 Whip Stall and Tumble Awareness A Scenario As discussed in chapter 2, the WSC aircraft does not have a  tail with a vertical stabilizer similar to an airplane, and there  is the possibility of the wing tucking and tumbling. If a WSC  tumbles, this will most likely result in a structural failure  of the WSC and serious injury or death to the pilot and/or  passenger. It is most important for the pilot to understand  tumble awareness and use all means to avoid such an  occurrence. The pilot can avoid a tuck and tumble by: Flying within the manufacturer’s pitch and airspeed  limitations is simply adhering to the POH/AFM limitations.  Depending on the manufacturer, this could mean no full  power stalls, not exceeding pitch limits of ± 40 pitch angle,  not flying below the safe flying speed in turbulence, etc.  Manufacturer’s limitations are provided for the specifi c  aircraft to avoid tucks and tumbles. Preflight preparation is the first step to avoid the possibility  of a tuck/tumble to avoid flying in strong weather conditions.  This could be strong winds that create wind shear or strong  convective thermals that create updrafts and downdrafts. This  weather analysis is part of the preflight preparation weather  analysis. The second pilot decision regarding appropriate  weather while flying is to look at the environment during  flight to understand and evaluate the situation. Weather  conditions should always be evaluated as the fl ight progresses  with ADM used to determine the best outcome for the  situation. This could be turning back or landing depending  on the situation. As a student or pilot progresses, turbulence will be  encountered. Use the procedures for flying straight and level  as shown in  Figure 6-8.  Use this exercise as a foundation for  developing pitch control awareness to keep the wing managed  with proper control bar pitch and throttle control. For high pitch angles, the POH may have specifi c procedures  that should be followed for the particular WSC aircraft,  but the following general guidelines are provided. After  reviewing the aerodynamic aspects of the tuck/tumble in  chapter 2, refer to the following tuck/tumble awareness and  avoidance procedures.  As defined in the aerodynamics section, a whip stall is a high  pitch angle when the tips stall because they exceed the critical  angle of attack. This can be the result of strong turbulence  or power-on stall, pilot induced, or any combination of  these factors. A pilot must avoid all of these factors to avoid  the possibility of a whip stall resulting in a tumble, but the  following procedures are provided for tumble avoidance  in case a whip stall or a nose rotating down below the  manufacturer’s limitations is encountered. The aircraft rotates nose down.  [Figure 6-23,  Whip Stall  to  Phase 1]  Push the control bar out to the  front tube and level wings while increasing to full power  and keeping control bar full out to reduce overpitching.  [Figure 6-23, Phase 1  to  Phase 2]  If rotation is so severe that  it progresses to phase 4 and the WSC aircraft is tumbling, the  ballistic parachute (if so equipped) should be deployed. There are other weather situations in which the nose is not  at a high pitch attitude, where the back of the wing can get  pushed up and enter phase 1 without an unusually high pitch  attitude or whip stall. If pitched nose low, increase to full  power while pushing the control bar full out to reduce nose- down pitching rotation. Generally, the control bar full out  and full throttle create a nose-up moment. It takes extremely strong weather conditions and/or pilot  error to tuck/tumble a WSC aircraft. Experienced pilots fl y  all day in moderate turbulence, but building experience fl ying  in turbulence should be approached slowly and cautiously to  determine the pilot and aircraft capabilities and limitations.  The following is one example of a scenario that could lead to  a tuck/tumble. It is based on a viable training program in one  location but lack of experience in another location. A student obtains his or her pilot’s license with the minimum  number of hours for the pilot certificate. The new pilot trained,  soloed, and obtained his or her license only in conditions near  the ocean where there was typically an inverted midday sea  breeze with little to no convective turbulence (thermals). This  developed confidence for flying in winds up to 15 knots but  no experience was gained in thermals. In fact, the pilot was  not aware that strong thermals could be hazardous.  Now, with a new license, the pilot visits his parents in the  middle of the high desert of Colorado. Unfamiliar with  the local conditions, the new pilot gets a weather report  of winds to 15 knots, something the pilot has experienced  before. By the time the pilot arrives at the airport, discusses  the situation with the airport officials, and sets up the WSC  aircraft, it is 2:00 in the afternoon. The wind is generally calm  but increasing to 15 knots occasionally. There are towering  6-24 •  Flying within the manufacturer’s limitations.  •  Flying in conditions that are not conducive to tucks  and tumbles. •  Obtaining the proper training in pitch stability for the  WSC.