Airworthiness Directive · Amendment 39-14950 · Learjet Model 23, 24, 24A, 24B, 24B-A, 24C, 24D, 24D-A, 24E, 24F, 24F-A, 25, 25A, 25B, 25C, 25D, 25F, 28, 29, 31, 31A, 35, 35A (C-21A), 36, 36A, 55, 55B, and 55C Airplanes
Learjet Model 23, 24, 24A, 24B, 24B-A, 24C, 24D, 24D-A, 24E, 24F, 24F-A, 25, 25A, 25B, 25C, 25D, 25F, 28, 29, 31, 31A, 35, 35A (C-21A), 36, 36A, 55, 55B, and 55C Airplanes
This AD applies to the Learjet models identified in the applicable Bombardier service bulletin listed in Table 1 of this AD.
| Bombardier service bulletin | Revision level | Date | Learjet model(s) |
|---|---|---|---|
| SB 23-28-6 | Original | April 21, 1998 | 23. |
| SB 24/25-28-3 | 2 | February 21, 1998 | 24, 24A, 24B, 24B-A, 24C, 24D, 24D-A, 24E, 24F, and 24F-A airplanes; and 25, 25A, 25B, 25C, 25D, and 25F airplanes. |
| SB 28/29-28-4 | 3 | June 2, 1999 | 28 and 29 airplanes. |
| SB 31-28-7 | 3 | January 26, 2001 | 31 and 31A airplanes. |
| SB 35/36-28-11 | 4 | December 4, 2000 | 35 and 35A (C-21A) airplanes; 36 and 36A airplanes. |
| SB 55-28-13 | 3 | December 15, 2000 | 55, 55B and 55C airplanes. |
The FAA is adopting a new airworthiness directive (AD) for certain Learjet Model 23, 24, 24A, 24B, 24B-A, 24C, 24D, 24D-A, 24E, 24F, 24F-A, 25, 25A, 25B, 25C, 25D, 25F, 28, 29, 31, 31A, 35, 35A (C- 21A), 36, 36A, 55, 55B, and 55C airplanes. This AD requires modifying the left- and right-hand standby fuel pump switches. This AD also requires revising the Emergency and Abnormal Procedures sections of the airplane flight manual to advise the flightcrew of the proper procedures to follow in the event of failure of the standby fuel pump to shut off. This AD results from a report of inadvertent operation of a standby fuel pump due to an electrical system malfunction. We are issuing this AD to prevent this inadvertent operation, which could result in inadvertent fuel transfer by the left or right wing fuel system and subsequent over-limit fuel imbalance between the left and right wing fuel loads. This imbalance could affect lateral control of the airplane which could result in reduced controllability.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Within 24 months after the effective date of this AD: Modify the left- and right-hand standby fuel pump switches, in accordance with the Accomplishment Instructions of the applicable service bulletin identified in Table 1 of this AD.
Before further flight after accomplishing the modification required by paragraph (f) of this AD: Revise the Emergency and Abnormal Procedures sections of the applicable Learjet AFM to advise the flightcrew of proper procedures to follow in the event of failure of the standby fuel pump to shut off by including the information in the applicable Learjet temporary flight manual (TFM) changes identified in Table 2 of this AD. This may be done by inserting a copy of the TFM changes into the AFM. When the TFM changes have been included in the general revisions of the AFM, those general revisions may be inserted into the AFM, provided the relevant information in the general revisions is identical to that in the TFM changes.
| Learjet model(s) | Learjet TFM change | Date | To the Learjet AFM |
|---|---|---|---|
| 24, 25, 28, 29, 31, 35, 36, and 55 airplanes | TFM 96-08 | May 30, 1996 | 24 (FM-004), 24B (FM-006), 24D (FM-009), 24E (FM-011), 24F (FM-012), 24 ECR 736 (FM-008), 25 (FM-014), 25B/C (FM-016), 25D/F (FM-018), 28/29 (FM-100), 31 (FM-112), 31A (FM-121), 35/36 (FM-019), 35A/36A FC-200 (FM-102), 35A/36A FC-530 (FM-108), 55 (FM-103), 55B (FM-110), 55C (FM-114). |
| 24, 25, 28, 29, 31, 35, 36, and 55 airplanes | TFM 96-09 | May 30, 1996 | 24 (FM-004), 24B (FM-006), 24D (FM-009), 24E (FM-011), 24F (FM-012), 24 ECR 736 (FM-008), 25 (FM-014), 25B/C (FM-016), 25D/F (FM-018), 28/29 (FM-100), 31 (FM-112), 31A (FM-121), 35/36 (FM-019), 35A/36A FC-200 (FM-102), 35A/36A FC-530 (FM-108), 55 (FM-103), 55B (FM-110), 55C (FM-114). |
| 23 airplanes | TFM 98-01 | May 11, 1999 | 23 (FM-003). |
| 23 airplanes | TFM 98-02 | May 11, 1999 | 23 (FM-003). |
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
