Avox Systems, the Zodiac Aerospace Oxygen Systems subsidiary, has earned regulatory approval for a “plug-and-play” lavatory emergency oxygen system that satisfies what industry fears is a costly directive with a challenging compliance window, Aviation Week has learned.

The product, branded LavOx, was granted FAA supplemental type certificate (STC) approval for the Boeing 737NG series this week after a successful demonstration on a Sun Country 737-800 last month. Similar approvals have been granted by Brazil’s ANAC for Embraer jets and Transport Canada for all Bombardier regional jets, says Avox VP-Engineering and Technology Ashok Jain, who believes his company is first to market with an approved system for any aircraft.

Carriers need LavOx or an equivalent product to satisfy a June 2012 airworthiness directive (AD) that requires installing tamper-proof lavatory passenger oxygen systems by September 10, 2015.

FAA in 2011 ordered operators to remove or disable existing oxygen generations to prevent passengers from using them to start fires. The June 2012 directive laid out the timeframe for installing new units, giving operators 37 months to complete the work. FAA originally proposed a 24-month window, but industry expressed concerns that a compliant system wasn’t available, and that the downtime required for the work significantly disrupt flight schedules if it couldn’t be done during scheduled maintenance checks (DAILY, June 27, 2012).

Jain says the LavOx design eliminates those concerns. Avox studied lavatory oxygen systems on many types of aircraft and designed LavOx to be “directly interchangeable” with the old oxygen generators. Variances in the installations are accounted for through sets of collars and other hardware that adapt LavOx to what’s already on each aircraft.

“There are absolutely no changes required on the aircraft side,” Jain tells Aviation Week.

The system factors in more than just delivering oxygen to a passenger, he explains. For instance, on some aircraft, leaked lavatory oxygen gets routed into the cabin. On others, the system keeps it within a panel in the lavatory. LavOx works with both types, Jain explains.

“Our approach has been a systems engineering approach,” Jain says. “We didn’t just look at the lavatory oxygen part. We focused on performance, installation, discharge, maintenance, reliability--the entire life cycle process.”

LavOx’s system uses the same metering assembly and offers three different sized bottles with oxygen duration capacities up to 22 min. to meet existing regulations and installations.

The system includes compressed gaseous oxygen in a single-use, sealed steel cylinder and a brass activation assembly, Jain explains.

The bottles are designed to be leak-proof and maintenance-free for at least 15 years, says Jain.

Jain says installation can be done in as little as 15 minutes on aircraft that still have the installation hardware from the old systems. Most U.S. carriers disabled their systems without puling the entire hardware box, Jain says, while some foreign carriers removed the hardware as part of disassembly.

Now that the first STCs are done, Jain is confident that approvals for other aircraft will quickly follow. Jain says Avox is working with

“several major airlines” for follow-on orders and certification on six more aircraft types.

Jain estimates that 40,000 lavatories need new systems by next year’s deadline. Avox’s Lancaster, N.Y. factory is working three shifts in anticipation of a fast ramp-up.