January 2018 Issue

Where’s It Say That?

I read Jeb Burnside’s article about ILS and LPV approaches, (“Say Approach Request,” December 2017) and therein was a comment that had me doing internet searches: “I’m sure all of us are completing that paperwork every 30 days, right along with logging when we update the GPS navigator’s database.”

I have always done the 30-day check for my VORs and logged them, but I don’t think that GPS database updates are required to be manually logged as long as the update is done according to the manufacturer’s procedure and that the function test is complete after the update. Would you clarify (and help make us smarter!)?

Thanks for a great magazine!


Travis Brannon
Via email

Good question! It turns out there had been a recordkeeping requirement when updating navigation/flight information databases for installed (e.g., IFR-approved) GPS navigators and flight management systems, but the rule underlying it was changed in 2013. (We really need to update our 1975 copy of the FAR/AIM.)

The applicable FAR is 43.3(k), which was added in 2013 and states, “Updates of databases in installed avionics...are not considered maintenance and may be performed by pilots.” When it published this rule, the FAA specifically stated, “We have considered the comments and agree that it is unnecessary for the pilot to make a record of the update. Recordkeeping requirements for the pilot have been eliminated.”

There are some conditions, including disassembly must not be required, no special tools or equipment should be necessary, and the update must be capable of being “initiated” from the flight deck; which covers physically exchanging database cards or updating over ground-based wi-fi. Hope this helps, and thanks for asking!

Maneuvering Speed

A very well-written article about the 2015 Van’s RV-7 crash in Hurricane, Utah (Accident Probe, December 2017), but I think Mr. Burnside could have devoted a little more time emphasizing the dynamics of gross weight and the adjustment of maneuvering speed to compensate. The concept seems counterintuitive, particularly to inexperienced pilots.

There is a misconception that the lighter an airplane becomes, the bigger the jolt or G load it can withstand. However, if you think of the maneuvering speed as a “safety valve” which will cause the wing to stall just prior to the design load limit, thus unloading it, one realizes the lower the gross weight, the higher the G-load required to stall the wing, which can result in G-loads exceeding the aircraft’s design load limit!

Unless you’re an airshow performer doing aerobatics in turbulence, that doesn’t sound like such a great idea!

Jim Piper
Via email

Space limitations for each month’s Accident Probe often prevent us from diving into all the nuances of a given situation. In December’s article, we were emphasizing the risk of combining increased-G maneuvering flight with turbulent air. We noted, “The NTSB’s probable cause finding combines the G-loading effects of those maneuvers with the atmospheric conditions forecast to exist and concludes the aircraft encountered a wind gust that combined with the G-loading to impose on the airframe loads in excess of its design.” More to your point, however, is the relationship of weight to maneuvering speed, or VA. Our January 2011 issue included an article, “Slow Down, You Move Too Fast,” which stated, “Flying faster than VA when experiencing or anticipating very rough air or applying full control deflection risks aircraft damage, or even loss of the aircraft. The speed is not shown on the face of the airspeed indicator because VA decreases as the aircraft’s gross weight decreases. An easy way to remember this is to imagine a heavy wood log and a same size cork log floating down a stream rapids. Obviously, the cork log will get tossed about more violently.” Even well-designed safety valves must be allowed to operate within their engineering specifications. But you highlight what may be a gap in some pilots’ knowledge about choosing the correct airspeed(s) for given situations. Look for an upcoming feature article on this very topic. Thanks!