Go Back  PPRuNe Forums > Flight Deck Forums > Tech Log
Reload this Page >

Would you evacuate ?

Wikiposts
Search
Tech Log The very best in practical technical discussion on the web

Would you evacuate ?

Thread Tools
 
Search this Thread
 
Old 13th Aug 2006, 19:03
  #1 (permalink)  
LEM
Thread Starter
 
Join Date: May 2003
Location: The Roman Empire
Posts: 831
Likes: 0
Received 0 Likes on 0 Posts
Would you evacuate ?

Would you evacuate if landing with the nose gear retracted?

I'm operating 737, but I think it's the same for every model...

The Partial or Gear Up Landing Non Normal cklist calls for the Evacuation to be performed, whilst the Training manual says "if required".

Not in the sim, but in real life if I see no evident reason to evacuate, probably I would not.

On the 737 you can open the cockpit windows and have a good look at the engines.
Not so on other types...

Your opinions are most welcome.
LEM is offline  
Old 13th Aug 2006, 19:33
  #2 (permalink)  
 
Join Date: Apr 1999
Location: UK
Posts: 1,691
Likes: 0
Received 0 Likes on 0 Posts
Given the non-normal checklist is probably Boeing derived whereas the training manual has had more domestic input I'd be inclined to go with the evacuation. You can't necessarily see what damage has been done to the engines from the flight deck and the wasted seconds could be important. To turn the question on its head, can you see a reason not to evacuate the 737 in the case of a partial gear landing?
Carnage Matey! is offline  
Old 13th Aug 2006, 20:58
  #3 (permalink)  
 
Join Date: Jan 2006
Location: In a far better place
Posts: 2,480
Likes: 0
Received 0 Likes on 0 Posts
There is a greater rist of injury during an emergency evacuation than the emergency landing itself. It takes a strong crew to convince the neophytes on the jet to remain calm and not to evacuate even when the aircraft comes to rest in an unusual ground attitude with one or more gear not extended.
captjns is offline  
Old 13th Aug 2006, 21:30
  #4 (permalink)  
 
Join Date: Jun 2001
Location: Boldly going where no split infinitive has gone before..
Posts: 4,789
Received 45 Likes on 21 Posts
Deciding to exacuate is deciding to hurt people.

Ansett had a 747 land NG up and, after deciding not to evecuate, got away with zero injuries.

Unless you have a reason, keep them in the nice, safe aircraft until they can be convieniently de-planned.
Wizofoz is offline  
Old 13th Aug 2006, 21:52
  #5 (permalink)  
 
Join Date: Apr 1999
Location: UK
Posts: 1,691
Likes: 0
Received 0 Likes on 0 Posts
To play devils advocate here, I don't think the risk of injury from an orderly evacuation from a 737 without it's nose gear is likely to be that significant. From a 747 yes, maybe even from an A320, but the 737 is low enough that you could step out of the front door and slide off the rear of the wings on your backside. Sitting in an aircraft thats just skidded half a mile along the runway on its engine cowls doesn't give me a warm and fuzzy feeling. If the geometry of the 737 is such that the engines remain clear of the ground when the nose gear is retracted then I'd reconsider, but the risk assessment from staying in an aircraft with potentially knackered engines versus a controlled evacuation with the majority of pax directed towards the forward exits suggests to me the latter option is the safer. We have to assess the risks in terms of probability mulitplied by severity.

Evac: Probabilty of injury high, severity of injury low = risk A
Sit tight: Probability of injury low, severity of injury (if plane goes up in smoke) massive = risk B
Carnage Matey! is offline  
Old 13th Aug 2006, 21:53
  #6 (permalink)  
 
Join Date: Jan 2005
Location: Europe
Posts: 262
Likes: 0
Received 6 Likes on 3 Posts
Originally Posted by captjns
It takes a strong crew to convince the neophytes on the jet to remain calm and not to evacuate even when the aircraft comes to rest in an unusual ground attitude with one or more gear not extended.
Exactly. There have been several cases in the past where passengers started an evacuation on their own initiative, with or without the crew assisting. If you decide not to evacuate, be sure to brief all passengers very thoroughly beforehand, so that they are absolutely aware about your intentions. My take: if panic starts spreading, better assist them with an orderly evacuation than try to stop the mob.
xetroV is online now  
Old 14th Aug 2006, 05:45
  #7 (permalink)  
 
Join Date: Jan 2006
Location: US
Posts: 2,205
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Carnage Matey!
To play devils advocate here, I don't think the risk of injury from an orderly evacuation from a 737 without it's nose gear is likely to be that significant. From a 747 yes, maybe even from an A320, but the 737 is low enough that you could step out of the front door and slide off the rear of the wings on your backside. Sitting in an aircraft thats just skidded half a mile along the runway on its engine cowls doesn't give me a warm and fuzzy feeling. If the geometry of the 737 is such that the engines remain clear of the ground when the nose gear is retracted then I'd reconsider, but the risk assessment from staying in an aircraft with potentially knackered engines versus a controlled evacuation with the majority of pax directed towards the forward exits suggests to me the latter option is the safer. We have to assess the risks in terms of probability mulitplied by severity.

