Airco DH4

LeicesterTiger · 5 November 2009, 05:01 AM

I keep coming across references on websites, books etc that the Airco DH4 was nicknamed the 'flaming coffin', yet despite what i've read about the DH4 including from those who flew them in RFC/RNAS/RAF operational service, i've never seen this nickname mentioned - does anyone know where/how it actually came about? By all accounts it was a superb aircraft and, personally, I consider the macabre nickname undeserved

Chock · 5 November 2009, 05:35 AM

The Flaming Coffin nickname was a disparaging term apparently coined in the US when the DH4 was being tested in preparation for production over in the United States. DH4 A7532 was sent over as a pattern for manufacture and to test out and as you probably know, the Liberty-engine US version made some changes to the design based on the reports written after that DH4 was assessed. It's that assessment which was the catalyst for the nickname, as the report was fairly critical of the DH4, claiming the French Breguet was a better day bomber. The Flying Coffin nickname is often mistakenly thought to refer to the fact that the DH4 was prone to fire in the air, but that is not the reason for the nickname, and most RFC crews completely disagreed with the assessment and didn't use that nickname, they were in fact very fond of the aircraft in most cases. Most casualties were due to the fact that a lot was asked of the DH4 crews, flying deep penetration missions over Germany for several hours, so it actually did very well under the circumstances.

The real reason for the nickname is that the location of the fuel tank on the DH4 (between the pilot and the rear gunner, which changed on the US version) could potentially lead to a grim fate for pilots if the thing crash landed. What could happen is the weight of the fuel in the tank would cause it to carry on traveling forward under momentum as the aircraft came to an abrupt stop in a forced landing or crash, thus it could break loose from its mountings and carry forward, pinning the pilot between the fuel tank and the engine. If that happened and the fuel tank ruptured, it might possibly spill fuel onto a hot engine part and cause a fire, which would cremate the pilot since he would be pinned to the hot engine by the fuel tank and unable to escape. Thus he would be in a 'flaming coffin'. The truth is, if a crash was severe enough to do that, he'd probably be dead anyway.

So in reality, that's more based on fear than an actual probability, as the kind of fuel carried by the DH4 is actually fairly hard to ignite if simply spilled onto a hot metal part, oil on the other hand will often quite easily burn. You can try that for yourself (be careful though); tip a small amount of petrol into a dish and drop a lighted match into it; the fuel will most likely put the match out rather than ignite. This is because fuel like that tends to have to 'mist' in order to ignite, i.e. fuel vapour is far more likely to ignite. So in the case of the DH4, you would have to have some sort of flame at the engine and the fuel tank rupturing in the crash, and throwing a fuel/air mixture into the flame to really have a good chance of igniting things. That could certainly happen, but merely spilling petrol on a hot engine would not necessarily do it. This is why modern aviation fuels are often designed to 'gel' if they get a shock, in the hope that they will not mist and ignite if a fuel tank ruptures in a crash. You have probably seen the very famous NASA test footage of a Boeing 707 airliner being remotely piloted and belly landed in the US desert onto some spikes intended to rip open the wing fuel tanks, where it rolls over and is engulfed in a fireball. That test was part of the research into such fuel ignition, amongst other things.

You can try that experiment for yourself too (wear an apron): Get a bowl of custard, place it on a table and thump your fist hard into it. You'd expect it to splash everywhere, but that doesn't happen because the shock you deliver to the custard forces it to gel.

Al

LeicesterTiger · 5 November 2009, 06:48 AM

Al, thanks for a superb post. Many thanks especially for the explanation of the flying coffin term - like that description, i've often thought it bizarre in modern literature especially when describing WW1 aircraft that whatever particular aircraft was being described was unsafe because of the possibility of a sequence of events happening which could prove fatal, no matter how unlikely all events happening at the same time being

LewisS · 6 November 2009, 01:23 PM

I actually think a lot of different aircraft got this derisive moniker. The DH2 was called this during the "Fokker Scourge" because if they got hit from behind, ( their fuel tank was fairly tall and placed behind the pilot..) they tended to have fuel leaks that went straight back into the spinning Gnome. The Vickers Gunbus, the various French pushers like the Farman MF11...

FOKKERJ · 6 November 2009, 04:34 PM

Hi Rob,

For all the reasons that Al gave, plus I believe the fact that the Pilot and Gunner/Observer's offices were so far apart to hinder efficient communications between the two was a major draw back that was later remedied as a modification by moving the two closer together on some D.H.4's and was a major design improvement on all D.H. 9/9a's.
Having the petrol tank where the Gunner should have been was probably the main issue to feed the "Flaming Coffin" complaint.

Cheers, Jay

Chock · 6 November 2009, 04:52 PM

Many combat aircraft end up with such names, often more than one of them. The DH2 was invariably nicknamed 'the Spinning Incinerator'. In more modern times the F-104 Starfighter had a huge list of such nicknames including: 'the widowmaker' 'the flying coffin' 'the aluminum death tube' 'the lawn dart' 'the ground nail' 'the wicked one' 'the eff one oh floor' and more besides. A lot of it is down to the gallows humour you find on flight lines.

Al

rainbase · 6 November 2009, 07:54 PM

Quote:

Originally Posted by Chock

Many combat aircraft end up with such names, often more than one of them. The DH2 was invariably nicknamed 'the Spinning Incinerator'. In more modern times the F-104 Starfighter had a huge list of such nicknames including: 'the widowmaker' 'the flying coffin' 'the aluminum death tube' 'the lawn dart' 'the ground nail' 'the wicked one' 'the eff one oh floor' and more besides. A lot of it is down to the gallows humour you find on flight lines.

Al

I heard a joke back when I was living in Germany that basically went:
How can you get your own F-104 Starfighter?
Buy a field and wait....