probably better to land asap when on fire.

[skadi]

You don't need to be a heli pilot or indeed a pilot to know it's probably better to land asap when on fire.

But you have to know that you are on fire.

skadi

[malabo]

We get myopic from the systems installed and our subsequent training. Fire is only ever engine, occasionally electrical. We think we have lots of time to sort it out.

Was this a 135, does it have a baggage fire warning? Fire location doesn't seem related to engines, though on ATC they say one quit. They got out a mile and turned around, tower didn't see them trailing smoke when they left, so the tail boom fell off within what, 60 seconds of the fire starting?

Food for thought when you're flying those IA crews around with the 212/412 tail boom full of propane and jugs of gas.

[skadi]

Was this a 135, does it have a baggage fire warning? Fire location doesn't seem related to engines, though on ATC they say one quit.

This was a HEMS machine so no baggage compartment. No problem, especially for the CabinCrew, to look aft through the whole cabin. As seen on the videos the fire took place in the aft section of engine bay or even battery/Aircondition compartement. Fire is seen on both sides of the fuselage on different videos.

skadi

[Jack Carson]

The EC-135 a Very Robust Aircraft built to the latest crash worthiness criteria. Those that survived this incident are living proof of this.

[helithree]

Could it be due to a medical oxygen cylinder explosion?

[wrench1]

This appears to be the aircraft. It also had a littler kit so no baggage compartment to deal with. Fire/smoke seem to be coming from the bottom aft corner of the engine deck. And given the angle of deck this is where any fluids would be gathering at. It also looks like the tailboom failed aft of the mount flange where the structure is mainly carbon layers and nomex core. Something not very fire proof or excessive heat resistant. Hopefully all the data modules survived the post fire and will give a picture of what transpired so quickly.
https://live.staticflickr.com/65535/49822465068_4dfb468a85_b.jpg

[skadi]

Fire/smoke seem to be coming from the bottom aft corner of the engine deck.

There is another video which shows the starboard side and there is also visible fire at or behind the engine bay. There is a titanium firewall between and aft of both engines. I don't think that <2min of flighttime is enough to break these walls with fire.

skadi

[wrench1]

There is another video which shows the starboard side and there is also visible fire at or behind the engine bay. There is a titanium firewall between and aft of both engines. I don't think that <2min of flighttime is enough to break these walls with fire.
Here's a different video which the #1 side much more involved. And if fuel/oil is leaking past the firewalls or worse out the exhaust then not much to stop it. Here is also a recent press conference. They knew they had fire and I believe blew the bottle. Unfortunately a paramedic died.

https://youtu.be/MzIClw5H7q0


https://youtu.be/vZBvnLSMacE

[skadi]

Unfortunately the pilot died.

According to the sheriffs press conference it was one of the flight nurses.

skadi

[wrench1]

According to the sheriffs press conference it was one of the flight nurses.

skadi
You're right. My bad. Corrected.

[sycamore]

Could it be a rotor-brake fire..?

[gipsymagpie]

The Arrius engine had a service bulletin a while back for missing dampers on the power turbine. The dampers stop vibration of the blades in the turbine wheel. In the incident that precipitated the service bulletin, there was an uncontained release of turbine blades (on the ground in that case). That type of engine failure could lead to a fire.

There have also been 2 previous in flight uncontained engine failures on EC135 but both were on P1 variants due to inadvertant entry into manual mode and subsequent overspeeds. That particular failure mode is not possible on the T1.

[wrench1]

Could it be a rotor-brake fire..?
The rotorbrake is mounted on the xsmn and in front of the engines and its no more powerful than a BO105 brake.

[RVDT]

Oil fires are a different thing. Fuel you can shut off and stop, oil not so much and it moves slowly and sticks to surfaces.

If you look at the flight track they got it turned around and heading back and the whole flight time was about 3 minutes.

[SLFMS]

Found the guy with zero multi-time.


Are you serious? What an aggressive comment, further more you seem to have opened you mouth and removed all doubt.

I agree with Bellringers comment, Uncontained fire is land immediately. Assuming he fired his suppression bottles. It’s possible the airport was the only option without endangering 3rd parties but I agree if there’s a place to set it down to do so.

Proximity to the airport can be a killer for any serious emergency. If on fire OEI and close to an airport, landing in a sports field vs a short flight to a runway is going to be very tempting.

Surely it’s a miracle anyone survived not only inflight break up but also on fire with post crash fire. I hope the ones that didn’t were unconscious.

[LTP90]

Food for thought when you're flying those IA crews around with the 212/412 tail boom full of propane and jugs of gas.
thats one of several reasons my crew(along with many around us at the time) never used the tailboom baggage compartment.

Will be interesting to see how much intrusion into the structure the initial impact made, for 2 injured and disoriented parties to exit the aircraft. Landing on the apartments might have absorbed some of the downward energy in a better manner than pancaking Into the concrete.

[Gtep]

Can’t post a picture showing the overhead map of where they crashed. There wasn’t an option of performing an emergency landing without putting life/property at risk. I suspect he knew exactly how bad the fire was and was praying that it would hold up a couple more blocks to the airport. I’m guessing he was 2 miles away at most.

[Devil 49]

Proximity to the airport can be a killer for any serious emergency. If on fire OEI and close the an airport landing in a sports field vs a short flight to a runway is going to be very tempting.
Amen. It's really hard to take the decision to land short, damage the aircraft but survive. Sometimes survival is as much as you can hope for, sacrificing the airframe.

[SLFMS]

It will be interesting to read the Pilot transcript. Watching the video after the tail boom failed the initial descent seems fairly low and appears he’s keeping the power on.
Once spinning you normally see guys dump the collective.
I think that potentially saved their lives and kept ROD to a survivable amount.

[SilsoeSid]

Pic from Sky News site look as if fire is from ‘a particular panel’s’ location on the starboard side, close and accessible to tail boom connection point.
https://news.sky.com/story/two-killed-after-helicopter-crashes-into-apartment-building-in-florida-12949832
https://cimg4.ibsrv.net/gimg/pprune.org-vbulletin/925x1377/img_3883_154ded5d58d44ebc6da0d9abe78d6b4cac5b0883.jpeg


Video from ABC News site shows fire to be from that specific area only; the flames also don’t look like fuel to me. https://abcnews.go.com/amp/US/fire-rescue-helicopter-crashes-florida-2-hospitalized/story?id=102617239

(Just saying what I see without assumption, despite many hours on type) (https://abcnews.go.com/amp/US/fire-rescue-helicopter-crashes-florida-2-hospitalized/story?id=102617239)

[EDLB]

Looks like the fire is below the engine exhausts and below the engines.

[Winnie]

[QUOTE=SilsoeSid;11493222]Pic from Sky News site look as if fire is from a particular panelled location on the starboard side, close to tail boom connection point. (Drivers will know where I mean)
https://news.sky.com/story/two-killed-after-helicopter-crashes-into-apartment-building-in-florida-12949832

Video from ABC News site shows fire to be from that specific area only; the flames don’t look like fuel to me.

It looks to be from the battery compartment or near. aft of the engine compartment...

[Gtep]

Could it be due to a medical oxygen cylinder explosion?

Tank exploding would cause serious harm to the individuals on boards.

[Sir Korsky]

Pretty sure that 135 had no fire bottles installed. I've flown 4 or 5 airframes and all of them had no bottles. Never liked the 135 because of this. They all had the fire PB's but alert/shutoff only. That aircraft spent most of its time out on the swamp looking for drunken sailors. Would have been hard to look back and see that fire glowing in the daytime.

[Scattercat]

The 135 has a Fire Extinguisher system available as a supplemental kit option (FMS 9.2-9) ... the basic configuration has a Fire Warning system only. It will be interesting to see how this aircraft was configured. Anyone in the know?

[Aser]

That looks to me like the battery compartment... :ooh:

[skadi]

Pretty sure that 135 had no fire bottles installed. I've flown 4 or 5 airframes and all of them had no bottles. Never liked the 135 because of this.

The 135 has a Fire Extinguisher system available as a supplemental kit option (FMS 9.2-9) ... the basic configuration has a Fire Warning system only.

I had flown many 135 from 1997 on, all of them had the bottles installed. Never saw one without. As for the supplements, the SAS is also in there and I've never seen one without

skadi

[Sir Korsky]

Welcome to the USA, where those pesky heavy fire bottles can be seen as a weight shave. I'd be surprised if any HAA 135's in the US had them installed.

[SilsoeSid]

Discussion of whether fire extinguisher bottle(s) were fitted/used is a moot point considering the location of the fire.

[212man]

Discussion of whether fire extinguisher bottle(s) were fitted/used is a moot point considering the location of the fire.
and that the crew seemed unaware they were on fire (ATC recording)

[RVDT]

Pretty sure FMS 9-2-9 Engine Fire Extinguisher (available in 1 shot or 2) is required if you are going to use the Cat A supplement.

[SLFMS]

Isn’t the 135 IFR capable? I would have thought that would require fire suppression, or is that the point of the option?
It’s crazy it’s a choice.

[SilsoeSid]

Watching the ABC News vid, the initial shot viewing the port side with ac moving right to left, the ‘source’ may be more inboard, under the ‘connecting flange’.

I wonder if the ac had recently been washed.

[[email protected]]

If it is an uncontained fuel driven fire, that will be like a blowtorch so no wonder the TRDS and tailboom gave way.

[SilsoeSid]

If it is an uncontained fuel driven fire, that will be like a blowtorch so no wonder the TRDS and tailboom gave way.
Talking of possible blowtorches, the hydraulic line connectors are directly above the connecting flange, with fluid at a far greater pressure than fuel.
(Hyd@103 bar / Fuel press caution @ 0.6 bar P/W, 1.3 bar Arr2B1)

Effect rather than cause of fire?

[NutLoose]

This looks like part of the fire was in the boom where it failed?.

https://twitter.com/realpeacenotwar/status/1696404445524058234

https://twitter.com/realpeacenotwar/status/1696404445524058234

[hoistop]

There is another video which shows the starboard side and there is also visible fire at or behind the engine bay. There is a titanium firewall between and aft of both engines. I don't think that <2min of flighttime is enough to break these walls with fire.

skadi
It is not the firewalls, the problem is that structure, attaching tailboom and/or tailboom itself failed. Tailboom is completelly made of composite, while attachment flange and fuselage is metal structure - Aluminum and titanium apron and firewalls. I worked many years on EC-135 and am astonished how fast the fire destroyed the primary structure. Like Concorde in Paris.

[hoistop]

there was no tailboom baggage compartment on this helicopter-or any separate "baggage compartment" at all, as it is an EC-135 type.

[[email protected]]

Effect rather than cause of fire? If, as someone suggested above, the initial failure was a turbine burst with blades being shed - that would make a lot of sense Sid.:ok:​​​​​​​

[212man]

If, as someone suggested above, the initial failure was a turbine burst with blades being shed - that would make a lot of sense Sid.:ok:
Well, the crew did report an engine failure, so it seems more like the fire was a consequence.

[SilsoeSid]

Well, the crew did report an engine failure, so it seems more like the fire was a consequence.