Evac: Probabilty of injury high, severity of injury low = risk A
Sit tight: Probability of injury low, severity of injury (if plane goes up in smoke) massive = risk B
How high would the aft slides bewith a collapsed nose gear? Would people still try to use the aft slides in their haste? I forget which event it was but folks got seriously injured, if not killed, using slides that didn't reach the ground due to the unusual aircraft attitude.

Friend had folks panic and evac out of a 737 that had hot brakes. Minor event became an 'accident' due to folks getting injuried and getting hospitalized. If they'd just sat on their hands for a couple of minutes more they could have used the airstairs to deplane. Panic started and the injuries began. Few, but still injured with broken bones, etc.
misd-agin is offline  
Old 14th Aug 2006, 05:49
  #8 (permalink)  
 
Join Date: Jan 2006
Location: US
Posts: 2,205
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Carnage Matey!
the 737 is low enough that you could step out of the front door and slide off the rear of the wings on your backside.
It's "only" a several foot drop onto asphalt or concrete. Try jumping of the roof of you car onto asphalt or concrete and landing on your backside. Try that about 100-150 times to equal the number of passengers on board. Let us know how it turns out....
misd-agin is offline  
Old 14th Aug 2006, 07:51
  #9 (permalink)  
 
Join Date: Jan 2004
Location: UK
Posts: 8
Likes: 0
Received 0 Likes on 0 Posts
During my sim training we were told to consider the safest place is for the passengers. As someone said earlier evacuation=injuries
Forward Slip is offline  
Old 14th Aug 2006, 08:27
  #10 (permalink)  

Only half a speed-brake
 
Join Date: Apr 2003
Location: Commuting not home
Age: 46
Posts: 4,321
Received 3 Likes on 3 Posts
Originally Posted by misd-agin
Try jumping of the roof of you car onto asphalt or concrete and landing on your backside. Try that about 100-150 times
You do have a point. However to simulate properly you SIT on the roof and push yourselve over the edge trying NOT to land on your back. And you only have about 20-30 tries, all others would leave via the front doors.

FD. (the un-real)
FlightDetent is offline  
Old 14th Aug 2006, 10:47
  #11 (permalink)  
 
Join Date: Dec 2002
Location: UK
Posts: 2,455
Likes: 0
Received 9 Likes on 5 Posts
Perhaps the most important aspect is not to prejudge the situation beyond what might have already been considered in SOPs – policy etc. There could be many aircraft type-specific variables, which can be pre considered for SOPs, and then implemented if and when the decision to evacuate is made.
This situation definitely requires good communication to prevent any passenger instigated action.
There is a (horrific) video of an evacuation from an ATP that landed with the nose-wheel retracted. The rear slides were deployed, but they did not reach the ground; they hung vertically. Several passengers had serious injuries, one fell head first onto the concrete. Apparently, the slide arrangement is acceptable in certification; perhaps the authorities assume that crews understand these aspects. Worthwhile checking any assumptions made about your aircraft.
Only base the evacuation decision on the threat at the time, i.e after landing. By all means, consider an evacuation in the pre-landing assessment and any possible restrictions / changes to a standard procedures – i.e. forward doors only. Do not commit to a course of action without first updating the situation.
Note that the risk of fire from fuselage contact is low based on several instances. For the ATP landing there was a foam strip on the runway, but the nosewheel was lowered beyond the foam, thus it played not part.
safetypee is offline  
Old 15th Aug 2006, 03:58
  #12 (permalink)  
 
Join Date: May 2005
Location: On a good day - at sea
Posts: 263
Likes: 0
Received 0 Likes on 0 Posts
We just had one in YOW today from a CRJ. I haven't seen the incident report yet (I might have just deleted it - not my fleet) but press reports say the plane made emer ldg due to smoke in cabin.

From what I gather, the main door was opened to allow passengers to rapidly disembark but in the shadow of the LHR episode some passenger in the back opened an emer exit of their own accord. One woman jumped onto the wing and the guy behind her jumped right on top of her breaking her arm and causing her some ankle injury.

There's a few lessons there I suppose.
nnc0 is offline  
Old 15th Aug 2006, 08:27
  #13 (permalink)  
LEM
Thread Starter
 
Join Date: May 2003
Location: The Roman Empire
Posts: 831
Likes: 0
Received 0 Likes on 0 Posts
Great to see so many replies.

