BMAA Defect Alert #0052: Semperit Fuel Hose FUB 386 3Q/2014 Update: 11/06/2015 Skydrive have realised an updated version of Service Bulletin titled: Safety Bulletin 040615 –
Issue 2, a copy of which is attached to the end of this alert.
Please assist with the promulgation of the bulletin, but please note this official BMAA comment: ‘The BMAA endorses the diligent investigation and promulgation of the alert bulletin produced by Skydrive regarding Semperit FUB386 3Q/2014 fuel hose. Following distribution of the bulletin the BMAA and Skydrive have discussed the requirement for BMAA Inspector sign‐off. As this is an owner maintenance activity, there is no requirement for a BMAA Inspector to sign‐off the replacement fuel hose, nor in fact is it authorised by the BMAA. SIGMA allows the owner/operator to perform such tasks without direct oversight via the Qualified Persons framework. Hence please take this as official notification that the BMAA does not require or authorise any BMAA Inspector to perform this function or to sign any airframe logbook using their inspector number. If you are asked to do this by an owner please inform them accordingly and if necessary refer them to the BMAA or Skydrive for clarification.’ As always if you have any questions please feel free to contact me directly. Kind regards, Rob Rob Mott Chief Inspector British Microlight Aircraft Association 01869 336005 [email protected]
‐ 1 ‐ BMAA, The Bullring, Deddington, Oxon, OX15 0TT. Tel 01869 336006 Fax 01869 337116 www.bmaa.org
Safety Bulletin 040615 – Issue 2
9th June 2015
Faulty Fuel Hose – Semperit FUB386 dated 3Q2014
Background
Semperit FUB386 fuel hose has been successfully used on the fuel systems of microlight and light aircraft
for many years without problems. Skydrive also use it on their fuel pressure kits and on their carburetter
heat kits (with coolant not fuel).
We have been informed of a problem with a recently manufactured batch of this hose. The affected batch is
clearly printed with 3Q/2014 (manufactured in 3 rd quarter 2014). As far as we know there has been no
reported fault with earlier batches of the hose.
The problem was first noticed as a disintegration of the inner hose layer and a partial blocking of the flow.
Subsequently we had reports of swelling and softening of the outer protective layer and a fuel smell
emanating from the hose. Some faulty hose pieces were returned to Semperit and they have agreed that the
3Q/2014 batch is faulty and has “no or a reduced fuel resistance which may cause serious malfunction.”
They have confirmed that some of the inner tube layer has been manufactured from a mix of wrong raw
material and can either degrade or allow fuel to permeate through to the outer protective layer, which is not
intended to be a fuel resistant layer.
Only since this problem has come to light, Semperit have informed us that the hose is not suitable for aircraft
and should not be used, although we can find no reference to this in their literature. Indeed this hose has
been approved on a number of UK aircraft and is also supplied on a number of imported aircraft.
Airworthiness Implications
1) Possible blockage of fuel lines leading to reduced fuel flow and possible engine failure.
2) Gradual degradation of the fuel lines, with possible penetration of fuel through the hose, with
accompanying fuel smell and fire risk if leakage occurs.
Aircraft Affected
1) Any aircraft fitted with Semperit FUB386 3Q/2014 fuel hose.
2) Hose supplied by us from 19th September 2014 to the date of this bulletin, and marked with 3Q/2014.
3) Any imported aircraft fitted with 3Q/2014 hose (we know that a number of European aircraft use this
hose but we have no details).
4) Skydrive fuel pressure kits supplied between 19th September 2014 and the date of this bulletin, and
with hose marked with 3Q/2014. These kits use 2.75m of FUB386 hose.
5) Backup Fuel Pump Kits supplied after 19 th September 2014 and with hose marked 3Q/2014
Aircraft Not Affected
1) Aircraft fitted with Semperit FUB386 hose with an earlier date than 3Q/2014 (for example 2Q/2012)
2) Skydrive carburetter heat systems fitted to 912/914 series engine on aircraft, even if using 3Q/2014
hose (The Skydrive carb heat system uses FUB386 hose with coolant, not fuel, flowing through it,
and our tests have shown that coolant does not degrade the hose).
Page 1 of 2
SKYDRIVE Limited, Burnside, Deppers Bridge, Southam, CV47 2SU
Tel: 01926 612188. Fax: 01926 613781. Email: [email protected]
Registered in England No. 3361211, VAT No. 335 2061 89, Directors N R Beale B.Sc., M.Sc., M Hurtubise, Company Secretary P J Beale.