The op link says:

’According to officials, on Monday, the chopper had just taken off from the Pompano Air Park at 8:42 a.m. and was heading to a call in North Lauderdale regarding a car crash where a vehicle hit a bus stop at Prospect Road and State Road 7. Three minutes later, the BSFR helicopter had an engine failure that occurred shortly after takeoff.”

However, it also says… “It is unclear how they managed to maneuver onto the roof.”

:confused:

[SLFMS]

This was my initial thoughts too, engine failure cause the fire. Seems most likely given engine failure was reported assuming that was correct

[[email protected]]

If an engine does go bang as opposed to just turning itself off, who knows what collateral damage there could be and to which systems.

[wrench1]

I worked many years on EC-135 and am astonished how fast the fire destroyed the primary structure.
Agree. But for a "fuel" fire he's trailing a lot of smoke for a long time if the valve was closed. Oil/Hyd fire something different. Maybe an oil leak ingested by engine causing performance issues then a fire at the end? Have even seen oil leaks on the xsmn deck dump excessive oil down the intake tunnel.

[212man]

This was my initial thoughts too, engine failure cause the fire. Seems most likely given engine failure was reported assuming that was correct
I've heard the ATC tape, but can't find a link. It was on LI.......

They say they had an engine failure and are requesting a priority landing using a runway. ATC (Pompano Tower) clears them to land RWY06 (or, RWY Six, as they say over there.....)

[Warren Peace]

How many more aircraft will be lost before everyone understands the importance of land right away?

What could be worse than this outcome, if they had set it down as soon as they had a problem?

Maybe bringing the fire to the rescue scene is not great, but getting out in one piece is more practical if you try it before you crash.

[SilsoeSid]

KB4TEZ at Live ATC
“video in the link, I've attached the short clip of the emerg audio.“

Audio Link (https://forums.liveatc.net/atcaviation-audio-clips/fire-rescue-helicopter-crash-in-florida-sends-2-to-hospital/?action=dlattach;attach=11911)

https://forums.liveatc.net/atcaviation-audio-clips/fire-rescue-helicopter-crash-in-florida-sends-2-to-hospital/

[[email protected]]

It will be interesting to discover if he did the shut down drills on the failed engine or just assumed it had turned itself off and didn't need further attention.

A pretty standard action post any engine malfunction would be to check for dangerous indications.

[NutLoose]

For want of a simple mounted mirror on a stalk or a camera, so the pilot can see the rear of his aircraft.
Rather like the Puma had to see the intakes, but mounted so they could view the rear of the helicopter..

[212man]

How many more aircraft will be lost before everyone understands the importance of land right away?

What could be worse than this outcome, if they had set it down as soon as they had a problem?

Maybe bringing the fire to the rescue scene is not great, but getting out in one piece is more practical if you try it before you crash.
Well, as I think has been made abundantly clear, the crew were unaware they were on fire! Had they been aware I think there's a fair chance they would have landed sooner.

Not sure what you mean by "how many more aircraft...." - it's not exactly a common occurrence!

[SilsoeSid]

For want of a simple mounted mirror on a stalk or a camera, so the pilot can see the rear of his aircraft.
Rather like the Puma had to see the intakes, but mounted so they could view the rear of the helicopter..
… or a simple ‘S’ turn as part of the ‘any indications of fire’ check post an eng fail.

I’d have thought that if it shredded a turbine blade, or something similar that would affect or destroy other systems, there would be quite a disturbance to the rear that may have been reflected in the radio transmission.

[RVDT]

Isn’t the 135 IFR capable? I would have thought that would require fire suppression, or is that the point of the option?
It’s crazy it’s a choice.
Cat A ops requirement only. Never seen fire suppression connected to IFR ops requirement.
Part 27 helicopter. Not all are IFR equipped either.

[DogTailRed2]

Pressing the fire button when lit cuts off fuel to the engine.
Would that influence the pilots decision to press it over a built up area?

[whoknows idont]

Both the visual and the audio warning for fire are way too inconspicuous and can be missed very easily when faced with a lot of other indications that come with an engine failure. So it's a scenario that a fire indication was not recognized and fuel not shut off.
On the other hand I don't think it's "abundantly clear" that the crew was unaware of the fire, based on the communication with the tower only.

According to googled images N109BC seems to have had the hole in the cowl aft of the battery door. The hole that's there in order to read the fire bottle pressure indicator. I don't know if that hole is always there or only on machines equipped with the fire suppression kit.

[212man]

Pressing the fire button when lit cuts off fuel to the engine.
Would that influence the pilots decision to press it over a built up area?
not if they already lost the engine, and shouldn’t for a twin anyway.

[RVDT]

CS 27.861 Fire protection of structure, controls, and other parts

Each part of the structure, controls, rotor mechanism, and other parts essential to a controlled landing that would be affected by powerplant fires must be fireproof or protected so they can perform their essential functions for at least 5 minutes under any foreseeable powerplant fire conditions.




CS 27.1195 Fire detector systems

Each turbine engine-powered rotorcraft must have approved quick-acting fire detectors in numbers and locations insuring prompt detection of fire in the engine compartment which cannot be readily observed in flight by the pilot in the cockpit.


Of note - engine containment is the engine manufacturers purview.

Looking at the various media it seems the fire is from both sides? Imagine one engine had an un-contained wheel failure which would destroy the firewalls. One has stopped and you have 2 x FIRE warnings? How many buttons do you push? What does LAND IMMEDIATELY mean when you have just left the airport?

The FIRE button in the 135 will shut off the main fuel valve only. If ENG FIRE EXT is fitted the system will release when the following logic is present - an active FIRE warning, N1 < 55% and the main fuel valve is closed - from memory. You have one shot for either engine with the standard fit.

Next time you have an engine fire keep the 5 minutes in mind.

I have seen the result of a few turbines burst over the years - two happened on the ground - B206 RRA 250 #1 Wheel shed all the blades and they went down through the engine tub, through the baggage compartment floor and onto the ground. AS350B Arriel 1 shed the PT wheel and as the aircraft was in long grass.......................not much to see. AS355 NP turbine burst at about 500' - land immediately and the TRDS was hanging by a thread.

An old instructor on a check ride once told me - if you have a fire and secured everything make a gentle turn and look over your shoulder behind you.

[ShyTorque]

For want of a simple mounted mirror on a stalk or a camera, so the pilot can see the rear of his aircraft.
Rather like the Puma had to see the intakes, but mounted so they could view the rear of the helicopter..

Unfortunately the Puma mirrors were only installed as an interim mod prior to the polyvalent intakes. They were there to extend the flight in potential icing conditions and as Nutty mentioned, they were initially angled to look at the engine intakes. But they were convex mirrors and could be angled to see down the sides of the aircraft.

When the PV intakes were fitted they were removed, despite Squadron pilot requests (especially myself) for them to be retained. For exactly this type of scenario. Part of the engine failure checklist was to check for signs of fire. Easy with mirrors, but without them the only way was to turn the aircraft and see if it was trailing smoke.

[KiwiNedNZ]

Here is a video we did with BSO and their EC135 - some of the footage might give a clue as to what equipment in the back might have caused this - if any. From first look doesnt seem to be anything that sticks out.

https://youtu.be/9pe4OriSExI?si=qynqMl_IrBfiQcNM

[NutLoose]

Do you think they were possibly taking the quickest route to safety and clear ground over a built up area knowing it was bad and turning to check for smoke may have reduced their chances and increased the time in getting there, with the possibility of causing deaths on the ground?

[RVDT]

https://cimg8.ibsrv.net/gimg/pprune.org-vbulletin/1766x1114/screen_shot_2023_08_30_at_9_37_00_am_b6b319979d4b905bcb5e071 e67ac27d0180fba84.jpg
Some more perspective

[SilsoeSid]

https://cimg8.ibsrv.net/gimg/pprune.org-vbulletin/1766x1114/screen_shot_2023_08_30_at_9_37_00_am_b6b319979d4b905bcb5e071 e67ac27d0180fba84.jpg
Some more perspective

Closeness of the airport could possibly a distraction in itself; plenty of sports areas and open areas in which to land immediately in the area of the 180 for options, (not clearly shown on the above map screenshot). Having said that, an immediate landing wouldn’t necessarily be on the cards for a twin following an engine failure anyway, especially if no other dangers were perceived by the crew.

My 135 experience in this area is a night sortie with the smell of burning and smoke becoming apparent in the cabin <5 mins from BHX, with recced night landing sites along the way if that option was taken. However, a hurried but thermally scanned recce of a school football pitch ‘underfoot’ saw us land and shut down safely. The cause was found to be dry grass in the heating system, but we weren’t to know it wasn’t anything more serious at the time.

Be interesting to read how a fire that apparent from the outside, was perceived from the inside. Thankfully, all our thoughts will be put in their place with the investigation and first hand accounts.

[SilsoeSid]

Here is a video we did with BSO and their EC135 - some of the footage might give a clue as to what equipment in the back might have caused this - if any. From first look doesnt seem to be anything that sticks out.

https://youtu.be/9pe4OriSExI?si=qynqMl_IrBfiQcNM

In addition, there is also the avionics rack tucked up in the roof.

[chopper2004]

Glad crew ok and speedy recovery, my first thoughts were, reminiscent of the early accidents with Robinson R22 , tail snapping off due to pulling back too hard on cyclic and chopping tailboom off. Then hang on, its a semi rigid head...what the hell could have cuased fire..

Anyhow this was a P3/T3 equipped with Helionix, there are cameras below fuselage and I think in tailboom (my pic playing with D-HECB 6 years ago at Le Bourget)

https://scontent-lcy1-1.xx.fbcdn.net/v/t31.18172-8/26685133_10156429376071490_4590177202786918803_o.jpg?_nc_cat =106&ccb=1-7&_nc_sid=cdbe9c&_nc_ohc=Ogqd6mb8RjwAX8Fc6K1&_nc_ht=scontent-lcy1-1.xx&oh=00_AfBqwqSMduBkheyN0s8jBMoSf5uBj2sumGTYXjczNUDQqA&oe=6515DD2C

How old is this BCSO Fire Ec135? When was its last inspection / G check??

cheers

[Thud_and_Blunder]

Am not current on any type, although I operated 135s for several years. Having seen the effects of a thermal runaway on an aircraft battery, I shall be interested to see if this is a contender.

As for survivability, kudos to the designers. Looking at the rate of rotation after tail-boom separation, I very much doubt whether any pilot would be able to keep hands/feet on controls under those centripetal forces, so there goes the option for double-engine shutdown.

[SLFMS]

Cat A ops requirement only. Never seen fire suppression connected to IFR ops requirement.
Part 27 helicopter. Not all are IFR equipped either.

Thanks RVDT I assumed it was required for IFR certification, it should be….
That is the problem with the option, some guy in an office decides it hardly ever happens and the system costs a lot. “We can’t account for everything”

The pic you posted is telling not many options before the airfield which was close.

[SLFMS]

It will be interesting to discover if he did the shut down drills on the failed engine or just assumed it had turned itself off and didn't need further attention.

A pretty standard action post any engine malfunction would be to check for dangerous indications.