The Captain can order to keep the unsafe exits closed before ordering the evacuation.
"Attention Captain speaking: keep after doors closed, evacuation evacuation evacuation !" would be the announcement in my company.

Even then, people would use the overwing exits, and for sure there would be some injuries.

After the situation is assessed and under control, a reletively fast deplaning via the front doors would probably be my choice, but without forgetting that people starting to run on the runway can easily get injured by the full speed oncoming fire brigade vehicles.

So really, the safest place for them is inside the airplane.

As has been said, it takes a good briefing and a convincing loud voice to prevent passengers in panic from starting their own evac.

"It would have been easy to chew him out for disobeying a mission rule. But we didn't pay these guys to always follow the rules. By intuition and experience, this Commander saved the day. When I later met him, I simply said Thank You Wally".
Flight Director Chris Kraft about W.Shirra's decision not to eject from Gemini something when it failed to ignite properly, even if that was a crystal clear NASA mission rule.
LEM is offline  
Old 15th Aug 2006, 15:27
  #14 (permalink)  
 
Join Date: Jan 2006
Location: US
Posts: 2,205
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Forward Slip
During my sim training we were told to consider the safest place is for the passengers. As someone said earlier evacuation=injuries
Recent recurrent training had max gross weight abort for engine fire. Ask if outside observer could tell us what they see since we can't see the engine "Smoke everywhere, can't tell about any fire".

So we decide to evac. "Uh, no....." is the instructor's opinion. Ok, then why not evac? "That's just the fire extinguisher cloud."

Ah, fire the bottles at significant speed, with headwind...and afterwards the tower observer several kilometers away see's lots of smoke but it isn't from a fire but just residual chemicals???

Talked with others and they agreed that given that scenario they'd take the injury risk of evacuating vs. the 'smoke' (chemicals or real fire...) being just smoke.

There are times to evacuate. Gearing all training scenarios to not evauate will lead to problems someday. And having piss poor scenarios end up with the instructor pushing the 'do not evac' line could lead to a disaster someday.
misd-agin is offline  
Old 15th Aug 2006, 15:43
  #15 (permalink)  
Per Ardua ad Astraeus
 
Join Date: Mar 2000
Location: UK
Posts: 18,579
Likes: 0
Received 0 Likes on 0 Posts
Ah, fire the bottles at significant speed
- that differs from ?most? SOPs where the aircraft is halted before bottles are fired. I would be impressed? if a correct diagnosis as to which bottle should be fired and the correct bottle fired during a max energy stop!
BOAC is offline  
Old 16th Aug 2006, 01:50
  #16 (permalink)  
 
Join Date: Jan 2006
Location: US
Posts: 2,205
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by BOAC
- that differs from ?most? SOPs where the aircraft is halted before bottles are fired. I would be impressed? if a correct diagnosis as to which bottle should be fired and the correct bottle fired during a max energy stop!
I reread the post and wondered about my wording...we weren't stopped but it wasn't at high speed.

SOP and the debate about when can you start fighting the fire if you know the drill...it seems to change with the seasons.

Round and round we go.
misd-agin is offline  
Old 16th Aug 2006, 07:21
  #17 (permalink)  

Bottums Up
 
Join Date: Feb 2000
Location: dunnunda
Age: 66
Posts: 3,440
Likes: 0
Received 1 Like on 1 Post
A neighbour was on the QF A330 which evacuated in Japan (Osaka?) a year or so ago. She was stuck in the back by the person coming down the slide behinde her and is now waiting for a hip replacement!
Capt Claret is offline  
Old 16th Aug 2006, 08:11
  #18 (permalink)  
Per Ardua ad Astraeus
 
Join Date: Mar 2000
Location: UK
Posts: 18,579
Likes: 0
Received 0 Likes on 0 Posts
Well, misd - not in my experience. Always 'stationary' to prevent losing too much extinguishant due to airflow.

There is another thread running on 'would you evac' elsewhere, this following a fire warning.
BOAC is offline  
Old 18th Aug 2006, 12:33
  #19 (permalink)  
 
Join Date: Jul 2006
Location: Earth
Age: 61
Posts: 66
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by LEM
Would you evacuate if landing with the nose gear retracted?

I'm operating 737, but I think it's the same for every model...

The Partial or Gear Up Landing Non Normal cklist calls for the Evacuation to be performed, whilst the Training manual says "if required".
I'm not sure that there is anyway to avoid an evacuation with this one.

Provided that no additional significant threat to the safety of the passengers and crew exists or develops, that "Evacuation" could be via the forward doors only, as the rear doors and over wing exits may not be best suited for this type of "Evacuation".

However, if you are asking about an "Evacuation" in the text-book sense of the word - as you have briefly explained the facts to be - I would say that the "text-book" evacuation is probably not the best choice for this event.

Very important, is that you will have to assess all the conditions, and then make an informed decision

.
captain_jeeves is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.