(article) Flying Speed, Part 3

[Wilfred]

We've been reviewing the FAA's list of the Top 10 causes of pilot-error accidents, which includes failure to attain or maintain flying speed. We've already discussed speed control for <STRONG title=http://www.aero-news.net/news/featurestories.cfm?ContentBlockID=59e6d7cb-4bb7-463e-a0b0-2cb8e06c69b9&Dynamic=1>takeoff[/b] and <STRONG title=http://www.aero-news.net/news/featurestories.cfm?ContentBlockID=bb25b465-ed72-4360-b199-684ef2312bf8&Dynamic=1>landing[/b]. Now let's discuss airspeed control in abnormal situations, and in emergencies.

 

Fly the Plane

 

This is the cardinal rule of all aircraft emergencies -- concentrate first on basic control of the airplane, then deal with the emergency. "Fly the plane", more than anything else, means "maintain bank and airspeed control". Hold a constant speed, and you won't trend toward either a spiral or a stall.

 

The Need for (Air)Speed

 

From the NTSB:

 

The pilot obtained a full Direct User Access Terminal (DUATS) briefing the night before the accident. The briefing was not valid for the time of the accident. The National Weather Service (NWS) issued AIRMET Zulu update 3 for icing and freezing level data valid from 1445 CST until 2100 CST. The advisory warned of occasional moderate to mixed icing-in-clouds and in precipitation between 3,000 to 8,000 feet. The departure airport and the accident site were within the boundaries of the advisory. The pilot requested an abbreviated DUATS weather briefing at 1244 EST for his route of flight…. The in-flight advisories were to expire at 1500 CST. The briefing provided several adverse weather phenomena impacting the route of flight from icing, turbulence, and thunderstorms. The pilot stated he was not aware of AIRMET ZULU UPT 3…. The AIRMET was transmitted …over the XM radio installed in the airplane…. The airplane entered the clouds at 5,000 feet on autopilot climbing at 120 knots. Upon reaching 7,000 feet the airplane encountered icing conditions. The pilot informed the controller that he would like to climb to 9,000 feet which was approved. As the airplane reached the cloud tops in visual flight conditions at 8,000 feet the airplane began to buffet. The pilot looked at his airspeed indicator and it indicated 80 knots. The airplane stalled, entered a spin back into instrument flight conditions. The pilot deployed the ballistic parachute system and informed the air traffic controller…. The airplane descended under the parachute canopy into the trees. Probable cause: The pilot's inadequate preflight planning, failure to obtain a current weather briefing, and his decision to operate the airplane into a known area of icing outside the airplanes certification standards resulting in the aircraft accumulating ice, a loss of airspeed, an inadvertent stall/spin and subsequent collision with trees

 

The "Impossible Turn"

 

From the NTSB:

 

The airplane departed runway 33. During the initial climb out, the airplane made a steep roll to the left, pitched down, descended and impacted terrain. A witness said he saw the airplane "in a high left bank like it was trying to land on runway 15. Suddenly, the plane made an abrupt (steep) descent (approximately 45 degrees) nose down. About 50 feet above the ground, it seemed the pilot tried to level off. The plane impacted the ground at a lower angle of attack (I would say 15-20 degrees). An FAA inspector…found the fuel selector valve on the left tank and the left fuel tank was empty. The right fuel tank contained approximately "one inch" of fuel…. There was no fuel in the engine-driven fuel pump, electrically-driven fuel pump, or fuel injectors. Probable cause: the pilot inadvertently stalling the airplane and descending into the ground. Contributing factors were the pilot's inadequate preflight planning/preparation and his failure to refuel the airplane, resulting in a loss of engine power due to fuel exhaustion.

 

Aero-tip of the day: More than any other time, when in an abnormal or emergency situation airspeed control is key to success and, often, survival.