While I agree Crab there was not a lot of time. My company requires engine shut downs to be done from ECL(believe it or not Fire drills too……)Works great for a chip light perhaps not for an uncontained engine failure with fire.
“IF” you follow the process it takes forever.

[RVDT]

N109BC was a 1999 T1 SN 139 - so could even be a CDS "steam gauges" model.

[albatross]

Thanks RVDT I assumed it was required for IFR certification, it should be….
That is the problem with the option, some guy in an office decides it hardly ever happens and the system costs a lot. “We can’t account for everything”
The pic you posted is telling not many options before the airfield which was close.


Not to second guess their decisions as we do not know how bad they knew the problem was.

problem/warning—-start turn back ——carry out ECL items…call tower….by that time the open areas Just where he starts the turn back ——a baseball diamond and 2 athletic/football fields would probably have been out of sight behind him.

https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/1387x1151/img_6835_4aad6e2e841bac4e31ff3d1214b9e477cf3120dd.jpeg



.

[RVDT]

Am not current on any type, although I operated 135s for several years. Having seen the effects of a thermal runaway on an aircraft battery, I shall be interested to see if this is a contender.

As for survivability, kudos to the designers. Looking at the rate of rotation after tail-boom separation, I very much doubt whether any pilot would be able to keep hands/feet on controls under those centripetal forces, so there goes the option for double-engine shutdown.

Battery boxes are stainless steel and about 15 times the thickness of the engine firewalls?

[RVDT]

While I agree Crab there was not a lot of time. My company requires engine shut downs to be done from ECL(believe it or not Fire drills too……)Works great for a chip light perhaps not for an uncontained engine failure with fire.
“IF” you follow the process it takes forever.

Is that some sort of alleviation from the RFM?

[SilsoeSid]

Battery boxes are stainless steel and about 15 times the thickness of the engine firewalls?

… and that potential little bomb is extremely close to the connecting flange.

https://cimg3.ibsrv.net/gimg/pprune.org-vbulletin/1486x960/img_3886_0e226ef3f3a0ed048b740555eb58139acbb8437d.jpeg
https://gama.aero/wp-content/uploads/AH-Ground-Rescue-Booklet_EC135.pdf

Internal video of the battery bay at 36:3 (https://m.youtube.com/watch?v=bm4iGfPw5sI&feature=youtu.be)4 <~~ Click there.

[SLFMS]

Is that some sort of alleviation from the RFM?

No follows the RFM. You could debate if immediate actions are that or not. I know my view

Ass Ticket Job

[wrench1]

N109BC was a 1999 T1 SN 139 - so could even be a CDS "steam gauges" model.
However, as I recall it used the same Warning Unit which contained the fire warning indictor and bottle switches if installed.
Not to second guess their decisions as we do not know how bad they knew the problem was.
Word from local pilots is the problem became apparent prior to the turn-around and a number of open areas would have been in view. The fact the crew let the fire department comm center know they could not respond to the call in the same time frame gives the impression the issue was not initially serious to the crew. The question remains in the local discussion what did the crew see in the cockpit. However, trailing smoke for close to 40+ seconds prior to the boom failure have generated more questions. Once the aircraft hit the roof the pilot and a 2nd medic were able to self- extricate and there are pics and videos of them moving across the roof away from the aircraft until a ladder was provided for them to get down. From what I've heard the answers to those pertinent questions will be forthcoming sooner than later.
Having seen the effects of a thermal runaway on an aircraft battery, I shall be interested to see if this is a contender.
While I don't personally know about this aircraft a number of operators have switched to AGM batteries on 135s in warmer climates. All the ones (30+) I was around in O&G and EMS had AGM installed when completed from the factory. Regardless, all that smoke was fed by something that didn't run out of quantity.

[Harrynz]

In the video just after the boom folds, There is something ejected from the airframe. It is smoking and falling rapidly to the ground.
It looks the right size for the aircraft battery.

[dragon6172]

The sports fields at the high school would be available, but all of those other open fields in that satellite view are currently construction sites for new residential buildings according to the most recent Google Street View shots from Feb 2023.

[Sir Korsky]

In addition, there is also the avionics rack tucked up in the roof.

An electrical disaster in the Pelican rack is a distinct possibility - but this is the archetypal arrogant Pprune thread. Lots of input from expertise from folk who've never been thrown the keys and flown the damn thing.

[lelebebbel]

The sports fields at the high school would be available, but all of those other open fields in that satellite view are currently construction sites for new residential buildings according to the most recent Google Street View shots from Feb 2023.

I honestly think that even if they had a fire indication and the intention to land as soon as they could, there's a good chance they would have still picked the airport from that position. Yes the fields are closer and allow a faster landing in theory, but setting up a proper approach (on one engine no less) to those fields would still require some maneuvers. Then there's the risk of hitting unseen obstacles like wires without a proper reconnaissance of the site. And the availability of emergency services at the airport.

If you know your tail boom is about to melt off you'd just slam the collective down and land no matter where or on what, but they obviously didn't know that.

In an alternate reality, the article could also read "EC135 pilot panics after false fire warning light, and hits wires while attempting an emergency landing on a baseball diamond a mile away from a wide open airport. 3 little league players in critical condition "

Armed with hindsight and an external view of the machine, we all know what the right call would've been - get down anywhere and disregard potential damage during landing. That call is not so easy to make when you don't have all the information though. How many false fire lights has everyone here had?
​​

[RVDT]

An electrical disaster in the Pelican rack is a distinct possibility - but this is the archetypal arrogant Pprune thread. Lots of input from expertise from folk who've never been thrown the keys and flown the damn thing.
Looks like a machine with no AP and steam gauges - No Pelican rack required for the FCDM or AP modules?

[KiwiNedNZ]

One question I had is if it was on fire that close to the airport wonder why the tower wouldnt have seen it ??

[[email protected]]

Unfortunately, the safety logic and emergency handling protocols that have evolved following many instances of the 'flashing white glove' shutting down the wrong engine or selecting the wrong system off, mean that sometimes we will see malfunctions like this where the old school are shouting 'Do the drills from memory and shut down the engine because you don't know what else is wrong' and others are following company policy and the RFM because then you can't be hanged in court.

This guy was possibly caught between a rock and a hard place and just followed what he had been trained to do.

[Gordy]

In an alternate reality, the article could also read "EC135 pilot panics after false fire warning light, and hits wires while attempting an emergency landing on a baseball diamond a mile away from a wide open airport. 3 little league players in critical condition "
Armed with hindsight and an external view of the machine, we all know what the right call would've been How many false fire lights has everyone here had?
​​
Bingo.......

[skadi]

This guy was possibly caught between a rock and a hard place and just followed what he had been trained to do.

I am still convinced that he didn't know that there was a fire in the back

skadi

[SilsoeSid]

Quote:
Originally Posted by SilsoeSid
In addition, there is also the avionics rack tucked up in the roof.
An electrical disaster in the Pelican rack is a distinct possibility - but this is the archetypal arrogant Pprune thread. Lots of input from expertise from folk who've never been thrown the keys and flown the damn thing.


Thanks for that Sir Korsky.
Not sure what the qualifying hours we must all have for input on this subject are, clearly my 2,825 hrs on the EC-135, both T&P, is not enough. I don’t recall keys for the 135, however I believe the MD902 had a set. But with only 946 hrs on that type, I wouldn’t be qualified to say.
:rolleyes:

[Bell_ringer]

Armed with hindsight and an external view of the machine, we all know what the right call would've been - get down anywhere and disregard potential damage during landing. That call is not so easy to make when you don't have all the information though. How many false fire lights has everyone here had?
​​

In the absence of information, assume the worst and act accordingly.
Reminds me of one pilot that had a TR chip caution and parked it in the nearest carpark. Tourists were a bit miffed about the bus trip home and it turned out to be a false alarm.
Then there was the other guy who decided to return to base only to have the gearbox depart enroute.

You can over analyse and find reasons to justify any course of action if you try hard enough.
First priority should always be to save your ass, not to cover it.

[hoistop]

I believe this pilot did things quite right - asking to land on unknown terrain a minute away from an airport is a long shot. It seems that he, his crew and unfortunate homeowners might be let down by this:

CS 27.861 Fire protection of structure, controls, and other parts
Each part of the structure, controls, rotor mechanism, and other parts essential to a controlled landing that would be affected by powerplant fires must be fireproof or protected so they can perform their essential functions for at least 5 minutes under any foreseeable powerplant fire conditions.

Presuming this was an engine fire. (It seems that fire was coming from underneath the engine, not direcly from engine itself, but hard to say.) There is also:

CS 27.863 Flammable fluid fire protection
(a) In each area where flammable fluids or vapours might escape by leakage of a fluid system, there must be means to minimise the probability of ignition of the fluids and vapours, and the resultant hazards if ignition does occur.
(b) ....

This will be interesting to follow, when relatives and their attorneys will try to blame manufacturer to get millions $.

[lelebebbel]

In the absence of information, assume the worst and act accordingly.
Reminds me of one pilot that had a TR chip caution and parked it in the nearest carpark. Tourists were a bit miffed about the bus trip home and it turned out to be a false alarm.
Then there was the other guy who decided to return to base only to have the gearbox depart enroute.

You can over analyse and find reasons to justify any course of action if you try hard enough.
First priority should always be to save your ass, not to cover it.

I'm not talking about covering your ass. Making an unplanned, rapid emergency landing in a populated area can very well result in an accident itself. Not wanting to do that, and weighing it against the risk of flying a mile back to an airport prioritizes saving your ass just as much.

If I had assumed I was about to have a structural failure last time I had a fire light, I would have had to land in tall trees. In my case that would've been the entirely wrong call and I could've killed or hurt myself and my passengers doing so.
In this case here it was different. The failure also happened rather quickly, even though it looks like an eternity when you watch it from the comfort of home on video.
But we don't know what indications the pilot had. Hindsight, that's all.

[the coyote]

I am still convinced that he didn't know that there was a fire in the back

I'm wondering the same, as it also wasn't in the distress call it seems.

I find it hard to believe that anyone, who knows that they have an uncontained fire on board, would not elect to land immediately.

I've had 1 baggage bay and 3 engine fire warnings in my time, all of them proved to be false indications. All of them had no secondary indications, and had we continued to follow the checklist, three would have resulted in a ditching. The "confirm the fire" part of the checklist is perhaps not given the consideration it deserves, and usually offers no guidance as to what to do if you cannot confirm the fire at that time.

[NutLoose]

The sports fields at the high school would be available, but all of those other open fields in that satellite view are currently construction sites for new residential buildings according to the most recent Google Street View shots from Feb 2023.

But if it was a school day, those fields may well have been full of kids, we probably will never know.

[[email protected]]

I have no doubt that he was unaware of the fire - my point was that he may well have followed his training and delayed shutting down a failed engine until he had time to refer to the check list.

In this case that could well turn out to have been a mistake but that is with 20/20 hindsight.

[wrench1]

The initial FAA (https://www.asias.faa.gov/apex/f?p=100:96:15054457192459::::P96_ENTRY_DATE,P96_MAKE_NAME,P9 6_FATAL_FLG:29-AUG-23,EUROCOPTER) notice lists the accident as due to unknown circumstances.

