Scotland Helicopter Crash

Author
Discussion

ralphrj

3,535 posts

192 months

Friday 14th February 2014
quotequote all
AAIB say crash caused by double engine failure as a result of fuel supply problem.

http://www.aaib.gov.uk/publications/special_bullet...



Edited by ralphrj on Friday 14th February 14:44

amancalledrob

1,248 posts

135 months

Friday 14th February 2014
quotequote all
ralphrj said:
AAIB say crash caused by double engine failure as a result of fuel supply problem.
You'd expect it to have autorotated, wouldn't you? I wonder what happened

Eric Mc

122,100 posts

266 months

Friday 14th February 2014
quotequote all
It's an interim report at the moment.

It can be read in full here -

http://www.aaib.gov.uk/publications/special_bullet...

Oops - there wasn't a link posted in the previous post.


ralphrj

3,535 posts

192 months

Friday 14th February 2014
quotequote all
amancalledrob said:
You'd expect it to have autorotated, wouldn't you? I wonder what happened
Exactly, a very curious incident.

AAIB still trying to establish:

1. Why the engines flamed out when there was still 76kg of fuel onboard.
2. Why no emergency call from the Pilot.
3. Why the Pilot wasn't able to autorotate.

tenohfive

6,276 posts

183 months

Friday 14th February 2014
quotequote all
Page not found coming up for me on the interim report. Even when I found it through Google and relinked it the page throws a wobbler, but is linked in the below article and works that way:
BBC Article

Sounds like it raises as many questions as it answers, but good that they're keeping a steady stream of information coming out as and when appropriate.

Scuffers

20,887 posts

275 months

Friday 14th February 2014
quotequote all
ralphrj said:
amancalledrob said:
You'd expect it to have autorotated, wouldn't you? I wonder what happened
Exactly, a very curious incident.

AAIB still trying to establish:

1. Why the engines flamed out when there was still 76kg of fuel onboard.
2. Why no emergency call from the Pilot.
3. Why the Pilot wasn't able to autorotate.
read the update...

both transfer pumps were turned off, so as soon as the fuel level in the main tank was below the 'dam', the supply tanks would start to run down, till, as in this case, they ran out.

it would appear the pilot ignore the LOW FUEL 1 / LOW FUEL 2 warnings or did not understand their significance (ie, checked with the main tank gauge, check transfer pump switches)

either way, on receipt of these warnings, the manufacturer’s flight manual for the helicopter instructs the pilot to ‘LAND WITHIN 10 MINUTES’.

that clearly did not happen.

essayer

9,087 posts

195 months

Friday 14th February 2014
quotequote all
ralphrj said:
Exactly, a very curious incident.

AAIB still trying to establish:

1. Why the engines flamed out when there was still 76kg of fuel onboard.
2. Why no emergency call from the Pilot.
3. Why the Pilot wasn't able to autorotate.
It seems that 1) may be linked to the fact that the transfer pumps were switched off..? Fuel available in main tank (albeit seemingly below the operator minimums demanding an immediate landing)

You wonder about some form of incapacitation..

ralphrj

3,535 posts

192 months

Friday 14th February 2014
quotequote all
Scuffers and Essayer, you are both correct - I made an error when I paraphrased the ongoing investigation part of the report to "why the engines flamed out" instead of "why a situation arose that resulted in the engines flaming out".

GadgeS3C

4,516 posts

165 months

Friday 14th February 2014
quotequote all
essayer said:
You wonder about some form of incapacitation..
yes skimming that report it's hard to see a pilot of that experience could have got it wrong otherwise.

Scuffers

20,887 posts

275 months

Friday 14th February 2014
quotequote all
GadgeS3C said:
essayer said:
You wonder about some form of incapacitation..
yes skimming that report it's hard to see a pilot of that experience could have got it wrong otherwise.
yes, it's not like from first fuel warning you have no time to react, you have more than 10 mins fuel at that point, also, as the two feed tanks are different sized, one engine would flame out before the other, more warning of impending doom before total failure...

the fact that no radio call at fuel warning was given suggests the pilot was not 100% situational aware...

Edited by Scuffers on Friday 14th February 16:00

GadgeS3C

4,516 posts

165 months

Friday 14th February 2014
quotequote all
Scuffers said:
yes, it's not like from first fuel warning you have no time to react, you have more than 10 mins fuel at that point, also, as the two feed tanks are different sized, one engine would flame out before the other, more warning of impending doom before total failure...

the fact that no radio call at fuel warning was given suggests the pilot was not 100% situational aware...

