It was noticed over a number of years there have been a number of fatalities to participants in hang glider aerotow instruction. The president of the USHPA, therefore, formed an Ad Hoc Joint Committee of the chairs of Safety and Training, Tandem and Towing to investigate this, appointing the Chair of Safety and Training to preside. Tandem instructors, Matt Taber and David Glover were invited to participate.
This committee reviewed a number of possible causes for aerotow tandem fatalities. One particular possible cause stood out as predominate. This was the common belief that when a glider gets low on tow the pilot can safely push out and let the glider climb up to the level of the tow plane safely because the glider will not stall under tow.
This issue is so important that this committee and the towing committee have recommended that the following message be sent to all aerotow pilots and all Aero-Tug pilots with a particular emphasis to aerotow tandem pilots.
Experiences in hang glider tandem flight using aero-tow launch along with analysis of accidents and incidents that have occurred during such flight strongly suggest, for safety reasons, the following cautions be observed.
If the pilot of the tandem glider finds that he/she is too low behind the tug and slow enough that the glider will not climb without pushing out pass trim, then the pilot should pull in and release rather than trying to push out and climb to the tug altitude. Though pushing out to climb to the tug altitude has been a common practice usually accomplished without incident, there is a deep underlying danger in doing this. Should the tandem glider become unattached from the tug during this maneuver, the nose high attitude of the tandem glider attained while doing this will cause a very abrupt stall which will result in a much greater altitude loss than one would expect (possibly more than 750 ft.) The most extreme cases may result in structural failure of the glider.
Towing tandems requires extra awareness on the part of the tug pilots, particularly in the early part of the tow to help the tandem pilot avoid the development of critical situations. Prior to the start of the tow, proper tow speeds based on the gross weight of the tandem glider should be determined. Greater total weight will require correspondingly higher tow speeds. It is CRITICAL to understand that the towed hang glider is at risk when the tow is slow and the glider is low. When towing a tandem glider, the tug pilot should fly the appropriate airspeed to keep the tandem glider in the proper position and if there is any doubt the tug pilot should fly slightly faster and avoid flying slightly slow.. The tug pilot should avoid pulling up abruptly and leaving the tandem glider low. If the glider is low on tow, the tug pilot should attempt to speed up and to descend to the altitude of the towed glider, releasing the tow rope only as a last resort.
These points are crucial to the safety of aerotow tandem flight. However, this letter is addressed to all aerotow rated pilots and tug pilots, not just to tandem pilots. This is because in consulting with pilots about this issue, we found that this problem is exhibited under the same circumstances with solo gliders as well. Because of the lighter wing loading of the solo gliders, the reaction of a solo glider is not as severe, but can still be violent.
To insure that all AT rated tandem pilots are notified, we are asking that the AT-rated tandem pilots sign on to the USHPA web site (www.ushga.org) and fill out a form that states that they have read and understand the safety notice. If you are an AT-rated tandem pilot and do not have computer access (ie. no email address) you will be sent the form to fill out and sign, and a USHPA addressed, stamped envelope. Understand that we are not asking if you agree with the safety notice, but that you have read it and understand what it says. You will need to do this in order to have your tandem rating renewed.
Flying with a tandem passenger is a special privilege which the FAA allows us to grant to qualified pilots. These pilots are supposed to be highly skilled. We expect tandem flights to be safer than solo flights, not more dangerous. Safety records do not currently seem to support this expectation. We expect tandem flights under the rules of the USHPA to be conducted in such a way that this expectation is realized.
David G. Broyles, Chairman of Safety and Training Committee
Steve Kroop, Chairman of Tow Committee
Paul Voight, Chairman of Tandem Committee