Inspection Required – Recommended Before Further Flight
For aircraft manufactured after 1 st July 2014 inspect the fuel hose to check whether the affected batch has
been fitted.
For aircraft fitted with replacement hose supplied by Skydrive after 19th September 2014, inspect the fuel
hose to check whether the affected batch has been fitted. For supplies from other sources we recommend
checking from 1st July 2014.
For aircraft fitted with a fuel pressure kit after 19th September 2014, inspect the fuel hose to check whether
the affected batch has been fitted.
For loose hose not yet fitted, inspect to check whether it is the affected batch.
Rectification Action Required
All affected hose should be replaced before further flight. Skydrive are vigorously seeking an alternative
make of hose, but there may be other suppliers of suitable hose. [BMAA Type Approved (eg factory built
aircraft from current A1 Approved Companies) – please contact the Manufacturer or the BMAA for advice
on replacement hose].
Remove the affected hose. Check the ends of each piece for any signs of degradation or disintegration. If
there is degradation then it will be necessary to check the fuel inlet to each carb, the float chambers and the
fuel restrictor on the “return to tank” for any rubber fragments. If found, clean the complete fuel system
carefully. Replace hose with suitable alternative.
It is recommended to carry out a fuel flow check in accordance with BCAR Section S, and to monitor the
fuel pressure during initial testing and at all times during subsequent operation. (We always recommend that
a permanently installed fuel pressure gauge is fitted to all aircraft).
LAA Aircraft - When the rectification is completed, the installation should be inspected by an LAA inspector
and an appropriate logbook entry made.
BMAA types - inspected by the person carrying out the work and a logbook entry made by that person
(BMAA Inspector sign-off is not required).
Keep a copy of this bulletin in the aircraft records.
Refunding System
Skydrive will reimburse or credit the cost of faulty hose supplied, provided that an invoice number or other
proof of purchase is provided. The affected hose can be destroyed by the customer provided that this is
confirmed in writing, via the attached form. All refunds must be completed by 31st December 2015.
If you are a trader who has supplied the affected fuel hose to end customers, or in aircraft kits, please pass a
copy of this bulletin onto those customers.
Best Regards
Nigel Beale, Director.
9th June 2015
Page 2 of 2
SKYDRIVE Limited, Burnside, Deppers Bridge, Southam, CV47 2SU
Tel: 01926 612188. Fax: 01926 613781. Email: [email protected]
Registered in England No. 3361211, VAT No. 335 2061 89, Directors N R Beale B.Sc., M.Sc., M Hurtubise, Company Secretary P J Beale.
Dated: 29/05/2015 The BMAA has been informed very recently of some occurrences where a particular batch of Semperit fuel hosing has become defective or showed early signs of degradation. So far all cases have been reported to regard a specific batch of Semperit Fuel Hose FUB 386 3Q/2014. Please see picture below. Case 1: Eurostar suffering from reducing fuel pressure, leading to a reduction in power. Upon investigation the fuel tubing was found to be failing internally. The affected tubing had taken on a sponge like texture. On the negative pressure side, the hose would could collapse and block, on the positive side it would swell restricting flow.
Case 2: Eurostar with very soft fuel hosing again having a soft sponge‐like texture. This is especially noticeable when compared to the firmness of the coolant carb heater lines (which in this case use the same hose). No sign of leakage. Case 3: Escapade with a very strong (almost overpowering) smell of petrol in the cockpit. Faint before takeoff, but was very strong by the time of landing an hour later. No signs of dampness or leakage, again the tubing had become softer than normal. It is believed (but not as of yet confirmed) that in all the above cases automotive unleaded fuel (MOGAS) was being used. INVESTIGATION Skydrive in conjunction with the hose manufacturer Semperit, are currently in the process of investigating the cause and extent of this issue. As soon as more information becomes available it will be disseminated. All owners and operators are encouraged to check fuel hosing thoroughly before next flight. Please report any further occurrences to the BMAA and Skydrive in order to assist with the investigation. ‐ 2 ‐ BMAA, The Bullring, Deddington, Oxon, OX15 0TT. Tel 01869 336006 Fax 01869 337116 www.bmaa.org
If you have any questions please feel free to get in touch. Kind regards, Rob Rob Mott Chief Inspector British Microlight Aircraft Association 01869 336005 [email protected]
‐ 3 ‐ BMAA, The Bullring, Deddington, Oxon, OX15 0TT. Tel 01869 336006 Fax 01869 337116 www.bmaa.org