By Pat Veillette
The pilot climbed to 6,000 feet msl to practice aerobatic maneuvers and entered a left upright spin. After two turns, the pilot initiated a forward movement of the stick to recover. Much to his disconcertment, he found that the stick was jammed in the full aft position and wouldnt move.
With the aircraft still spinning earthward, he looked in the rear seat area and discovered that the rear seat back frame had fallen forward, looped over the stick, and was holding it in place. He tried unsuccessfully to reach the seat back and recover. With the aircraft out of control, the pilot was left with no option other than to abandon the airplane. He parachuted to the ground. The aircraft continued to spin until ground impact.
The airplane was supposed to be equipped with a safety cable to hold the rear seat back frame upright. The pilot reported that during the preflight inspection he observed that the safety cable was present. After the accident, a flight instructor told the pilot that the cable had been disconnected from its attach point by maintenance personnel to facilitate access to the aircraft battery and the ELT area behind the rear seat.
The NTSB concluded the pilot failed to ensure all loose items inside the cockpit were secure before attempting the flight.
Loose items pose a particular risk for many reasons. They can jam the flight control systems on rotation and during any kind of maneuvers, particularly after you encounter turbulence. Loose items can fly forward during an abrupt stop or when the air gets bumpy, sometimes causing severe injuries. They can jam doors closed and prevent an emergency egress. And if the airplane should come to grief for other reasons, they become dangerous projectiles during the crash sequence.
Jammed Flight Controls
Perhaps the most troubling of the problems loose items cause comes when something jams the flight controls. One pilot reported the yoke jammed, but by pulling hard he got it unstuck. Post-flight examination revealed a pencil had gotten stuck between the elevator cable and a pulley. If it had been a pen, it might not have broken in half as the pencil did.
Any pilot who has experienced a temporary flight control jam will tell you that it instantly feels like a hopeless situation having no control over the aircraft. During the preflight and before takeoff checks, aircraft manuals tell you to check for freedom of movement of the flight controls.
This really is an important check. For starters, you want to make certain that you can fully move the flight controls to the full extent of the control stops and that the control surfaces move in the correct direction. But while that check may ensure that the flight controls are working properly before you leave the ground, you can have problems in the air if you dont restrain things in the cockpit.
Pencils can wind up in cables, handhelds can slide in front of rudder pedals. Heck, even your headset cord can wrap your arm as you reach for a switch. Before takeoff, every item must be secured – and that includes wires going to portable equipment. Empty seats should be securely latched into position – you might even want to clip the seat belts to prevent them from being in the way during a quick exit.
Loose items such as flight bags must be secured. It is best to minimize loose objects floating around a cockpit – and that includes children and pets.
Jammed flight controls arent the only risk created by loose items. I once attended a scientific conference during which there was a discussion of the high injury rate in EMS helicopter accidents. One of the researchers examined some of the causes of the high injury rate in EMS helicopter accidents and discovered that, upon impact, oxygen bottles were dislodging from their attachment points and striking the medical patients.
Obviously that was the last thing that critically injured medical patients needed. A 20-pound oxygen bottle crashing down on a patient at 15 gs is basically equivalent to a 300-pound weight sitting on you.
Everyone is familiar with the airline requirement that the seatbacks and trays must be in the full upright position and that all of the pre-flight drink and meal items have been picked up. Most general aviation aircraft dont have fold-down trays – unless you count the stowable tables found in airplanes such as Bonanzas, Barons and Saratogas with club seating.
There is a paragraph buried in the back of the FARs, 91.535, that requires a pilot to ensure that any food, beverage or tableware provided by the pilot is secured prior to moving the aircraft. It also requires a pilot to ensure that trays and tables are secured in their stowed positions. This paragraph also addresses movie screens, which are increasingly finding their way into airplanes as portable and installed DVD players.
While that reg specifically mentions food, beverages, tableware, trays, serving carts and movie screens, its important to extend that thinking to apply to all loose items. You may think that a pencil has negligible mass, but its a different story when it comes catapulting through the cockpit during a sudden impact. And if the pencil can be a threat, imagine the whollop an unsecured flight bag, suitcase or tool box might carry.
A 30-pound bag just flung into the back cargo compartment and not adequately constrained is going to feel like a Mack truck during a sudden stop. This is reason number two that all loose items should be secured before takeoff and landing, and controlled during flight. Reason three is closely related.
Even if that unsecured bag doesnt conk you, it can pose a problem if you need to exit the airplane quickly. The last thing you want during an emergency egress is to have the door blocked or jammed by debris.
An accident scene is chaos. Its likely that the fuel tanks and fuel lines will rupture, spilling fuel around the wreckage. Any source of ignition, such as a sparking battery, can potentially ignite the fuel. Once the aircraft comes to a stop, you may only have a very short time to get out before a fire starts.
Speaking of emergency egress, there is a paragraph deep in Part 91 requiring that cargo be kept from blocking emergency exits. Part 91.525 is very specific in that all items have to be properly restrained. If you place cargo in a cargo area, the cargo should still be secured.
Use a cargo net to secure the cargo in place and to prevent it from blasting forward during an impact. (For the record, that cargo net needs to be certified.) If the cargo is in a separate compartment, it needs to be loaded so that the pilot can effectively reach all parts of the compartment with a hand fire extinguisher.
Now, since the baggage space in most general aviation aircraft is on the limited side, you may find yourself wanting to place some of the items on a passenger seat. Thats allowed, as long as it is properly secured by a seat belt to prevent shifting under anticipated flight and ground conditions. The weight of the package must be within the loading limits for the seat. Baggage is not allowed to block an emergency or regular exit.
Miscellaneous Loose Items
Loose items can also cause trouble through distraction. I once had a student who accidentally knocked open the latch on the cockpit window as he was trying to refold a chart. The sudden rush of noise and air was very distracting.
Cockpit disorganization is, of course, a contributing factor in many accidents. Kneeboards are very valuable devices for organizing your charts, radio frequencies and airport information for a flight.
However, there is a possible drawback to using a kneeboard in an impact sequence – particularly if the kneeboard is metal. There is merit to considering the size, shape and material of any kneeboard or lap board and how this could possibly cause further injury during a rapid deceleration.
During the critical phases of flight, such as takeoff and landing, it might be advisable to securely store the kneeboard. You really dont want a kneeboard that can interfere with your movement in case of an aborted landing or an emergency egress. A yoke clip can function to hold your charts for the takeoff and departure phase if your kneeboard interferes with your range of motion.
Whether it be knee boards, pencils, beverages, approach plates, seat belts, or empty seat backs, you really need to make certain that all loose items are adequately secured at all times. It is just too easy for a loose item to create a potentially serious problem. This is definitely a case in which a small amount of proactive attention is valuable in preventing worse problems.
Pat Veillette is an aviation safety researcher and transport category pilot.