[RVDT]

I have no doubt that he was unaware of the fire - my point was that he may well have followed his training and delayed shutting down a failed engine until he had time to refer to the check list.

In this case that could well turn out to have been a mistake but that is with 20/20 hindsight.

Company policy overrides the RFM procedure? Unless there is an approved supplement?


Below would be following the RFM.

Note the reference to memory items and the requirement to "perform immediately" with the grey background when it arises.

https://cimg4.ibsrv.net/gimg/pprune.org-vbulletin/1188x564/eng_fail_e9f86b3d19c7cf45d59e36e58f283b205a3c199e.png
https://cimg7.ibsrv.net/gimg/pprune.org-vbulletin/1062x322/memory_items_382ef13518cf18893713ac0714aa5de282fcd1c9.png
OEI Flight condition - Establish - means - a condition where you can operate effectively with the "normal" engine within OEI limits

Affected Engine - Identify - means - all the Captions which will be numerous in addition to instrumentation.

Single Engine Emergency Shutdown - Perform - means ENG MAIN sw - IDLE, Check indications (confirm), then OFF.


Fire in flight only has one additional item - EMER OFF switch - which closes the fuel supply valve. IF you have Engine Fire Extinguisher fitted it will automatically fire when FIRE is active, fuel valve is closed and N1 < 55% - there is no way to activate it manually.

https://cimg0.ibsrv.net/gimg/pprune.org-vbulletin/2000x962/fire_bb83654a41ad22cc41e5fba8cb1e43596c30a251.png
The extracts are from a CPDS type RFM which this particular aircraft may not have been but the items are the same.

[Bell_ringer]

The initial FAA report (https://www.asias.faa.gov/apex/f?p=100:96:15054457192459::::P96_ENTRY_DATE,P96_MAKE_NAME,P9 6_FATAL_FLG:29-AUG-23,EUROCOPTER) lists the accident as due to unknown circumstances.

It does not appear to be a report, merely a notice related to the accident occurrence.

[BFM]

I'm lucky enough to only be a pax with other talented and well-trained people. But - excuse me, a fire causing terminal structural damage in 3 minutes?

[[email protected]]

Until we know the actual cause of the fire and the actions taken, it may well be within the limits of the certification.

[FH1100 Pilot]

A lot of people are criticizing this EC135 pilot for not landing sooner. We know the pilot had an engine failure - he reported that to the Tower as his reason for returning. Once the engine quit, he had a couple of things to do (e.g. secure the engine, set OEI power, attain best OEI speed, start a turn back to the airport). A lot going on and a lot going through his mind. Sure, these things don't take forever, but they eat up seconds. And in his case, he only had seconds. (And honestly, who among us - actual pilots, that is - thinks that if we get a fire, our helicopter will come apart so quickly? That's some pretty scary ****!) A lot of people assume that he also knew that he was on fire. We do not know this...yet. But we will. Maybe it was not a catastrophic engine failure. Maybe the fire was aft of the detectors and did not set them off (which is what it looks like to me).

At PHI, when I checked out in the BO-105, we were anecdotally told of an incident in which an in-flight fire occurred, but the tail boom fell off before the guy could get it on the ground (or perhaps it was just after he landed on the water - I forget). The point was to take EVERY fire light seriously. Perform a tight turn to see if you were leaving a smoke trail, or look at your shadow on the water if you could see it...or have a pax slide the rear door open and look. Those things were all well and good, but in the summer, I'd often climb that Bolkow up to 4,500 or 5,500 feet where the air was cool, the viz was better and there was less traffic. And it would take at least a minute or two to get down, even in a screaming descent. Which brings me to my point: What if the EC135 pilot had been higher...higher to the point that he could not get it on the ground quickly enough even if he had decided to LAND IMMEDIATELY? I cannot say for sure what I would do in this very specific case, but with an engine out and that big airport right behind me, with the field boundary nearly within gliding distance, I might have just turned around and gone back too. Until we hear what this EC135 guy has to say, I'm going to give him a huge benefit of the doubt.

[megan]

That looks to me like the battery compartmentTending to think the same, if engine shrapnel had punctured the the engine deck could have allowed oil/fuel from busted lines to drain into the compartment, no engine fire indications perhaps in that case. We had a Turbomeca in a 76 disintegrate and cause oil lines to burst, caused a fire, authorities considered the design of oil lines not an airworthy installation, didn't see that idea get up though.

[Bell_ringer]

A lot of people are criticizing this EC135 pilot for not landing sooner.

There has been a fair bit of discussion on that topic, but I haven't read it as criticism.
They did the best they could, under the circumstances. Hindsight is perfect vision, we will have to wait for the detail to become public knowledge before drawing conclusions, but discussing the could-have, would-have and should-haves shouldn't be considered a negative.
It can be a very fine line between success and failure, one that may be outside of anyones control.

[wrench1]

But - excuse me, a fire causing terminal structural damage in 3 minutes?
But you have to put it into context. The process to repair a 135 tailboom requires hot bond temperatures of about 125 C. The T1 fire detectors actuate at 210 C - 270 C. Composite structural strength becomes compromised starting around 300 C. And any fuel/oil fire will burn at a much higher temperature. Given the use of heat resistant composites (800+ C) is regulated to areas that may see high heat or fire like an engine bay, the rest of the structures use various standard methods. For reference, most aluminum structures begin to structurally degrade at 600+C.

[haihio]

Company policy overrides the RFM procedure? Unless there is an approved supplement?


Below would be following the RFM.

Note the reference to memory items and the requirement to "perform immediately" with the grey background when it arises.

https://cimg4.ibsrv.net/gimg/pprune.org-vbulletin/1188x564/eng_fail_e9f86b3d19c7cf45d59e36e58f283b205a3c199e.png
https://cimg7.ibsrv.net/gimg/pprune.org-vbulletin/1062x322/memory_items_382ef13518cf18893713ac0714aa5de282fcd1c9.png
OEI Flight condition - Establish - means - a condition where you can operate effectively with the "normal" engine within OEI limits

Affected Engine - Identify - means - all the Captions which will be numerous in addition to instrumentation.

Single Engine Emergency Shutdown - Perform - means ENG MAIN sw - IDLE, Check indications (confirm), then OFF.


Fire in flight only has one additional item - EMER OFF switch - which closes the fuel supply valve. IF you have Engine Fire Extinguisher fitted it will automatically fire when FIRE is active, fuel valve is closed and N1 < 55% - there is no way to activate it manually.

https://cimg0.ibsrv.net/gimg/pprune.org-vbulletin/2000x962/fire_bb83654a41ad22cc41e5fba8cb1e43596c30a251.png
The extracts are from a CPDS type RFM which this particular aircraft may not have been but the items are the same.


One minor inaccuracy is the N1 has to be < 50% for the fire bottle to go off.

[wrench1]

Interesting side discussion (https://www.nbcmiami.com/news/local/after-deadly-crash-bso-sheriff-says-new-air-rescue-helicopters-are-on-the-way/3101434/). I wonder if this was a Public Use ops and who was overseeing the "piece-mealing" of parts and maintenance?

As the agency mourns Monday's fatal crash of its air rescue helicopter (https://www.nbcmiami.com/news/local/2-killed-4-injured-after-bso-fire-rescue-helicopter-crashes-in-pompano-beach/3099973/), Sheriff Gregory Tony says it’s time for action. He said he met with the county’s mayor and assistant administrator Tuesday, and was assured the county would provide funding for two new helicopters.

​​​​​​​“Fire rescue helicopter that we’re utilizing has been around since 1999, we’ve been piece-mealing parts for years to maintain the flight capability,” Tony said at that meeting.

​​​​​​​“Listening back to my statements from June,” the sheriff said Tuesday, “You probably heard more of an awareness tone of, 'hey, we need to get this done,' because eventually the aircraft are not gonna be capable of flying and the risk factor of one falling out of the sky was too great, and now it’s happened.”

[[email protected]]

There's no reason you can't keep a 24 year old helicopter flying safely for many more years unless you fail to invest in maintenance and parts at the right time - it rather looks like that is where the investigation may have to do some digging.

They have sadly just learned the reason for the old saying 'If you think safety is expensive, try having a crash'.

[alfaman]

One question I had is if it was on fire that close to the airport wonder why the tower wouldn't have seen it ??
Because the fire is at the rear, & the aircraft is flying towards the airport, perhaps? At that distance, chances are a human will see a small back dot getting closer, perhaps trailing smoke. That's discounting any buildings obstructing the view.

[skadi]

At that distance, chances are a human will see a small back dot getting closer, perhaps trailing smoke.

The farthest distance from the tower was 1,3 nautical miles, thats pretty close

skadi

[DOUBLE BOGEY]

Given the short flight time, fire trailing and persistent and the pilot reporting and engine failure.....maybe a turbine burst (looking like engine failure with zero Tq/Nf), That savages the tail boom flange area with shrapnel. Meanwhile the Gas Generator is still working and the FADEC response to Zero NF is to open the fuel to max chat. The fire escaping from the compromised combustion chamber finishes the job. I have no idea why the pilot did not have a fire warning or if he missed this in the mix of confusing indications.

With an engine fully failed (ie all parts stop rotating) the fuel pressure becomes zero everywhere in that firewall box and the chances of a persistent fire almost zero. Maybe!

DB

[whoknows idont]

I have no idea why the pilot did not have a fire warning or if he missed this in the mix of confusing indications.

Unfortunately it's very easy to miss the fire indication on the EC135. All you get is one gong and the light on the guarded switch, that's it.

https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/883x114/warning_panel_5c82a405a515ddefd96a5c9570d42e8db4742561.png

[haihio]

Unfortunately it's very easy to miss the fire indication on the EC135. All you get is one gong and the light on the guarded switch, that's it.

https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/883x114/warning_panel_5c82a405a515ddefd96a5c9570d42e8db4742561.png


There’s an intermittent sound, Eurocopter-Airbus call it a bell for the Fire Warning.
There isn’t a gong.

[gipsymagpie]

Given the short flight time, fire trailing and persistent and the pilot reporting and engine failure.....maybe a turbine burst (looking like engine failure with zero Tq/Nf), That savages the tail boom flange area with shrapnel. Meanwhile the Gas Generator is still working and the FADEC response to Zero NF is to open the fuel to max chat. The fire escaping from the compromised combustion chamber finishes the job. I have no idea why the pilot did not have a fire warning or if he missed this in the mix of confusing indications.

With an engine fully failed (ie all parts stop rotating) the fuel pressure becomes zero everywhere in that firewall box and the chances of a persistent fire almost zero. Maybe!

DB
Worth noting that for the T1, the engine overspeed protection system was optional so if he did suffer a fault which led to a runaway up, the engine may not have automatically shutdown (and event which has happened on a T1 albeit during start when the pilot started before the FADEC had fully booted).
​​​​​​
As mentioned before, all 3 occasions in the ASN history of EC135 incidents where there has been an in flight engine fire have all been after engine overspeed events (all on P1 thus far due to inadvertant entry into manual).
​​​​

[alfaman]

The farthest distance from the tower was 1,3 nautical miles, thats pretty close

skadi
Have you ever tried it professionally? It's nowhere near as simple as just the distance. For starters, the tower would seem to be lower than some of the buildings surrounding the airport, which won't help. Many factors influence how well an object stands out against the background, I doubt the controller would have seen the fire & decided not to say anything.

