The International Cessna^® 170 Association

The FAA "clarification" you provided is not a rule change. It is a discussion of how the FAA interprets the rule and in its conclusion appears to "recommend" that pilots make a determination rather than requiring them to do so. The author points out the difficulty the FAA has in changing or adding rules. This resulted from an NTSB recommendation and I don't think it has been widely disseminated. It is an interesting document, however, and I applaud your efforts to obtain an STC for adding an additional seatbelt as oppose to sharing one of the 2 installed. I have heard stories of pilots getting in trouble with the FAA for having too many occupants on an airplane but it takes a specific Flight Manual or TCDS restriction to sustain an enforcement. Your STC makes your operation entirely legal and is well worth it. My point was that we should make decisions based on our experience, integrity , and compliance with safety rules, not in fear of an FAA inspector. Thanks for your reply and your investment in safety.

I agree wholeheartedly that a pilot's decision making process should be based on experience and integrity and not out of fear of an FAA inspector. As a professional pilot, my decision process always starts something like this ... Is it safe? Is it legal? Is it the right thing to do? I don't ask myself if it's legal out of fear of an inspector or enforcement action; however, the reality is that if it's not legal, it's probably not safe or practical and enforcement action could result.

Furthermore, the 170 TCDS specifically states that it is a 4 place airplane, as does the owners manual (on the linear graph of the W&B section). So is it legal to carry 5 passengers in a C170? Not without legal modification ... the STC is that legal modification.

TCDS (Type Certificate Data Sheet) (reference page 2 - Number of Seats)
http://rgl.faa.gov/Regulatory_and_Guida ... /A-799.pdf

Owners Manual (reference page 40 - "Front Seats 2" - "Rear Seats 2")
http://www.bowmaneagles.com/documents/C ... Manual.pdf

And, as a 170 owner thank you for getting this STC!

The Owner's Manual is not an approved document and has no legal bearing. The TCDS describes the number of seats but does not limit the number of occupants.
In earlier times it was common for more than one occupant to share a seat belt. (It was also under different belt certification rules which are no longer valid.)

In a related matter, it was also required under earlier rules that the baggage compartment door be locked if a child's seat was installed/utilized in the baggage compartment. Today, if the bag-door is considered an emergency egress exit then it may not be locked if the compartment is occupied.

The point I wish to make is that the FARs...AND...good common sense changes over time as we learn from previous experiences and accidents. I agree with modern practice that each occupant should have an individual, dedicated restraint/seat-belt.

Matt, if you are marketing this as a commercial-venture, you might consider placing an ad in The 170 News, The Directory, and in the TradeMart.

Sold the first STC to an Alaska based Cessna 170B last week ...

Matt, again, please observe the rules and do not advertise in this area of the Forums. Thank you.