November 21, 1998
SUBJECT: Tailpipe "V-Band" Clamp. Aeroquip part number 4404C375-M

REASON: This service bulletin is being issued to inspect the tailpipe V-band clamp for possible deformation or cracks in the stainless band that secures the V-band. A cracked clamp could cause the tailpipe to detach from the turbo causing severe damage to the aircraft.

EFFECTIVITY: All Beechcraft Bonanza models and all Cessna 185 models equipped with a Turbo-Flite/FliteCraft/Turbo 2000 turbonormalizing system.

COMPLIANCE: Tornado Alley Turbo, Inc. considers this to be a mandatory inspection, and inspection of this clamp should be accomplished prior to further flight.




REFERENCES: Turbo-Flite 520/550 Maintenance Manual. See also the attached illustrative drawing of the subject V-band Clamp. See also the photograph of a failed clamp which can be found at


a) Remove left cowl flap and/or lower cowling in order to gain access to the tailpipe clamp.

b) Verify that the exhaust pipe is securely attached to the turbo by manual attempts to move the exhaust pipe. Visually inspect the tailpipe and clamp with mirror and light. Pay particular attention to the stainless band in the area from the T-bolt to approximately 3.5" on either side of the T-bolt. Any deformation of the flat, outer, stainless steel band below the nominal surface, indicating any previous plastic deformation of the stainless steel band is cause to reject the clamp and cause it to be permanently removed from service. Pay additional special attention to the area adjacent to each of the two spot welds on either side of the T-bolt, which first attach the flat stainless band to the V-band portions of the assembly. See the illustration, attached to MSB TAT 98-1. Perform a further close visual inspection of the balance of the V-band clamp for wear, nicks, corrosion, cracks, and/or heat damage. If the clamp is deformed or cracked, or in any other way defective, it should be removed from service, tagged with the aircraft N number from which it is removed, labeled with the number of hours in service, and for further inspection, sent to:

300 Airport Road
Ada, Oklahoma 74820

c) If the clamp is defective or removed from service, install a new clamp, Aeroquip part number 4404C375-M, in accordance with the existing service manual instructions. Copies of those instructions are attached to this Mandatory Service Bulletin, TAT 98-1. Pay particular attention to the torque limits and instructions.

NOTE: If the aircraft needs to be ferried for the required inspection, it may be flown directly to the nearest facility suitable for repairs, but ONLY after the pilot/owner/operator inspection described in paragraph 4, below, is accomplished, and it is determined that the exhaust pipe is securely attached to the turbo.

Contact Tornado Alley Turbo, Inc. at (580)332-3510

After securing the required parts, proceed with Step 1.c (above) ensuring that the specified clamp torque is not exceeded.

3. Reinstall the cowling and/or cowl flap which were removed in Step 1a (above), in accordance with the manufacturers’ Maintenance Manual.

4. AT NOT MORE THAN SUBSEQUENT 25 HOUR INTERVALS: The pilot/owner/operator of one of these turbonormalized systems should, with the engine cold, simply grasp (with one hand) the cold exhaust stack that extends from the left lower cowl flap area, and give the part a firm push/pull from side to side. If the part appears in any way to be loose, or insecure, the aircraft should be grounded until a mechanic can remove and inspect the exhaust stack and the associated V-band clamp, in accordance with the suggested inspection and reinstallation instructions described herein, and in the "Turbo-Flite 520/550 System Maintenance and Trouble Shooting Manual".

5. AT NOT MORE THAN 400 HOUR OR 4 YEAR INTERVALS: Replace the subject clamp with a new clamp if the clamp has been in service for more than 400 hours or 4 years, whichever first occurs. If the part has more than 400 hours or more than 4 years in service, but passes the visual inspection described in paragraph 1.a (above) and 1.b (above), the affected "V-band" clamp may be temporarily continued in service until a new part can be installed, but in no case for more than 25 additional hours, prior to removal and replacement.

RECORD COMPLIANCE Upon completion of this service bulletin, make an appropriate maintenance record entry in aircraft logbooks.

NOTE: Until superceded, this Mandatory Service Bulletin TAT 98-1, is to be made a permanent part of the aircraft logbooks and must be adhered to by all persons involved in ownership or operation of the affected aircraft.

Please notify TAT by fax of the results of this inspection at (580) 332 - 4577, using the form provided for this purpose.
If Fax is unavailable, then mail to: TAT, 300 Airport Road, Ada, Oklahoma 74820.