[LTP90]

Interesting side discussion (https://www.nbcmiami.com/news/local/after-deadly-crash-bso-sheriff-says-new-air-rescue-helicopters-are-on-the-way/3101434/). I wonder if this was a Public Use ops and who was overseeing the "piece-mealing" of parts and maintenance?
That sounds like politics to me. I don't know anything about their program or the history. But reading between the lines, the sheriff has probably been pushing for more funding, and maybe not just for helicopters. Politicians never waste an opportunity, especially a highly visible tragedy to get what they want. It's also of note that airbus just happens to have 2 helicopters on their hands that someone else backed out of, that I'm sure they want to unload. I'm sure they are in the same boat of not letting any tragedy go wasted.

[helispotter]

This was a HEMS machine so no baggage compartment. No problem, especially for the CabinCrew, to look aft through the whole cabin. As seen on the videos the fire took place in the aft section of engine bay or even battery/Aircondition compartment. Fire is seen on both sides of the fuselage on different videos.

skadi

A few posts have discussed location of the fire. It struck me looking at the video clips that fire seemed to extend down to well below the height of the underside of the tailboom, perhaps to the clamshell doors? Two extracts from video here, showing both sides prior to the tailboom failure:

https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/113x60/broward_county_ec135_fire_2_cropped_464084d3ad3b7e3cd16d4580 5a279a08a7a632c8.jpg https://cimg2.ibsrv.net/gimg/pprune.org-vbulletin/315x167/broward_county_ec135_fire_1e18817cf5425e375400cc0ed7f70e0cad ae4bf4.jpg

Here are a few images from the internet showing the engine bay and how, if there was a fuel line failure, fuel could flow to quite low down in that bay, and probably aft once it caught hold. But fire seemed to have spread beyond that area if indeed that was the origin:
https://cimg7.ibsrv.net/gimg/pprune.org-vbulletin/594x230/ec135t1_sn_034_nweb_cropped_lr_d2dcbb1510f0ec5d9d95dad5d2b17 17c9e025e74.jpg

https://cimg8.ibsrv.net/gimg/pprune.org-vbulletin/800x533/eurocopter_ec_135_p2_oh_hco_tour_de_sky_2014_08_10_06_lr_e6f f52596b3dc38cb0951fb68b8f8a508c827ed6.jpg

Sadly, the footage is a demonstration that lightweight structures desirable for efficient rotorcraft don't equate to prolonged fire resistance.

[[email protected]]

It looks to me like that sloping area at the back of the engine bay is a perfect place for fuel/oil/etc to pool and would give the impression the fire is lower than the engine

[Bell_ringer]

Here are a few images from the internet showing the engine bay and how, if there was a fuel line failure, fuel could flow to quite low down in that bay, and probably aft once it caught hold. .

Presumably she would be much more level, or nose down in forward flight, than standing on the apron.

[wrench1]

A few posts have discussed location of the fire. It struck me looking at the video clips that fire seemed to extend down to well below the height of the underside of the tailboom, perhaps to the clamshell doors?
I can’t get the pic to post, but this link is a 135 with Arrius engines (https://www.safety4flight.com/en/images/2015-09-16-09.52.06.jpg) and most the firewalls removed. The area between the engines is the common intake duct which is open to the xsmn deck and somewhat sealed on the aft end. Any fire in this duct area or outside the firewalls would not be detected.The question is IF he had a fire light, one would think he would have told the tower he was possibly on fire and to roll the equipment. At a minimum one would think when he called his fire dispatch people to tell them he couldn’t make the scene call he would have asked them to roll some units or at least call the airport to request same.

But if he had a fire outside the engine bays he probably wouldn’t know unless he looked for smoke. And IMO if it was a fuel fire this would have ended earlier and been trailing darker smoke. Unfortunately they didn’t have the clam shell door window mod installed as it may have resulted in a different ending.
Sadly, the footage is a demonstration that lightweight structures desirable for efficient rotorcraft don't equate to prolonged fire resistance.
Light structures can be fire resistant. The light weight 135 engine cowls are made from high temp composites and I believe are rated for 800+C. However, components that reside outside known fire or heat areas are usually made from standard composites.

That sounds like politics to me. .
Definitely politics. And if this was a Public Use ops with no FAA oversight then politics also influenced how the aircraft was maintained and operated. Especially with the Sheriff’s comments above. Time will definitely tell.

[skadi]

It looks to me like that sloping area at the back of the engine bay is a perfect place for fuel/oil/etc to pool and would give the impression the fire is lower than the engine

Not when the drain holes are not clogged. Having washed the engine bay floor many times and if the drain is clear water could easily leave the bay through the lines. When clogged any fluid will leave the bay at the lower edge to the outside

skadi

[SLFMS]

I’m not convinced decision based off if he knew he was on fire or not is valid based off the radio calls or not landing immediately.

Aviate Navigate Communicate.

He had made an emergency call and been given priority landing.
Further com’s on fire update would not have changed any response from the tower. They still press the big red button. I guarantee it would have initiated more coms back from the tower when he had his hands full.

less than 1 minute from the initial problem, definitely still trouble shooting and resolving. If I was in that position, updating the tower would have been low priority unless needing the tower to confirm it.

[FH1100 Pilot]

I see a lot of criticism of this BSO pilot on social media and YouTube. Everybody simply assumes that he screwed-up by not pulling the good engine off and autorotating into a schoolyard. The internet is chock-full of experts.

But the Big Question...the one we do not yet have the answer...is whether the EC135 pilot knew he was on fire? All he told the Tower was that he'd had an engine failure. Unless the fire had breached the cabin (which I doubt), I'd bet that those people onboard had their eyes focused forward - if there was no fire warning indication, there would have been no reason to look rearward. But would it have mattered? We do know that he was only about a mile away from the Pompano Beach Airport field boundary when he began his turn back - about a minute away at 60 knots. So even if he did know that he was on fire, would a "LAND IMMEDIATELY" situation have made a difference? Just how "immediately" is immediately when you have an airport with fire/rescue a minute away and you're busy dealing with a problem (engine failure)? Had he been at 5,000 feet instead of 500 feet, how "immediately" could he have gotten it on the ground?

Which, to me, brings up a bigger question: Should that pilot have expected that his aircraft would fail so catastrophically and so quickly? How come we're not pointing fingers at Airbus for their plastic, junky airframes?

[rotorrookie]

I see a lot of criticism of this BSO pilot on social media and YouTube. Everybody simply assumes that he screwed-up by not pulling the good engine off and autorotating into a schoolyard. The internet is chock-full of experts.

But the Big Question...the one we do not yet have the answer...is whether the EC135 pilot knew he was on fire? All he told the Tower was that he'd had an engine failure. Unless the fire had breached the cabin (which I doubt), I'd bet that those people onboard had their eyes focused forward - if there was no fire warning indication, there would have been no reason to look rearward. But would it have mattered? We do know that he was only about a mile away from the Pompano Beach Airport field boundary when he began his turn back - about a minute away at 60 knots. So even if he did know that he was on fire, would a "LAND IMMEDIATELY" situation have made a difference? Just how "immediately" is immediately when you have an airport with fire/rescue a minute away and you're busy dealing with a problem (engine failure)? Had he been at 5,000 feet instead of 500 feet, how "immediately" could he have gotten it on the ground?

Which, to me, brings up a bigger question: Should that pilot have expected that his aircraft would fail so catastrophically and so quickly? How come we're not pointing fingers at Airbus for their plastic, junky airframes?
Being this close to an airport or "safe landing spot" is probably the double edge sword here.
I think we would all try to make it back to an airfield were you have emergency service ready and being only 1 mile out vs landing in highly populated area during midday traffic, even if it was confirmed fire.
But we would also in our heads expect the airframe to withstand fire for 1 or 2 min.

[60FltMech]

To add another speculative angle, how long was the aircraft running on the ground or taxiing for departure? Maybe the fire was burning longer than we all think.

Again, pure speculation but would be interesting when the final chain of events is announced.

I try to take everything in when doing final checks on my side of the aircraft (exterior) before getting in, like am I taking everything in or just glancing it over. I would hope a fire would be readily detected but would depend on where it started I suppose.

Just one more thing to make you think about what you’re doing. At least I’m fairly confident primary structure in my airframe will last longer than a few minutes in the unfortunate case of fire, still rather not experience it!

FltMech

[roscoe1]

Civil versus public use is a non issue. Any agency that has a certificated aircraft most likley flies both civil ops. and PAOs. It is the mission, not the agency or the aircraft that determines if a particular flight is public or civil; as long as the aircraft has a non-restricted type certificate, like the EC 135. If they ever fly non-required crew members, dignitaries or anyone who would be designated a passenger they are conductiing civil operations and must adhere to at least part 91 maintenance guidelines. Any agency not doing so woild be foolish indeed if a savy laywer gets involved.

[DOUBLE BOGEY]

I don't believe we should start blaming the airframe. If this was a turbine casing breach/overspeed event, that's not assumed in the certification. Hence O/S protection and no turbine containment device for the shrapnel.

I also recall 2 pilots in Aberdeen suffering a high pressure fuel fire in the AS332 Engine bay shortly after taking off on a test flight. The reacted promptly, the fire extinguished 6 seconds after the warning activated, if my memory has served me well! They completed the circuit they started and upon landing, were horrified at the extent of the damage.

If my memory can be relied on a bit further, I recall the Norwegian AS332L1 suffering an engine overspeed that resulted in the turbine bursting. That one took out the MR Hydraulics and fired shrapnel into the occupants. The resulting conflagration did not permit time for a fire to become the salient point. Loss of control and impact the the sea finished the job sadly for all of the occupants.

I am surprised nothing has been released thus far seeing as the Pilot survived the event. The initial sequence and cause of the fire need to be identified quickly enough for the rest of us operating/flying the type to understand how we can mitigate.

Ultimately, we bear in mind aluminum is a bit like butter in a microwave when subjected to fire and the composites are stuffed full of things that will burn nicely. Fire sucks. It always has I think if we consider every serious fire event, Concorde etc.

DB

[wrench1]

At least I’m fairly confident primary structure in my airframe will last longer than a few minutes in the unfortunate case of fire, still rather not experience it!
I guess it all depends on how you view it. Off the top I can remember one incident where the primary flight control support was compromised by fire on an S-92. Luckily it was on the ground, but the post fire review indicated had it been in flight it would have had about the same time frame as the EC above before control would have been lost. Ironically if it had been in flight it was outside the fire detection areas and doubtful the crew would have known. I still don’t think the EC crew knew they were on fire. And we still don’t know what the engine failure was and even if he shutdown the engine or merely put it in idle. Given after he radioed the tower he took the time to radio his department comm center that he couldn’t make the scene gives the impression there was no urgency. I can recall several past instances where an aircraft was on fire and the pilot was not aware. Regardless, since the accident has finally been posted in the NTSB database the preliminary should be close to release.
must adhere to at least part 91 maintenance guidelines. Any agency not doing so woild be foolish indeed if a savy laywer gets involved.
For a private entity I would agree as they might fly a Part 135, Part 91, and PAO flight all in the same day. However, for a public entity with no regulatory oversight and minimal requirements not so much. A privately owned Cessna 172 flown only on Sundays has more FAA oversight and regulatory requirements than a PAO EC135. And unfortunately there are “foolish” ops out there, especially small flight departments with tight budgets. Whether this is the case with this department has yet to be seen.

