How hard to bend a firewall
Thread Starter
Joined: Nov 2013
Posts: 13
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From: Australia
How hard to bend a firewall
Hi Guys,
I observed another PPL nose wheel 1st a 182 recently as a waited at the thresehold.
It didn't look too bad, he looked just a bit late of roundout, so the nose wheel kind of seemed to run along the ground before coming up again and settling on mains.
Anyhow, it got me thinking, how hard does the hit have to be to bend the firewall. And as I hire aircraft, how do I check for firewall integrity?
I observed another PPL nose wheel 1st a 182 recently as a waited at the thresehold.
It didn't look too bad, he looked just a bit late of roundout, so the nose wheel kind of seemed to run along the ground before coming up again and settling on mains.
Anyhow, it got me thinking, how hard does the hit have to be to bend the firewall. And as I hire aircraft, how do I check for firewall integrity?
Moderator
Joined: Feb 2000
Aviation Qualifications: CPL
Posts: 14,480
Likes: 178
From: UK
I think it's near impossible to tell how much load generically is needed to damage a firewall, because it's so dependent upon the loading pattern, and the individual design.
How to check for integrity? Have a good hard look at it visually with the cowlings open.
In general however, the firewall carries very little load - the bits I'd worry about getting damaged are the carry through engine mounts and airframe structural components. Even if there are bends or ripples in a firewall, that in itself doesn't compromise it as a firewall - although it may well be indicative of damage elsewhere.
And of course, if in doubt, have it checked by local and suitably qualified maintenance staff.
G
How to check for integrity? Have a good hard look at it visually with the cowlings open.
In general however, the firewall carries very little load - the bits I'd worry about getting damaged are the carry through engine mounts and airframe structural components. Even if there are bends or ripples in a firewall, that in itself doesn't compromise it as a firewall - although it may well be indicative of damage elsewhere.
And of course, if in doubt, have it checked by local and suitably qualified maintenance staff.
G
Joined: Apr 2009
Posts: 2,817
Likes: 1
From: Hotel Gypsy
It's normally the second bounce that does it, just about the same time as the propeller gets modified!
GtE has it. If the firewall is bent you would also need to check inside the cockpit, notably the footwell area (take the carpets out). On the 172/182 I've seen this floor area damaged as far back as the seat rails.
GtE has it. If the firewall is bent you would also need to check inside the cockpit, notably the footwell area (take the carpets out). On the 172/182 I've seen this floor area damaged as far back as the seat rails.
Joined: Dec 2007
Aviation Qualifications: PPL
Posts: 2,011
Likes: 156
From: Westnoreastsouth
Many years ago at an RAF airfield near Abingdon - a solo Bulldog student messed up his landing somewhat - he damaged the nosewheel support structure and had a propstrike ! ..... so (good man) - he did a roller and found that his rudder was jammed 
ISTR that he had pushed up the structure so much he had bent the nosewheel steering rod(s).
Successfully landed next time round
ISTR that he had pushed up the structure so much he had bent the nosewheel steering rod(s).
Successfully landed next time round
Moderator
Joined: Feb 2000
Aviation Qualifications: CPL
Posts: 14,480
Likes: 178
From: UK
Many years ago at an RAF airfield near Abingdon - a solo Bulldog student messed up his landing somewhat - he damaged the nosewheel support structure and had a propstrike ! ..... so (good man) - he did a roller and found that his rudder was jammed
ISTR that he had pushed up the structure so much he had bent the nosewheel steering rod(s).
Successfully landed next time round
ISTR that he had pushed up the structure so much he had bent the nosewheel steering rod(s).
Successfully landed next time round
G
Joined: Dec 2007
Aviation Qualifications: PPL
Posts: 2,011
Likes: 156
From: Westnoreastsouth
Cannot remember exactly what year but between 1980 - 83 (my last tour)
I cannot even remember what Cat the damage was assessed as,sfunny how patchy the memory is.
Sorry G I cannot remember if the sump was damaged...he did a successful landing from the next circuit I believe.
I cannot even remember what Cat the damage was assessed as,sfunny how patchy the memory is
.Sorry G I cannot remember if the sump was damaged...he did a successful landing from the next circuit I believe.
