AW139 unexpected float deployment

[helihub]

Lider AW139 off Brazil

https://www.jornalterceiravia.com.br/2023/01/17/video-helicoptero-tem-pane-durante-voo-na-bacia-de-campos/


https://youtu.be/L_LylVPkK20

[Sir Korsky]

If I remember rightly, the 139 floats are immersion activated with manual back up. My money on collective F up.

[Nescafe]

Originally Posted by Sir Korsky

If I remember rightly, the 139 floats are immersion activated with manual back up. My money on collective F up.

Activation from the collective mounted switch requires a three stage action, arm floats, lift the collective switch guard then press the button. If the floats are armed, the ‘float test’ button being pressed inadvertently, (by a flight board or iPad etc) would also make the circuit, which could be more likely.

[gwelo shamwari]

Originally Posted by Nescafe

Activation from the collective mounted switch requires a three stage action, arm floats, lift the collective switch guard then press the button. If the floats are armed, the ‘float test’ button being pressed inadvertently, (by a flight board or iPad etc) would also make the circuit, which could be more likely.

Pressing the test button with the floats armed does not cause them to inflate.

[Non-PC Plod]

Originally Posted by gwelo shamwari

Pressing the test button with the floats armed does not cause them to inflate.

Yes- hopefully. However there must be a reason for the limitation: "Do not activate the test switch in flight"..............!

[ericferret]

Originally Posted by Non-PC Plod

Yes- hopefully. However there must be a reason for the limitation: "Do not activate the test switch in flight"..............!

I seem to recall a similar incident with a UK registered aircraft.
A wiring short under the baggage bay floor.
There was a mod to increase the clearance around the cylinder firing heads.

[wrench1]

Originally Posted by ericferret

I seem to recall a similar incident with a UK registered aircraft. A wiring short under the baggage bay floor. There was a mod to increase the clearance around the cylinder firing heads.

There were several incidents which led to a Leo ASB and then to an AD.
https://drs.faa.gov/browse/excelExte...5004BDBCB.0001

[malabo]

Always thought the Agusta SOP of flying over water with floats armed was superior and a natural evolution over the old S76 (and others) restriction of limiting arming by airspeed. We blew lots of floats in the 76 at 140 knots with only embarrassment as a consequence. After we got the belly sensors to auto inflate all we really needed was a guard on the manual activation button on the cyclic, that alas never came.

Glad Agusta never backpedaled on SOP after the first few inadvertent float deployments.

[gwelo shamwari]

Uncommanded float activation

Not sure how common this is but I overheard that a Middle East Gulf operator has had 4 unexpected activations this year alone. CHC apparently had multiple last year too.

I wonder if MX has anything to do with the number of unexpected activations as the operators I have flown for never had a single one with hundreds of thousands of operating hours?

Is there anywhere where this information is available for analysis?

[Zar_1]

How pricey would something like this be though? (an inadvertent deployment)

I've seen videos of people inflating these floats for fun, once their useable lifespan is consumed...

[Sir Korsky]

the 'traditional' dropping of the iPad on the unguarded float switch was a $60k FU on the S76 - to give you some idea. Squibs ain't cheap.

[megan]

We blew lots of floats in the 76 at 140 knots with only embarrassment as a consequence

You flew with floats armed in the cruise and had finger trouble on the cyclic I assume?

'traditional' dropping of the iPad on the unguarded float switch was a $60k FU on the S76

Unable to understand how dropping an iPad can blow the floats I'm afraid. Flew the 76 for 24 years and 12,000K and we never had an inadvertent inflation in any of our six aircraft, nor an intentional one. floats disarmed in the after take off check from a rig, armed on the prelanding check.

[Sir Korsky]

Glad to hear that Megan. You must have been around far smarter folk than I've been used to !

[noooby]

Originally Posted by gwelo shamwari

Not sure how common this is but I overheard that a Middle East Gulf operator has had 4 unexpected activations this year alone. CHC apparently had multiple last year too.

I wonder if MX has anything to do with the number of unexpected activations as the operators I have flown for never had a single one with hundreds of thousands of operating hours?

Is there anywhere where this information is available for analysis?

Records show 2 inflight float deployments in the last 3 years and that includes the recent one in Brazil. That is across all Leonardo aircraft types. 109/119, 139, 169 and 189.

I can't find any records for unintentional float operation on the ground in that time frame. Normally the OEM would at least be told and also regulatory authority, IF it was a problem with an aircraft system.

[gwelo shamwari]

I am a bit sceptical at the claim of so many unintentional/unexpected deployments.

Where exactly did you check? it would interesting to have a look at what is actually happening to the fleet.

[albatross]

Originally Posted by gwelo shamwari

I am a bit sceptical at the claim of so many unintentional/unexpected deployments.

Where exactly did you check? it would interesting to have a look at what is actually happening to the fleet.

I have heard of. a lot on 76s over the years. More than one occurred on hand over of controls for a deck landing. One poor fellow was present at 2 in 4 months. Forever after he lived with the nickname “Pops”. One thing we discovered was that the red button on the cyclic, which all thought required a good hard push, would activate at the merest touch.

[gwelo shamwari]

Originally Posted by albatross

I have heard of. a lot on 76s over the years. More than one occurred on hand over of controls for a deck landing. One poor fellow was present at 2 in 4 months. Forever after he lived with the nickname “Pops”. One thing we discovered was that the red button on the cyclic, which all thought required a good hard push, would activate at the merest touch.

Correct me if I am wrong, the S76 has a raised rim around the float deployment so as to distinguish it from the force trim release. I have heard it's real common for a freshly transitioned pilot to mix the two up. However, the float deployments on the s76 were from that button being played with on the cyclic. The AW139 requires a switch cover on the collective to be lifted fully open before access is even given to the button.

[Sir Korsky]

There have been many inadvertent 76 float deployments, probably hundreds over the years. Usually on the deck after one pilot exits with the float switch still on. Many operators failed to install the STC float guard and fumbling on exit, or even getting the cyclic trim PB mixed up with the pop button set them off. Easy to do if you're stupid or tired. If the 139 system works as advertised, you should never have to manually activate the float switch.

[Shackman]

Can happen to anyone:

[whoknows idont]

The key lies in selling it as a functional test.