Hence O/S protection and no turbine containment device for the shrapnel.
FYI: I believe all Arrius have integral turbine containment shields. But not all have O/S protection.

[roscoe1]

For a private entity I would agree as they might fly a Part 135, Part 91, and PAO flight all in the same day. However, for a public entity with no regulatory oversight and minimal requirements not so much. A privately owned Cessna 172 flown only on Sundays has more FAA oversight and regulatory requirements than a PAO EC135. And unfortunately there are “foolish” ops out there, especially small flight departments with tight budgets. Whether this is the case with this department has yet to be seen.

The agency being public has naught to do with it. If they are flying civil missions the FAA has jurisdiction over them, their pilots must be appropriately rated and part 91 is the rule. That many people don't understand this is because the FAA on a local level has traditionally left them alone in part out of their own ignorance and because they must simply feel they have better things to do. Right or wrong. Ref. AC 00-1.1B. Also, there have been almost no cases of an agency flying a civil mission that ended tragically that they claimed was a PAO. So little opportunity for ambulance chasing lawyers to do their thing. They can fly dopes on a rope tied to the skid in the morning but when they fly a local or state official or a reporter to show how cool the helicopter is, they should be in compliance with part 91 at the minimum.

[brogul]

I see a lot of criticism of this BSO pilot on social media and YouTube. Everybody simply assumes that he screwed-up by not pulling the good engine off and autorotating into a schoolyard. The internet is chock-full of experts.

Which, to me, brings up a bigger question: Should that pilot have expected that his aircraft would fail so catastrophically and so quickly? How come we're not pointing fingers at Airbus for their plastic, junky airframes?

I agree that it is probably unwarranted and certainly premature to criticize the pilot's decisions here. But that is a separate issue from the general lesson regarding the urgency of an immediate landing when there is a fire. Dropping straight down into a median or park has its risks, going back to an airport that is only a mile away (which would seem a safe bet most days) also has risks. Even if the pilot knew how bad the fire was and had opted to simply drop out of the sky, we don't know if he could have selected a site and gotten down to it in time. It doesn't matter much what you are flying, if your airframe disintegrates 60 seconds after your first indication of a problem, that's a pretty rough day.

[SilsoeSid]

Proud of you ! Where should I send the ' you're a special guy ' card to ?

Considering my reply was in response to your comment on one of my posts, your statement being… Lots of input from expertise from folk who've never been thrown the keys and flown the damn thing. a simple ‘fair enough’ would have sufficed, but once again you’ve shown your true character.
Good day.

[wrench1]

That many people don't understand this is because the FAA on a local level has traditionally left them alone in part out of their own ignorance and because they must simply feel they have better things to do. Right or wrong..
Exactly my point when it comes to oversight. And in my experience on the mx side with PAO, its only the public entities that enjoy such traditions.

[SASless]

Start your clock.....at the time the Pilot is first aware of any kind of problem then check the time at which he notifies Tower of a problem....then check the time at which the aircraft begins a left turn to begin its return to airport (which is not far away at all)....consider the aircraft is flying fine on the remaining engine....check the time at which the aircraft is pointed back at the airport for Runway 06.

Consider the open areas available to the. pilot tend to be about 300-400 feet long and surrounded by wires....the highways are busy with traffic....city streets are a maze of wires and trees....and the runway beckons so close. What would you really do....especially if you were not aware of a fire that was going to cause the tail boom to fail and cause a catstrophic failure of control? In the meanwhile....trouble shoot the failure(s) and indications, brief your passengers, notify the Tower, carry out emergency procedures.....oh and fly the aircraft and devise a plan to cope with it all.

Now stop the Clock where the tail boom failure occurred.

Who would have the ability to even think the tail boom might fail?

Sometimes no matter how good we are it is still not good enough when the unthinkable happens.

We saw something similar in the Accident Report of the Stadium crash that resulted from a mechanical failure that made control of the aircraft impossible.

Fate hunts us all.

My condolences to the families, friends, co-workers of those lost in this tragedy.

[wrench1]

Prelim released. It also stated the aircraft was operated under Part 135.
https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/192950/pdf

During an interview, the pilot reported that the helicopter was dispatched to transport a patient from the scene of an automobile accident. During initial climb, west of Pompano Beach Airpark (PMP), Pompano Beach, Florida, about 300 to 400 ft above ground level, the pilot heard a “bang” from the rear of the helicopter and noticed that the turbine outlet temperature (TOT) was rising on the No. 1 engine. He set the No.1 engine throttle to idle, declared an emergency to air traffic control, and reversed direction to return to the airport. He scanned the cockpit instrument panel and noticed that the No.1 engine fire button had illuminated. He pressed the button to activate the fire suppression system; however, the TOT continued to rise on the No. 1 engine. The pilot subsequently heard a second “bang,” and was unable to control the helicopter. It spun and descended into an apartment building.

[SLFMS]

Start your clock.....at the time the Pilot is first aware of any kind of problem then check the time at which he notifies Tower of a problem....then check the time at which the aircraft begins a left turn to begin its return to airport (which is not far away at all)....consider the aircraft is flying fine on the remaining engine....check the time at which the aircraft is pointed back at the airport for Runway 06.

Consider the open areas available to the. pilot tend to be about 300-400 feet long and surrounded by wires....the highways are busy with traffic....city streets are a maze of wires and trees....and the runway beckons so close. What would you really do....especially if you were not aware of a fire that was going to cause the tail boom to fail and cause a catstrophic failure of control? In the meanwhile....trouble shoot the failure(s) and indications, brief your passengers, notify the Tower, carry out emergency procedures.....oh and fly the aircraft and devise a plan to cope with it all.

Now stop the Clock where the tail boom failure occurred.

Who would have the ability to even think the tail boom might fail?

Sometimes no matter how good we are it is still not good enough when the unthinkable happens.

We saw something similar in the Accident Report of the Stadium crash that resulted from a mechanical failure that made control of the aircraft impossible.

Fate hunts us all.

My condolences to the families, friends, co-workers of those lost in this tragedy.


Good post SASless

[[email protected]]

A question for those familiar with the aircraft - does initiating the fire suppression also shut down the engine?

He put the bad engine to idle but didn't shut it down before activating the fire bottle.

Is there an eductor fan that would blow the suppressant out of the engine bay while the engine is still running?

[lelebebbel]

A question for those familiar with the aircraft - does initiating the fire suppression also shut down the engine?

He put the bad engine to idle but didn't shut it down before activating the fire bottle.

Is there an eductor fan that would blow the suppressant out of the engine bay while the engine is still running?

Someone posted the relevant part of the flight manual here earlier I believe. In short, yes, hitting the button will cut the fuel. Also, the fire supression is smart enough to delay the bottle (if fitted!) until N1 has dropped.

[TeeS]

Hi Crab
As lelebebbel says, the EMER OFF SW / FIRE Button closes the fuel valve but this is located just above the fuel tanks so there is a reasonable amount of left in the fuel lines between the valve and the engine. This takes some time to burn off and for the engine to run down (I would guess about seven seconds, maybe longer at idle). The idea, I assume, is to burn as much fuel inside the engine rather than allowing it to feed an engine bay fire, once the engine runs down, the extinguisher will automatically fire if there is still a fire indicated.
There is no fan.
Cheers
TeeS

[whoknows idont]

Actually the procedure is to hit the EMER OFF sw immediately followed by a single engine emergency shutdown. Not to let the engine run until the fuel in the line is depleted.

[[email protected]]

Thanks guys, I think we can assume therefore that there was some delay between selecting the engine to idle (as a reaction to high TOT and the bang) and then pressing the fire button or it wouldn't have kept burning.

Selecting an engine to idle would normally be a precursor to selecting shutoff, just to make sure you have got the correct engine - wouldn't most pilots have then shut it down quickly given the explosive nature of the failure?

[TeeS]

Actually the procedure is to hit the EMER OFF sw immediately followed by a single engine emergency shutdown. Not to let the engine run until the fuel in the line is depleted.

Thanks whoknows idont: Quite true, I meandered into my usual description of why I think Eurocopter/Airbus tells us to close the fuel valve and arm the fire extinguisher before shutting down the engine, rather than shutting down the engine and then shutting the fuel valve. Quite agree, there is no delay shown in the drills and I have never taught a delay in shutting the engine down after pressing the emergency off switch but I do recommend running your hand down the CAD indications of Fuel Valve Posn/Fuel Valve Closed indications to lead your hand to the correct engine control switch.

Cheers
TeeS

[212man]

The idea, I assume, is to burn as much fuel inside the engine rather than allowing it to feed an engine bay fire, once the engine runs down,
Nothing as complex as that, I'm sure. Fuel valves are part of the airframe fuel system and inevitably are a long way upstream of the HP Engine fuel pumps. Their primary purpose is not emergency engine shutdown.

[whoknows idont]

Selecting an engine to idle would normally be a precursor to selecting shutoff, just to make sure you have got the correct engine - wouldn't most pilots have then shut it down quickly given the explosive nature of the failure?

Yes, the single engine emergency shutdown goes IDLE, check indications, then OFF.

[wrench1]

Just to add, ground idle is about 70% N1 and it takes less than 50% N1 for the fire bottle to actuate. If the gas turbine was still turning above 50% then the bottle would not fire. The emergency switch would only close the fuel shutoff valve in that scenario. And the fuel valve is located about 1 foot below the engine deck on the sidewall next to the aft incline frame where the clam shell hinges are mounted.

[Bo Darville]

Taken from the report
He pressed the button to activate the fire suppression system

This would suggest the aircraft was fitted with a fire system.

The pilot subsequently heard a second “bang,” and was unable to control the
helicopter.

Reading this one does assume these two events were together and the bang was the tail boom failing. It could have of course been the squib firing (he would have heard it in flight, I know this) had the engine gone below 50%N1 and the boom failing simultaneously or very shortly after.

Of course by this time either way no fire bottle could have made a difference as the fire had apparently spread outside off the engine bay.

[[email protected]]

Yes, the single engine emergency shutdown goes IDLE, check indications, then OFF.

Thanks whoknows - is that a from memory item in the QRH emerg section?

[RVDT]

Thanks whoknows - is that a from memory item in the QRH emerg section?

Post #106 - it is a memory item from the RFM.

