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AOPA concerned with actions proposed in Raytheon SB-27-3205 regarding control gust lockAOPA concerned with actions proposed in Raytheon SB-27-3205 regarding control gust lock

March 16, 1999

Mr. T. N. Baktha
Federal Aviation Administration
Wichita Aircraft Certification Office
Mid Continent Airport
1801 Airport Road, Room 100
Wichita, KS 67209

Dear Mr. Baktha:

Thank you for contacting the Aircraft Owners and Pilots Association (AOPA) concerning the developing issue involving flight control gust lock devices on various models of Raytheon Beechcraft twin-engine aircraft. AOPA believes it is critically important to have a high level of coordination between industry and the Federal Aviation Administration (FAA) on all matters affecting airworthiness. The present issue serves as an example of how FAA and industry coordination efforts can lead to safer, more affordable methods of remedying airworthiness concerns.

In Service Bulletin SB-17-3205 Raytheon states that it has received one report of an accident in which the pilot attempted takeoff without removing the flight control gust lock. To prevent further incidents of this nature, Raytheon issued SB-17-3205 and has recommended that the FAA issue an airworthiness directive (AD) requiring the drilling of a new hole in the control column and the installation of a newly designed flight control gust lock. Although Raytheon�s proposed actions may remedy the above mentioned situation, AOPA maintains that there are several more practical and affordable solutions that would similarly reduce the likelihood of a pilot attempting flight with the gust lock installed. Furthermore, a search of the available accident and incident data reveals that this sort of problem has occurred only three times in over thirty years. AOPA maintains that this level of incidence does not warrant FAA issuance of an AD.

AOPA�s primary concern with the actions proposed in Raytheon SB-27-3205 lies in the very nature of the problem itself. A pilot�s failure to remove a flight control gust lock prior to attempting flight raises several operational concerns having nothing to do with the airworthiness of the aircraft. An examination of the three incidents involving failure to remove the gust lock prior to take-off brings into question specific operational tasks common to all aircraft such as completeness of pre-flight inspections, proper use of checklists, and proper taxi techniques. If the pilots involved in any of three incidents had correctly completed just one of these actions, the flight control gust lock would have been discovered and removed long before takeoff was attempted. For this reason, AOPA maintains that the issue at hand is an operational issue, rather than an airworthiness concern.

As a remedy to this minor issue, Raytheon has proposed actions that require removal of the flight control column, drilling a new gust lock installation hole, and installing a new flight control gust lock. FAA cost estimates indicates that this modification will cost a minimum of $1200 per aircraft. Based on the very low incidence of occurrence combined with the significant cost associated with the proposed modification, AOPA feels that this problem does not warrant such invasive or costly actions.

Rather than reworking the control column and installing a newly designed gust lock, AOPA recommends that the FAA issue a Special Airworthiness Information Bulletin (SAIB) reminding pilots to remove the gust lock prior to attempting flight. Such an SAIB would be mailed to all affected registered owners in the same manner as an AD, but it would focus on addressing the true operational nature of the problem rather than trying to modify the aircraft. It is our belief that the flight control gust lock concerns can be resolved without the issuance of an AD by heightening the awareness of the problem to the pilot community. AOPA and FAA together have experienced tremendous success in reducing accident rates due to specific operational or airworthiness problems in the past simply by informing and educating the general aviation pilot and aircraft owner communities of specific problems. We believe that similar success could be achieved in this instance.

If however, the FAA feels that the issuance of an AD is the only appropriate means to remedy this situation, AOPA recommends that the FAA require more appropriate compliance actions than those outlined in Raytheon SB-27-3205. It is common knowledge among pilots and owners of the affected airplanes, that the plastic warning flag and its associated cable designed to warn the pilot that the gust lock is installed has a tendency to break off. When this occurs, few pilots or owners bother to replace it. If against our advice the FAA feels that an AD must be issued, AOPA recommends that the FAA simply require that the warning flag and its cable be maintained or installed on all flight control gust locks listed in SB-27-3205. This particular action is relatively inexpensive, does not run the risk of compromising the flight control system through improper conduct of the procedures outlined in SB-27-3205, and focuses on the underlying cause of the incidents and accidents, pilot inattention and awareness.

In summary, AOPA recommends that the FAA issue a Special Airworthiness Information Bulletin reminding pilots of aircraft listed in Raytheon SB-27-3205 to remove the flight control gust lock prior to attempting takeoff and highlighting the dangers and consequences of failing to do so. However, if the FAA feels an AD is required, AOPA recommends that the AD focus on maintaining and using the warning devices already a part of the existing gust lock system.

Thank you for your time and consideration on this matter. AOPA stands ready to provide any assistance necessary in reaching a safe, effective, and affordable solution to this situation.


Douglas C. Macnair
Regulatory and Certification Policy