Just a precaution.

In a comment to yesterday’s post about my work drying cherries, Miraz asked:

Could you write a post about your Nomex flight suit. What is it? What’s special about it? Why don’t you just wear whatever you normally wear when flying?

A good topic for a post, so here it is.

First, Nomex. Wikipedia describes Nomex as follows:

Nomex (styled NOMEX) is a registered trademark for flame resistant meta-aramid material developed in the early 1960s by DuPont and first marketed in 1967.

It can be considered an aromatic nylon, the meta variant of the para-aramid Kevlar. It is sold in both fiber and sheet forms and is used as a fabric wherever resistance from heat and flame is required […] Both the firefighting and vehicle racing industries use Nomex to create clothing and equipment that can withstand intense heat. All aramids are heat and flame resistant but Kevlar, having a para orientation, can be molecularly aligned and gives high strength….

The Wikipedia piece goes on to list the different uses of Nomex fabric, including this statement:

Military pilots and aircrew wear flight suits made of over 92 percent Nomex to protect them from the possibility of cockpit fires and other mishaps.

Here’s an example of a flight suit available on Flightsuits.com. (And no, it doesn’t come with the guy.)

It’s not just military pilots. Nomex is also widely used in flight suits worn by EMS pilots and crew members and law enforcement pilots.

A flight suit is usually a one-piece, zip up garment, often with many pockets, that is worn by pilots and aircraft crew members. While they come in many colors and styles, they’re usually a military green or khaki color. The green suits (see photo) are sometimes referred to by the folks who wear them as “pickle suits.”

Flight suits can be made of any fabric, but since they’re available in Nomex, it seems silly to wear one that doesn’t offer the additional protection of the Nomex fabric. And although they come in long sleeve and short sleeve styles, it also seems silly to have Nomex protection on only half of your arms when you can get full arm coverage.

At least that’s the way I see it.

Why does a pilot need protection at all? Well, it’s mostly to save your life (or even just your skin) in the event of a post-crash fire. And fires are definitely possible when you’re carrying fuel (which you should be) if you hit the ground hard in a crash.

Robinson Helicopter Company recommends that all pilots — and even passengers! — wear flight suits. Safety Notice 40 was released in July 2006, possibly in response to an accident with a post-crash fire in Texas. Robinson often releases Safety Notices in response to what it sees as dangerous or potentially dangerous situations. Safety Notices are not requirements; they’re suggestions. They’re also Robinson’s way of “covering its butt.” The company is owned by Frank Robinson and is self-insured. By recommending that we wear flight suits, Robinson Helicopter cannot be held accountable for burn injuries if we’re not following their recommendation.

That’s not to say it isn’t good advice. It is. But it isn’t exactly practical to require every person on board a flight to wear a flight suit. And while I might be tempted to wear a flight suit more often if I actually looked good in one, I don’t. Besides, I’ve decided on a more professional “corporate pilot” appearance for my charter flights: slacks with a polo shirt or pilot shirt.

It’s a matter of risk assessment. Tour and charter flying has much lower risk associated with it. I’m usually operating at airports, landing and departing from locations very suitable for that kind of activity. Flight profiles remain outside the “deadman’s curve.” There isn’t anything unusually risky about these flights. Even most of my photo and survey flights are relatively low-risk.

But hovering 5-10 feet over cherry trees at 5-10 knots ground speed puts me firmly into the deadman’s curve. If I have an engine failure, there’s nothing I can do to prevent a messy crash into the trees. With lots of fuel on board, a post-crash fire is possible. Wearing a Nomex flight suit seems like a pretty good idea.

A helicopter helmet like the one I wear. This is a low-cost model available from AviationHelmets.com.

So does wearing a helmet. I can’t tell you how many articles I’ve read in helicopter flying magazines about the importance of wearing a helmet on high-risk missions. The main thing that worries me is the flinging parts that might just enter the cockpit in the event of a crash. It would be awful to have a soft landing only to have a main rotor blade enter the cockpit and split your head open like a coconut. (Ick. What a terrible visual.) Or even to just clock your head on the door frame hard enough to cause serious damage. The helmet protects me against this.

But I don’t think my passengers would feel very comfortable if I wore it on a charter flight.

So, in answer to Miraz’s question, I wear a flight suit for cherry drying because of the increased risks associated with that kind of flying. I don’t wear it for other, less risky missions because I’m trying to maintain a “corporate pilot” professional look for my passengers. And I look like a big khaki sausage in my flight suit.

Fortunately, the cherry trees — and growers — don’t care what I look like.