[whoknows idont]

Yes, as posted by RVDT the memory items are bold on grey background.

https://cimg8.ibsrv.net/gimg/pprune.org-vbulletin/708x1104/1_e3d8fed76bcff6e057c3ee0ed85c845dcdbe956e.png

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https://cimg9.ibsrv.net/gimg/pprune.org-vbulletin/724x846/2_0a0273e629c6241f6e56afae3fa2f4cb25d6e0e4.png

[EXDAC]

Perhaps fixed wing pilots are not intended to understand this but I'll ask anyway - what is the difference between "land as soon as possible" and " land immediately"? To this simple engineeer and fixed wing pilot "land as soon as possible" means that it would not be possible to land any sooner. How can "immediately" be any sooner or more urgent?

[Nescafe]

‘Land as soon as possible’ means to proceed to the nearest area that a safe landing can be made. That could involve continued flight to a clearing or airfield.

‘Land immediately’ means exactly that, you put it down straight away, accepting that continued flight may be riskier than landing say in a wooded area or ditching in water.

These scenarios are where a captain earns their corn.

[SASless]

During an interview, the pilot reported that the helicopter was dispatched to transport a patient from the scene of an automobile accident. During initial climb, west of Pompano Beach Airpark (PMP), Pompano Beach, Florida, about 300 to 400 ft above ground level, the pilot heard a “bang” from the rear of the helicopter and noticed that the turbine outlet temperature (TOT) was rising on the No. 1 engine. He set the No.1 engine throttle to idle, declared an emergency to air traffic control, and reversed direction to return to the airport. He scanned the cockpit instrument panel and noticed that the No.1 engine fire button had illuminated. He pressed the button to activate the fire suppression system; however, the TOT continued to rise on the No. 1 engine. The pilot subsequently heard a second “bang,” and was unable to control the helicopter. It spun and descended into an apartment building.

Taken from the Preliminary Report posted earlier by someone.

The interview closely followed the Pilot being involved in a horrific event that resulted in two people being killed as a result of a violent and tragic experience.

A quick visit to Google Earth and using their measuring stick it appears the aircraft at most was one and a half statute miles (or there about ) from the approach end of Runway 06 which he was trying to return to for an emergency landing.

For sure he was a very busy fellow coping with the situation he was confronted with and I view his quoted statement as being something that will be amended in due time as the investigation progresses and he has a better recollection of events than he probably did at the time of the interview.

I find it quite understandable why he would have elected to return to the airfield as by the time the true extent of the problem was determined......the airfield was close in front of the aircraft and probably only about minute or less away.

One of the things we have to wait for is for the Investigation to determine the sequence of actions that were taken and what effect they could have had on the outcome and whether fire damage prevented then from working as designed.

If we look back to the Louisiana accident where the 139 had the electrical fire that badly interfered with the flight controls of that aircraft we might also see that unanticipated damage can occur due to a fire......such as the tailbone failing in flight,.

All emergencies do not fall nicely into a printed checklist and not all emergencies are in a checklist.

The question that arises is what do you do when the checklist and symptoms do not agree?

Wires melt, electronics fail to work, odd things happen.

Basic actions set forth in checklists are there for guidance but you have to consider that they might not be effective for some reason.

Until the cause of the fire, its location, and extent of damage to the aircraf systems and structure, it shall be impossible to know what the situation really was at the time.

​​​​​​​

[[email protected]]

I don't think anyone has an issue with him returning to the field with what ostensibly looks like an engine failure (albeit an explosive one).

It seems that he didn't shut the engine down - just set it to idle - and then subsequently noticed the fire and banged off the bottle. Although it seems the idle N1 would be too high to allow the bottle to discharge.

Elements of the tail boom/TRDS could have been damaged by the engine trashing itself and it might have failed anyway but why didn't he shut the engine down completely?

If he had put it to idle, checked the indications (he said he did this) and then completed emergency shutdown - we probably wouldn't be discussing this as the fire would hopefully have gone out and he would have made a safe OEI landing at the field.

One of the videos shows he flew for over a minute before the tail boom failed - more than enough time to secure the engine properly.

[whoknows idont]

the pilot heard a “bang” from the rear of the helicopter and noticed that the turbine outlet temperature (TOT) was rising on the No. 1 engine

Does not sound like a textbook engine failure?

[zaq]

Would initial diagnosis have been compressor stall - bang, rising TOT? No cause for alarm, not an emergency. Change/reduce power setting, try idle for a while, see if it fixes?<br />Subsequent Fire warning changes diagnosis and heart rate.

[[email protected]]

Does not sound like a textbook engine failure? No, so why would he treat it like one?

Zaq - ​​​​​​​Comp stall is usually more than one bang.

[SASless]

If one runs with the un-contained catastrophic engine failure causing a high and increasing TOT.....what would you expect the N1/NG to be?

Would moving the ECL to Idle have any effect?

Compressor stall would probably show fluctuations in both TOT and N1/Ng rather than just an increase in TOT (which I take the Pilot was describing....TOT going one direction....up, hot, and staying hot.)

Is compressor stall more commonly a problem during power increases or very high power demand and relatively rare in steady state flight?

Are some of you assuming the account by the pilot in the Preliminary Report a full detailed account of this actions which it most likely is not?

In time we shall be able to compare the Final Report to the Preliminary Report and confirm what the Pilot actions actually were.

One can apply Text Book reactions to Text Book events but if One is encountering a non-textbook failure you might just be making a mistake.

If this was an un-contained compressor failure and there was "shrapnel" damage to fuel lines/feul valves/ fire suppression system or the control systems for them.....it very well was not a text book situation.

That is was anything but textbook is a possiblilty that cannot be discounted.

One thing we can all agree is this was a very unusual occurrence partly because we have both video recordings of the event from "witnesses" and the Pilot who can offer very useful and pertinent information.

Querying the pilot's actions based upon the preliminary report is fair but should consider that it might not be the full accounting of all of his actions.

One explanation of why the Fire. Suppression system may not. have functioned based upon the failed Engine's N1/Ng makes good sense and asking what position the ECL should have been in is also a fair question.

[gipsymagpie]

If one runs with the un-contained catastrophic engine failure causing a high and increasing TOT.....what would you expect the N1/NG to be?

Would moving the ECL to Idle have any effect?

Now that causes me to remember another accident where there are a lot of parallels. It was an EC145 (same cockpit with CPDS) but different engines. There were two incidents where an oil pipe got blocked by coking (insufficient cool down post flight) and oil was starved from a rear bearing on the engine. The bearing temperature went through the roof from friction and one symptom was a TOT rise without any appreciable change in either N1 or torque. The first incident resulted in an engine fire (first parallel) (see here - EC145 has seized bearing leading to engine fire (http://aviation-safety.net/wikibase/194270). The second resulted in an engine failure (see here Loss of EC145 following loss of oil and rapidly rising TOT (https://aerossurance.com/safety-management/amc-bk117-ec145-hems-psmicr-hf/)) - it was significantly made worse because the pilot shut down the wrong engine.

The EC135 FLI on the CPDS is uniquely misleading if you have a runaway TOT and you bring the "good" engine back to idle - it looks like you've done the right thing (the extreme TOT AEO is suddenly not so extreme OEI). You have now loaded up the bad engine and it fails. Very easy to demonstrate on a EC135 simulator.

So I think a blocked oil pipe and seized bearing is a possible culprit (or an uncontained runaway up - although the pilot would almost certainly have commented on this).

[212man]

The EC135 FLI on the CPDS is uniquely misleading if you have a runaway TOT and you bring the "good" engine back to idle - it looks like you've done the right thing (the extreme TOT AEO is suddenly not so extreme OEI). You have now loaded up the bad engine and it fails. Very easy to demonstrate on a EC135 simulator.

Why would you have retarded the good engine?

[SASless]

How would you determine which engine to retard or shut down based upon the indications seen on the gauges?


What would be the indications?


How would you quickly determine what was going wrong?


Ball is in your court 212man!

[helichris]

The FLI screen would have switched from torque to TOT when the bad engine got hot. The pilot may thought he was still looking at torque which made him think the hot engine had picked up the load and then shut down the good engine. The only indication would be a retangle next to whatever engine parameter the gauge is reading (the first limit). There were probably secondary indications on the CAD and warning panel but not sure. Good lesson to not to get in a rush when things go to hell.

[RVDT]

The EC135 FLI on the CPDS is uniquely misleading if you have a runaway TOT and you bring the "good" engine back to idle - it looks like you've done the right thing (the extreme TOT AEO is suddenly not so extreme OEI). You have now loaded up the bad engine and it fails. Very easy to demonstrate on a EC135 simulator.

Correct and that's why training / understanding the FLI is essential and simulation is worth it's weight in gold. Reading the digital values is the key. Ng - Q - TOT and where the rectangle is adjacent to plus there is a coloured underline when in yellow or red range which will flash as appropriate.

Why would you have retarded the good engine?

Split FLI needles? "Usually" the one indicating higher is assumed to be the good one?

The other "classic" in the sim is - engine failure - FIRE indication on the remaining good engine - watch how many reach up to push the FIRE button without hesitation or thinking through the consequences and planning things a little better.

[helithree]

Years ago in Hungary a HEMS 135 crashed because pilot had an engine failure and shut down the working engine by mistake. No survivors.
I haven't flown 135 or similar, but with russian machines you see pretty quickly and clearly which engine is the one to shut down.

I'd like to see the VEMD and gauges as one engine fails in a 135, anyone have a video?

[[email protected]]

The pilot says he saw high TOT on No1 and that was the one he brought to idle. No suggestion of shutting down the wrong engine - just of not shutting down the failed engine.

[DOUBLE BOGEY]

[[email protected];11500100]I don't think anyone has an issue with him returning to the field with what ostensibly looks like an engine failure (albeit an explosive one).

It seems that he didn't shut the engine down - just set it to idle - and then subsequently noticed the fire and banged off the bottle. Although it seems the idle N1 would be too high to allow the bottle to discharge.

Elements of the tail boom/TRDS could have been damaged by the engine trashing itself and it might have failed anyway but why didn't he shut the engine down completely?

If he had put it to idle, checked the indications (he said he did this) and then completed emergency shutdown - we probably wouldn't be discussing this as the fire would hopefully have gone out and he would have made a safe OEI landing

crab, I can put this to bed early. Idle provides around 70% N1. Pressing the Emergency fir burrow on the CwP shuts down the engine by closing the fuel valve. After that, IF the fire warning is active, (the pilot states Yes) then the fire bottle should discharge when N1 drops below 50%.

[LTP90]

After that, IF the fire warning is active, (the pilot states Yes) then the fire bottle should discharge when N1 drops below 50%.
Why does it not fire until 50%? I don't understand the mechanics of that.

[SLFMS]

The other "classic" in the sim is - engine failure - FIRE indication on the remaining good engine - watch how many reach up to push the FIRE button without hesitation or thinking through the consequences and planning things a little better.[/QUOTE]


This one always gets me in the RFM. After securing the fire, return fire system switch to centre position so if there is a fire on the opposite side you can use the system on that side. Big choice removing both your engines (not saying it’s not ever appropriate)
That would be a bad day….

