Amendments to Aerotow Operations in the UK

In October 2011 a tragic accident happened during aerotow training resulting in the death of a young woman. In a subsequent investigation, the school was found not to be complying with some aspects of the BHPA technical manual. Over the following year, Mark Dale from the BHPA, began reviewing Aerotow operations across the whole of the UK and in early 2013, published new guidelines.

One of the main issues was that of matching the tow speed of the tug (microlight) to that of the hang glider. Previously, this was near impossible due to the unreliability of statistics published by hang glider manufacturers. As part of the review, Mark Dale formulated a table that determined the 'approved' method of aerotowing a hang gliding based upon the aspect ratio of that wing. This is summarised in the table below:

NOTE: This is not the official list and is provided here for illustrative purposes; please refer to the BHPA for the definitive list.

The above list will be maintained and updated by Mark Dale, the BHPA Technical Manager.

The report then discusses the use of fins:

Keel fins have been used since aerotowing became mainstream in the early 1990s. During this 20-year history no reports failures or other issues have been reported in the UK, USA, Germany, France or Australia.

Evidence from the FSC's own flight testing is that aerotowing with a fin creates worthwhile benefits.

Modifications made to certified gliders usually require that the glider be registered, but FSC have decided that fins attached to hang glider keels are not regarded as modifications (so no glider registration is required) provided that their weight, including fittings, does not exceed 0.5kg, the vertical area does not exceed 0.2m2 and the fitment does not compromise the primary glider structure. The keel fitment must also be suitably secure (i.e. no permanent deformation or displacement of the fin following a 5kg side force applied at top of the fin), there must be no protruding elements below the keel that could interfere with a rear trolley support ,and in the case of a removable rear keel the sections must be through-bolted or pinned (not spring-button, etc). Any fins to be used should be flight tested by the Senior Aerotow Coach (SAC) or Senior Air Experience Instructor (SAEI). This should include assessing any pitch trim adjustment to compensate for the weight of fin assembly, high-speed straight flight characteristics and checking for any adverse effects on normal handling off tow. Fins, subject to the definition above, are highly recommended for all aerotow conversion training.

And finally, the use of the tow rope, which was highlighted as one of the non compliances to the technical manual in the accident:

Minimum Aerotow Rope Length for Initial Aerotow Conversion Flights Initial tows in all aerotow conversion training must use a tow rope of 100m minimum length. All the above changes are with immediate effect. Changes to ab-initio Aerotow Training Procedures Other changes have been made to ab-initio aerotow (tandem) training procedures; these have already been communicated to the relevant schools. Aerotow clubs will need to absorb the fact that newly-trained CP Aerotow pilots joining them will have always flown with a fin, and may have no experience of foot launching or landing.

Subsequently, in light of these new amendments, I will be revising the way with which I aerotow on my Sting 3; that's using a 50:50 bridle and no foot launching. Later in the year I will be visiting FlyLight to equip my glider in this configuration. I have also been in discussion with Mark Dale; there may be the possibility (although not yet confirmed), for pilots that already Aerotow to have exemptions permitting them to continue. All this is still being explored, but based on the high bar pressures I've experienced during aerotowing, I'll be actively pursuing the use of a 50:50 bridle option.

• http://www.bbc.co.uk/news/uk-england-derbyshire-21327275
• http://www.bhpa.co.uk/members/safety/inquiry/index.php?