Airworthiness Directive · Amendment 39-17285 · Tail rotor
Eurocopter France Helicopters
Superseded. A later AD replaced this one: AD 2014-05-10. Comply with the one in force.
This AD applies to Eurocopter France (Eurocopter) Model AS350B3 helicopters with Modification (MOD) 07 5601 installed, certificated in any category.
Note 1 to paragraph (a): MOD 07 5601 is an integral part of a specific Model AS350B3 configuration, commercially identified as “AS350B3e” and is not fitted on Model AS350B3 helicopters of other configurations.
We are superseding an existing emergency airworthiness directive (EAD) for Eurocopter France (Eurocopter) Model AS350B3 helicopters with certain part-numbered laminated half-bearings (bearings) and tail rotor (T/R) blades installed. The existing EAD currently requires installing two placards and revising the Rotorcraft Flight Manual (RFM). The EAD also requires certain checks and inspecting and replacing, if necessary, all four bearings. Finally, the EAD requires a one-time removal and inspection of the bearings, and replacing the bearings if necessary. Since we issued that EAD, we have determined that newly-designed helicopters with other part-numbered T/R blades may be affected by this unsafe condition and that the requirements should allow the bearing removal and inspection to be performed before the last flight of the day. This superseding AD removes the bearing and T/R blade part numbers (P/N) from the applicability paragraph and clarifies when the bearing removal and inspection is required. The actions are intended to prevent vibration due to a failed bearing, failure of the T/R, and subsequent loss of control of the helicopter.
You are responsible for performing each action required by this AD within the specified compliance time unless it has already been accomplished prior to that time.
(1) Before further flight:
(i) Install a velocity never exceed (V NE) placard that reads as follows on the instrument panel in full view of the pilot and co-pilot with 6-millimeter red letters on a white background:
VNE LIMITED TO 100 KTS IAS.
(ii) Replace the IAS limit versus the flight altitude placard located inside the cabin on the center post with the placard as depicted in Table 1 to paragraph (f) of this AD:
| Hp (ft) | IAS (kts) |
|---|---|
| 0 | 100 |
| 2000 | 97 |
| 4000 | 94 |
| 6000 | 91 |
| 8000 | 88 |
| 10000 | 85 |
| 12000 | 82 |
| 14000 | 79 |
| 16000 | 76 |
| 18000 | 73 |
| 20000 | 70 |
| 22000 | 67 |
| Valid for VNE | |
| POWER OFF |
(2) Before further flight, revise the Rotorcraft Flight Manual (RFM) by inserting a copy of this AD into the RFM or by making pen and ink changes as follows:
(i) Revise paragraph 2.3 of the RFM by inserting the following:
VNE limited to 100 kts IAS.
(ii) Revise paragraph 2.6 of the RFM by inserting Table 2 to Paragraph (f) of this AD.
| Hp (ft) | IAS (kts) |
|---|---|
| 0 | 100 |
| 2000 | 97 |
| 4000 | 94 |
| 6000 | 91 |
| 8000 | 88 |
| 10000 | 85 |
| 12000 | 82 |
| 14000 | 79 |
| 16000 | 76 |
| 18000 | 73 |
| 20000 | 70 |
| 22000 | 67 |
| Valid for VNE | |
| POWER OFF |
(iii) Add the following as paragraph 3.3.3 to the RFM:
3.3.3 IN-FLIGHT VIBRATIONS FELT IN THE PEDALS
Symptom:
IN-FLIGHT VIBRATIONS FELT IN THE PEDALS
1. CHECK PEDAL EFFECTIVENESS
2. SMOOTHLY REDUCE THE SPEED TO VY
3. AVOID SIDESLIP AS MUCH AS POSSIBLE
LAND AS SOON AS POSSIBLE
(3) Before further flight, and thereafter after each flight, without exceeding 3 hours time-in-service between two checks, visually check each bearing as follows:
(i) Position both tail rotor blades horizontally.
(ii) Apply load (F) by hand, perpendicular to the pressure face of one tail rotor blade (a), as shown in Figure 1 to paragraph (f) of this AD, taking care not to reach the extreme position against the tail rotor hub. The load will deflect the tail rotor blade towards the tail boom.
(iii) While maintaining the load, check all the visible faces of the bearings (front and side faces) in area B of DETAIL A of Figure 1 to paragraph (f) of this AD for separation between the elastomer and metal parts, a crack in the elastomer, or an extrusion (see example in Figure 2 to paragraph (f) of this AD). A flashlight may be used to enhance the check.
(iv) Repeat paragraphs (f)(3)(i) through (f)(3)(iii) on the other tail rotor blade.
(v) Apply load (G) by hand perpendicular to the suction face of one tail rotor blade as shown in Figure 3 to paragraph (f) of this AD. The load will deflect the tail rotor blade away from the tail boom.
(vi) While maintaining the load, check visible faces of Area C as shown in Figure 3 to paragraph (f) of this AD for any extrusion. A flashlight may be used to enhance the check.
(vii) Repeat paragraphs (f)(3)(v) and (f)(3)(vi) on the other tail rotor blade.
(4) The actions required by paragraphs (f)(3)(i) through (f)(3)(vii) of this AD may be performed by the owner/operator (pilot) holding at least a private pilot certificate, and must be entered into the aircraft records showing compliance with this AD in accordance with 14 CFR 43.9 (a)(1)-(4) and 14 CFR 91.417(a)(2)(v). The record must be maintained as required by 14 CFR 91.173, 121.380, or 135.439.
(5) If there is an extrusion on any bearing, before further flight, replace the four bearings with airworthy bearings.
(6) If there is a separation or a crack on the pressure side bearing, measure the separation or the crack. If the separation or crack is greater than 5 millimeters (.196 inches) as indicated by dimension “L” in Figure 4 to paragraph (f), before further flight, replace the four bearings with airworthy bearings.
(7) No later than after the last flight of the day, perform a one-time inspection by removing the bearings and inspecting for a separation, a crack, or an extrusion. This inspection is not a daily inspection. If there is a separation, crack, or extrusion, before further flight, replace the four bearings with airworthy bearings.
