Aircraft sign-towing

 

EAC91-3.1 Applicability:

The rules mentioned in this circular apply to aircraft registered in Egypt and certified in aerial work category and intended for use in sign-towing aerial type of operations.

 

EAC91-3.3 Responsibility for compliance with the rules of this circular:

The pilot in command of an aircraft certificated for sign towing type of operations shall, whether manipulating the controls or not , be responsible for the operation of the aircraft in accordance with ECAR's, except that he may depart from those regulations only in emergency circumstances that render such departure absolutely necessary in the interests of safety.

 

EAC91-3.5 Eligibility:

To be eligible for aircraft sign-towing  certification; it is necessary to get an approved tow hook installation on the towing airplane, and have a tow pilot that meets the requirements for this type of rating and the operator must have the facilities to maintain and operate the aircraft under this certification in accordance to the requirements specified in this circular .

 

EAC91-3.7 Type certification requirements for sign tow release installations:

(a) Tow release installations on certificated aircraft must be approved by the ECAA.  This approval can be accomplished by either of the following methods:

(1) Approved original equipment item:

Here the aircraft manufacturer designed, tested and received a type approval for the tow hook installation as a part of the approved equipment items for a specific aircraft. In this case the design and manufacture organization shall supply the ECAA with the declaration of design and performance containing at least the following:

(i) Particulars identifying the aircraft and its design standards including references to the specifications to which it is designed, and a record of drawings.

(ii) Any limitations applying to its use. This shall include limiting conditions implicit to the design and the ability of the various items to perform under different ambient conditions.

Note: All aircraft, modifications or equipment related to sign towing manufactured in the A.R.E. shall, in general, be designed and constructed under the supervision of an organization approved by the ECAA for that purpose, and in compliance with the relevant technical standards.

(2) Supplemental type certificate approval

Here one can design, engineer and test (in accordance with the relevant technical standards) and obtain approval of an installation on a specific airplane model under the provision of an ECAA supplemental type certificate. This installation can be accomplished on other aircraft of the same model with the approval of the supplemental type certificate holder.

(b) The aircraft design and manufacture organization, in conjunction with the aircraft sign towing design and manufacture organization, shall prepare the relevant installation, maintenance and operations manuals or such parts thereof as are appropriate.

 

EAC91-3.8 Specific maintenance and inspection requirements

(a) A continuous maintenance and inspection program should be conducted on the aircraft and supplemental sign towing installations through an approved maintenance organization .

(b) To assure proper release operation after attachment of a tow hook assembly to the structure, a proof test must be accomplished after each new installation not previously tested.

(c) Care should be taken to attach  the appropriate tow rope applicable for each  flight condition and landing field according to the related instructions in the manufacturer's manual.

 

EAC91-3.9 Specific sign towing operation requirements :

 (a) If the tow rope is dropped, care has to be taken to see that the proper end is attached to the tow plane. If not, in an overload condition, the weak link could fail at the tow plane end.

(b) Tow planes landing with their tow ropes attached should be avoided because weak links may fail and release prematurely.

(c) No aircraft shall be flown for sign towing without a flight permit from the appropriate air traffic service unit.

(d) Aircraft shall not be flown for sign towing in a prohibited area or in a restricted area, except in accordance with special authorization from the appropriate authorities having jurisdiction over those areas.

(e) Aircraft shall not perform sign towing operations over congested areas except at such height permitted by the authorities controlling those areas and the altitudes permitted in the manufacturer manual for proper and safe operation  and to allow  in the event of an emergency, a landing to be made without undue hazard to persons or property on the surface.

 

EAC91-3.11 Application

(a) The applicant should be either a holder of a valid air operator certificate or contracting with a holder of such a certificate, otherwise he should apply for an air operator certificate along with this application.

(b) Application should be submitted to the Executive Chairman of the ECAA using the appropriate form issued for that purpose , along with the related fees.