Building and Maintaining a DB-7 Replica: What Nobody Tells You
Most people who stumble onto the world of twin-engine wartime aircraft through Doublegunshop have no idea what they're stepping into. The site itself is a mess of scattered forums, fragmented builder logs, and technical discussions that assume you already know half the vocabulary. It works if you're persistent. It drives everyone else insane within a week. I spent about eighteen months trying to assemble enough information to start a project that made sense to me. The DB-7 family — the Douglas aircraft that became the A-20 Havoc in US service — was never mass-produced in complete airworthy examples the way the P-51 or the Spitfire has. What survives falls into three categories: museum pieces sitting in climate-controlled hangars, private collectors who treat theirs like bank accounts, and the small group of builders attempting replicas or kit conversions. Doublegunshop exists at the intersection of all three, and it's barely held together.
The Unrivaled World Of Doublegunshop Uncovering The Unique Features And Benefits Of This Relic Of Aerial Warfare
The core value of the site isn't any single feature. It's the accumulation of builder notes from people who have actually cut metal, drilled rivet patterns, and fought with fabric covering on airframes that were designed before the Korean War. Most aviation forums move on to whatever shiny new thing comes out. This one stays fixed on aircraft that are older than most of the people posting on it. The technical content is uneven. Some threads contain detailed structural calculations and material specifications that would take years to reproduce independently. Other threads are just people arguing about whether a particular radiator duct shape is historically correct. You learn to scroll past the arguments quickly. One thing the community gets right is the emphasis on sourcing materials. The original DB-7 used aluminum alloy stock and fabric types that aren't always available off the shelf anymore. Builder logs on the site document exactly which suppliers worked and which didn't. I've referenced at least four separate threads when tracking down period-correct fabric compounds for a wing covering job, and every single one turned out to be useful. That kind of accumulated detail doesn't exist anywhere else.
Here's the part nobody mentions: the DB-7 airframe is fundamentally simpler to build than many contemporaries because of its construction philosophy. The fuselage is a semi-monocoque design with relatively straightforward bulkhead spacing. The wings use a two-spar arrangement that's forgiving if your spar alignment is within reasonable tolerances. The landing gear is a classic trailing link setup that doesn't require the complex retraction mechanisms found on later aircraft. For someone attempting a replica, these are genuinely advantageous choices made by engineers fifty years ago. But there are real problems you'll hit that the forums gloss over. The DB-7 was designed around Pratt & Whitney R-1830 engines or their variants. If you're building a replica and deciding on powerplant, the original engines are either impossible to maintain or cost more than the airframe is worth. Most builders end up going radial piston alternatives like the R-985 or even modern Lycoming installs with custom mounts. The site has threads on this but they're buried under restoration discussions for original aircraft. You have to dig for it. I ran into a specific issue during my own project that took me three months to resolve. The original DB-7 electrical system runs on a 24-volt DC grid with a generator and a storage battery arrangement that's completely unlike anything in modern aircraft. I was trying to wire a replica instrument panel with modern gauges and a basic nav/com setup, and the forum advice was contradictory. Some people said to keep the original system as the primary bus and add a modern auxiliary. Others said to run a completely separate 14-volt system and leave the original untouched.
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The workaround I ended up using was neither of those. I installed a standalone voltage regulator and alternator kit for the main instruments and radios, kept the original wiring intact as a secondary bus for the landing lights and nav lights only, and bonded everything to a common ground point near the firewall. It's not period-correct in the purest sense. It works reliably and doesn't require hunting down a 1940s-era generator that probably hasn't been manufactured in decades. The forum members who saw my configuration mostly agreed it was sensible, even if it wouldn't pass a strict historical restoration review. Another thing the site doesn't make clear is how much time these projects actually take. A full DB-7 replica build, based on the few complete builder accounts I've tracked, runs roughly 3,000 to 5,000 hours of labor depending on how much you fabricate from scratch versus using pre-formed parts. That's one to three years of serious work for a single person. Most people underestimate by a factor of two at minimum. The community does have genuine strengths. The member base includes people who worked at Douglas during the later production years and people who maintained these aircraft in various military services. Their firsthand accounts of how the planes actually flew, what broke first, and what maintenance schedules looked like are irreplaceable. No amount of reading manuals gives you the same information as a guy who actually worked on the hydraulic system when it was fresh out of the factory.
There are significant limitations to relying on the site as your primary resource. The search functionality is inadequate. Thread organization is poor. A lot of valuable technical data sits in attachments from 2008 through 2014 that may no longer be accessible if the hosting service changes. The moderation is minimal, which means some persistent misinformation goes uncorrected for years. I've seen threads where a builder's incorrect measurement was repeated as fact across multiple subsequent posts with nobody stepping in to flag it. If you're approaching this hobby seriously, you'll need resources outside the forum. The official type certificate data for the DB-7 and its variants, the Douglas service bulletins, and the relevant FAA advisory circulars for homebuilt aircraft give you a factual baseline. The forum is best used for practical problem-solving and sourcing information, not as a substitute for primary documentation. The aircraft themselves are remarkable machines. The DB-7 was fast for its era, structurally robust, and surprisingly versatile in its service roles. It served as a bomber, a night fighter, a reconnaissance platform, and a transport in various configurations. The fact that any of them survive at all is remarkable. The fact that people are still building accurate replicas of them speaks to a level of dedication that most hobbies don't attract.
Doublegunshop is the closest thing to a centralized hub for this activity, even though calling it centralized would be generous. It's where the information pools, however slowly and imperfectly. If you're willing to navigate it carefully, verify what you read, and invest the time that these projects demand, it can be genuinely useful. If you're looking for a clean organized repository of instructions and specifications, you'll be disappointed. Nothing about this hobby or the community that surrounds it is clean or organized.
