Ground loops and prop strikes

A ground loop is not violent at the start. The tail moves a few inches to one side, and the airplane, which has been going where you pointed it, begins going where it wants. There is about a second in which the rudder will still fix this. After that second the airplane finishes the maneuver on its own.

The mechanism is one fact about where the wheels are. In a tricycle-gear airplane the mass sits ahead of the main wheels, so a yaw pulls the nose back into line and the airplane straightens itself. In a taildragger the mass sits behind them. A yaw swings that mass outward, the swing increases the yaw, and the yaw increases the swing. It does not settle. It accelerates.

That is why the correction has to start before you have finished noticing the problem, and it is why the first lesson is spent taxiing.

• Landing with lateral drift. The wheels are going one way and the airplane is going another, and the moment they touch, the mass keeps going where it was going.
• Losing directional control on rollout as the rudder becomes less effective and the tailwheel has not yet taken over.
• Braking to steer, which works until the day it puts a wheel on the ground harder than the other.
• A crosswind taken without the windward wing down.
• A bounce answered with hope rather than with a decision.

A ground loop that scrapes a wingtip is a few thousand dollars.

A ground loop that ends in a prop strike is not. A prop strike means a replacement propeller and the teardown inspection the engine manufacturer's service bulletin calls for, and on an engine this old that inspection tends to find other things. Five figures is the ordinary outcome, not the bad one.

Your responsibility is North Aero's hull insurance deductible, currently $3,200, and never more than $5,000. North Aero's policy carries the rest. Aircraft Rental & Flight Instruction Agreement §8(b) sets the cap, and it applies regardless of fault.

The cap has limits worth knowing. It does not apply where insurance is denied because of a breach of the rental agreement, operation outside the FARs or the aircraft limitations, flying while not current or checked out, or operating under the influence. In those cases the full loss is yours.

North Aero recommends non-owned aircraft insurance and does not require it.

Understand what it is for. It covers your deductible exposure and your third-party liability. It does not cover the hull, because North Aero's policy already does. So the number you are insuring against is $3,200 and whatever a third party might claim, not the cost of the airplane.

That is a small policy and an easy decision. Aircraft Rental & Flight Instruction Agreement §8(d) records that North Aero has advised you to obtain it, and that a decision not to is yours.

From Aircraft Rental & Flight Instruction Agreement §15(b), and this is the part worth remembering in the ninety seconds afterwards:

If the Aircraft leaves the taxiway, runway, or paved surface for any reason during taxi, takeoff, or landing, Renter shall IMMEDIATELY stop the engine and shall NOT move the Aircraft until North Aero personnel have inspected it and assisted in repositioning it.

Stop the engine. Leave the airplane where it is. Call.

Do not taxi back to the ramp to see whether anything is bent. A propeller that struck the ground turning is a different repair from one that struck the ground stopped, and moving the airplane can convert damage you can see into damage you cannot.

Then report it. §15(c) requires you to report any damage, accident, or incident as soon as possible, and to cooperate with North Aero and its insurer.

The airplane is grounded until it has been inspected. If a claim is made, you will be asked for a written account of what happened while it is fresh.

Nobody loses their membership over a ground loop. People lose it over not reporting one.