A seizing turbine section is a good failure in the Sim, I’ve seen plenty diagnose that wrong. Good engine looks like low side failure with bad engine taking the load, high ITT etc. N2 is the diagnostic tool


A lot been read into the initial comments by the Pilot. I personally take it with a grain of salt, memory is not reliable in high stress situations. Perhaps Turbine section has let go as N2 drops engine feeds more fuel to keep governed speed ITT/ToT climbs through the roof. Sounds perfectly feasible to me and turbine failure could explain the fire.
I know first hand and discussed with crew after a compressor failure aided by a rag, loud bang follow by very high ITT and secondary bangs pops.
Both loud bangs followed by multiple other bangs with high ITT. Very different failure points.

[RVDT]

Why does it not fire until 50%? I don't understand the mechanics of that.

If the engine is still running it is unlikely that you will extinguish the fire. i.e. a leak at the flow divider or nozzle manifold burst.

Hence the logic to try and make it shall we say "idiot" proof.

[SASless]

SLFMS is spot on ;when he said.....A lot been read into the initial comments by the Pilot. I personally take it with a grain of salt, memory is not reliable in high stress situations..

Anyone who has experienced a very high stress fast paced event will understand the accuracy of that statement.

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[RVDT]

This one always gets me in the RFM. After securing the fire, return fire system switch to centre position so if there is a fire on the opposite side you can use the system on that side. Big choice removing both your engines (not saying it’s not ever appropriate)
That would be a bad day….

Centre position? Are you flying an AW109?

[wrench1]

Why does it not fire until 50%? I don't understand the mechanics of that.
50% N1 is the point the engine can self-sustain combustion and run without external assistance. The start sequence also shuts off at 50% N1. So for the extinguisher system to have full effectiveness it's activation is delayed until the N1 is below that self-sustain level.

And another point on the engine shutdown procedure is if the engine switch is turned OFF and the engine still runs or there still is a TOT increase the final measure is to perform a shutdown via the manual twist grip. I believe there is a mx check to verify the manual shutoff rigging is correct.

[SLFMS]

Why does it not fire until 50%? I don't understand the mechanics of that.


It can be unexpected reasons. On the 412 pulling the t handles shuts the fuel valve and energises the fire suppression system.
The procedure requires closing the throttle first, I used to think why? It’s slower, there is more likelihood of selecting the wrong engine and the throttles can be awkward, why not just pull the T handle?
Turns out it relates to the particle separator, it will suck all of your suppressant out of the engine bay. When you shut the throttle it closes the system, the time it takes to continue the SOP after closing the throttle is enough to close the particle separator door.

You could of course pull the T handle (which also closes the particle separator) and wait 10seconds which will achieve the same thing but evidently Bell has decided Pilots who’s aircraft are on fire might not be the best at accurately guessing time and might waste their first fire bottle.

[SLFMS]

Centre position? Are you flying an AW109?

No not 109, perhaps inactive position would have been better choice of words

[megan]

On the 412 pulling the t handles shuts the fuel valve and energises the fire suppression system.
The procedure requires closing the throttle first, I used to think why? It’s slower, there is more likelihood of selecting the wrong engine and the throttles can be awkward, why not just pull the T handle?
Turns out it relates to the particle separator, it will suck all of your suppressant out of the engine bay. When you shut the throttle it closes the system, the time it takes to continue the SOP after closing the throttle is enough to close the particle separator door.

You could of course pull the T handle (which also closes the particle separator) and wait 10seconds which will achieve the same thing but evidently Bell has decided Pilots who’s aircraft are on fire might not be the best at accurately guessing time and might waste their first fire bottleHas the 412 check list been changed (old copy)?
https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/317x532/ab270_5bccfddefe26d836985dd20210363171838b1b74.png

[RVDT]

No not 109, perhaps inactive position would have been better choice of words

Curious to see that procedure in the RFM - can you post a copy - wondering why you would be turning the fuel valve back on - which is all that FIRE push button does.

The actual activation of the FIRE EXT sequence does not have any further pilot controlled input.

If you have a FIRE and you push the button (which only closes the firewall fuel valve) and the sequence continues with N1 < 50% and the FIRE warning is present (pre SN 955 pre SB EC135-26-006) the bottle will discharge which is the first action on the list and then you continue on with caging the engine.

Kind of pointless thinking the fire bottle has another shot in it? Most only have single shot and the 2 shot system is another story altogether and rare on the 135 yet stolen from the BK117-C2 and up.

The logic within the system was changed after SN955 and after incorporation of SB EC135-26-006 where the fuel valve closed feed back was incorporated in the sequence but operationally there was no change.
Prior - the system was ARMED as long as the BAT MSTR was ON and FIRE warning present and N1 < 50% would discharge the bottle. Pushing the button still closed the fuel valve.
Post - the addition that the fuel valve was closed was included in the logic.

Reason being that there were a few procedures i.e. a test of the TOT probes with a heat gun up the tail pipe which if you were not careful where you pointed the heat gun - guess what!
"Normally" on maintenance you would not have the FIRE pb pressed.

[TorqueOfTheDevil]

[[email protected];11500100]I don't think anyone has an issue with him returning to the field with what ostensibly looks like an engine failure (albeit an explosive one).

It seems that he didn't shut the engine down - just set it to idle - and then subsequently noticed the fire and banged off the bottle. Although it seems the idle N1 would be too high to allow the bottle to discharge.

Elements of the tail boom/TRDS could have been damaged by the engine trashing itself and it might have failed anyway but why didn't he shut the engine down completely?

If he had put it to idle, checked the indications (he said he did this) and then completed emergency shutdown - we probably wouldn't be discussing this as the fire would hopefully have gone out and he would have made a safe OEI landing

crab, I can put this to bed early. Idle provides around 70% N1. Pressing the Emergency fir burrow on the CwP shuts down the engine by closing the fuel valve. After that, IF the fire warning is active, (the pilot states Yes) then the fire bottle should discharge when N1 drops below 50%.But the contributor to this thread who has flown the accident aircraft is pretty confident that there was no fire bottle! These aircraft apparently had the warning and push button, but there was no extinguisher. If you don't believe me, take it from him (#39):

"Pretty sure that 135 had no fire bottles installed. I've flown 4 or 5 airframes and all of them had no bottles. Never liked the 135 because of this. They all had the fire PB's but alert/shutoff only."

Based on this, all the talk about fire bottles and operation thereof may be a red herring. Time will tell...

[SASless]

Based on this, all the talk about fire bottles and operation thereof may be a red herring. Time will tell...

True.....but the discussion is useful even if not applicable to the accident aircraft assuming the aircraft did in fact have no fire bottle)s) installed.

The discussion does raise questions that if it is found to be true the aircraft did not have fire bottle(s) then their absence would have a direct impact upon what happened and beg questions as to why the decision not to have them occurred and how that absence was handled during training over the many years the aircraft has been in operation.

Hopefully the Investigators shall sort all of that out during their investigation.

[[email protected]]

If there was no fire bottle then even more reason to secure the engine quickly.

[TorqueOfTheDevil]

If there was no fire bottle then even more reason to secure the engine quickly.

He did! He pushed the button installed specifically for that purpose. Now it might have been slightly quicker to use the Eng Main switch to secure it, but he would have had to hit the button to cancel the fire bell (correct me if I'm wrong T1 operators? I'm only famliar with the T3H), and he was somewhat busy at the time...

[RVDT]

He did! He pushed the button installed specifically for that purpose. Now it might have been slightly quicker to use the Eng Main switch to secure it, but he would have had to hit the button to cancel the fire bell (correct me if I'm wrong T1 operators? I'm only famliar with the T3H), and he was somewhat busy at the time...

If the fire detector senses an "overheat" you will have the FIRE indication and the BELL for as long as that is true. Activating the pb will not cancel anything.

[SLFMS]

[QUOTE=RVDT;11500710]Curious to see that procedure in the RFM - can you post a copy - wondering why you would be turning the fuel valve back on - which is all that FIRE push button does.

The actual activation of the FIRE EXT sequence does not have any further pilot controlled input.

If you have a FIRE and you push the button (which only closes the firewall fuel valve) and the sequence continues with N1 < 50% and the FIRE warning is present (pre SN 955 pre SB EC135-26-006) the bottle will discharge which is the first action on the list and then you continue on with caging the engine.

Kind of pointless thinking the fire bottle has another shot in it? Most only have single shot and the 2 shot system is another story altogether and rare on the 135 yet stolen from the BK117-C2 and up.

RVDT sorry do not have copy of RFM handy but process is the same for the twins I have flown. To be clear they have all had duel fire bottles/duel activation(and detection) systems so we are probably straying from the thread, however all require resetting of the suppression system after successfully firing one bottle so the other side can be used correctly if there is a fire there. As you alluded to earlier use of the other side suppression will result in OEI -1.

You must have misread my comment as I did not say anything regarding turning the fuel valve back on. edited note perhaps in my earlier comment I was not clear it was generic and not specific to the 135.

[[email protected]]

He did! He pushed the button installed specifically for that purpose. He did - eventually, my point was why not do it quickly.

If you have an explosive failure in a twin and a huge area to make an OEI landing (airport) then select to idle, check you have the correct engine and select off, straight away.

[gipsymagpie]

If the engine is still running it is unlikely that you will extinguish the fire. i.e. a leak at the flow divider or nozzle manifold burst.

Hence the logic to try and make it shall we say "idiot" proof.
Actually I think it's all to do with where the fire bottle discharges into. It doesn't discharge into the engine but rather into the engine compartment. The engine compartment is ventilated by means of air being sucked out the back by the eductor exhaust. If you popped a fire bottle into the engine bay with the engine running at any appreciable speed, the gaseous halon would get immediately sucked out the back by the exhaust flow. Waiting until the engine is not making any appreciable power means the Halon lingers and has a chance to extinguish the fire. What's going on inside the engine is not pertinent as the Halon isn't inside the engine but as you say the delay also means the fuel is less likely to be flowing.

[albatross]

It can be unexpected reasons. On the 412 pulling the t handles shuts the fuel valve and energises the fire suppression system.
The procedure requires closing the throttle first, I used to think why? It’s slower, there is more likelihood of selecting the wrong engine and the throttles can be awkward, why not just pull the T handle?
Turns out it relates to the particle separator, it will suck all of your suppressant out of the engine bay. When you shut the throttle it closes the system, the time it takes to continue the SOP after closing the throttle is enough to close the particle separator door.

You could of course pull the T handle (which also closes the particle separator) and wait 10seconds which will achieve the same thing but evidently Bell has decided Pilots who’s aircraft are on fire might not be the best at accurately guessing time and might waste their first fire bottle.

Does not pulling the T-Handle: Close the fuel Valve, close the particle separator door, arm the fire extinguisher and shut off the bleed air? Hence the old “ Handle, Bottle, Throttle” memory VMC checklist a la 212. Confirm the fire while establishing single engine flight parameters,, identify and confirm the correct fire handle, Reconfirm and Pull the correct T-Handle, confirm engine shut down, if the light is still on: Fire the Main Bottle, confirm safe OEI flight, if the light is still on: Fire the Reserve Bottle, Confirm and slowly close the throttle of the engine on fire. Is the light still on? YES…..now you have some hard decisions to make!