Safe Landings - May 2011
It has been said that the only voluntary act in aviation is the decision to take-off. Every action after take-off involves the skillful management of risk, the enjoyment of flight and a continuous stream of decisions that result in a safe landing.
In 1974, NASA created the Aviation Safety Reporting System (ASRS) to allow aviation professionals to share experiences in a frank, non-punitive manner. The ASRS structure allows pilots and other aviation professionals to file an anonymous report of an incident, error or occurrence that the contributor feels might be of value to others. These reports are gathered, analyzed and data based by NASA experts and made available to all interested parties as a tool for creating pro-active aviation safety programs. Additionally, NASA distributes an electronic publication, “CALLBACK,” which contains selected, de-identified, reports on a free subscription basis. In Flight USA is proud to reprint selected reports, exerted from “CALLBACK,” for our readers to read, study, occasional laugh at and always, learn from. Visit http://asrs.arc.nasa.gov/ to learn how you can participate in the ASRS program.
Motor Skills: Getting Off to a Good Start
A motor skill is a learned sequence of movements that combine to produce a smooth, efficient action. This month’s we look into another type of motor skill- the skill required to produce a smooth, efficient (and safe) aircraft engine start.
Lesson One: Know Your Crew
This pilot was familiar with the proper procedures for hand-propping, but despite a conscientious effort, one critical assumption led to a nose-to-nose encounter. One should also note that training was an issue in this event. Anyone sitting behind the controls of an airplane, alone, with the engine running, should be ready and capable of flying that plane.
• I was going to fly a 65 HP taildragger with no electrical system and no starting system. It requires the pilot to hand-prop the engine and either requires the aircraft to be tied down or a person to hold the brakes…. [I] instructed the passenger how to hold the brakes and how to pull the throttle to idle after engine start. Both holding the brakes and pulling the throttle to idle had been practiced. The passenger was in the rear seat, with the seatbelt fastened. After hand propping the engine, I noticed what sounded like an increase in engine rpm and the aircraft started to move forward rapidly. I got out of the way of the moving aircraft and around to the door. I was halfway inside the aircraft getting the engine to idle while telling the passenger to push the brakes when the aircraft struck a parked Cessna. The aircraft hit nose-to-nose…. The aircraft had traveled approximately 25 yards across the tarmac. [There was] prop and cowling damage…and both passenger and pilot were unhurt.
I had incorrectly assumed that the passenger would be able to hold the brakes after engine start and I placed too much confidence in the abilities of a non-pilot…. The very act of hand-propping an aircraft is dangerous and I will never again pull the prop through without the aircraft being tied down…. Even 65 HP is enough to overpower the person starting the engine.
Lesson Two: What “Should Have” Been Done
Resorting to hand-propping due to a faulty battery could lead to the aircraft taxiing on its own for about 100 feet before being stopped by a collision.
• The aircraft was pulled from the tie-down spot and turned 90-degrees for starting and taxi to the hangar. Due to a weak battery the aircraft did not start. The wheels were chocked for hand-propping and the throttle was cracked open. When the engine started, it revved up to approximately 1,800 RPM and then the aircraft rolled over the chocks and proceeded ahead about 100 feet where it contacted a parked aircraft. There was minor damage to both aircraft, but no injuries beyond a scraped knee when [I] scrambled from the rotating prop and fell under the wing. The chocks were insufficient to hold the airplane past a certain engine RPM.
The brakes should have been set. The tail should have been secured as well. The throttle setting should have been lower. A second pilot in the cockpit holding the brakes and controlling the throttle would have been best.
While it is possible to find any number of published recommendations and checklists for solo hand-propping, it remains an extremely dangerous practice. The best procedure is to follow the Federal Aviation Administration’s advice found in the Airplane Flying Handbook (FAA-H-8083-3) which states in part: “An engine should not be hand-propped unless two people, both familiar with the airplane and hand-propping techniques, are available to perform the procedure…. The procedure should never be attempted alone.”