Edited by Scuffers on Friday 14th February 16:00
This is total speculation from someone that doesn't know what they're talking about
you don't hear that often on PH!

but if the pilot had been incapacitated for several minutes would things not have gone wrong sooner? Or would the passengers have been able to use the radio?

saaby93

32,038 posts

179 months

Friday 14th February 2014
quotequote all
GadgeS3C said:
yes skimming that report it's hard to see a pilot of that experience could have got it wrong otherwise.
unable to find the report but earlier on wasnt the pilot of limited experience in this type?

GadgeS3C

4,516 posts

165 months

Friday 14th February 2014
quotequote all
saaby93 said:
nable to find the report but earlier on wasnt the pilot of limited experience in this type?
646 hrs are the hours on type the pilot had accumulated since 2010.
From AAIB report

eccles

13,742 posts

223 months

Friday 14th February 2014
quotequote all
They mentioned on the news that the AAIB are investigating to see if there was anything wrong with indications the pilot was seeing.

Zad

12,708 posts

237 months

Friday 14th February 2014
quotequote all
AAIB Report said:
Commander’s Flying Experience 5,592 hours (of which 646 were on type)
Last 90 days - 38 hours
Last 28 days - 192 hours
It is a real puzzler. From the diagram, the engines pick up the fuel from the sub-tanks, which were both effectively empty. Plenty (enough anyway) in the forward tank, but nothing being pumped to the sub-tanks. That part is relatively simple. Zero comms and zero rotor speed are the big head-scratcher. It all seems to point to the pilot having autorotated and flared way too early, and lost all rotor inertia at considerable altitude.

Maybe the comms gear dropped out quickly due to low voltage when both generators powered down? That should be easy enough to check, as all the equipment seems to have been functionally undamaged.

Kudos to the design and development engineers who worked on the fuel tanks, fuel supply system and engines though. From the report, they remained largely intact and functional despite high shock loads.

mattyn1

5,799 posts

156 months

Friday 14th February 2014
quotequote all
Possibly losing spatial or situational awareness at the moment of the low-fuel warnings - or another warning that caused the pilot to switch off the fuel.

The black box would have been really useful wouldn't it.

Scuffers

20,887 posts

275 months

Friday 14th February 2014
quotequote all
GadgeS3C said:
This is total speculation from someone that doesn't know what they're talking about
you don't hear that often on PH!

but if the pilot had been incapacitated for several minutes would things not have gone wrong sooner? Or would the passengers have been able to use the radio?
How so?

All i am doing is quoting the aib report and parts of the ec135 manual.

Simple facts are that for whatever reason, the pilot did not react to the main tank fuel gauge, did not turn the xfer pumps on, then did not react to the low fuel warnings from running tanks 1 and 2, carried on for another 12-17 minutes before both engines flamed out.

At any point, switching on the xfer pumps would have gained them access to the remaining 73kg of fuel.

HoHoHo

14,988 posts

251 months

Friday 14th February 2014
quotequote all
I'm probably being stupid here, but why didn't he autorotate, was he totally confused and essentially he simply dropped with no inertia in the blades into the roof?

Remembering images in the media at the time the blades didn't have any evidence of being 'bent' which leads me to believe they weren't turning.

As a non-pilot it doesn't make any sense to me confused

fatboy b

9,500 posts

217 months

Friday 14th February 2014
quotequote all
amancalledrob said:
ralphrj said:
AAIB say crash caused by double engine failure as a result of fuel supply problem.
You'd expect it to have autorotated, wouldn't you? I wonder what happened
Only if he had forward momentum. If he were hovering, then he's pretty fooked if he's low.

GadgeS3C

4,516 posts

165 months

Friday 14th February 2014
quotequote all
Scuffers said:
GadgeS3C said:
This is total speculation from someone that doesn't know what they're talking about
you don't hear that often on PH!

but if the pilot had been incapacitated for several minutes would things not have gone wrong sooner? Or would the passengers have been able to use the radio?
How so?

All i am doing is quoting the aib report and parts of the ec135 manual.

Simple facts are that for whatever reason, the pilot did not react to the main tank fuel gauge, did not turn the xfer pumps on, then did not react to the low fuel warnings from running tanks 1 and 2, carried on for another 12-17 minutes before both engines flamed out.

At any point, switching on the xfer pumps would have gained them access to the remaining 73kg of fuel.
Understood - my question was that there seem to be quite a lot of time from the fuel warning to the crash. Would the helicopter have stayed in the air that long with the pilot incapacitated? Is there an autopilot?